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Sample records for forest biomass litter

  1. [Dynamics of microbial biomass carbon and nitrogen during foliar litter decomposition under artificial forest gap in Pinus massoniana plantation.

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    Zhang, Ming Jin; Chen, Liang Hua; Zhang, Jian; Yang, Wan Qin; Liu, Hua; Li, Xun; Zhang, Yan

    2016-03-01

    Nowadays large areas of plantations have caused serious ecological problems such as soil degradation and biodiversity decline. Artificial tending thinning and construction of mixed forest are frequently used ways when we manage plantations. To understand the effect of this operation mode on nutrient cycle of plantation ecosystem, we detected the dynamics of microbial bio-mass carbon and nitrogen during foliar litter decomposition of Pinus massoniana and Toona ciliate in seven types of gap in different sizes (G 1 : 100 m 2 , G 2 : 225 m 2 , G 3 : 400 m 2 , G 4 : 625 m 2 , G 5 : 900 m 2 , G 6 : 1225 m 2 , G 7 : 1600 m 2 ) of 42-year-old P. massoniana plantations in a hilly area of the upper Yang-tze River. The results showed that small and medium-sized forest gaps(G 1 -G 5 ) were more advantageous for the increment of microbial biomass carbon and nitrogen in the process of foliar litter decomposition. Along with the foliar litter decomposition during the experiment (360 d), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) in P. massoniana foliar litter and MBN in T. ciliata foliar litter first increased and then decreased, and respectively reached the maxima 9.87, 0.22 and 0.80 g·kg -1 on the 180 th d. But the peak (44.40 g·kg -1 ) of MBC in T. ciliata foliar litter appeared on the 90 th d. Microbial biomass carbon and nitrogen in T. ciliate was significantly higher than that of P. massoniana during foliar litter decomposition. Microbial biomass carbon and nitrogen in foliar litter was not only significantly associated with average daily temperature and the water content of foliar litter, but also closely related to the change of the quality of litter. Therefore, in the thinning, forest gap size could be controlled in the range of from 100 to 900 m 2 to facilitate the increase of microbial biomass carbon and nitrogen in the process of foliar litter decomposition, accelerate the decomposition of foliar litter and improve soil fertility of plantations.

  2. Mistletoes and epiphytic lichens contribute to litter input in Nothofagus antarctica forests

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    Soler, Rosina; Pastur, Guillermo Martínez; Lencinas, María Vanessa; Peri, Pablo Luis

    2015-10-01

    Litter input is one of the key components that define nutrient cycling in forests and the majority of studies only consider the tree components of litterfall. However, epiphytic species can play a crucial role in litter input throughout the growing season. This work evaluates changes in litter production by mistletoe (Misodendrum sp.) and epiphytic lichen (Usnea sp.), related to crown cover in mature unmanaged, second-growth and managed (thinned for silvopastoral use) forests in Tierra del Fuego (Argentina). We used plastic traps to collect litterfall biomass from trees, lichens and mistletoes on a monthly basis over three consecutive years. Tree litter was considerable during autumn (March to May), which is typical of Nothofagus deciduous species in the Southern hemisphere. In contrast, peak litterfall from mistletoes and lichens occurred during spring and summer seasons. Tree litter (1954-3398 kg dry matter ha-1 year-1) was correlated with crown cover gradient being highest in second-growth forests and lowest in thinned sites. While litter input from mistletoes did not vary among forest types (307-333 kg dry matter ha-1 year-1), lichen litter (11-40 kg dry matter ha-1 year-1) was higher in unmanaged and thinned mature forests despite differences in tree crown cover. Contrary to what we expected, the management practices investigated here did not affect the biomass of canopy communities compared to unmanaged mature forests. Mistletoes and lichens significantly increased the spatial (forest type) and temporal complexity (extended period of falling) of litterfall in Nothofagus antarctica forests. This study provides a starting point to understand the ecological relevance of canopy communities in the Patagonian forests of southern Argentina.

  3. Resource stoichiometry and availability modulate species richness and biomass of tropical litter macro-invertebrates.

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    Jochum, Malte; Barnes, Andrew D; Weigelt, Patrick; Ott, David; Rembold, Katja; Farajallah, Achmad; Brose, Ulrich

    2017-09-01

    High biodiversity and biomass of soil communities are crucial for litter decomposition in terrestrial ecosystems such as tropical forests. However, the leaf litter that these communities consume is of particularly poor quality as indicated by elemental stoichiometry. The impact of resource quantity, quality and other habitat parameters on species richness and biomass of consumer communities is often studied in isolation, although much can be learned from simultaneously studying both community characteristics. Using a dataset of 780 macro-invertebrate consumer species across 32 sites in tropical lowland rain forest and agricultural systems on Sumatra, Indonesia, we investigated the effects of basal resource stoichiometry (C:X ratios of N, P, K, Ca, Mg, Na, S in local leaf litter), litter mass (basal resource quantity and habitat space), plant species richness (surrogate for litter habitat heterogeneity), and soil pH (acidity) on consumer species richness and biomass across different consumer groups (i.e. 3 feeding guilds and 10 selected taxonomic groups). In order to distinguish the most important predictors of consumer species richness and biomass, we applied a standardised model averaging approach investigating the effects of basal resource stoichiometry, litter mass, plant species richness and soil pH on both consumer community characteristics. This standardised approach enabled us to identify differences and similarities in the magnitude and importance of such effects on consumer species richness and biomass. Across consumer groups, we found litter mass to be the most important predictor of both species richness and biomass. Resource stoichiometry had a more pronounced impact on consumer species richness than on their biomass. As expected, taxonomic groups differed in which resource and habitat parameters (basal resource stoichiometry, litter mass, plant species richness and pH) were most important for modulating their community characteristics. The importance

  4. Nitrogen and carbon reallocation in fungal mycelia during decomposition of boreal forest litter.

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    Johanna B Boberg

    Full Text Available Boreal forests are characterized by spatially heterogeneous soils with low N availability. The decomposition of coniferous litter in these systems is primarily performed by basidiomycete fungi, which often form large mycelia with a well-developed capacity to reallocate resources spatially- an advantageous trait in heterogeneous environments. In axenic microcosm systems we tested whether fungi increase their biomass production by reallocating N between Pinus sylvestris (Scots pine needles at different stages of decomposition. We estimated fungal biomass production by analysing the accumulation of the fungal cell wall compound chitin. Monospecific systems were compared with systems with interspecific interactions. We found that the fungi reallocated assimilated N and mycelial growth away from well-degraded litter towards fresh litter components. This redistribution was accompanied by reduced decomposition of older litter. Interconnection of substrates increased over-all fungal C use efficiency (i.e. the allocation of assimilated C to biomass rather than respiration, presumably by enabling fungal translocation of growth-limiting N to litter with higher C quality. Fungal connection between different substrates also restricted N-mineralization and production of dissolved organic N, suggesting that litter saprotrophs in boreal forest ecosystems primarily act to redistribute rather than release N. This spatial integration of different resource qualities was hindered by interspecific interactions, in which litters of contrasting quality were colonised by two different basidiomycete species. The experiments provide a detailed picture of how resource reallocation in two decomposer fungi leads to a more efficient utilisation of spatially separated resources under N-limitation. From an ecosystem point of view, such economic fungal behaviour could potentially contribute to organic matter accumulation in the litter layers of boreal forests.

  5. Nitrogen and carbon reallocation in fungal mycelia during decomposition of boreal forest litter.

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    Boberg, Johanna B; Finlay, Roger D; Stenlid, Jan; Ekblad, Alf; Lindahl, Björn D

    2014-01-01

    Boreal forests are characterized by spatially heterogeneous soils with low N availability. The decomposition of coniferous litter in these systems is primarily performed by basidiomycete fungi, which often form large mycelia with a well-developed capacity to reallocate resources spatially- an advantageous trait in heterogeneous environments. In axenic microcosm systems we tested whether fungi increase their biomass production by reallocating N between Pinus sylvestris (Scots pine) needles at different stages of decomposition. We estimated fungal biomass production by analysing the accumulation of the fungal cell wall compound chitin. Monospecific systems were compared with systems with interspecific interactions. We found that the fungi reallocated assimilated N and mycelial growth away from well-degraded litter towards fresh litter components. This redistribution was accompanied by reduced decomposition of older litter. Interconnection of substrates increased over-all fungal C use efficiency (i.e. the allocation of assimilated C to biomass rather than respiration), presumably by enabling fungal translocation of growth-limiting N to litter with higher C quality. Fungal connection between different substrates also restricted N-mineralization and production of dissolved organic N, suggesting that litter saprotrophs in boreal forest ecosystems primarily act to redistribute rather than release N. This spatial integration of different resource qualities was hindered by interspecific interactions, in which litters of contrasting quality were colonised by two different basidiomycete species. The experiments provide a detailed picture of how resource reallocation in two decomposer fungi leads to a more efficient utilisation of spatially separated resources under N-limitation. From an ecosystem point of view, such economic fungal behaviour could potentially contribute to organic matter accumulation in the litter layers of boreal forests.

  6. Variation of biomass and carbon pools with forest type in temperate forests of Kashmir Himalaya, India.

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    Dar, Javid Ahmad; Sundarapandian, Somaiah

    2015-02-01

    An accurate characterization of tree, understory, deadwood, floor litter, and soil organic carbon (SOC) pools in temperate forest ecosystems is important to estimate their contribution to global carbon (C) stocks. However, this information on temperate forests of the Himalayas is lacking and fragmented. In this study, we measured C stocks of tree (aboveground and belowground biomass), understory (shrubs and herbaceous), deadwood (standing and fallen trees and stumps), floor litter, and soil from 111 plots of 50 m × 50 m each, in seven forest types: Populus deltoides (PD), Juglans regia (JR), Cedrus deodara (CD), Pinus wallichiana (PW), mixed coniferous (MC), Abies pindrow (AP), and Betula utilis (BU) in temperate forests of Kashmir Himalaya, India. The main objective of the present study is to quantify the ecosystem C pool in these seven forest types. The results showed that the tree biomass ranged from 100.8 Mg ha(-1) in BU forest to 294.8 Mg ha(-1) for the AP forest. The understory biomass ranged from 0.16 Mg ha(-1) in PD forest to 2.36 Mg ha(-1) in PW forest. Deadwood biomass ranged from 1.5 Mg ha(-1) in PD forest to 14.9 Mg ha(-1) for the AP forest, whereas forest floor litter ranged from 2.5 Mg ha(-1) in BU and JR forests to 3.1 Mg ha(-1) in MC forest. The total ecosystem carbon stocks varied from 112.5 to 205.7 Mg C ha(-1) across all the forest types. The C stocks of tree, understory, deadwood, litter, and soil ranged from 45.4 to 135.6, 0.08 to 1.18, 0.7 to 6.8, 1.1 to 1.4, and 39.1-91.4 Mg ha(-1), respectively, which accounted for 61.3, 0.2, 1.4, 0.8, and 36.3 % of the total carbon stock. BU forest accounted 65 % from soil C and 35 % from biomass, whereas PD forest contributed only 26 % from soil C and 74 % from biomass. Of the total C stock in the 0-30-cm soil, about 55 % was stored in the upper 0-10 cm. Soil C stocks in BU forest were significantly higher than those in other forests. The variability of C pools of different ecosystem components is

  7. Biomass is the main driver of changes in ecosystem process rates during tropical forest succession.

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    Lohbeck, Madelon; Poorter, Lourens; Martínez-Ramos, Miguel; Bongers, Frans

    2015-05-01

    Over half of the world's forests are disturbed, and the rate at which ecosystem processes recover after disturbance is important for the services these forests can provide. We analyze the drivers' underlying changes in rates of key ecosystem processes (biomass productivity, litter productivity, actual litter decomposition, and potential litter decomposition) during secondary succession after shifting cultivation in wet tropical forest of Mexico. We test the importance of three alternative drivers of ecosystem processes: vegetation biomass (vegetation quantity hypothesis), community-weighted trait mean (mass ratio hypothesis), and functional diversity (niche complementarity hypothesis) using structural equation modeling. This allows us to infer the relative importance of different mechanisms underlying ecosystem process recovery. Ecosystem process rates changed during succession, and the strongest driver was aboveground biomass for each of the processes. Productivity of aboveground stem biomass and leaf litter as well as actual litter decomposition increased with initial standing vegetation biomass, whereas potential litter decomposition decreased with standing biomass. Additionally, biomass productivity was positively affected by community-weighted mean of specific leaf area, and potential decomposition was positively affected by functional divergence, and negatively by community-weighted mean of leaf dry matter content. Our empirical results show that functional diversity and community-weighted means are of secondary importance for explaining changes in ecosystem process rates during tropical forest succession. Instead, simply, the amount of vegetation in a site is the major driver of changes, perhaps because there is a steep biomass buildup during succession that overrides more subtle effects of community functional properties on ecosystem processes. We recommend future studies in the field of biodiversity and ecosystem functioning to separate the effects of

  8. Estimate of biomass and carbon pools in disturbed and undisturbed oak forests in Tunisia

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    Zribi, L.; Chaar, H.; Khaldi, A.; Henchi, B.; Mouillot, F.; Gharbi, F.

    2016-07-01

    Aim of the study. To estimate biomass and carbon accumulation in a young and disturbed forest (regenerated after a tornado) and an aged cork oak forest (undisturbed forest) as well as its distribution among the different pools (tree, litter and soil). Area of study. The north west of Tunisia. Material and methods. Carbon stocks were evaluated in the above and belowground cork oak trees, the litter and the 150 cm of the soil. Tree biomass was estimated in both young and aged forests using allometric biomass equations developed for wood stem, cork stem, wood branch, cork branch, leaves, roots and total tree biomass based on combinations of diameter at breast height, total height and crown length as independent variables. Main results. Total tree biomass in forests was 240.58 Mg ha-1 in the young forest and 411.30 Mg ha-1 in the aged forest with a low root/shoot ratio (0.41 for young forest and 0.31 for aged forest). Total stored carbon was 419.46 Mg C ha-1 in the young forest and 658.09 Mg C ha-1 in the aged forest. Carbon stock (Mg C ha-1) was estimated to be113.61(27.08%) and 194.08 (29.49%) in trees, 3.55 (0.85%) and 5.73 (0.87%) in litter and 302.30 (72.07%) and 458.27 (69.64%) in soil in the young and aged forests, respectively. Research highlights. Aged undisturbed forest had the largest tree biomass but a lower potential for accumulation of carbon in the future; in contrast, young disturbed forest had both higher growth and carbon storage potential. (Author)

  9. Forest composition modifies litter dynamics and decomposition in regenerating tropical dry forest.

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    Schilling, Erik M; Waring, Bonnie G; Schilling, Jonathan S; Powers, Jennifer S

    2016-09-01

    We investigated how forest composition, litter quality, and rainfall interact to affect leaf litter decomposition across three successional tropical dry forests in Costa Rica. We monitored litter stocks and bulk litter turnover in 18 plots that exhibit substantial variation in soil characteristics, tree community structure, fungal communities (including forests dominated by ecto- or arbuscular mycorrhizal host trees), and forest age. Simultaneously, we decomposed three standard litter substrates over a 6-month period spanning an unusually intense drought. Decay rates of standard substrates depended on the interaction between litter identity and forest type. Decomposition rates were correlated with tree and soil fungal community composition as well as soil fertility, but these relationships differed among litter types. In low fertility soils dominated by ectomycorrhizal oak trees, bulk litter turnover rates were low, regardless of soil moisture. By contrast, in higher fertility soils that supported mostly arbuscular mycorrhizal trees, bulk litter decay rates were strongly dependent on seasonal water availability. Both measures of decomposition increased with forest age, as did the frequency of termite-mediated wood decay. Taken together, our results demonstrate that soils and forest age exert strong control over decomposition dynamics in these tropical dry forests, either directly through effects on microclimate and nutrients, or indirectly by affecting tree and microbial community composition and traits, such as litter quality.

  10. Forest litter stocks in Korean pine-broad-leaved forests of the southern Sikhote Alin

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    A. V. Ivanov

    2015-10-01

    Full Text Available The article presents the data on the forest litter of the Korean pine-broad-leaved forests of the South of Primorsky krai. The focus of the research is plantations dominated by Korean pine; areas of the main tree species with ages of 50, 80, 130 and 200 years were selected. The dynamics of the forest litter stock in the pine and broadleaved forests of different ages according to the measurement results for the season in 2014 is stated. In the studied plantation, the forest litter stock varies between 9.7–20.3 t ha-1. The greatest value of the forest litter stock is recorded in old-growth cedar forest (200 years. Relatively high power and the stock of litter are typical for young Korean pine forest that can explain the lower speed of the litter properties change against the dynamics of taxation indicators of the forest stand. The difference between the amount of the litter in the 200-year-old and remaining pine trees are statistically significant at p = 0.05. The dependence of the litter power on the age is not revealed. The coefficient of the forest litter decomposition ranges from 2.55–10.60 that characterizes the high speed of its rotting. The highest coefficient of the litter decomposition has an old-growing pine forest. The schedule of seasonal humidity fluctuations of the forest litter on the chosen plot is made; with increasing cedar forest age, the volumetric moisture content of the forest litter increases; volumetric moisture content on the plots remain relatively unchanged during the season. The area of the Korean pine forests of Primorsky State Academy of Agriculture is 6835 ha. The amount of carbon stock in the forest litter is 38.7 thousand tons C. in this area, while the system of regional assessment of the forest carbon balance estimates this index as 24.3 tons С. The data obtained can be used to adjust the coefficients of regional assessment of the forest carbon balance for cedar forests of Primorsky krai.

  11. Effects of litter manipulation on litter decomposition in a successional gradients of tropical forests in southern China

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    Chen, Hao; Gurmesa, Geshere A.; Liu, Lei

    2014-01-01

    Global changes such as increasing CO2, rising temperature, and land-use change are likely to drive shifts in litter inputs to forest floors, but the effects of such changes on litter decomposition remain largely unknown. We initiated a litter manipulation experiment to test the response of litter...... decomposition to litter removal/addition in three successional forests in southern China, namely masson pine forest (MPF), mixed coniferous and broadleaved forest (MF) and monsoon evergreen broadleaved forest (MEBF). Results showed that litter removal decreased litter decomposition rates by 27%, 10% and 8...

  12. Revegetation of coal mine soil with forest litter

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    Day, A.D.; Ludeke, K.L.; Thames, J.L.

    1986-11-01

    Forest litter, a good source of organic matter and seeds, was applied on undisturbed soil and on coal mine (spoils) in experiments conducted on the Black Mesa Coal Mine near Kayenta, Arizona over a 2-year period (1977-1978). Germination, seedling establishment, plant height and ground cover were evaluated for two seeding treatments (forest litter and no forest litter) and two soil moisture treatments (natural rainfall and natural rainfall plus irrigation). The forest litter was obtained at random from the Coconino National Forest, broadcast over the surface of the soil materials and incorporated into the surface 5 cm of each soil material. Germination, seedling establishment, plant height and ground cover on undisturbed soil and coal mine soil were higher when forest litter was applied than when it was not applied and when natural rainfall was supplemented with sprinkler irrigation than when rainfall was not supplemented with irrigation. Applications of forest litter and supplemental irrigation may ensure successful establishment of vegetation on areas disturbed by open-pit coal mining.

  13. Biomass Carbon Content in Schima- Castanopsis Forest of Midhills of Nepal: A Case Study from Jaisikuna Community Forest, Kaski

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    Sushma Tripathi

    2018-01-01

    Full Text Available Community forests of Nepal’s midhills have high potentiality to sequester carbon. This paper tries to analyze the biomass carbon stock in Schima-Castanopsis forest of Jaisikuna community forests of Kaski district, Nepal. Forest area was divided into two blocks and 18 sample plots (9 in each block which were laid randomly. Diameter at Breast Height (DBH and height of trees (DBH≥5cm were measured using the DBH tape and clinometer. Leaf litter, herbs, grasses and seedlings were collected from 1*1m2 plot and fresh weight was taken. For calculating carbon biomass is multiplied by default value 0.47. The AGTB carbon content of Chilaune, Katus and other species were found 19.56 t/ha, 18.66 t/ha and 3.59 t/ha respectively. The AGTB of Chilaune dominated, Katus dominated and whole forest was found 43.78 t/ha, 39.83 t/ha and 41.81 t/ha respectively. Carbon content at leaf litter, herbs, grasses and seedlings was found 2.73 t/ha. Below ground biomass carbon at whole forest was found 6.27 t/ha. Total biomass and carbon of the forest was found 108.09 t/ha and 50.80 t/ha respectively. Difference in biomass and carbon content at Chilaune dominated block and Katus dominated block was found insignificant. This study record very low biomass carbon content than average of Nepal's forest but this variation in carbon stock is not necessarily due to dominant species present in the forest. Carbon estimation at forest of different elevation, aspect and location are recommended for further research. International Journal of EnvironmentVolume-6, Issue-4, Sep-Nov 2017, page: 72-84

  14. Correlation between earthworms and plant litter decomposition in a tropical wet forest of Puerto Rico.

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    Jennifer Dechainea; Honghua Ruanb; Yaniria Sanchez-de Leon; Xiaoming Zou

    2005-01-01

    Earthworms are recognized to play an important role in the decomposition of organic materials. To test the use of earthworms as an indicator of plant litter decomposition, we examined the abundance and biomass of earthworms in relation to plant litter decomposition in a tropical wet forest of Puerto Rico. We collected earthworms at 0–0.1m and 0.1–0.25m soil depths from...

  15. Environmental correlates underlying elevational richness, abundance, and biomass patterns of multi-feeding guilds in litter invertebrates across the treeline.

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    Xu, Guorui; Zhang, Shuang; Zhang, Yuxin; Ma, Keming

    2018-08-15

    Elevational richness patterns and underlying environmental correlates have contributed greatly to a range of general theories of biodiversity. However, the mechanisms underlying elevational abundance and biomass patterns across several trophic levels in belowground food webs remain largely unknown. In this study, we aimed to disentangle the relationships between the elevational patterns of different trophic levels of litter invertebrates and their underlying environmental correlates for two contrasting ecosystems separated by the treeline. We sampled 119 plots from 1020 to 1770 asl in forest and 21 plots from 1790 to 2280 asl in meadow on Dongling Mountain, northwest of Beijing, China. Four functional guilds were divided based on feeding regime: omnivores, herbivores, predators, and detritivores. We used eigenvector-based spatial filters to account for spatial autocorrelation and multi-model selection to determine the best environmental correlates for the community attributes of the different feeding guilds. The results showed that the richness, abundance and biomass of omnivores declined with increasing elevation in the meadow, whereas there was a hump-shaped richness pattern for detritivores. The richness and abundance of different feeding guilds were positively correlated in the forest, while not in the meadow. In the forest, the variances of richness in omnivores, predators, and detritivores were mostly correlated with litter thickness, with omnivores being best explained by mean annual temperature in the meadow. In conclusion, hump-shaped elevational richness, abundance and biomass patterns driven by the forest gradient below the treeline existed in all feeding guilds of litter invertebrates. Climate replaced productivity as the primary factor that drove the richness patterns of omnivores above the treeline, whereas heterogeneity replaced climate for herbivores. Our results highlight that the correlated elevational richness, abundance, and biomass patterns of

  16. Can't See the Wood for the Litter: Evaluation of Litter Behavior Modification in a Forest

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    Lindemann-Matthies, Petra; Bonigk, Isabel; Benkowitz, Dorothee

    2012-01-01

    This study investigated elementary school children's (n = 171) litter behavior during guided forest tours following two different treatments. Four classes received a verbal appeal not to litter in the forest, while another four classes received both a verbal appeal and a demonstration of the desired litter behavior (picking up litter, putting it…

  17. Remote Characterization of Biomass Measurements: Case Study of Mangrove Forests

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    Fatoyinbo, Temilola E.

    2010-01-01

    Accurately quantifying forest biomass is of crucial importance for climate change studies. By quantifying the amount of above and below ground biomass and consequently carbon stored in forest ecosystems, we are able to derive estimates of carbon sequestration, emission and storage and help close the carbon budget. Mangrove forests, in addition to providing habitat and nursery grounds for over 1300 animal species, are also an important sink of biomass. Although they only constitute about 3% of the total forested area globally, their carbon storage capacity -- in forested biomass and soil carbon -- is greater than that of tropical forests (Lucas et al, 2007). In addition, the amount of mangrove carbon -- in the form of litter and leaves exported into offshore areas is immense, resulting in over 10% of the ocean's dissolved organic carbon originating from mangroves (Dittmar et al, 2006) The measurement of forest above ground biomass is carried out on two major scales: on the plot scale, biomass can be measured using field measurements through allometric equation derivation and measurements of forest plots. On the larger scale, the field data are used to calibrate remotely sensed data to obtain stand-wide or even regional estimates of biomass. Currently, biomass can be calculated using average stand biomass values and optical data, such as aerial photography or satellite images (Landsat, Modis, Ikonos, SPOT, etc.). More recent studies have concentrated on deriving forest biomass values using radar (JERS, SIR-C, SRTM, Airsar) and/or lidar (ICEsat/GLAS, LVIS) active remote sensing to retrieve more accurate and detailed measurements of forest biomass. The implementation of a generation of new active sensors (UAVSar, DesdynI, Alos/Palsar, TerraX) has prompted the development of new tecm'liques of biomass estimation that use the combination of multiple sensors and datasets, to quantify past, current and future biomass stocks. Focusing on mangrove forest biomass estimation

  18. Negative and positive interactions among plants: effects of competitors and litter on seedling emergence and growth of forest and grassland species.

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    Loydi, A; Donath, T W; Otte, A; Eckstein, R L

    2015-05-01

    Living plant neighbours, but also their dead aboveground remains (i.e. litter), may individually exert negative or positive effects on plant recruitment. Although living plants and litter co-occur in most ecosystems, few studies have addressed their combined effects, and conclusions are ambivalent. Therefore, we examined the response in terms of seedling emergence and growth of herbaceous grassland and forest species to different litter types and amounts and the presence of competitors. We conducted a pot experiment testing the effects of litter type (grass, oak), litter amount (low, medium, high) and interspecific competition (presence or absence of four Festuca arundinacea individuals) on seedling emergence and biomass of four congeneric pairs of hemicryptophytes from two habitat types (woodland, grassland). Interactions between litter and competition were weak. Litter presence increased competitor biomass. It also had positive effects on seedling emergence at low litter amounts and negative effects at high litter amounts, while competition had no effect on seedling emergence. Seedling biomass was negatively affected by the presence of competitors, and this effect was stronger in combination with high amounts of litter. Litter affected seedling emergence while competition determined the biomass of the emerged individuals, both affecting early stages of seedling recruitment. High litter accumulation also reduced seedling biomass, but this effect seemed to be additive to competitor effects. This suggests that live and dead plant mass can affect species recruitment in natural systems, but the mechanisms by which they operate and their timing differ. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Microbial biomass and activity in litter during the initial development of pure and mixed plantations of Eucalyptus grandis and Acacia mangium

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    Daniel Bini

    2013-02-01

    Full Text Available Studies on microbial activity and biomass in forestry plantations often overlook the role of litter, typically focusing instead on soil nutrient contents to explain plant and microorganism development. However, since the litter is a significant source of recycled nutrients that affect nutrient dynamics in the soil, litter composition may be more strongly correlated with forest growth and development than soil nutrient contents. This study aimed to test this hypothesis by examining correlations between soil C, N, and P; litter C, N, P, lignin content, and polyphenol content; and microbial biomass and activity in pure and mixed second-rotation plantations of Eucalyptus grandis and Acacia mangium before and after senescent leaf drop. The numbers of cultivable fungi and bacteria were also estimated. All properties were correlated with litter C, N, P, lignin and polyphenols, and with soil C and N. We found higher microbial activity (CO2 evolution in litter than in soil. In the E. grandis monoculture before senescent leaf drop, microbial biomass C was 46 % higher in litter than in soil. After leaf drop, this difference decreased to 16 %. In A. mangium plantations, however, microbial biomass C was lower in litter than in soil both before and after leaf drop. Microbial biomass N of litter was approximately 94 % greater than that of the soil in summer and winter in all plantations. The number of cultivable fungi and bacteria increased after leaf drop, especially so in the litter. Fungi were also more abundant in the E. grandis litter. In general, the A. mangium monoculture was associated with higher levels of litter lignin and N, especially after leaf drop. In contrast, the polyphenol and C levels in E. grandis monoculture litter were higher after leaf drop. These properties were negatively correlated with total soil C and N. Litter in the mixed stands had lower C:N and C:P ratios and higher N, P, and C levels in the microbial biomass. This suggests more

  20. Spatial Distribution of Biomass and Woody Litter for Bio-Energy in Biscay (Spain

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    Esperanza Mateos

    2018-05-01

    Full Text Available Forest management has been considered a subject of interest, because they act as carbon (C sinks to mitigate CO 2 emissions and also as producers of woody litter (WL for bio-energy. Overall, a sustainably managed system of forests and forest products contributes to carbon mitigation in a positive, stable way. With increasing demand for sustainable production, the need to effectively utilise site-based resources increases. The utilization of WL for bio-energy can help meet the need for renewable energy production. The objective of the present study was to investigate biomass production (including C sequestration from the most representative forestry species (Pinus radiata D. Don and Ecualyptus globulus Labill of Biscay (Spain. Data from the third and fourth Spanish Forest Inventories (NFI3-2005 and NFI4-2011 were used. We also estimated the potential WL produced in the forest activities. Our findings were as follows: Forests of Biscay stored 12.084 Tg of biomass (dry basis, with a mean of 147.34 Mg ha - 1 in 2005 and 14.509 Tg of biomass (dry basis, with a mean of 179.82 Mg ha - 1 in 2011. The total equivalent CO 2 in Biscay’s forests increased by 1.629 Tg year - 1 between 2005 and 2011. The study shows that the energy potential of carbon accumulated in the WL amounted to 1283.2 million MJ year - 1 . These results suggest a considerable potential for energy production.

  1. Biomass is the main driver of changes in ecosystem process rates during tropical forest succession

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    Lohbeck, M.W.M.; Poorter, L.; Martinez-Ramos, M.; Bongers, F.

    2015-01-01

    Over half of the world's forests are disturbed, and the rate at which ecosystem processes recover after disturbance is important for the services these forests can provide. We analyze the drivers' underlying changes in rates of key ecosystem processes (biomass productivity, litter productivity,

  2. Carbon stocks in tree biomass and soils of German forests

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    Wellbrock Nicole

    2017-06-01

    Full Text Available Close to one third of Germany is forested. Forests are able to store significant quantities of carbon (C in the biomass and in the soil. Coordinated by the Thünen Institute, the German National Forest Inventory (NFI and the National Forest Soil Inventory (NFSI have generated data to estimate the carbon storage capacity of forests. The second NFI started in 2002 and had been repeated in 2012. The reporting time for the NFSI was 1990 to 2006. Living forest biomass, deadwood, litter and soils up to a depth of 90 cm have stored 2500 t of carbon within the reporting time. Over all 224 t C ha-1 in aboveground and belowground biomass, deadwood and soil are stored in forests. Specifically, 46% stored in above-ground and below-ground biomass, 1% in dead wood and 53% in the organic layer together with soil up to 90 cm. Carbon stocks in mineral soils up to 30 cm mineral soil increase about 0.4 t C ha-1 yr-1 stocks between the inventories while the carbon pool in the organic layers declined slightly. In the living biomass carbon stocks increased about 1.0 t C ha-1 yr-1. In Germany, approximately 58 mill. tonnes of CO2 were sequestered in 2012 (NIR 2017.

  3. The role of microbial communities in phosphorus cycling during litter decomposition in a tropical forest

    Science.gov (United States)

    Lloret Sevilla, E.; Brodie, E.; Bouskill, N.; Hao, Z.

    2016-12-01

    Phosphorus is an essential nutrient with a reduced availability in tropical forests. In these ecosystems, P is recycled highly efficiently through resorption and mineralization and P immobilization in the microbial biomass prevents its loss through occlusion in the soil mineral fraction. To improve models of ecosystem response to global change, further studies of the above and belowground plant and microbial traits related to P availability and uptake, are required. In tropical forests, high temperature and rainfall lead to some of the highest rates of litter decomposition on earth. Litter decomposition is a complex process mediated by a range of trophic groups: meso and microfauna initiate litter turnover through litter fragmentation facilitating colonization by fungi, and bacteria mediate the mineralization of organic matter and release of nutrients. To determine the important functional traits of these players in the efficient cycling of P in soils with low P availability, we are performing a leaf litter decomposition experiment in a humid tropical forest in Puerto Rico. Nylon litterbags with three mesh sizes (2mm, 20 μm and 0.45 μm) containing litter with different chemistry (tabonuco and palm) will be deployed on soil surface and sampled 6 times throughout 12 months. The use of different mesh sizes will allow us to identify the leading roles in litter turnover by physical allowance and/or exclusion of the decomposers. The 2 mm bags allow meso and microfauna, roots, fungi and bacteria. 20 μm bags will exclude fauna and roots and 0.45 μm only allow some bacteria. We hypothesize that fungi will dominate over bacteria in earlier stages of the decomposition with a higher production of extracellular hydrolytic enzymes. On the other hand, bacterial biomass is expected to increase with time. Qualitative changes in both fungal and bacterial communities along the decomposition process are also expected leading to changes in enzyme activity. We also postulate an

  4. Rain forest nutrient cycling and productivity in response to large-scale litter manipulation.

    Science.gov (United States)

    Wood, Tana E; Lawrence, Deborah; Clark, Deborah A; Chazdon, Robin L

    2009-01-01

    Litter-induced pulses of nutrient availability could play an important role in the productivity and nutrient cycling of forested ecosystems, especially tropical forests. Tropical forests experience such pulses as a result of wet-dry seasonality and during major climatic events, such as strong El Niños. We hypothesized that (1) an increase in the quantity and quality of litter inputs would stimulate leaf litter production, woody growth, and leaf litter nutrient cycling, and (2) the timing and magnitude of this response would be influenced by soil fertility and forest age. To test these hypotheses in a Costa Rican wet tropical forest, we established a large-scale litter manipulation experiment in two secondary forest sites and four old-growth forest sites of differing soil fertility. In replicated plots at each site, leaves and twigs (forest floor. We analyzed leaf litter mass, [N] and [P], and N and P inputs for addition, removal, and control plots over a two-year period. We also evaluated basal area increment of trees in removal and addition plots. There was no response of forest productivity or nutrient cycling to litter removal; however, litter addition significantly increased leaf litter production and N and P inputs 4-5 months following litter application. Litter production increased as much as 92%, and P and N inputs as much as 85% and 156%, respectively. In contrast, litter manipulation had no significant effect on woody growth. The increase in leaf litter production and N and P inputs were significantly positively related to the total P that was applied in litter form. Neither litter treatment nor forest type influenced the temporal pattern of any of the variables measured. Thus, environmental factors such as rainfall drive temporal variability in litter and nutrient inputs, while nutrient release from decomposing litter influences the magnitude. Seasonal or annual variation in leaf litter mass, such as occurs in strong El Niño events, could positively

  5. Phosphatase activity in relation to key litter and soil properties in mature subtropical forests in China.

    Science.gov (United States)

    Hou, Enqing; Chen, Chengrong; Wen, Dazhi; Liu, Xian

    2015-05-15

    Phosphatase-mediated phosphorus (P) mineralization is one of the critical processes in biogeochemical cycling of P and determines soil P availability in forest ecosystems; however, the regulation of soil phosphatase activity remains elusive. This study investigated the potential extracellular activities of acid phosphomonoesterase (AcPME) and phosphodiesterase (PDE) and how they were related to key edaphic properties in the L horizon (undecomposed litter) and F/H horizon (fermented and humified litter) and the underlying mineral soil at the 0-15cm depth in eight mature subtropical forests in China. AcPME activity decreased significantly in the order of F/H horizon>L horizon>mineral soil horizon, while the order for PDE activity was L horizon=F/H horizon>mineral soil horizon. AcPME (X axis) and PDE (Y axis) activities were positively correlated in all horizons with significantly higher slope in the L and F/H horizons than in the mineral soil horizon. Both AcPME and PDE activities were positively related to microbial biomass C, moisture content and water-holding capacity in the L horizon, and were positively related to soil C:P, N:P and C:N ratios and fine root (diameter≤2mm) biomass in the mineral soil horizon. Both enzyme activities were also interactively affected by forest and horizon, partly due to the interactive effect of forest and horizon on microbial biomass. Our results suggest that modulator(s) of the potential extracellular activity of phosphatases vary with horizon, depending on the relative C, P and water availability of the horizon. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Litter input controls on soil carbon in a temperate deciduous forest

    DEFF Research Database (Denmark)

    Bowden, Richard D.; Deem, Lauren; Plante, Alain F.

    2014-01-01

    Above- and belowground litter inputs in a temperate deciduous forest were altered for 20 yr to determine the importance of leaves and roots on soil C and soil organic matter (SOM) quantity and quality. Carbon and SOM quantity and quality were measured in the O horizon and mineral soil to 50 cm...... soil C, but decreases in litter inputs resulted in rapid soil C declines. Root litter may ultimately provide more stable sources of soil C. Management activities or environmental alterations that decrease litter inputs in mature forests can lower soil C content; however, increases in forest...

  7. Morphogenetic Litter Types of Bog Spruce Forests

    Directory of Open Access Journals (Sweden)

    T. T. Efremova

    2015-02-01

    Full Text Available For the first time the representation of moss litter morphogenetic structure of valley-riverside and streamside spruce forests was determined for the wetland intermountain area of Kuznetsk Alatau. In general, the litter of (green moss-hypnum spruce forest can be characterized as medium thickness (9–17 cm with high storage of organic matter (77–99 t/ha, which differs in neutral environmental conditions pH 6.8–7.0 and high percentage of ash 11–28 %. Formation litter types were identified, which depend on the content of mineral inclusions in organogenic substrate and the degree of its drainage. The differentiation of litter subhorizons was performed, visual diagnostic indicators of fermentative layers were characterized, and additional (indexes to indicate their specificity were developed. Peat- and peaty-fermentative, humified-fermentative and (black mold humus-fermentative layers were selected. Peat- and peaty-fermentative layers are characterized by content of platy peat macroaggregates of coarse vegetable composition, the presence of abundant fungal mycelium and soil animals are the primary decomposers – myriopoda, gastropoda mollusks. Humified-fermentative layers are identified by including the newly formed amorphous humus-like substances, nutty-granular structural parts of humus nature and soil animals’ humificators – enchytraeids and earthworms. (Black mold humus-fermentative layers are diagnosed by indicators with similar humified-fermentative, but differ from them in clay-humus composition of nutty-granular blue-grey parts. The nomenclature and classification of moss litter were developed on the basis of their diagnostic characteristics of fermentative layers – peat, peaty, reduced peaty, (black mold humus-peaty, reduced (black mold humus-peaty. Using the method of discriminant analysis, we revealed that the physical-chemical properties, mainly percentage of ash and decomposition degree of plant substrate, objectively

  8. Phosphorus 32 cycling in the root-litter mat of Pernambuco atlantic coastal forest, Brazil

    International Nuclear Information System (INIS)

    Salcedo, I.H.; Sampaio, E.V.S.; Elliott, E.T.

    1991-01-01

    We propose a compartmental model to describe P cycling in the root-litter mat and surface mineral soil of an Atlantic coastal forest. Considerable amounts of P accumulate in this root-litter mat, relative to available P in the underlying mineral soil. We studied the mechanisms responsible for P retention five days after addition of sup(32)P on the surface of the 02 horizon. Total sup(31)P and sup(32)P were determined in leaves, humus, mineral soil and roots. In addition, we determined sup(31)P and sup(32)P in the solution and microbial biomass of the humus material. Fluxes of sup(31)P were obtained from published data and from experimental results of sup(32)P distribution among compartments. The main fluxes taking P out from the soils solution were uptake by the microbial biomass and sorption by the humus (12.9 e 5.2 mg P m sup(-2) week sup(-1), respectively), while the mean flux into the roots was 3.1 mg P m sup(-2) week sup(-1). The main compartment responsible for P accumulation was the humus+fragments, which had the highest P content (61% of total P in the forest floor) and the longest turnover time (15.5 months). (author)

  9. Correlation between the morphogenetic types of litter and their properties in bog birch forests

    Science.gov (United States)

    Efremova, T. T.; Efremov, S. P.; Avrova, A. F.

    2010-08-01

    A formalized arrangement of morphogenetic types of litter according to the physicochemical parameters provided their significant grouping in three genetic associations. The litter group (highly decomposed + moderately decomposed) is confined to the tall-grass group of bog birch forests. The rhizomatous (roughly decomposed) litter is formed in the sedge-reed grass bog birch forests. The litter group (peaty + peatified + peat) is associated with the bog-herbaceous-moss group of forest types. The genetic associations of the litters (a) reliably characterize the edaphic conditions of bog birch forests and (b)correspond to formation of the peat of certain ecological groups. We found highly informative the acid-base parameters, the exchangeable cations (Ca2+ + Mg2+) and the total potential acidity, which differentiated the genetic associations of litter practically with 100% probability. The expediency of studying litters under groups of forest types rather than under separate types of bog birch forests was demonstrated.

  10. Analysis of litter mesofauna of Poltava region forest ecosystems

    Directory of Open Access Journals (Sweden)

    O. S. Komarov

    2007-08-01

    Full Text Available On the basis of research of litter mesofauna of 48 forest biogeocenoses the regularities of invertebrate communities formation on the species and families levels are determined. The degree of similarity of test plots are analysed by taxonomic structure of the communities. The factors of the litter invertebrate communities formation in forest ecosystems of the Poltava region are revealed.

  11. Effects of post-hurricane fertilization and debris removal on earthworm abundance and biomass in subtropical forests in Puerto Rico

    Science.gov (United States)

    Grizelle Gonzalez; Y. Li; X. Zou

    2007-01-01

    Hurricanes are a common disturbance in the Caribbean, striking the island of Puerto Rico on average every 21 years. Hurricane Hugo (1989) distributed the canopy litter onto the forest floor changing the chemistry and quantity of litter inputs to the soil. In this study, we determined the effect of inorganic fertilization on earthworm abundance, biomass, and species...

  12. Long-term litter manipulation alters soil organic matter turnover in a temperate deciduous forest.

    Science.gov (United States)

    Wang, Jun-Jian; Pisani, Oliva; Lin, Lisa H; Lun, Olivia O Y; Bowden, Richard D; Lajtha, Kate; Simpson, André J; Simpson, Myrna J

    2017-12-31

    Understanding soil organic matter (OM) biogeochemistry at the molecular-level is essential for assessing potential impacts from management practices and climate change on shifts in soil carbon storage. Biomarker analyses and nuclear magnetic resonance (NMR) spectroscopy were used in an ongoing detrital input and removal treatment experiment in a temperate deciduous forest in Pennsylvania, USA, to examine how above- and below-ground plant inputs control soil OM quantity and quality at the molecular-level. From plant material to surface soils, the free acyclic lipids and cutin, suberin, and lignin biomarkers were preferentially retained over free sugars and free cyclic lipids. After 20years of above-ground litter addition (Double Litter) or exclusion (No Litter) treatments, soil OM composition was relatively more degraded, as revealed by solid-state 13 C NMR spectroscopy. Under Doubled Litter inputs, soil carbon and phospholipid fatty acid (PLFA) concentrations were unchanged, suggesting that the current OM degradation status is a reflection of microbial-mediated degradation that occurred prior to the 20-year sampling campaign. Soil OM degradation was higher in the No Litter treatments, likely due to the decline in fresh, above-ground litter inputs over time. Furthermore, root and root and litter exclusion treatments (No Roots and No Inputs, respectively) both significantly reduced free sugars and PLFAs and increased preservation of suberin-derived compounds. PLFA stress ratios and the low N-acetyl resonances from diffusion edited 1 H NMR also indicate substrate limitations and reduced microbial biomass with these treatments. Overall, we highlight that storage of soil carbon and its biochemical composition do not linearly increase with plant inputs because the microbial processing of soil OM is also likely altered in the studied forest. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Effects of Forest Gaps on Litter Lignin and Cellulose Dynamics Vary Seasonally in an Alpine Forest

    Directory of Open Access Journals (Sweden)

    Han Li

    2016-01-01

    Full Text Available To understand how forest gaps and the associated canopy control litter lignin and cellulose dynamics by redistributing the winter snow coverage and hydrothermal conditions in the growing season, a field litterbag trial was conducted in the alpine Minjiang fir (Abies faxoniana Rehder and E.H. Wilson forest in a transitional area located in the upper reaches of the Yangtze River and the eastern Tibetan Plateau. Over the first year of litter decomposition, the litter exhibited absolute cellulose loss and absolute lignin accumulation except for the red birch litter. The changes in litter cellulose and lignin were significantly affected by the interactions among gap position, period and species. Litter cellulose exhibited a greater loss in the winter with the highest daily loss rate observed during the snow cover period. Both cellulose and lignin exhibited greater changes under the deep snow cover at the gap center in the winter, but the opposite pattern occurred under the closed canopy in the growing season. The results suggest that decreased snowpack seasonality due to winter warming may limit litter cellulose and lignin degradation in alpine forest ecosystems, which could further inhibit litter decomposition. As a result, the ongoing winter warming and gap vanishing would slow soil carbon sequestration from foliar litter in cold biomes.

  14. Radiocesium migration in the litter layer of different forest types in Fukushima, Japan.

    Science.gov (United States)

    Kurihara, Momo; Onda, Yuichi; Kato, Hiroaki; Loffredo, Nicolas; Yasutaka, Tetsuo; Coppin, Frederic

    2018-07-01

    Cesium-137 ( 137 Cs) migration in the litter layer consists of various processes, such as input via throughfall, output via litter decomposition, and input from deeper layers via soil organism activity. We conducted litter bag experiments over 2 years (December 2014-November 2016) to quantify the inputs and outputs of 137 Cs in the litter layer in a Japanese cedar plantation (Cryptomeria japonica) and a mixed broadleaf forest dominated by Quercus serrata located 40 km northwest of the Fukushima Dai-ichi Nuclear Power Plant. The experiments included four conditions, combining contaminated and non-contaminated litter and deeper layer material, and the inputs and outputs were estimated from the combination of 137 Cs increases and decreases in the litter layer under each condition. The 137 Cs dynamics differed between the two forests. In the C. japonica forest, some 137 Cs input via throughfall remained in the litter layer, and downward 137 Cs flux passed through the litter layer was 0.42 (/year).Upward flux of 137 Cs from the deeper layer was very restricted, layers was restricted, downward 137 Cs flux was less than 0.003 (/year).Upward input of 137 Cs from the deeper layer was prominent, 0.037 (/year). 137 Cs output via litter decomposition was observed in both forests. The flux in the C. japonica forest was slower than that in the broadleaf forest, 0.12 and 0.15 (/year), respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Intensive biomass harvesting in forests - what about the carbon balance?

    International Nuclear Information System (INIS)

    Berg, Bjoern; Johansson, Maj-Britt

    1998-08-01

    The use of biofuels is considered to be CO 2 -neutral. This means that the use of forest biomass for fuel does not add more CO 2 to the atmosphere than what has been taken up over a stand age by photosynthesis. However, the biomass that may be harvested only contains part of the CO 2 immobilized through fixation during the growth of the forest stand. A fraction of the produced biomass will always decompose on and in the soil, in part producing humus and in part CO 2 . To this fraction belongs the litter formed during the period of stand growth, e.g. the annual foliar litterfall. The decomposition of both foliar litter and green needles have been shown to follow an asymptotic function, meaning that the decomposition approaches a limit value. This means that recalcitrant remains are left. The decomposition of felling residues have been assumed to follow the same function. The obvious question is how the amount of humus is affected by removal of felling residues. In an investigation of humus storage in five stands of Norway spruce in south Sweden limit values were estimated for the decomposition of local spruce needle litter giving a variation from 63 to 85 per cent. With the use of these limit values and the amount of litterfall the accumulation of humus was estimated. These calculations showed that there is a growth of the humus layer in the period of stand growth. The rate of humus accumulation varied among the stands and on the average a theoretical humus accumulation of about 42 tons per hectare was estimated for a stand age of 60 years. This amount of already accumulated humus is not affected by harvests of remains from thinnings or clearcuts. If, on the other hand the felling residues are not removed that means that the amount of humus should increase. Experiments with soil scarification showed that for litter buried under plowed-up mineral soil the decomposition went further than in soil not scarified. The estimated limit value was on the average about 40 per

  16. Radiocesium leaching from contaminated litter in forest streams

    International Nuclear Information System (INIS)

    Sakai, Masaru; Gomi, Takashi; Naito, Risa S.; Negishi, Junjiro N.; Sasaki, Michiko; Toda, Hiroto; Nunokawa, Masanori; Murase, Kaori

    2015-01-01

    In Japanese forests suffering from the Fukushima Daiichi Nuclear Power Plant accident, litter fall provides a large amount of radiocesium from forests to streams. Submerged litter is processed to become a vital food resource for various stream organisms through initial leaching and subsequent decomposition. Although leaching from litter can detach radiocesium similarly to potassium, radiocesium leaching and its migration are poorly understood. We examined both radiocesium and potassium leaching to the water column and radiocesium allocation to minerals (glass beads, silica sand, and vermiculite) in the laboratory using soaked litter with and without minerals on a water column. The mineral types did not affect radiocesium leaching from litter, but soaking in water for 1, 7, and 30 days decreased the radiocesium concentration in litter by ×0.71, ×0.66, and ×0.56, respectively. Meanwhile, the 1-, 7-, and 30-day experiments decreased potassium concentration in litter by ×0.17, ×0.11, and ×0.09, respectively. Leached radiocesium remained in a dissolved form when there was no mineral phases present in the water, whereas there was sorption onto the minerals when they were present. In particular, vermiculite adsorbed radiocesium by two to three orders of magnitude more effectively than the other minerals. Because radiocesium forms (such as that dissolved or adsorbed to organic matter or minerals) can further mobilize to ecosystems, our findings will increase our understanding regarding the dynamics of radiocesium in stream ecosystems. - Highlights: • Radiocesium in contaminated litter was leached when soaked in water. • Radiocesium in litter leached slowly compared to potassium. • Minerals adsorbed dissolved radiocesium that was leached from litter. • Vermiculite effectively adsorbed radiocesium leached from litter

  17. Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter.

    Science.gov (United States)

    Rinkes, Zachary L; Sinsabaugh, Robert L; Moorhead, Daryl L; Grandy, A Stuart; Weintraub, Michael N

    2013-01-01

    Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early (40% mass loss) decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C) ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N) accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab conditions.

  18. Power production from radioactively contaminated biomass and forest litter in Belarus - Phase 1b

    Energy Technology Data Exchange (ETDEWEB)

    Roed, J.; Andersson, K.G.; Fogh, C.L. [and others

    2000-03-01

    The Chernobyl accident has led to radioactive contamination of vast Belarussian forest areas. A total scheme for remediation of contaminated forest areas and utilisation of the removed biomass in safe energy production is being investigated in a Belarussian-American-Danish collaborative project. Here the total radiological impact of the scheme is considered. This means that not only the dose reductive effect of the forest decontamination is taken into account, but also the possible adverse health effects in connection with the much needed bio-energy production. This report presents the results of an in-country, commercial-scale investigation of the effect of a baghouse filter in retaining contaminants so that they are not released to the atmosphere in the biomass energy production process. Approximately 99,5 % of the activity of a commercially representative, dust-laden boiler flue gas was removed from the stream by using a combination of a cyclone and a baghouse filter. (au)

  19. Assimilation of repeated woody biomass observations constrains decadal ecosystem carbon cycle uncertainty in aggrading forests

    Science.gov (United States)

    Smallman, T. L.; Exbrayat, J.-F.; Mencuccini, M.; Bloom, A. A.; Williams, M.

    2017-03-01

    Forest carbon sink strengths are governed by plant growth, mineralization of dead organic matter, and disturbance. Across landscapes, remote sensing can provide information about aboveground states of forests and this information can be linked to models to estimate carbon cycling in forests close to steady state. For aggrading forests this approach is more challenging and has not been demonstrated. Here we apply a Bayesian approach, linking a simple model to a range of data, to evaluate their information content, for two aggrading forests. We compare high information content analyses using local observations with retrievals using progressively sparser remotely sensed information (repeated, single, and no woody biomass observations). The net biome productivity of both forests is constrained to be a net sink with litter dynamics at one forest, while at the second forest total dead organic matter estimates are within observational uncertainty. The uncertainty of retrieved ecosystem traits in the repeated biomass analysis is reduced by up to 50% compared to analyses with less biomass information. This study quantifies the importance of repeated woody observations in constraining the dynamics of both wood and dead organic matter, highlighting the benefit of proposed remote sensing missions.

  20. Power production from radioactively contaminated biomass and forest litter in Belarus - Phase 1b

    DEFF Research Database (Denmark)

    Roed, Jørn; Andersson, Kasper Grann; Fogh, C.L.

    2000-01-01

    The Chernobyl accident has led to radioactive contamination of vast Belarussian forest areas. A total scheme for remediation of contaminated forest areas and utilisation of the removed biomass in safe energy production is being investigated in aBelarussian-American-Danish collaborative project....... Here the total radiological impact of the scheme is considered. This means that not only the dose reductive effect of the forest decontamination is taken into account, but also the possible adverse healtheffects in connection with the much needed bio-energy production. This report presents the results...

  1. High-frequency fire alters C : N : P stoichiometry in forest litter.

    Science.gov (United States)

    Toberman, Hannah; Chen, Chengrong; Lewis, Tom; Elser, James J

    2014-07-01

    Fire is a major driver of ecosystem change and can disproportionately affect the cycling of different nutrients. Thus, a stoichiometric approach to investigate the relationships between nutrient availability and microbial resource use during decomposition is likely to provide insight into the effects of fire on ecosystem functioning. We conducted a field litter bag experiment to investigate the long-term impact of repeated fire on the stoichiometry of leaf litter C, N and P pools, and nutrient-acquiring enzyme activities during decomposition in a wet sclerophyll eucalypt forest in Queensland, Australia. Fire frequency treatments have been maintained since 1972, including burning every 2 years (2yrB), burning every 4 years (4 yrB) and no burning (NB). C : N ratios in freshly fallen litter were 29-42% higher and C : P ratios were 6-25% lower for 2 yrB than NB during decomposition, with correspondingly lower 2yrB N : P ratios (27-32) than for NB (34-49). Trends in litter soluble and microbial N : P ratios were similar to the overall litter N : P ratios across fire treatments. Consistent with these, the ratio of activities for N-acquiring to P-acquiring enzymes in litter was higher for 2 yrB than NB, whereas 4 yrB was generally intermediate between 2 yrB and NB. Decomposition rates of freshly fallen litter were significantly lower for 2 yrB (72 ± 2% mass remaining at the end of experiment) than for 4 yrB (59 ± 3%) and NB (62 ± 3%), a difference that may be related to effects of N limitation, lower moisture content, and/or litter C quality. Results for older mixed-age litter were similar to those for freshly fallen litter although treatment differences were less pronounced. Overall, these findings show that frequent fire (2 yrB) decoupled N and P cycling, as manifested in litter C : N : P stoichiometry and in microbial biomass N : P ratio and enzymatic activities. Furthermore, these data indicate that fire induced a transient shift to N-limited ecosystem conditions

  2. Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter

    Directory of Open Access Journals (Sweden)

    Zachary L Rinkes

    2013-09-01

    Full Text Available Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early (< 10% mass loss, mid- (10-40% mass loss, and late (> 40% mass loss decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood < maple < maple-oak mixture < oak. In the field, mass loss was minimal (< 10% over the first 50 days (January-February, even for labile litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab

  3. Cellulose Dynamics during Foliar Litter Decomposition in an Alpine Forest Meta-Ecosystem

    Directory of Open Access Journals (Sweden)

    Kai Yue

    2016-08-01

    Full Text Available To investigate the dynamics and relative drivers of cellulose degradation during litter decomposition, a field experiment was conducted in three individual ecosystems (i.e., forest floor, stream, and riparian zone of an alpine forest meta-ecosystem on the eastern Tibetan Plateau. Four litter species (i.e., willow: Salix paraplesia, azalea: Rhododendron lapponicum, cypress: Sabina saltuaria, and larch: Larix mastersiana that had varying initial litter chemical traits were placed separately in litterbags and then incubated on the soil surface of forest floor plots or in the water of the stream and riparian zone plots. Litterbags were retrieved five times each year during the two-year experiment, with nine replicates each time for each treatment. The results suggested that foliar litter lost 32.2%–89.2% of the initial dry mass depending on litter species and ecosystem type after two-year’s incubation. The cellulose lost 60.1%–96.8% of the initial mass with degradation rate in the order of stream > riparian zone > forest floor. Substantial cellulose degradation occurred at the very beginning (i.e., in the first pre-freezing period of litter decomposition. Litter initial concentrations of phosphorus (P and lignin were found to be the dominant chemical traits controlling cellulose degradation regardless of ecosystems type. The local-scale environmental factors such as temperature, pH, and nutrient availability were important moderators of cellulose degradation rate. Although the effects of common litter chemical traits (e.g., P and lignin concentrations on cellulose degradation across different individual ecosystems were identified, local-scale environmental factors such as temperature and nutrient availability were found to be of great importance for cellulose degradation. These results indicated that local-scale environmental factors should be considered apart from litter quality for generating a reliable predictive framework for the drivers

  4. Effect of leaf litter quantity and type on forest soil fauna and biological quality

    OpenAIRE

    Zhizhong Yuan; Yang Cui; Shaokui Yan

    2013-01-01

    It is important to assess forest litter management. Here we examined the effects of leaf litter addition on the soil faunal community in Huitong subtropical forest region in Hunan Province, China. The microcosm experiment involving leaf-litter manipulation using a block and nested experimental design, respectively, was established in May, 2011. In the block design, the effects of litter quantity and its control were examined, while in the nested design a comparison was made of litter quality ...

  5. Fungal mycelium and decomposition of needle litter in three contrasting coniferous forests

    Science.gov (United States)

    Virzo De Santo, Amalia; Rutigliano, Flora Angela; Berg, Björn; Fioretto, Antonietta; Puppi, Gigliola; Alfani, Anna

    2002-08-01

    The fungal mycelium ingrowth and the rates of mass loss and respiration of needle litter of Pinus pinea, Pinus laricio, Pinus sylvestris, and Abies alba were investigated, in three coniferous forests, over a 3-year period by means of a composite set of incubations. In the early stages, the fungal flora of the decomposing needles was dominated by dematiaceous hyphomycetes and coelomycetes. Basidiomycetes reached a peak after 6 months on pine needles, but were absent from the N-rich needles of A. alba. Soil fungi ( Penicillium, Trichoderma, Absidia, Mucor sp. pl.) became most frequent in later stages. At the end of the study period, the total mycelium amount showed the lowest values in all pine needles incubated in the P. laricio forest and the highest ones in P. pinea needles incubated in the P. pinea forest. In all data sets, as in data for boreal forests examined for comparison, the concentration of litter fungal mycelium versus litter mass loss followed a common exponential model. However, in later stages, the amount of litter fungal mycelium was very close to that of the humus at the incubation site, thus supporting the hypothesis of a logistic growth pattern. Respiration rates of decomposing litters varied with season and decreased with litter age to values close to those of the humus at the incubation site. Respiration of water-saturated litter was negatively correlated with the total mycelium concentration, and this was consistent with the observation that in far-decomposed litter only a minor fraction of the total mycelium is alive.

  6. [Carbon storage of forest vegetation and allocation for main forest types in the east of Da-xing'an Mountains based on additive biomass model].

    Science.gov (United States)

    Peng, Wei; Dong, Li Hu; Li, Feng Ri

    2016-12-01

    Based on the biomass investigation data of main forest types in the east of Daxing'an Mountains, the additive biomass models of 3 main tree species were developed and the changes of carbon storage and allocation of forest community of tree layer, shrub layer, herb layer and litter layer from different forest types were discussed. The results showed that the carbon storage of tree layer, shrub layer, herb layer and litter layer for Rhododendron dauricum-Larix gmelinii forest was 71.00, 0.34, 0.05 and 11.97 t·hm -2 , respectively. Similarly, the carbon storage of the four layers of Ledum palustre-L. gmelinii forest was 47.82, 0.88, 0, 5.04 t·hm -2 , 56.56, 0.44, 0.04, 8.72 t·hm -2 for R. dauricum-mixed forest of L. gmelinii-Betula platyphylla, 46.21, 0.66, 0.07, 6.16 t·hm -2 for L. palustre-mixed forest of L. gmelinii-B. platyphylla, 40.90, 1.37, 0.04, 3.67 t·hm -2 for R. dauricum-B. platyphylla forest, 36.28, 1.12, 0.18, 4.35 t·hm -2 for L. palustre-B. platyphylla forest. The carbon storage of forest community for the understory vegetation of R. dauricum was higher than that of the forest with L. palustre. In the condition of similar circumstances for the understory, the order of carbon storage for forest community was L. gmelinii forest > the mixed forest of L. gmelinii-B. platyphylla > B. platyphylla forest. The carbon storage of different forest types was different with the order of R. dauricum-L. gmelinii forest (83.36 t·hm -2 )> R. dauricum-mixed forest of L. gmelinii-B. platyphylla (65.76 t·hm -2 ) > L. palustre-L. gmelinii forest (53.74 t·hm -2 )> L. palustre-mixed forest of L. gmelinii-B. platyphylla (53.10 t·hm -2 )> R. dauricum-B. platyphylla forest (45.98 t·hm -2 ) > L. palustre-B. platyphylla forest (41.93 t·hm -2 ). The order of carbon storage for the vertical distribution in forest communities with diffe-rent forest types was the tree layer (85.2%-89.0%) > litter layer (8.0%-14.4%) > shrub layer (0.4%-2.7%) > herb layer (0-0.4%).

  7. Leaf litter arthropod responses to tropical forest restoration.

    Science.gov (United States)

    Cole, Rebecca J; Holl, Karen D; Zahawi, Rakan A; Wickey, Philipp; Townsend, Alan R

    2016-08-01

    Soil and litter arthropods represent a large proportion of tropical biodiversity and perform important ecosystem functions, but little is known about the efficacy of different tropical forest restoration strategies in facilitating their recovery in degraded habitats. We sampled arthropods in four 7- to 8-year-old restoration treatments and in nearby reference forests. Sampling was conducted during the wet and dry seasons using extractions from litter and pitfall samples. Restoration treatments were replicated in 50 × 50-m plots in four former pasture sites in southern Costa Rica: plantation - trees planted throughout the plot; applied nucleation/islands - trees planted in patches of different sizes; and natural regeneration - no tree planting. Arthropod abundance, measures of richness and diversity, and a number of functional groups were greater in the island treatment than in natural regeneration or plantation treatments and, in many cases, were similar to reference forest. Litter and pitfall morphospecies and functional group composition in all three restoration treatments were significantly different than reference sites, but island and plantation treatments showed more recovery than natural regeneration. Abundance and functional group diversity showed a much greater degree of recovery than community composition. Synthesis and applications: The less resource-intensive restoration strategy of planting tree islands was more effective than tree plantations in restoring arthropod abundance, richness, and functional diversity. None of the restoration strategies, however, resulted in similar community composition as reference forest after 8 years of recovery, highlighting the slow rate of recovery of arthropod communities after disturbance, and underscoring the importance of conservation of remnant forests in fragmented landscapes.

  8. Effects of forest management practices in temperate beech forests on bacterial and fungal communities involved in leaf litter degradation.

    Science.gov (United States)

    Purahong, Witoon; Kapturska, Danuta; Pecyna, Marek J; Jariyavidyanont, Katalee; Kaunzner, Jennifer; Juncheed, Kantida; Uengwetwanit, Tanaporn; Rudloff, Renate; Schulz, Elke; Hofrichter, Martin; Schloter, Michael; Krüger, Dirk; Buscot, François

    2015-05-01

    Forest management practices (FMPs) significantly influence important ecological processes and services in Central European forests, such as leaf litter decomposition and nutrient cycling. Changes in leaf litter diversity, and thus, its quality as well as microbial community structure and function induced by different FMPs were hypothesized to be the main drivers causing shifts in decomposition rates and nutrient release in managed forests. In a litterbag experiment lasting 473 days, we aimed to investigate the effects of FMPs (even-aged timber management, selective logging and unmanaged) on bacterial and fungal communities involved in leaf litter degradation over time. Our results showed that microbial communities in leaf litter were strongly influenced by both FMPs and sampling date. The results from nonmetric multidimensional scaling (NMDS) ordination revealed distinct patterns of bacterial and fungal successions over time in leaf litter. We demonstrated that FMPs and sampling dates can influence a range of factors, including leaf litter quality, microbial macronutrients, and pH, which significantly correlate with microbial community successions.

  9. Efficient way back litters nutrient potential of a tropical forest of bank. Sierra Nevada of Santa Marta Colombia

    International Nuclear Information System (INIS)

    Fuentes Molina, Natalia; Rodriguez Barrios, Javier Alfredo

    2012-01-01

    In three representative forests along the River Gaira, (subtropical wet forest, subtropical moist forest and tropical thorn mount), were measured over six months (wet and dry seasons) fluxes of nitrogen and phosphorus through the litter. Concentrations of nutrients (nitrogen and phosphorus) in the litter were relatively similar in the three Nevada de Santa Marta Colombia. Fuentes, Rodriguez. vegetation types (1.71% n and 0.12% p for the subtropical moist forest, followed by the tropical thorn mount with 1.50% n and 0.10% p and the subtropical wet forest with 1.39% n and 0.08% p), with the most significant differences found for nitrogen, which is the major nutrient with the absolute maximum in the subtropical rain forest set in the middle stretch of the basin. The greatest returns on biomass and nutrients occurred in the subtropical moist forest and tropical thorn mount set in the middle and lower reaches of the basin. The leaves showed high concentration of n and consequently, given the high production values of the different fractions, a high potential return of n (78.6 kg ha-1 yr-1). The foliar p concentration showed a potential return of 4.9 kgha1yr-1 and high values of the indices of efficiency in their use (iev: 2888.5) and foliar resorption (ern: 98.2), was the nutrient most limiting.

  10. Leaf litter decomposition rates increase with rising mean annual temperature in Hawaiian tropical montane wet forests

    Directory of Open Access Journals (Sweden)

    Lori D. Bothwell

    2014-12-01

    Full Text Available Decomposing litter in forest ecosystems supplies nutrients to plants, carbon to heterotrophic soil microorganisms and is a large source of CO2 to the atmosphere. Despite its essential role in carbon and nutrient cycling, the temperature sensitivity of leaf litter decay in tropical forest ecosystems remains poorly resolved, especially in tropical montane wet forests where the warming trend may be amplified compared to tropical wet forests at lower elevations. We quantified leaf litter decomposition rates along a highly constrained 5.2 °C mean annual temperature (MAT gradient in tropical montane wet forests on the Island of Hawaii. Dominant vegetation, substrate type and age, soil moisture, and disturbance history are all nearly constant across this gradient, allowing us to isolate the effect of rising MAT on leaf litter decomposition and nutrient release. Leaf litter decomposition rates were a positive linear function of MAT, causing the residence time of leaf litter on the forest floor to decline by ∼31 days for each 1 °C increase in MAT. Our estimate of the Q10 temperature coefficient for leaf litter decomposition was 2.17, within the commonly reported range for heterotrophic organic matter decomposition (1.5–2.5 across a broad range of ecosystems. The percentage of leaf litter nitrogen (N remaining after six months declined linearly with increasing MAT from ∼88% of initial N at the coolest site to ∼74% at the warmest site. The lack of net N immobilization during all three litter collection periods at all MAT plots indicates that N was not limiting to leaf litter decomposition, regardless of temperature. These results suggest that leaf litter decay in tropical montane wet forests may be more sensitive to rising MAT than in tropical lowland wet forests, and that increased rates of N release from decomposing litter could delay or prevent progressive N limitation to net primary productivity with climate warming.

  11. LBA-ECO CD-10 Forest Litter Data for km 67 Tower Site, Tapajos National Forest

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains a single text file which reports litter type and mass in the old-growth upland forest at the Para Western (Santarem) - km 67, Primary Forest...

  12. Secondary Forest Age and Tropical Forest Biomass Estimation Using TM

    Science.gov (United States)

    Nelson, R. F.; Kimes, D. S.; Salas, W. A.; Routhier, M.

    1999-01-01

    The age of secondary forests in the Amazon will become more critical with respect to the estimation of biomass and carbon budgets as tropical forest conversion continues. Multitemporal Thematic Mapper data were used to develop land cover histories for a 33,000 Square kM area near Ariquemes, Rondonia over a 7 year period from 1989-1995. The age of the secondary forest, a surrogate for the amount of biomass (or carbon) stored above-ground, was found to be unimportant in terms of biomass budget error rates in a forested TM scene which had undergone a 20% conversion to nonforest/agricultural cover types. In such a situation, the 80% of the scene still covered by primary forest accounted for over 98% of the scene biomass. The difference between secondary forest biomass estimates developed with and without age information were inconsequential relative to the estimate of biomass for the entire scene. However, in futuristic scenarios where all of the primary forest has been converted to agriculture and secondary forest (55% and 42% respectively), the ability to age secondary forest becomes critical. Depending on biomass accumulation rate assumptions, scene biomass budget errors on the order of -10% to +30% are likely if the age of the secondary forests are not taken into account. Single-date TM imagery cannot be used to accurately age secondary forests into single-year classes. A neural network utilizing TM band 2 and three TM spectral-texture measures (bands 3 and 5) predicted secondary forest age over a range of 0-7 years with an RMSE of 1.59 years and an R(Squared) (sub actual vs predicted) = 0.37. A proposal is made, based on a literature review, to use satellite imagery to identify general secondary forest age groups which, within group, exhibit relatively constant biomass accumulation rates.

  13. Microhabitat effects of litter temperature and moisture on forest-floor invertebrate communities

    Science.gov (United States)

    Tim A. Christiansen; Sue A. Perry; William B. Perry

    1996-01-01

    Litter temperature and moisture may be altered due to changes in global climate. We investigated the effect of small changes in litter temperature and moisture on forest-floor communities in West Virginia.

  14. Biomass resilience of Neotropical secondary forests.

    Science.gov (United States)

    Poorter, Lourens; Bongers, Frans; Aide, T Mitchell; Almeyda Zambrano, Angélica M; Balvanera, Patricia; Becknell, Justin M; Boukili, Vanessa; Brancalion, Pedro H S; Broadbent, Eben N; Chazdon, Robin L; Craven, Dylan; de Almeida-Cortez, Jarcilene S; Cabral, George A L; de Jong, Ben H J; Denslow, Julie S; Dent, Daisy H; DeWalt, Saara J; Dupuy, Juan M; Durán, Sandra M; Espírito-Santo, Mario M; Fandino, María C; César, Ricardo G; Hall, Jefferson S; Hernandez-Stefanoni, José Luis; Jakovac, Catarina C; Junqueira, André B; Kennard, Deborah; Letcher, Susan G; Licona, Juan-Carlos; Lohbeck, Madelon; Marín-Spiotta, Erika; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R F; Ochoa-Gaona, Susana; de Oliveira, Alexandre A; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A; Piotto, Daniel; Powers, Jennifer S; Rodríguez-Velázquez, Jorge; Romero-Pérez, I Eunice; Ruíz, Jorge; Saldarriaga, Juan G; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B; Steininger, Marc K; Swenson, Nathan G; Toledo, Marisol; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D M; Vester, Hans F M; Vicentini, Alberto; Vieira, Ima C G; Bentos, Tony Vizcarra; Williamson, G Bruce; Rozendaal, Danaë M A

    2016-02-11

    Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha(-1)), corresponding to a net carbon uptake of 3.05 Mg C ha(-1) yr(-1), 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha(-1)) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience.

  15. Foliage litter quality and annual net N mineralization: comparison across North American forest sites.

    Science.gov (United States)

    Scott, Neal A; Binkley, Dan

    1997-07-01

    The feedback between plant litterfall and nutrient cycling processes plays a major role in the regulation of nutrient availability and net primary production in terrestrial ecosystems. While several studies have examined site-specific feedbacks between litter chemistry and nitrogen (N) availability, little is known about the interaction between climate, litter chemistry, and N availability across different ecosystems. We assembled data from several studies spanning a wide range of vegetation, soils, and climatic regimes to examine the relationship between aboveground litter chemistry and annual net N mineralization. Net N mineralization declined strongly and non-linearly as the litter lignin:N ratio increased in forest ecosystems (r 2  = 0.74, P mineralization decreased linearly as litter lignin concentration increased, but the relationship was significant (r 2  = 0.63, P mineralization across this range of sites (r 2  litter lignin:N ratio and net N mineralization from forest floor and mineral soil was similar. The litter lignin:N ratio explained more of the variation in net N mineralization than climatic factors over a wide range of forest age classes, suggesting that litter quality (lignin:N ratio) may exert more than a proximal control over net N mineralization by influencing soil organic matter quality throughout the soil profile independent of climate.

  16. Leaf litter nitrogen concentration as related to climatic factors in Eurasian forests

    DEFF Research Database (Denmark)

    Liu, Chunjiang; Berg, Bjørn; Kutsch, Werner

    2006-01-01

    The aim of this study is to determine the patterns of nitrogen (N) concentrations in leaf litter of forest trees as functions of climatic factors, annual average temperature (Temp, °C) and annual precipitation (Precip, dm) and of forest type (coniferous vs. broadleaf, deciduous vs. evergreen, Pinus...... concentration and Temp and Precip by means of regression analysis. Leaf litter data from N2-fixing species were excluded from the analysis. Results: Over the Eurasian continent, leaf litter N concentration increased with increasing Temp and Precip within functional groups such as conifers, broadleaf, deciduous....... In the context of global warming, these regression equations are useful for a better understanding and modelling of the effects of geographical and climatic factors on leaf litter N at a regional and continental scale....

  17. PCDD/F EMISSIONS FROM FOREST FIRE SIMULATIONS

    Science.gov (United States)

    Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F) emissions from combustion of forest biomass were sampled to obtain an estimated emission factor for forest fires. An equal composition of live shoot and litter biomass from Oregon and North Carolina was b...

  18. Forest structure and downed woody debris in boreal, temperate, and tropical forest fragments.

    Science.gov (United States)

    Gould, William A; González, Grizelle; Hudak, Andrew T; Hollingsworth, Teresa Nettleton; Hollingsworth, Jamie

    2008-12-01

    Forest fragmentation affects the heterogeneity of accumulated fuels by increasing the diversity of forest types and by increasing forest edges. This heterogeneity has implications in how we manage fuels, fire, and forests. Understanding the relative importance of fragmentation on woody biomass within a single climatic regime, and along climatic gradients, will improve our ability to manage forest fuels and predict fire behavior. In this study we assessed forest fuel characteristics in stands of differing moisture, i.e., dry and moist forests, structure, i.e., open canopy (typically younger) vs. closed canopy (typically older) stands, and size, i.e., small (10-14 ha), medium (33 to 60 ha), and large (100-240 ha) along a climatic gradient of boreal, temperate, and tropical forests. We measured duff, litter, fine and coarse woody debris, standing dead, and live biomass in a series of plots along a transect from outside the forest edge to the fragment interior. The goal was to determine how forest structure and fuel characteristics varied along this transect and whether this variation differed with temperature, moisture, structure, and fragment size. We found nonlinear relationships of coarse woody debris, fine woody debris, standing dead and live tree biomass with mean annual median temperature. Biomass for these variables was greatest in temperate sites. Forest floor fuels (duff and litter) had a linear relationship with temperature and biomass was greatest in boreal sites. In a five-way multivariate analysis of variance we found that temperature, moisture, and age/structure had significant effects on forest floor fuels, downed woody debris, and live tree biomass. Fragment size had an effect on forest floor fuels and live tree biomass. Distance from forest edge had significant effects for only a few subgroups sampled. With some exceptions edges were not distinguishable from interiors in terms of fuels.

  19. SEASONAL AND TOPOGRAPHYCAL VARIATION OF THE LITTER NUTRIENT CONTENTS OF A ATLANTIC FOREST FRAGMENT

    Directory of Open Access Journals (Sweden)

    Rosângela A. Tristão Borém

    2002-01-01

    Full Text Available ABSTRACT: The objective of this work was to study the effects of forest degradation on the supplyand contents of nutrients in the litter of two toposequences. The study area is located in a fragment ofthe Atlantic Forest, in Silva Jardim, State of Rio de Janeiro, Brazil (42°31'W and 22°31'S. The twotoposequences are under low and high degrees of human intervention. They were divided in lower,middle and upper slope, and the vegetation sampled with plots of 600m2. The litter was collected forquantitative and qualitative characterisation using a wood frame of 0,25m2 randomly distributedwithin the sample plots. Litter collection was carried out in two distinct dates in order to capture seasonalpatterns. The average litter production did not differ significantly between the toposequences.The total litter production was higher at the end of the dry season, and lower at the end of the rainyseason, indicating the seasonal pattern of the forest. The chemical analyses showed that the nutrientscontents varied widely between the toposequences. The lower and middle slope of the toposequenceunder high degree of human intervention presented the highest nutrient contents in the litter.

  20. Plant litter dynamics in the forest-stream interface: precipitation is a major control across tropical biomes.

    Science.gov (United States)

    Tonin, Alan M; Gonçalves, José F; Bambi, Paulino; Couceiro, Sheyla R M; Feitoza, Lorrane A M; Fontana, Lucas E; Hamada, Neusa; Hepp, Luiz U; Lezan-Kowalczuk, Vânia G; Leite, Gustavo F M; Lemes-Silva, Aurea L; Lisboa, Leonardo K; Loureiro, Rafael C; Martins, Renato T; Medeiros, Adriana O; Morais, Paula B; Moretto, Yara; Oliveria, Patrícia C A; Pereira, Evelyn B; Ferreira, Lidiane P; Pérez, Javier; Petrucio, Mauricio M; Reis, Deusiano F; S Rezende, Renan; Roque, Nadia; Santos, Luiz E P; Siegloch, Ana E; Tonello, Gabriela; Boyero, Luz

    2017-09-07

    Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even though the tropics occupy 40% of the Earth's land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Amazon forest and Cerrado savanna), predicting major differences among biomes in relation to temperature and precipitation regimes. Precipitation explained most of litter inputs and storage, which were generally higher in more humid biomes (litterfall: 384, 422 and 308 g m -2 y -1 , storage: 55, 113 and 38 g m -2 , on average in Atlantic forest, Amazon and Cerrado, respectively). Temporal dynamics varied across biomes in relation to precipitation and temperature, with uniform litter inputs but seasonal storage in Atlantic forest streams, seasonal inputs in Amazon and Cerrado streams, and aseasonal storage in Amazon streams. Our findings suggest that litter dynamics vary greatly within the tropics, but point to the major role of precipitation, which contrasts with the main influence of temperature in temperate areas.

  1. Chapter 13: Recent Advances on the Genomics of Litter- and Soil-Inhabiting Agaricomycetes

    Science.gov (United States)

    Phil Kersten; Dan Cullen

    2013-01-01

    Woody biomass makes up the major portion of terrestrial carbon, and forest ecosystems contain enormous reservoirs of lignocellulose belowground, in dead trees, and litter. Decomposition of this recalcitrant material and mobilization of nutrients are essential for forest health [reviewed by Boddy and Watkinson (1995)]. Although mechanisms are incompletely understood,...

  2. Manganese in the litter fall-forest floor continuum of boreal and temperate pine and spruce forest ecosystems

    DEFF Research Database (Denmark)

    Berg, Björn; Erhagen, Björn; Johansson, Maj-Britt

    2015-01-01

    We have reviewed the literature on the role of manganese (Mn) in the litter fall-to-humus subsystem. Available data gives a focus on North European coniferous forests. Manganese concentrations in pine (Pinus spp.) foliar litter are highly variable both spatially and temporally within the same lit...

  3. Evaluating leaf litter beetle data sampled by Winkler extraction from Atlantic forest sites in southern Brazil

    Directory of Open Access Journals (Sweden)

    Philipp Werner Hopp

    2011-06-01

    Full Text Available Evaluating leaf litter beetle data sampled by Winkler extraction from Atlantic forest sites in southern Brazil. To evaluate the reliability of data obtained by Winkler extraction in Atlantic forest sites in southern Brazil, we studied litter beetle assemblages in secondary forests (5 to 55 years after abandonment and old-growth forests at two seasonally different points in time. For all regeneration stages, species density and abundance were lower in April compared to August; but, assemblage composition of the corresponding forest stages was similar in both months. We suggest that sampling of small litter inhabiting beetles at different points in time using the Winkler technique reveals identical ecological patterns, which are more likely to be influenced by sample incompleteness than by differences in their assemblage composition. A strong relationship between litter quantity and beetle occurrences indicates the importance of this variable for the temporal species density pattern. Additionally, the sampled beetle material was compared with beetle data obtained with pitfall traps in one old-growth forest. Over 60% of the focal species captured with pitfall traps were also sampled by Winkler extraction in different forest stages. Few beetles with a body size too large to be sampled by Winkler extraction were only sampled with pitfall traps. This indicates that the local litter beetle fauna is dominated by small species. Hence, being aware of the exclusion of large beetles and beetle species occurring during the wet season, the Winkler method reveals a reliable picture of the local leaf litter beetle community.

  4. Litter decomposing fungi in sal (Shorea robusta forests of central India

    Directory of Open Access Journals (Sweden)

    RAM KEERTI VERMA

    2011-11-01

    Full Text Available Soni KK, Pyasi A, Verma RK. 2011. Litter decomposing fungi in sal (Shorea robusta forests of central India. Nusantara Bioscience 3: 136-144. The present study aim on isolation and identification of fungi associated with decomposition of litter of sal forest in central India. Season wise successional changes in litter mycoflora were determined for four main seasons of the year namely, March-May, June-August, September-November and December-February. Fungi like Aspergillus flavus, A. niger and Rhizopus stolonifer were associated with litter decomposition throughout the year, while Aspergillus fumigatus, Cladosporium cladosporioides, C. oxysporum, Curvularia indica, and C. lunata were recorded in three seasons. Some fungi including ectomycorrhiza forming occur only in the rainy season (June-August these are Astraeus hygrometricus, Boletus fallax, Calvatia elata, Colletotrichum dematium, Corticium rolfsii, Mycena roseus, Periconia minutissima, Russula emetica, Scleroderma bovista, S. geaster, S. verrucosum, Scopulariopsis alba and four sterile fungi. Fungi like Alternaria citri, Gleocladium virens, Helicosporium phragmitis and Pithomyces cortarum were rarely recorded only in one season.

  5. Fungal Community and Ligninolytic Enzyme Activities in Quercus deserticola Trel. Litter from Forest Fragments with Increasing Levels of Disturbance

    Directory of Open Access Journals (Sweden)

    Jesús A. Rosales-Castillo

    2017-12-01

    Full Text Available Litter fungal communities and their ligninolytic enzyme activities (laccase, Mn-peroxidase, and lignin-peroxidase play a vital role in forest biogeochemical cycles by breaking down plant cell wall polymers, including recalcitrant lignin. However, litter fungal communities and ligninolytic enzyme activities have rarely been studied in Neotropical, non-coniferous forests. Here, we found no significant differences in litter ligninolytic enzyme activities from well preserved, moderately disturbed, and heavily disturbed Quercus deserticola Trel. forests in central Mexico. However, we did find seasonal effects on enzyme activities: during the dry season, we observed lower laccase, and increased Mn-peroxidase and lignin-peroxidase activities, and in the rainy season, Mn-peroxidase and lignin-peroxidase activities were lower, while laccase activity peaked. Fungal diversity (Shannon-Weaver and Simpson indices based on ITS-rDNA analyses decreased with increased disturbance, and principal component analysis showed that litter fungal communities are structured differently between forest types. White-rot Polyporales and Auriculariales only occurred in the well preserved forest, and a high number of Ascomycota were shared between forests. While the degree of forest disturbance significantly affected the litter fungal community structure, the ligninolytic enzyme activities remained unaffected, suggesting functional redundancy and a possible role of generalist Ascomycota taxa in litter delignification. Forest conservation and restoration strategies must account for leaf litter and its associated fungal community.

  6. Theme E: Forest Biomass and Bioenergy

    DEFF Research Database (Denmark)

    Bentsen, Niclas Scott; Stupak, Inge; Smith, C

    2014-01-01

    Several countries in the world have policies for increased use of biomass for energy and biomaterials. It is likely that such policies will lead to increased international demand for wood and increased pressure on the world’s forests. Concerns for forest sustainability have been expressed, especi...... challenges in the different regions for consideration by institutions developing energy biomass sourcing polices and biomass sustainability criteria in the public and private sector......., especially in the EU and its biomass importing countries. As countries and companies search worldwide for new biomass sourcing areas, there is a need to review and compare the biomass potentials in different regions and the associated forest sustainability challenges. We reviewed the literature to assess...

  7. [Contribution of soil fauna to the mass loss of Betula albosinensis leaf litter at early decomposition stage of subalpine forest litter in western Sichuan].

    Science.gov (United States)

    Xia, Lei; Wu, Fu-Zhong; Yang, Wan-Qin; Tan, Bo

    2012-02-01

    In order to quantify the contribution of soil fauna to the decomposition of birch (Betula albosinensis) leaf litter in subalpine forests in western Sichuan of Southwest China during freeze-thaw season, a field experiment with different mesh sizes (0.02, 0.125, 1 and 3 mm) of litterbags was conducted in a representative birch-fir (Abies faxoniana) forest to investigate the mass loss rate of the birch leaf litter from 26 October, 2010 to 18 April, 2011, and the contributions of micro-, meso- and macro-fauna to the decomposition of the leaf litter. Over the freeze-thaw season, 11.8%, 13.2%, 15.4% and 19.5% of the mass loss were detected in the litterbags with 0.02, 0. 125, 1 and 3 mm mesh sizes, respectively. The total contribution of soil fauna to the litter decomposition accounted for 39.5% of the mass loss, and the taxa and individual relative density of the soil fauna in the litterbags had the similar variation trend with that of the mass loss rate. The contribution rate of soil fauna to the leaf litter mass loss showed the order of micro- soil fauna played an important role in the litter decomposition in subalpine forests of western Sichuan during freeze-thaw season.

  8. Does the precipitation redistribution of the canopy sense in the moisture pattern of the forest litter?

    Science.gov (United States)

    Zagyvai-Kiss, Katalin Anita; Kalicz, Péter; Csáfordi, Péter; Kucsara, Mihály; Gribovszki, Zoltán

    2013-04-01

    Precipitation is trapped and temporarily stored by the surfaces of forest crown (canopy interception) and forest litter (litter interception). The stemflow and throughfall reach the litter, thus theoretically the litter moisture content depends on these parts of precipitation. Nowadays the moisture pattern of the forest floor, both spatial and temporal scale, have growing respect for the forestry. The transition to the continuous cover forestry induce much higher variability compared to the even aged, more-less homogeneous, monocultural stands. The gap cutting is one of the key methods in the Hungarian forestry. There is an active discussion among the forest professionals how to determine the optimal gap size to maintain the optimal conditions for the seedlings. Among the open questions is how to modify surrounding trees the moisture pattern of the forest floor in the gap? In the early steps of a multidisciplinary project we processed some available data, to estimate the spatial dependency between the water content of forest litter and the spatial pattern of the canopy represented by the tree trunk. The maximum water content depends on dry weight of litter, thus we also analysed that parameter. Data were measured in three different forest ecosystems: a middle age beech (Fagus sylvatica), a sessile oak (Quercus petraea) and a spruce (Picea abies) stand. The study site (Hidegvíz Valley Research Cathcment) is located in Sopron Hills at the eastern border of the Alps. Litter samples were collected under each stand (occasionally 10-10 pieces from 40?40 cm area) and locations of the samples and neighbouring trees were mapped. We determined dry weight and the water content of litter in laboratory. The relationship between water content and the distance of tree trunks in case of spruce and oak stands were not significant and in case of the beech stand was weakly significant. Climate change effects can influence significantly forest floor moisture content, therefore this

  9. Biomass and nutrient dynamics associated with slash fires in neotropical dry forests

    International Nuclear Information System (INIS)

    Kauffman, J.B.; Cummings, D.L.; Sanford, R.L. Jr.; Salcedo, I.H.; Sampaio, E.V.S.B.

    1993-01-01

    Unprecedented rates of deforestation and biomass burning in tropical dry forests are dramatically influencing biogeochemical cycles, resulting in resource depletion, declines in biodiversity, and atmospheric pollution. We quantified the effects of deforestation and varying levels of slash-fire severity on nutrient losses and redistribution in a second-growth tropical dry forest (open-quotes Caatingaclose quotes) near Serra Talhada, Pernambuco, Brazil. Total aboveground biomass prior to burning was ∼74 Mg/ha. Nitrogen and phosphorus concentrations were highest in litter, leaves attached to slash, and fine wood debris (< O.64 cm diameter). While these components comprised only 30% of the prefire aboveground biomass, they accounted for ∼60% of the aboveground pools of N and P. Three experimental fires were conducted during the 1989 burning season. Consumption was 78, 88, and 95% of the total aboveground biomass. As much as 96% of the prefire aboveground N and C pools and 56% of the prefire aboveground P pool was lost. Nitrogen losses exceeded 500 kg/ha and P losses exceeded 20 kg/ha in the fires of the greatest severity. With increasing fire severity, the concentrations of N and P in ash decreased while the concentration of Ca increased. Greater ecosystem losses of these nutrients occurred with increasing fire severity. Following fire, up to 47% of the residual aboveground N and 84% of the residual aboveground P were in the form of ash, quickly lost from the site via wind erosion. Fires appeared to have a minor immediate effect on total N, C, or P in the soils. However, soils in forests with no history of cultivation had significantly higher concentrations of C and P than second-growth forests. It would likely require a century or more of fallow for reaccumulation to occur. However, current fallow periods in this region are 15 yr or less. 38 refs., 2 figs., 7 tabs

  10. Microbial respiration per unit microbial biomass increases with carbon-to-nutrient ratios in soils

    Science.gov (United States)

    Spohn, Marie; Chodak, Marcin

    2015-04-01

    The ratio of carbon-to-nutrient in forest floors is usually much higher than the ratio of carbon-to-nutrient that soil microorganisms require for their nutrition. In order to understand how this mismatch affects carbon cycling, the respiration rate per unit soil microbial biomass carbon - the metabolic quotient (qCO2) - was studied. This was done in a field study (Spohn and Chodak, 2015) and in a meta-analysis of published data (Spohn, 2014). Cores of beech, spruce, and mixed spruce-beech forest soils were cut into slices of 1 cm from the top of the litter layer down to 5 cm in the mineral soil, and the relationship between the qCO2 and the soil carbon-to-nitrogen (C:N) and the soil carbon-to-phosphorus (C:P) ratio was analyzed. We found that the qCO2 was positively correlated with soil C:N ratio in spruce soils (R = 0.72), and with the soil C:P ratio in beech (R = 0.93), spruce (R = 0.80) and mixed forest soils (R = 0.96). We also observed a close correlation between the qCO2 and the soil C concentration in all three forest types. Yet, the qCO2 decreased less with depth than the C concentration in all three forest types, suggesting that the change in qCO2 is not only controlled by the soil C concentration. We conclude that microorganisms increase their respiration rate per unit biomass with increasing soil C:P ratio and C concentration, which adjusts the substrate to their nutritional demands in terms of stoichiometry. In an analysis of literature data, I tested the effect of the C:N ratio of soil litter layers on microbial respiration in absolute terms and per unit microbial biomass C. For this purpose, a global dataset on the microbial respiration rate per unit microbial biomass C - termed the metabolic quotient (qCO2) - was compiled form literature data. It was found that the qCO2 in the soil litter layers was positively correlated with the litter C:N ratio and negatively related with the litter nitrogen (N) concentration. The positive relation between the qCO2

  11. A trait-based framework for understanding how and why litter decay and resource stoichiometry promote biogeochemical syndromes in arbuscular- and ectomycorrhizal-dominated forests

    Science.gov (United States)

    Phillips, R.; Brzostek, E. R.; Fisher, J. B.; Sulman, B. N.; Midgley, M.; Craig, M.; Keller, A. B.

    2016-12-01

    While it has long been known that ecosystems dominated by arbuscular mycorrhizal (AM) plants (e.g., grasslands, tropical forests) cycle carbon (C) and nutrients differently than those dominated by ectomycorrhizal (ECM) plants (e.g., boreal and subarctic forests), demonstrations of these patterns in ecosystems where both mycorrhizal types co-occur are rare. We tested the hypothesis that variation between AM and ECM nutrient use traits (e.g., litter quality) promote distinct microbial traits that track biogeochemical syndromes in temperate forests. We then explored whether such belowground dynamics influence ecosystem responses to elevated CO2. To do this, we calculated the C to N ratios of litter, soil microbes and soil organic matter in AM- and ECM-dominated forests throughout the temperate region. We then used these data to parameterize a coupled plant uptake-microbial decomposition model, in order to determine how belowground interactions feedback to affect ecosystem C and N cycling in forests exposed to elevated CO2. We found support for our hypothesis: AM litters decomposed 50% faster than ECM litters (p litter decay rates were negatively correlated with the C:N of soils (including the microbial biomass and mineral soil; p < 0.05 for both) and positively correlated with net nitrification rates (p < 0.01). However, faster nitrogen (N) cycling in AM plots was also associated with a greater amount of physcially protected N in soil, suggesting that nutrient stabilizing mechanisms may constrain NPP in response to elevated CO2. Our model results supported this prediction. We found that while the C cost of acquiring of N is cheaper for AM trees than ECM trees, this cost difference is reduced under rising atmospheric CO2 owing to the enhanced protection of soil N in AM soils. Taken together, our results demonstrate that variation in AM- and ECM-associated plant and microbial traits promote predictable biogeochemical syndromes in temperate forests that can impact

  12. Measurement and characterization of cellulase activity in sclerophyllous forest litter.

    Science.gov (United States)

    Criquet, Stéven

    2002-07-01

    Cellulases are enzymatic proteins which hydrolyze cellulose polymers to smaller oligosaccharides, cellobiose and glucose. They consist in three major types of enzymes: endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) and beta-glucosidases (EC 3.2.1.21) which play an essential role in carbon turnover of forest ecosystem. The aim of this study was firstly to determine the parameters (i.e. buffer type, pH, temperature, quantity of litter, incubation time and reagent type) which affect the measurement of cellulase activity in a sclerophyllous forest litter, and secondly to compare two methods for measuring cellulase activity: a direct method and an extraction method. In the direct method, the litter was directly incubated with a buffered solution containing the enzyme substrate, whereas in the extraction method, the cellulases were firstly extracted before measuring their activity. The results were compared with other studies about soil cellulase activity, and it appeared that several parameters (buffer type, pH, temperature and sample quantity) which influence the measurement of cellulase activity differ according to whether a soil or a litter is considered. Concerning the procedure used for the measurement of cellulase activity, results showed that the activity values were higher when using an extraction procedure than when using a direct procedure. The extraction procedure, combined with a concentration stage of the extract, also allowed electrophoretic analysis (PAGE) of the cellulases extracted from the litter. The electrophoretic pattern revealed two cellulase isoenzymes which may be related to the occurrence of two pH-activity peaks of these enzymes when citrate buffer was used for the measurement of cellulase activity in the litter.

  13. [Microelement contents of litter, soil fauna and soil in Pinus koraiensis and broad-leaved mixed forest].

    Science.gov (United States)

    Yin, Xiu-qin; Li, Jin-xia; Dong, Wei-hua

    2007-02-01

    The analysis on the Mn, Zn and Cu contents of litter, soil fauna and soil in Pinus korazenszis and broad-leaved mixed forest in Liangshui Natural Reserve of Xiaoxing' an Mountains showed that the test microelement contents in the litter, soil fauna and soil all followed the sequence of Mn > Zn > Cu, but varied with these environmental components, being in the sequence of soil > litter > soil fauna for Mn, soil fauna > litter and soil for Zn, and soil fauna > soil > litter for Cu. The change range of test microelement contents in litter was larger in broad-leaved forest than in coniferous forest. Different soil fauna differed in their microelement-enrichment capability, e. g. , earthworm, centipede, diplopod had the highest content of Mn, Zn and Cu, respectively. The contents of test microelements in soil fauna had significant correlations with their environmental background values, litter decomposition rate, food habit of soil fauna, and its absorbing selectivity and enrichment to microelements. The microelements contained in 5-20 cm soil layer were more than those in 0-5 cm soil layer, and their dynamics differed in various soil layers.

  14. Litterfall and litter decomposition in chestnut high forest stands in northern Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Patricio, M. S.; Nunes, L. F.; Pereira, E. L.

    2012-11-01

    This research aimed to: estimate the inputs of litterfall; model the decomposition process and assess the rates of litter decay and turnover; study the litter decomposition process and dynamics of nutrients in old chestnut high forests. This study aimed to fill a gap in the knowledge of chestnut decomposition process as this type of ecosystems have never been modeled and studied from this point of view in Portugal. The study sites are located in the mountains of Marao, Padrela and Bornes in a west-to-east transect, across northern Portugal, from a more-Atlantic-to-lessmaritime influence. This research was developed on old chestnut high forests for quality timber production submitted to a silviculture management close-to-nature. We collected litterfall using littertraps and studied decomposition of leaf and bur litter by the nylon net bag technique. Simple and double exponential models were used to describe the decomposition of chestnut litterfall incubated in situ during 559 days. The results of the decomposition are discussed in relation to the initial litter quality (C, N, P, K, Ca, Mg) and the decomposition rates. Annually, the mature chestnut high-forest stands (density 360-1,260 tree ha1, age 55-73 years old) restore 4.9 Mg DM ha–1 of litter and 2.6 Mg ha{sup -}1 yr{sup -}1 of carbon to the soil. The two-component litter decay model proved to be more biologically realistic, providing a decay rate for the fast initial stage (46-58 yr{sup -}1for the leaves and 38-42 yr{sup -}1for the burs) and a decay rate related to the recalcitrant pool (0.45-0.60 yr{sup -}1for the leaves and 0.22-0.36 yr{sup -}1for the burs). This study pointed to some decay patterns and release of bioelements by the litterfall which can be useful for calibrating existing models and indicators of sustainability to improve both silvicultural and environmental approaches for the management of chestnut forests. (Author) 45 refs.

  15. Mapping Forest Biomass Using Remote Sensing and National Forest Inventory in China

    Directory of Open Access Journals (Sweden)

    Ling Du

    2014-06-01

    Full Text Available Quantifying the spatial pattern of large-scale forest biomass can provide a general picture of the carbon stocks within a region and is of great scientific and political importance. The combination of the advantages of remote sensing data and field survey data can reduce uncertainty as well as demonstrate the spatial distribution of forest biomass. In this study, the seventh national forest inventory statistics (for the period 2004–2008 and the spatially explicit MODIS Land Cover Type product (MCD12C1 were used together to quantitatively estimate the spatially-explicit distribution of forest biomass in China (with a resolution of 0.05°, ~5600 m. Our study demonstrated that the calibrated forest cover proportion maps allow proportionate downscaling of regional forest biomass statistics to forest cover pixels to produce a relatively fine-resolution biomass map. The total stock of forest biomass in China was 11.9 Pg with an average of 76.3 Mg ha−1 during the study period; the high values were located in mountain ranges in northeast, southwest and southeast China and were strongly correlated with forest age and forest density.

  16. Decomposition of leaf litter from a native tree and an actinorhizal invasive across riparian habitats.

    Science.gov (United States)

    Harner, Mary J; Crenshaw, Chelsea L; Abelho, Manuela; Stursova, Martina; Shah, Jennifer J Follstad; Sinsabaugh, Robert L

    2009-07-01

    Dynamics of nutrient exchange between floodplains and rivers have been altered by changes in flow management and proliferation of nonnative plants. We tested the hypothesis that the nonnative, actinorhizal tree, Russian olive (Elaeagnus angustifolia), alters dynamics of leaf litter decomposition compared to native cottonwood (Populus deltoides ssp. wislizeni) along the Rio Grande, a river with a modified flow regime, in central New Mexico (U.S.A.). Leaf litter was placed in the river channel and the surface and subsurface horizons of forest soil at seven riparian sites that differed in their hydrologic connection to the river. All sites had a cottonwood canopy with a Russian olive-dominated understory. Mass loss rates, nutrient content, fungal biomass, extracellular enzyme activities (EEA), and macroinvertebrate colonization were followed for three months in the river and one year in forests. Initial nitrogen (N) content of Russian olive litter (2.2%) was more than four times that of cottonwood (0.5%). Mass loss rates (k; in units of d(-1)) were greatest in the river (Russian olive, k = 0.0249; cottonwood, k = 0.0226), intermediate in subsurface soil (Russian olive, k = 0.0072; cottonwood, k = 0.0031), and slowest on the soil surface (Russian olive, k = 0.0034; cottonwood, k = 0.0012) in a ratio of about 10:2:1. Rates of mass loss in the river were indistinguishable between species and proportional to macroinvertebrate colonization. In the riparian forest, Russian olive decayed significantly faster than cottonwood in both soil horizons. Terrestrial decomposition rates were related positively to EEA, fungal biomass, and litter N, whereas differences among floodplain sites were related to hydrologic connectivity with the river. Because nutrient exchanges between riparian forests and the river have been constrained by flow management, Russian olive litter represents a significant annual input of N to riparian forests, which now retain a large portion of slowly

  17. Biomass carbon stocks in China's forests between 2000 and 2050: a prediction based on forest biomass-age relationships.

    Science.gov (United States)

    Xu, Bing; Guo, ZhaoDi; Piao, ShiLong; Fang, JingYun

    2010-07-01

    China's forests are characterized by young forest age, low carbon density and a large area of planted forests, and thus have high potential to act as carbon sinks in the future. Using China's national forest inventory data during 1994-1998 and 1999-2003, and direct field measurements, we investigated the relationships between forest biomass density and forest age for 36 major forest types. Statistical approaches and the predicted future forest area from the national forestry development plan were applied to estimate the potential of forest biomass carbon storage in China during 2000-2050. Under an assumption of continuous natural forest growth, China's existing forest biomass carbon (C) stock would increase from 5.86 Pg C (1 Pg=10(15) g) in 1999-2003 to 10.23 Pg C in 2050, resulting in a total increase of 4.37 Pg C. Newly planted forests through afforestation and reforestation will sequestrate an additional 2.86 Pg C in biomass. Overall, China's forests will potentially act as a carbon sink for 7.23 Pg C during the period 2000-2050, with an average carbon sink of 0.14 Pg C yr(-1). This suggests that China's forests will be a significant carbon sink in the next 50 years.

  18. Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests.

    Science.gov (United States)

    Liu, Lei; Gundersen, Per; Zhang, Wei; Zhang, Tao; Chen, Hao; Mo, Jiangming

    2015-09-23

    Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m(-2)·yr(-1)), P addition (15 g P m(-2)·yr(-1)), and N and P addition (15 + 15 g N and P m(-2)·yr(-1), respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests.

  19. Plant litter dynamics in the forest-stream interface: precipitation is a major control across tropical biomes

    OpenAIRE

    Tonin, Alan M.; Gon?alves, Jos? F.; Bambi, Paulino; Couceiro, Sheyla R. M.; Feitoza, Lorrane A. M.; Fontana, Lucas E.; Hamada, Neusa; Hepp, Luiz U.; Lezan-Kowalczuk, V?nia G.; Leite, Gustavo F. M.; Lemes-Silva, Aurea L.; Lisboa, Leonardo K.; Loureiro, Rafael C.; Martins, Renato T.; Medeiros, Adriana O.

    2017-01-01

    Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even?though the tropics occupy 40% of the Earth?s land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Ama...

  20. Using a rainforest-flame forest mosaic to test the hypothesis that leaf and litter fuel flammability is under natural selection.

    Science.gov (United States)

    Clarke, Peter J; Prior, Lynda D; French, Ben J; Vincent, Ben; Knox, Kirsten J E; Bowman, David M J S

    2014-12-01

    We used a mosaic of infrequently burnt temperate rainforest and adjacent, frequently burnt eucalypt forests in temperate eastern Australia to test whether: (1) there were differences in flammability of fresh and dried foliage amongst congeners from contrasting habitats, (2) habitat flammability was related to regeneration strategy, (3) litter fuels were more flammable in frequently burnt forests, (4) the severity of a recent fire influenced the flammability of litter (as this would suggest fire feedbacks), and (5) microclimate contributed to differences in fire hazard amongst habitats. Leaf-level comparisons were made among 11 congeneric pairs from rainforest and eucalypt forests. Leaf-level ignitability, combustibility and sustainability were not consistently higher for taxa from frequently burnt eucalypt forests, nor were they higher for species with fire-driven recruitment. The bulk density of litter-bed fuels strongly influenced flammability, but eucalypt forest litter was not less dense than rainforest litter. Ignitability, combustibility and flame sustainability of community surface fuels (litter) were compared using fuel arrays with standardized fuel mass and moisture content. Forests previously burned at high fire severity did not have consistently higher litter flammability than those burned at lower severity or long unburned. Thus, contrary to the Mutch hypothesis, there was no evidence of higher flammability of litter fuels or leaves from frequently burnt eucalypt forests compared with infrequently burnt rainforests. We suggest the manifest pyrogenicity of eucalypt forests is not due to natural selection for more flammable foliage, but better explained by differences in crown openness and associated microclimatic differences.

  1. Changes in forest biomass and linkage to climate and forest disturbances over Northeastern China.

    Science.gov (United States)

    Zhang, Yuzhen; Liang, Shunlin

    2014-08-01

    The forests of northeastern China store nearly half of the country's total biomass carbon stocks. In this study, we investigated the changes in forest biomass by using satellite observations and found that a significant increase in forest biomass took place between 2001 and 2010. To determine the possible reasons for this change, several statistical methods were used to analyze the correlations between forest biomass dynamics and forest disturbances (i.e. fires, insect damage, logging, and afforestation and reforestation), climatic factors, and forest development. Results showed that forest development was the most important contributor to the increasing trend of forest biomass from 2001 to 2010, and climate controls were the secondary important factor. Among the four types of forest disturbance considered in this study, forest recovery from fires, and afforestation and reforestation during the past few decades played an important role in short-term biomass dynamics. This study provided observational evidence and valuable information for the relationships between forest biomass and climate as well as forest disturbances. © 2014 John Wiley & Sons Ltd.

  2. [Characteristics of floor litter and soil arthropod community in different types ot subtropical forest in Ailao Mountain of Yunnan, Southwest China].

    Science.gov (United States)

    Yang, Zhao; Yang, Xiao-Dong

    2011-11-01

    By using line transect method, an investigation was conducted on the floor litter and soil arthropod community in a mid mountain wet evergreen broad-leaved forest, a mossy dwarf forest, and a Populus bonatii forest in Ailao Mountain of Yunnan in April (dry and hot season), June (rainy season), and December (dry and cold season), 2005. In both dry and rainy seasons, the existing floor litter mass, C storage, and C/N ratio in the three forests all increased in the order of mossy dwarf forest > P. bonatii forest > evergreen broad-leaved forest, but the N storage had less difference. In the floor litter layer of the forests, Acari and Collembola were the dominant groups of soil arthropod community, while Diptera larvae, Coleoptera, ants, and Homoptera were the common groups. The Sorenson coefficients of soil arthropod community in the three forests were extremely great. No significant differences were observed in the soil arthropod density (ind x m(-2)) in the floor litter layer among the three forests, but the relative density (ind x g(-1)) of soil arthropods was higher in the evergreen broad-leaved forest and P. bonatii forest than in the mossy dwarf forest. In the three forests, the density of soil arthropods was significantly higher in dry season than in rainy season, but the Shannon diversity index had less difference. There were significant positive correlations between the existing floor litter mass and the individual density (ind x m(-2)) and dominant groups of soil arthropod communities in dry and hot season (April), but negative correlations between the existing floor litter mass and the relative density (ind x g(-1)) of soil arthropod communities and Acari in dry and cold season (December). The individual densities of Collembola and Coleoptera also had positive correlations with the N storage of the existing floor litter mass in the three forests. It was considered that the floor litter and the development of soil arthropod community in the litter layer of

  3. Mapping Russian forest biomass with data from satellites and forest inventories

    International Nuclear Information System (INIS)

    Houghton, R A; Butman, D; Bunn, A G; Krankina, O N; Schlesinger, P; Stone, T A

    2007-01-01

    The forests of Russia cover a larger area and hold more carbon than the forests of any other nation and thus have the potential for a major role in global warming. Despite a systematic inventory of these forests, however, estimates of total carbon stocks vary, and spatial variations in the stocks within large aggregated units of land are unknown, thus hampering measurement of sources and sinks of carbon. We mapped the distribution of living forest biomass for the year 2000 by developing a relationship between ground measurements of wood volume at 12 sites throughout the Russian Federation and data from the MODIS satellite bidirectional reflectance distribution function (BRDF) product (MOD43B4). Based on the results of regression-tree analyses, we used the MOD43B4 product to assign biomass values to individual 500 m x 500 m cells in areas identified as forest by two satellite-based maps of land cover. According to the analysis, the total living biomass varied between 46 and 67 Pg, largely because of different estimates of forest area. Although optical data are limited in distinguishing differences in biomass in closed canopy forests, the estimates of total living biomass obtained here varied more in response to different definitions of forest than to saturation of the optical sensing of biomass

  4. Mapping Russian forest biomass with data from satellites and forest inventories

    Energy Technology Data Exchange (ETDEWEB)

    Houghton, R A [Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540 (United States); Butman, D [Yale School of Forestry and Environmental Science, Yale University, New Haven, CT 06511 (United States); Bunn, A G [Department of Environmental Sciences, Huxley College of the Environment, Western Washington University, 516 High Street, Bellingham, WA 98225-9181 (United States); Krankina, O N [Department of Forest Science, Oregon State University, 202 Richardson Hall, Corvallis, OR 97331-5752 (United States); Schlesinger, P [Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540 (United States); Stone, T A [Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540 (United States)

    2007-10-15

    The forests of Russia cover a larger area and hold more carbon than the forests of any other nation and thus have the potential for a major role in global warming. Despite a systematic inventory of these forests, however, estimates of total carbon stocks vary, and spatial variations in the stocks within large aggregated units of land are unknown, thus hampering measurement of sources and sinks of carbon. We mapped the distribution of living forest biomass for the year 2000 by developing a relationship between ground measurements of wood volume at 12 sites throughout the Russian Federation and data from the MODIS satellite bidirectional reflectance distribution function (BRDF) product (MOD43B4). Based on the results of regression-tree analyses, we used the MOD43B4 product to assign biomass values to individual 500 m x 500 m cells in areas identified as forest by two satellite-based maps of land cover. According to the analysis, the total living biomass varied between 46 and 67 Pg, largely because of different estimates of forest area. Although optical data are limited in distinguishing differences in biomass in closed canopy forests, the estimates of total living biomass obtained here varied more in response to different definitions of forest than to saturation of the optical sensing of biomass.

  5. Leaf litter decomposition rates increase with rising mean annual temperature in Hawaiian tropical montane wet forests

    Science.gov (United States)

    Lori D. Bothwell; Paul C. Selmants; Christian P. Giardina; Creighton M. Litton

    2014-01-01

    Decomposing litter in forest ecosystems supplies nutrients to plants, carbon to heterotrophic soil microorganisms and is a large source of CO2 to the atmosphere. Despite its essential role in carbon and nutrient cycling, the temperature sensitivityof leaf litter decay in tropical forest ecosystems remains poorly resolved, especially in tropical...

  6. VOC emission into the atmosphere by trees and leaf litter in Polish forests

    Science.gov (United States)

    Isidorov, V.; Smolewska, M.; Tyszkiewicz, Z.

    2009-04-01

    It is generally recognized at present that the vegetation of continents is the principal source of reactive volatile organic compounds (VOC) of the atmosphere. The upper limit of the evaluation of global phytogenic VOC is 1100-1500 Tg/yr (Isidorov, 1990; Guenther et al., 1995). Although these global evaluations showing the place of phytogenic emission among of other VOC sources are important, evaluations for individual countries are also very important. This poster represents the results of the estimation of VOC emission from Polish forests. Calculations took into account the composition and age of forests. According to our estimation, the total VOC emission by the arboreal vegetation differs from 190 to 750 kt/yr, depending of weather conditions in different years. There are only few studies conducted on decaying plant material as a source of atmospheric VOCs, but still they are able to give evidence of the importance of this source. For Polish forests, the litter mass is estimated to be (16-19)106 t/yr. These organic materials undergo decomposition by mesofauna and microorganisms. In these processes volatile organic compounds (VOC) stored in the litter and secondary metabolites of litter-destroying fungi are emitted into the atmosphere. The scale of the phenomenon makes leaf litter an important VOC source in the atmosphere. The filling of numerous gaps in researches of VOC emissions from decomposing leaf litter demands carrying out of long term field experiments in various climatic conditions. In this communication we report also the results of 3.5-year experiment on qualitative and quantitative GC-MS investigations of VOC emitted into the gas phase from leaves litter of some species of deciduous and coniferous trees of Polish forests. Apart from terpenes and their oxygenated derivatives, which are usual in plant tissues, leaf litter intensively emits vast amounts of lower alcohols and carbonyl compounds. We suppose that these volatile substances are products

  7. Effects of forest fragmentation and habitat degradation on West African leaf-litter frogs

    NARCIS (Netherlands)

    Hillers, A.; Veith, M.; Rödel, M.-O.

    2008-01-01

    Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We

  8. Potentials for forest woody biomass production in Serbia

    Directory of Open Access Journals (Sweden)

    Vasiljević Aleksandar Lj.

    2015-01-01

    Full Text Available The paper presents the analysis of possible potentials for the production of forest biomass in Serbia taking into consideration the condition of forests, present organizational and technical capacities as well as the needs and situation on the firewood market. Starting point for the estimation of production potentials for forest biomass is the condition of forests which is analyzed based on the available planning documents on all levels. Potentials for biomass production and use refer to initial periods in the production and use of forest biomass in Serbia.

  9. LBA-ECO CD-10 Forest Litter Data for km 67 Tower Site, Tapajos National Forest

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains a single text file which reports litter type and mass in the old-growth upland forest at the Para Western (Santarem) - km 67,...

  10. Leaf litter production of mahogany along street and campus forest of Universitas Negeri Semarang, Indonesia

    Science.gov (United States)

    Martin, F. P.; Abdullah, M.; Solichin; Hadiyanti, L. N.; Widianingrum, K.

    2018-03-01

    The leaf litter of trees along the existing streets on campus UNNES if not managed properly will be scattered and become garbage. Leaf litter Production in UNNES campus is not known for certain. UNNES does not own mapping of leaf litter Production of dominant tree species on campus. This cause leaf waste management is not optimal yet. There is still a lot of leaf litter that is discharged (not processed) because it exceeds the capacity of the fertilizer production equipment in the compost house. Aims of this study were to examine leaf litter production of dominant trees in Universitas Negeri Semarang and evaluate the relationship between leaf litter and average rainfall. Purposive sampling method placed pouches of nylon gauze measuring 1 × 1 mm2 as litter trap container with size 1 x l m2 (10 points mounted along street and campus forest). Litter trap mounted at the height of 50 cm above ground level. Leaf litter will be taken once a week for three months to observe the litter production. The litter was then dried by the oven at 70 ° C for 48 hours to obtain constant dry weight. Based on the results of the research, it was known that Mahogany tree in UNNES campus area has the potential to produce the litter of about 10 ton/ha / 3months in campus forest area and 2.5 ton/ha / 3months along campus street. There is a significant relationship between litter production of Mahogany leaves and precipitation during August - October 2017.

  11. Effects of Nitrogen Addition on Leaf Decomposition of Single-Species and Litter Mixture in Pinus tabulaeformis Forests

    Directory of Open Access Journals (Sweden)

    Jinsong Wang

    2015-12-01

    Full Text Available The litter decomposition process is closely correlated with nutrient cycling and the maintenance of soil fertility in the forest ecosystem. In particular, the intense environmental concern about atmospheric nitrogen (N deposition requires a better understanding of its influence on the litter decomposition process. This study examines the responses of single-species litter and litter mixture decomposition processes to N addition in Chinese pine (Pinus tabulaeformis Carr. ecosystems. Chinese pine litter, Mongolian oak (Quercus mongolica Fisch. ex Ledeb. litter, and a pine–oak mixture were selected from a plantation and a natural forest of Chinese pine. Four N addition treatments, i.e., control (N0: 0 kg N ha−1·year−1, low-N (N1: 5 kg N ha−1·year−1, medium-N (N2: 10 kg N ha−1·year−1, and high-N (N3: 15 kg N ha−1·year−1, were applied starting May 2010. In the plantation, N addition significantly stimulated the decomposition of the Chinese pine litter. In the natural forest, N addition had variable effects on the decomposition of single-species litter and the litter mixture. A stimulatory effect of the high-N treatment on the Chinese pine litter decomposition could be attributed to a decrease in the substrate C:N ratio. However, an opposite effect was found for the Mongolian oak litter decomposition. The stimulating effect of N addition on the Chinese pine litter may offset the suppressive effect on the Mongolian oak litter, resulting in a neutral effect on the litter mixture. These results suggest that the different responses in decomposition of single-species litter and the litter mixture to N addition are mainly attributed to litter chemical composition. Further investigations are required to characterize the effect of long-term high-level N addition on the litter decomposition as N deposition is likely to increase rapidly in the region where this study was conducted.

  12. Soil Fauna Affects Dissolved Carbon and Nitrogen in Foliar Litter in Alpine Forest and Alpine Meadow.

    Science.gov (United States)

    Liao, Shu; Yang, Wanqin; Tan, Yu; Peng, Yan; Li, Jun; Tan, Bo; Wu, Fuzhong

    2015-01-01

    Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) are generally considered important active biogeochemical pools of total carbon and nitrogen. Many studies have documented the contributions of soil fauna to litter decomposition, but the effects of the soil fauna on labile substances (i.e., DOC and TDN) in litter during early decomposition are not completely clear. Therefore, a field litterbag experiment was carried out from 13th November 2013 to 23rd October 2014 in an alpine forest and an alpine meadow located on the eastern Tibetan Plateau. Litterbags with different mesh sizes were used to provide access to or prohibit the access of the soil fauna, and the concentrations of DOC and TDN in the foliar litter were measured during the winter (the onset of freezing, deep freezing and thawing stage) and the growing season (early and late). After one year of field incubation, the concentration of DOC in the litter significantly decreased, whereas the TDN concentration in the litter increased. Similar dynamic patterns were detected under the effects of the soil fauna on both DOC and TDN in the litter between the alpine forest and the alpine meadow. The soil fauna showed greater positive effects on decreasing DOC concentration in the litter in the winter than in the growing season. In contrast, the dynamics of TND in the litter were related to seasonal changes in environmental factors, rather than the soil fauna. In addition, the soil fauna promoted a decrease in litter DOC/TDN ratio in both the alpine forest and the alpine meadow throughout the first year of decomposition, except for in the late growing season. These results suggest that the soil fauna can promote decreases in DOC and TDN concentrations in litter, contributing to early litter decomposition in these cold biomes.

  13. The effects of leaf litter nutrient pulses on Alliaria petiolata performance

    Directory of Open Access Journals (Sweden)

    Robert W. Heckman

    2015-08-01

    Full Text Available Nutrient pulses can facilitate species establishment and spread in new habitats, particularly when one species more effectively uses that nutrient pulse. Biological differences in nutrient acquisition between native and exotic species may facilitate invasions into a variety of habitats including deciduous forest understories. Alliaria petiolata (Bieb. Cavara & Grande is an important invader of deciduous forest understories throughout much of North America. These understory communities contain many species which perform the majority of their growth and reproduction before canopy closure in spring. Because A. petiolata is a wintergreen biennial that can be active during autumn and winter, it may utilize nutrients released from decaying leaf litter before its competitors. To investigate this we manipulated the timing of leaf litter addition (fall or spring and experimentally simulated the nutrient pulse from decaying leaves using artificial fertilizer. To determine whether A. petiolata affected the abundance of understory competitors, we also removed A. petiolata from one treatment. A. petiolata that received early nutrients exhibited greater growth. Treatments receiving fall leaf litter or artificial nutrients had greater A. petiolata adult biomass than plots receiving spring nutrient additions (leaf litter or artificial nutrients. However, fall leaf litter addition had no effect on the richness of competitor species. Thus, wintergreen phenology may contribute to the spread of A. petiolata through deciduous forest understories, but may not explain community-level impacts of A. petiolata in deciduous forests.

  14. MODIS Based Estimation of Forest Aboveground Biomass in China.

    Directory of Open Access Journals (Sweden)

    Guodong Yin

    Full Text Available Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS dataset in a machine learning algorithm (the model tree ensemble, MTE. We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests.

  15. MODIS Based Estimation of Forest Aboveground Biomass in China

    Science.gov (United States)

    Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

    2015-01-01

    Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha−1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y−1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y−1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y−1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests. PMID:26115195

  16. MODIS Based Estimation of Forest Aboveground Biomass in China.

    Science.gov (United States)

    Yin, Guodong; Zhang, Yuan; Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

    2015-01-01

    Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests.

  17. An empirical, integrated forest biomass monitoring system

    Science.gov (United States)

    Kennedy, Robert E.; Ohmann, Janet; Gregory, Matt; Roberts, Heather; Yang, Zhiqiang; Bell, David M.; Kane, Van; Hughes, M. Joseph; Cohen, Warren B.; Powell, Scott; Neeti, Neeti; Larrue, Tara; Hooper, Sam; Kane, Jonathan; Miller, David L.; Perkins, James; Braaten, Justin; Seidl, Rupert

    2018-02-01

    The fate of live forest biomass is largely controlled by growth and disturbance processes, both natural and anthropogenic. Thus, biomass monitoring strategies must characterize both the biomass of the forests at a given point in time and the dynamic processes that change it. Here, we describe and test an empirical monitoring system designed to meet those needs. Our system uses a mix of field data, statistical modeling, remotely-sensed time-series imagery, and small-footprint lidar data to build and evaluate maps of forest biomass. It ascribes biomass change to specific change agents, and attempts to capture the impact of uncertainty in methodology. We find that: • A common image framework for biomass estimation and for change detection allows for consistent comparison of both state and change processes controlling biomass dynamics. • Regional estimates of total biomass agree well with those from plot data alone. • The system tracks biomass densities up to 450-500 Mg ha-1 with little bias, but begins underestimating true biomass as densities increase further. • Scale considerations are important. Estimates at the 30 m grain size are noisy, but agreement at broad scales is good. Further investigation to determine the appropriate scales is underway. • Uncertainty from methodological choices is evident, but much smaller than uncertainty based on choice of allometric equation used to estimate biomass from tree data. • In this forest-dominated study area, growth and loss processes largely balance in most years, with loss processes dominated by human removal through harvest. In years with substantial fire activity, however, overall biomass loss greatly outpaces growth. Taken together, our methods represent a unique combination of elements foundational to an operational landscape-scale forest biomass monitoring program.

  18. Validating Community-Led Forest Biomass Assessments.

    Science.gov (United States)

    Venter, Michelle; Venter, Oscar; Edwards, Will; Bird, Michael I

    2015-01-01

    The lack of capacity to monitor forest carbon stocks in developing countries is undermining global efforts to reduce carbon emissions. Involving local people in monitoring forest carbon stocks could potentially address this capacity gap. This study conducts a complete expert remeasurement of community-led biomass inventories in remote tropical forests of Papua New Guinea. By fully remeasuring and isolating the effects of 4,481 field measurements, we demonstrate that programmes employing local people (non-experts) can produce forest monitoring data as reliable as those produced by scientists (experts). Overall, non-experts reported lower biomass estimates by an average of 9.1%, equivalent to 55.2 fewer tonnes of biomass ha(-1), which could have important financial implications for communities. However, there were no significant differences between forest biomass estimates of expert and non-expert, nor were there significant differences in some of the components used to calculate these estimates, such as tree diameter at breast height (DBH), tree counts and plot surface area, but were significant differences between tree heights. At the landscape level, the greatest biomass discrepancies resulted from height measurements (41%) and, unexpectedly, a few large missing trees contributing to a third of the overall discrepancies. We show that 85% of the biomass discrepancies at the tree level were caused by measurement taken on large trees (DBH ≥50 cm), even though they consisted of only 14% of the stems. We demonstrate that programmes that engage local people can provide high-quality forest carbon data that could help overcome barriers to reducing forest carbon emissions in developing countries. Nonetheless, community-based monitoring programmes should prioritise reducing errors in the field that lead to the most important discrepancies, notably; overcoming challenges to accurately measure large trees.

  19. Carbon and nitrogen dynamics of soil and litter along an altitudinal gradient in Atlantic Forest

    Science.gov (United States)

    Piccolo, M. D.; Martins, S. C.; Camargo, P. B.; Carmo, J. B.; Sousa Neto, E.; Martinelli, L. A.

    2008-12-01

    The Ombrophylus Dense Forest or Atlantic Forest is the second most important Biome in extension of Brazil, and it is considered a hot-spot in terms of biodiversity. It is localized in Brazilian Coast, and it covered originally 1.2 million km2, but currently only 8% of the original forest remains. The study was carried out in Sao Paulo State, Brazil (23° 24' S and 45° 11' W). The studied areas were: Restinga Vegetation (RV), 5 m above sea level; Low Altitude Ombrophylus Dense Forest (LAODF), 100 m asl; Submontane Ombrophylus Dense Forest (SODF), 600m asl and; Montane Ombrophylus Dense Forest (MODF), 1000 m asl. The aim of this study was to evaluate the effect of altitudinal gradient, with specific phytophysiognomies, on C and N dynamics in the soil and litter at Atlantic Forest. A sampling area of 1 ha was subdivided in contiguous sub- parcels (10 x 10 m). The forest floor litter accumulated (0.06 m2) was collected monthly (n=60), during 12 months, in each phytophysiognomies. Soils samples (0-0.05m depth) were collected (n=32) from square regular grids, 30 m away from each other. Changes in litter contents of C and N were not detected along the altitudinal gradient, and the values observed were 400 and 15g kg-1 for C and N, respectively. Litter ä13C values did not change significantly with the altitudinal gradient and were represented by C3 plants values. The C and N stocks were high in the clay soils (LAODF, SODF and MODF) when compared to sandy soil (RV). The soil C stocks (24 to 30 Mg ha-1) were similar among the altitudinal gradients, except RV (16 Mg ha-1). The areas of elevated altitude (MODF and SODF) showed high N stocks (2.3 Mg ha-1), followed by LAODF (1.8Mg ha-1) and RV (0.9Mg ha-1). In all altitudes there was 13C enrichment with soil depth, and it can be explained by the different fractions of the organic matter distributed along the soil profile, and also due the effect of the isotopic dilution between the forest floor litter and the soil.

  20. Litter Dynamics in a Forest Dune at Restinga da Marambaia, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Camara

    2018-03-01

    Full Text Available ABSTRACT Restingas are extremely degraded, tropical sandy ecosystems and are poorly studied in terms of nutrient cycling. The present study aimed to evaluate litter dynamics in a forest dune at Restinga da Marambaia, RJ. Litterfall was collected monthly using two parallel transects installed 200 m apart from each other with 15 litter traps (0.25 m2, over two consecutive years. The litterfall was sorted into leaves, twigs, flowers, fruits, and refuse. Litter decomposition was evaluated by the ratio between litterfall and litter layer on the soil surface, which was estimated every four months by quadrats (0.25 m2 placed next to the litter traps. The average annual litterfall was low (6.8 t ha-1 year-1 , mostly constituted by leaves (70%, with the greatest deposits occurring during the rainy season. The decomposition rate was low (0.85 and the turnover time was long (439 days. This litter dynamic contributes to the nutrient economy.

  1. STUDY OF SOIL AND LEAF LITTER MICROBIAL FATTY ACID PROFILES IN TABONUCO FOREST IN THE LUQUILLO EXPERIMENTAL FOREST IN PUERTO RICO

    Science.gov (United States)

    The results of this study suggests that there are two significantly distinct microbial communities in the leaf litter and soil components of this tropical forest. Fungi are more abundant in the leaf litter while bacteria are more abundant in the soil.

  2. Canada's forest biomass resources: deriving estimates from Canada's forest inventory

    International Nuclear Information System (INIS)

    Penner, M.; Power, K.; Muhairwe, C.; Tellier, R.; Wang, Y.

    1997-01-01

    A biomass inventory for Canada was undertaken to address the data needs of carbon budget modelers, specifically to provide estimates of above-ground tree components and of non-merchantable trees in Canadian forests. The objective was to produce a national method for converting volume estimates to biomass that was standardized, repeatable across the country, efficient and well documented. Different conversion methods were used for low productivity forests (productivity class 1) and higher productivity forests (productivity class 2). The conversion factors were computed by constructing hypothetical stands for each site, age, species and province combination, and estimating the merchantable volume and all the above-ground biomass components from suitable published equations. This report documents the procedures for deriving the national biomass inventory, and provides illustrative examples of the results. 46 refs., 9 tabs., 5 figs

  3. Forest biomass observation: current state and prospective

    Directory of Open Access Journals (Sweden)

    D. G. Schepaschenko

    2017-08-01

    Full Text Available With this article, we provide an overview of the methods, instruments and initiatives for forest biomass observation at global scale. We focus on the freely available information, provided by both remote and in-situ observations. The advantages and limitation of various space borne methods, including optical, radar (C, L and P band and LiDAR, as well as respective instruments available on the orbit (MODIS, Proba-V, Landsat, Sentinel-1, Sentinel-2 , ALOS PALSAR, Envisat ASAR or expecting (BIOMASS, GEDI, NISAR, SAOCOM-CS are discussed. We emphasize the role of in-situ methods in the development of a biomass models, providing calibration and validation of remote sensing data. We focus on freely available forest biomass maps, databases and empirical models. We describe the functionality of Biomass.Geo-Wiki.org portal, which provides access to a collection of global and regional biomass maps in full resolution with unified legend and units overplayed with high-resolution imagery. The Forest-Observation-System.net is announced as an international cooperation to establish a global in-situ forest biomass database to support earth observation and to encourage investment in relevant field-based observations and science. Prospects of unmanned aerial vehicles in the forest inventory are briefly discussed. The work was partly supported by ESA IFBN project (contract 4000114425/15/NL/FF/gp.

  4. Influence of different forest system management practices on leaf litter decomposition rates, nutrient dynamics and the activity of ligninolytic enzymes: a case study from central European forests.

    Science.gov (United States)

    Purahong, Witoon; Kapturska, Danuta; Pecyna, Marek J; Schulz, Elke; Schloter, Michael; Buscot, François; Hofrichter, Martin; Krüger, Dirk

    2014-01-01

    Leaf litter decomposition is the key ecological process that determines the sustainability of managed forest ecosystems, however very few studies hitherto have investigated this process with respect to silvicultural management practices. The aims of the present study were to investigate the effects of forest management practices on leaf litter decomposition rates, nutrient dynamics (C, N, Mg, K, Ca, P) and the activity of ligninolytic enzymes. We approached these questions using a 473 day long litterbag experiment. We found that age-class beech and spruce forests (high forest management intensity) had significantly higher decomposition rates and nutrient release (most nutrients) than unmanaged deciduous forest reserves (Pforest management (low forest management intensity) exhibited no significant differences in litter decomposition rate, C release, lignin decomposition, and C/N, lignin/N and ligninolytic enzyme patterns compared to the unmanaged deciduous forest reserves, but most nutrient dynamics examined in this study were significantly faster under such near-to-nature forest management practices. Analyzing the activities of ligninolytic enzymes provided evidence that different forest system management practices affect litter decomposition by changing microbial enzyme activities, at least over the investigated time frame of 473 days (laccase, Pforest system management practices can significantly affect important ecological processes and services such as decomposition and nutrient cycling.

  5. Four novel Talaromyces species isolated from leaf litter from Colombian Amazon rain forests

    DEFF Research Database (Denmark)

    Yilmaz, Neriman; López-Quintero, Carlos A.; Vasco-Palacios, Aída Marcela

    2016-01-01

    Various Talaromyces strains were isolated during a survey of fungi involved in leaf litter decomposition in tropical lowland forests in the Caquetá and Amacayacu areas of the Colombian Amazon. Four new Talaromyces species are described using a polyphasic approach, which includes phenotypic......). In addition to the new species, T. aculeatus and T. macrosporus were isolated during this study on leaf litter decomposition....

  6. Forest biomass-based energy

    Science.gov (United States)

    Janaki R. R. Alavalapati; Pankaj Lal; Andres Susaeta; Robert C. Abt; David N. Wear

    2013-01-01

    Key FindingsHarvesting woody biomass for use as bioenergy is projected to range from 170 million to 336 million green tons by 2050, an increase of 54 to 113 percent over current levels.Consumption projections for forest biomass-based energy, which are based on Energy Information Administration projections, have a high level of...

  7. Waveform LiDAR across forest biomass gradients

    Science.gov (United States)

    Montesano, P. M.; Nelson, R. F.; Dubayah, R.; Sun, G.; Ranson, J.

    2011-12-01

    Detailed information on the quantity and distribution of aboveground biomass (AGB) is needed to understand how it varies across space and changes over time. Waveform LiDAR data is routinely used to derive the heights of scattering elements in each illuminated footprint, and the vertical structure of vegetation is related to AGB. Changes in LiDAR waveforms across vegetation structure gradients can demonstrate instrument sensitivity to land cover transitions. A close examination of LiDAR waveforms in footprints across a forest gradient can provide new insight into the relationship of vegetation structure and forest AGB. In this study we use field measurements of individual trees within Laser Vegetation Imaging Sensor (LVIS) footprints along transects crossing forest to non-forest gradients to examine changes in LVIS waveform characteristics at sites with low (field AGB measurements to original and adjusted LVIS waveforms to detect the forest AGB interval along a forest - non-forest transition in which the LVIS waveform lose the ability to discern differences in AGB. Our results help identify the lower end the forest biomass range that a ~20m footprint waveform LiDAR can detect, which can help infer accumulation of biomass after disturbances and during forest expansion, and which can guide the use of LiDAR within a multi-sensor fusion biomass mapping approach.

  8. [Estimation of Shenyang urban forest green biomass].

    Science.gov (United States)

    Liu, Chang-fu; He, Xing-yuan; Chen, Wei; Zhao, Gui-ling; Xu, Wen-duo

    2007-06-01

    Based on ARC/GIS and by using the method of "planar biomass estimation", the green biomass (GB) of Shenyang urban forests was measured. The results demonstrated that the GB per unit area was the highest (3.86 m2.m(-2)) in landscape and relaxation forest, and the lowest (2.27 m2.m(-2)) in ecological and public welfare forest. The GB per unit area in urban forest distribution area was 2.99 m2.m(-2), and that of the whole Shenyang urban area was 0.25 m2.m(-2). The total GB of Shenyang urban forests was about 1.13 x 10(8) m2, among which, subordinated forest, ecological and public welfare forest, landscape and relaxation forest, road forest, and production and management forest accounted for 36.64% , 23.99% , 19.38% , 16.20% and 3.79%, with their GB being 4. 15 x 10(7), 2.72 x 10(7), 2.20 x 10(7), 1.84 x 10(7) and 0.43 x 10(7) m2, respectively. The precision of the method "planar biomass estimation" was 91.81% (alpha = 0.05) by credit test.

  9. Energy of forest biomass in Croatia

    International Nuclear Information System (INIS)

    Cupin, N.; Krivak, B.; Dundovic, J.

    2005-01-01

    Forest biomass is organic substance raised in forest ecosystem, consisting of trees and bushes which are used for mechanical processing and thermal use. Croatia, with 44 percent of surface under forests, has the renewable energy potential in forest biomass that could cover as much as about 50 percent of the current heating consumption. The existence of an appropriate heating consume and district heating are a prerequisite for exploitation of the mentioned potential. At the same time, heating consumption enables the utilization of cogeneration plants and the paper gives examples of such possibilities in industry, community and special facilities (sport centres, hotels, hospitals etc.). Among them, the so called 'Croatian energy absurdum' is mentioned. The paper underlines the feasibility of exploitation of forest biomass at the national level and suggests that, in order to promote and accelerate the development of cogeneration plants, the HED expert group should be established. The task of the expert group would be to draft proposal for appropriate measures in this regard and submit it to the Government for consideration.(author)

  10. Uncovering the abilities of Agaricus bisporus to degrade plant biomass throughout its life cycle

    NARCIS (Netherlands)

    Patyshakuliyeva, A.; Post, H.; Zhou, M.; Jurak, E.; Heck, A.J.R.; Hilden, K.S.; Kabel, M.A.; Makela, M.R.; Altenaar, M.A.F.; Vries, de R.P.

    2015-01-01

    The economically important edible basidiomycete mushroom Agaricus bisporus thrives on decaying plant material in forests and grasslands of North America and Europe. It degrades forest litter and con-tributes to global carbon recycling, depolymerizing (hemi-)cellulose and lignin in plant biomass.

  11. Chemical Properties of the Forest Litter in Istria and the Croatian Littoral

    Directory of Open Access Journals (Sweden)

    Špoljar Andrija

    2014-08-01

    Full Text Available The experiment was set up in the forest ecosystem with diverse vegetation zones in the area of Istria and the Croatian Littoral. Research included the following systematic soil units: lithic lepto-sols, rendzic leptosols, rendzic leptosols - eroded, mollic leptosols, chromic cambisol and chromic luvisols. The average quantity of the forest litter in the studied systematic soil units reaches 13.36 t/ha (Tables 1-3. The “wealth” of organic matter in the studied soil units can be presented with the following series: chromic cambisols (CMx > mollic leptosols (LPm, organogenic, rendzic leptosols (LPk > lithic leptosols (LPq > chromic cambisols (CMx - Terra rossa, chromic luvi-sols (LVx > rendzic leptosols (LPk - eroded. As expected, the lowest value of total nitrogen was found in the lithic leptosols in relation to almost all the other soils, except when compared with chromic cambisol and rendzic leptosols (p ⋋ 0.05. The statistically justified higher values of the percentage share of P2O5 in the forest litter were found in chromic luvisols and rendzic leptosols - eroded in relation to the other studied soils. Significantly higher level of copper contamination was inside rendzic leptosols - eroded in relation to the other studied soils. The exception is rendzic leptosols (p ⋋ 0.05. A significantly higher zinc content was detected in the lithic leptosols in relation to the other soil units, except for chromic luvisols, while a justifiably higher total lead and cadmium content in the forest litter was observed in chromic luvisols in relation to the other compared soils (p ⋋ 0.05.

  12. The leaf-litter earthworm fauna (Annelida: Oligochaeta) of forests in ...

    African Journals Online (AJOL)

    A qualitative survey of the leaf-litter earthworm fauna of 11 selected indigenous forests in Limpopo Province, South Africa, was conducted to identify the species present, to describe the communities and to assess the relationship between indigenous and exotic species. A total of 8185 individuals from 17 species (five ...

  13. Factors affecting the abundance of leaf-litter arthropods in unburned and thrice-burned seasonally-dry Amazonian forests.

    Science.gov (United States)

    Silveira, Juliana M; Barlow, Jos; Louzada, Julio; Moutinho, Paulo

    2010-09-21

    Fire is frequently used as a land management tool for cattle ranching and annual crops in the Amazon. However, these maintenance fires often escape into surrounding forests, with potentially severe impacts for forest biodiversity. We examined the effect of experimental fires on leaf-litter arthropod abundance in a seasonally-dry forest in the Brazilian Amazon. The study plots (50 ha each) included a thrice-burned forest and an unburned control forest. Pitfall-trap samples were collected at 160 randomly selected points in both plots, with sampling stratified across four intra-annual replicates across the dry and wet seasons, corresponding to 6, 8, 10 and 12 months after the most recent fire. Arthropods were identified to the level of order (separating Formicidae). In order to better understand the processes that determine arthropod abundance in thrice-burned forests, we measured canopy openness, understory density and litter depth. All arthropod taxa were significantly affected by fire and season. In addition, the interactions between burn treatment and season were highly significant for all taxa but Isoptera. The burned plot was characterized by a more open canopy, lower understory density and shallower litter depth. Hierarchical partitioning revealed that canopy openness was the most important factor explaining arthropod order abundances in the thrice-burned plot, whereas all three environmental variables were significant in the unburned control plot. These results reveal the marked impact of recurrent wildfires and seasonality on litter arthropods in this transitional forest, and demonstrate the overwhelming importance of canopy-openness in driving post-fire arthropod abundance.

  14. LBA-ECO CD-04 Leaf Litter Data, km 83 Tower Site, Tapajos National Forest, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — Above-ground litter productivity was measured in a 18 ha plot adjacent to the eddy flux tower at the logged forest tower site, km 83, Tapajos National Forest, Para,...

  15. Chemical Properties, Decomposition, and Methane Production of Tertiary Relict Plant Litters: Implications for Atmospheric Trace Gas Production in the Early Tertiary

    Science.gov (United States)

    Yavitt, J. B.; Bartella, T. M.; Williams, C. J.

    2006-12-01

    Throughout the early Tertiary (ca. 65-38 Ma) Taxodiaceae-dominated (redwood) wetland forests occupied the high latitudes and were circumpolar in their distribution. Many of these forests had high standing biomass with moderate primary productivity. The geographic extent and amount of Tertiary coals and fossil forests throughout Arctic Canada suggests large areas of wetland forests that may have cycled substantial quantities of carbon, particularly methane until they were replaced by cold tolerant Pinus, Picea, and Larix following climatic cooling associated with the Terminal Eocene Event. To test this hypothesis we compared physiochemical properties, decomposition, and trace gas production of litter from extant Metasequoia, Pinus, Picea, and Larix. Initial results from plantation-grown trees indicate Metasequoia litter is a better source of labile organic substrate than pinaceous litter. Metasequoia litter contained the least lignin and highest amounts of water-soluble compounds of the four litter types studied. Analysis of the lignin structure using cupric oxide oxidation indicates that Metasequoia lignin is enriched in 4'-hydroxyacetophenone and 4'- Hydroxy-3'-methoxyacetophenone relative to the pinaceous litter. In a 12-month decomposition study using litterbags, average litter mass loss was greater for Metasequoia litter (62%) compared to the pinaceous species (50%). Moreover, Metasequoia litter incubated under anoxic conditions produced nearly twice as much CO2 (ca. 4.2 umol/g.day) and CH4 (2.1 umol/g.day) as the pinaceous litter (2.4 umol/g.day for CO2; 1.2 umol/g.day for CH4). Our results support the idea of greater decomposability and palatability of Metasequoia litter as compared to Larix, Picea, or Pinus. Provided that the biochemical properties of Metasequoia have remained relatively stable through geologic time, it appears that early Tertiary Metasequoia-dominated wetland forests may have had higher microbial driven trace gas production than the

  16. Nontraditional Use of Biomass at Certified Forest Management Units: Forest Biomass for Energy Production and Carbon Emissions Reduction in Indonesia

    Directory of Open Access Journals (Sweden)

    Asep S. Suntana

    2012-01-01

    Full Text Available Biomass conversion technologies that produce energy and reduce carbon emissions have become more feasible to develop. This paper analyzes the potential of converting biomass into biomethanol at forest management units experiencing three forest management practices (community-based forest management (CBFM, plantation forest (PF, and natural production forest (NPF. Dry aboveground biomass collected varied considerably: 0.26–2.16 Mg/ha/year (CBFM, 8.08–8.35 Mg/ha/year (NPF, and 36.48–63.55 Mg/ha/year (PF. If 5% of the biomass was shifted to produce biomethanol for electricity production, the NPF and PF could provide continuous power to 138 and 2,762 households, respectively. Dedicating 5% of the biomass was not a viable option from one CBFM unit. However, if all biomasses were converted, the CBFM could provide electricity to 19–27 households. If 100% biomass from two selected PF was dedicated to biomethanol production: (1 52,200–72,600 households could be provided electricity for one year; (2 142–285% of the electricity demand in Jambi province could be satisfied; (3 all gasoline consumed in Jambi, in 2009, would be replaced. The net carbon emissions avoided could vary from 323 to 8,503 Mg when biomethanol was substituted for the natural gas methanol in fuel cells and from 294 to 7,730 Mg when it was used as a gasoline substitute.

  17. Responses of Two Litter-Based Invertebrate Communities to Changes in Canopy Cover in a Forest Subject to Hurricanes

    Science.gov (United States)

    Barbara Richardson; Michael Richardson; Grizelle González

    2018-01-01

    Tropical forests are subject to seasonal hurricanes resulting in cycles of canopy opening and deposition of litter, followed by periods of recovery and canopy closure. Herein, we review two studies of litter-based communities in Puerto Rico; (i) a survey of bromeliad invertebrates in three montane forest types along an elevational gradient in 1993–1997, during a period...

  18. Family forest owner preferences for biomass harvesting in Massachusetts

    Science.gov (United States)

    Marla Markowski-Lindsay; Thomas Stevens; David B. Kittredge; Brett J. Butler; Paul Catanzaro; David Damery

    2012-01-01

    U.S. forests, including family-owned forests, are a potential source of biomass for renewable energy. Family forest owners constitute a significant portion of the overall forestland in the U.S., yet little is known about family forest owners' preferences for supplying wood-based biomass. The goal of this study is to understand how Massachusetts family forest...

  19. Monitoring coniferous forest biomass change using a Landsat trajectory-based approach

    Science.gov (United States)

    Magdalena Main-Knorn; Warren B. Cohen; Robert E. Kennedy; Wojciech Grodzki; Dirk Pflugmacher; Patrick Griffiths; Patrick Hostert

    2013-01-01

    Forest biomass is a major store of carbon and thus plays an important role in the regional and global carbon cycle. Accurate forest carbon sequestration assessment requires estimation of both forest biomass and forest biomass dynamics over time. Forest dynamics are characterized by disturbances and recovery, key processes affecting site productivity and the forest...

  20. Forest Type and Tree Characteristics Determine the Vertical Distribution of Epiphytic Lichen Biomass in Subtropical Forests

    Directory of Open Access Journals (Sweden)

    Su Li

    2017-11-01

    Full Text Available Epiphytic lichens are an important component in subtropical forests and contribute greatly to forest biodiversity and biomass. However, information on epiphytic lichens still remains scarce in forest conservation owing to the difficulty of accessing all canopy layers for direct observation. Here, epiphytic lichens were quantified on 73 whole trees in five forest types in Southwest China to clarify the vertical stratification of their biomass in subtropical forests. Lichen biomass was significantly influenced by forest type and host attributes, varying from 187.11 to 8.55 g∙tree−1 among forest types and from 289.81 to <0.01 g∙tree−1 among tree species. The vertical stratification of lichen biomass was also determined by forest type, which peaked at the top in primary Lithocarpus forest and middle-aged oak secondary forest and in the middle upper heights in other forests. Overall, the proportion of lichen biomass accounted for 73.17–100.00% of total lichen biomass on branches and 0.00–26.83% on trunks in five forests, and 64.53–100.00% and 0.00–35.47% on eight host species. Seven functional groups showed marked and various responses to tree height between and among forest types. This information improves our understanding of the distribution of epiphytic lichens in forest ecosystems and the promotion of forest management in subtropical China.

  1. Spatial modeling of litter and soil carbon stocks with associated uncertainty on forest land in the conterminous United States

    Science.gov (United States)

    Cao, B.; Domke, G. M.; Russell, M.; McRoberts, R. E.; Walters, B. F.

    2017-12-01

    Forest ecosystems contribute substantially to carbon (C) storage. The dynamics of litter decomposition, translocation and stabilization into soil layers are essential processes in the functioning of forest ecosystems, as they control the cycling of soil organic matter and the accumulation and release of C to the atmosphere. Therefore, the spatial distributions of litter and soil C stocks are important in greenhouse gas estimation and reporting and inform land management decisions, policy, and climate change mitigation strategies. In this study, we explored the effects of spatial aggregation of climatic, biotic, topographic and soil input data on national estimates of litter and soil C stocks and characterized the spatial distribution of litter and soil C stocks in the conterminous United States. Data from the Forest Inventory and Analysis (FIA) program within the US Forest Service were used with vegetation phenology data estimated from LANDSAT imagery (30 m) and raster data describing relevant environmental parameters (e.g. temperature, precipitation, topographic properties) for the entire conterminous US. Litter and soil C stocks were estimated and mapped through geostatistical analysis and statistical uncertainty bounds on the pixel level predictions were constructed using a Monte Carlo-bootstrap technique, by which credible variance estimates for the C stocks were calculated. The sensitivity of model estimates to spatial aggregation depends on geographic region. Further, using long-term (30-year) climate averages during periods with strong climatic trends results in large differences in litter and soil C stock estimates. In addition, results suggest that local topographic aspect is an important variable in litter and soil C estimation at the continental scale.

  2. Species diversity and chemical properties of litter influence non-additive effects of litter mixtures on soil carbon and nitrogen cycling.

    Directory of Open Access Journals (Sweden)

    Bing Mao

    Full Text Available Decomposition of litter mixtures generally cannot be predicted from the component species incubated in isolation. Therefore, such non-additive effects of litter mixing on soil C and N dynamics remain poorly understood in terrestrial ecosystems. In this study, litters of Mongolian pine and three dominant understory species and soil were collected from a Mongolian pine plantation in Northeast China. In order to examine the effects of mixed-species litter on soil microbial biomass N, soil net N mineralization and soil respiration, four single litter species and their mixtures consisting of all possible 2-, 3- and 4-species combinations were added to soils, respectively. In most instances, species mixing produced synergistic non-additive effects on soil microbial biomass N and soil respiration, but antagonistic non-additive effects on net N mineralization. Species composition rather than species richness explained the non-additive effects of species mixing on soil microbial biomass N and net N mineralization, due to the interspecific differences in litter chemical composition. Both litter species composition and richness explained non-additive soil respiration responses to mixed-species litter, while litter chemical diversity and chemical composition did not. Our study indicated that litter mixtures promoted soil microbial biomass N and soil respiration, and inhibited net N mineralization. Soil N related processes rather than soil respiration were partly explained by litter chemical composition and chemical diversity, highlighting the importance of functional diversity of litter on soil N cycling.

  3. Species diversity and chemical properties of litter influence non-additive effects of litter mixtures on soil carbon and nitrogen cycling.

    Science.gov (United States)

    Mao, Bing; Mao, Rong; Zeng, De-Hui

    2017-01-01

    Decomposition of litter mixtures generally cannot be predicted from the component species incubated in isolation. Therefore, such non-additive effects of litter mixing on soil C and N dynamics remain poorly understood in terrestrial ecosystems. In this study, litters of Mongolian pine and three dominant understory species and soil were collected from a Mongolian pine plantation in Northeast China. In order to examine the effects of mixed-species litter on soil microbial biomass N, soil net N mineralization and soil respiration, four single litter species and their mixtures consisting of all possible 2-, 3- and 4-species combinations were added to soils, respectively. In most instances, species mixing produced synergistic non-additive effects on soil microbial biomass N and soil respiration, but antagonistic non-additive effects on net N mineralization. Species composition rather than species richness explained the non-additive effects of species mixing on soil microbial biomass N and net N mineralization, due to the interspecific differences in litter chemical composition. Both litter species composition and richness explained non-additive soil respiration responses to mixed-species litter, while litter chemical diversity and chemical composition did not. Our study indicated that litter mixtures promoted soil microbial biomass N and soil respiration, and inhibited net N mineralization. Soil N related processes rather than soil respiration were partly explained by litter chemical composition and chemical diversity, highlighting the importance of functional diversity of litter on soil N cycling.

  4. Decomposition of oak leaf litter and millipede faecal pellets in soil under temperate mixed oak forest

    Science.gov (United States)

    Tajovský, Karel; Šimek, Miloslav; Háněl, Ladislav; Šantrůčková, Hana; Frouz, Jan

    2015-04-01

    The millipedes Glomeris hexasticha (Diplopoda, Glomerida) were maintained under laboratory conditions and fed on oak leaf litter collected from a mixed oak forest (Abieto-Quercetum) in South Bohemia, Czech Republic. Every fourth day litter was changed and produced faecal pellets were separated and afterwards analysed. Content of organic carbon and C:N ratio lowered in faecal pellets as compared with consumed litter. Changes in content of chemical elements (P, K, Ca, Mg, Na) were recognised as those characteristic for the first stage of degradation of plant material. Samples of faecal pellets and oak leaf litter were then exposed in mesh bags between the F and H layers of forest soil for up to one year, subsequently harvested and analysed. A higher rate of decomposition of exposed litter than that of faecal pellets was found during the first two weeks. After 1-year exposure, the weight of litter was reduced to 51%, while that of pellets to 58% only, although the observed activity of present biotic components (algae, protozoans, nematodes; CO2 production, nitrogenase activity) in faecal pellets was higher as compared with litter. Different micro-morphological changes were observed in exposed litter and in pellets although these materials originated from the same initial sources. Comparing to intact leaf litter, another structural and functional processes occurred in pellets due to the fragmentation of plant material by millipedes. Both laboratory and field experiments showed that the millipede faecal pellets are not only a focal point of biodegradation activity in upper soil layers, but also confirmed that millipede feces undergo a slower decomposition than original leaf litter.

  5. Litter type control on soil C and N stabilization dynamics in a temperate forest.

    Science.gov (United States)

    Hatton, Pierre-Joseph; Castanha, Cristina; Torn, Margaret S; Bird, Jeffrey A

    2015-03-01

    While plant litters are the main source of soil organic matter (SOM) in forests, the controllers and pathways to stable SOM formation remain unclear. Here, we address how litter type ((13) C/(15) N-labeled needles vs. fine roots) and placement-depth (O vs. A horizon) affect in situ C and N dynamics in a temperate forest soil after 5 years. Litter type rather than placement-depth controlled soil C and N retention after 5 years in situ, with belowground fine root inputs greatly enhancing soil C (x1.4) and N (x1.2) retention compared with aboveground needles. While the proportions of added needle and fine root-derived C and N recovered into stable SOM fractions were similar, they followed different transformation pathways into stable SOM fractions: fine root transfer was slower than for needles, but proportionally more of the remaining needle-derived C and N was transferred into stable SOM fractions. The stoichiometry of litter-derived C vs. N within individual SOM fractions revealed the presence at least two pools of different turnover times (per SOM fraction) and emphasized the role of N-rich compounds for long-term persistence. Finally, a regression approach suggested that models may underestimate soil C retention from litter with fast decomposition rates. © 2014 John Wiley & Sons Ltd.

  6. Cosmic-ray neutron transport at a forest field site: the sensitivity to various environmental conditions with focus on biomass and canopy interception

    Science.gov (United States)

    Andreasen, Mie; Jensen, Karsten H.; Desilets, Darin; Zreda, Marek; Bogena, Heye R.; Looms, Majken C.

    2017-04-01

    Cosmic-ray neutron intensity is inversely correlated to all hydrogen present in the upper decimeters of the subsurface and the first few hectometers of the atmosphere above the ground surface. This correlation forms the base of the cosmic-ray neutron soil moisture estimation method. The method is, however, complicated by the fact that several hydrogen pools other than soil moisture affect the neutron intensity. In order to improve the cosmic-ray neutron soil moisture estimation method and explore the potential for additional applications, knowledge about the environmental effect on cosmic-ray neutron intensity is essential (e.g., the effect of vegetation, litter layer and soil type). In this study the environmental effect is examined by performing a sensitivity analysis using neutron transport modeling. We use a neutron transport model with various representations of the forest and different parameters describing the subsurface to match measured height profiles and time series of thermal and epithermal neutron intensities at a field site in Denmark. Overall, modeled thermal and epithermal neutron intensities are in satisfactory agreement with measurements; however, the choice of forest canopy conceptualization is found to be significant. Modeling results show that the effect of canopy interception, soil chemistry and dry bulk density of litter and mineral soil on neutron intensity is small. On the other hand, the neutron intensity decreases significantly with added litter-layer thickness, especially for epithermal neutron energies. Forest biomass also has a significant influence on the neutron intensity height profiles at the examined field site, altering both the shape of the profiles and the ground-level thermal-to-epithermal neutron ratio. This ratio increases with increasing amounts of biomass, and was confirmed by measurements from three sites representing agricultural, heathland and forest land cover. A much smaller effect of canopy interception on the ground

  7. Communities of saprobic fungi on leaf litter of Vismia guianensis in remnants of the Brazilian Atlantic Forest

    Institute of Scientific and Technical Information of China (English)

    Loise Araujo Costa

    2017-01-01

    We examined the mycobiota associated with Vismia guianensis leaf litter in three Atlantic Forest remnants of Brazil's semiarid region.Among the study sites,two remnants were protected forest reserves,whereas the third was influenced by major anthropogenic activities.Eighteen litter samples were collected in wet and dry seasons and were processed by particle filtration technique.A total of 4750 fungal isolates of 142 taxa were identified.Species richness was higher in litter samples collected during wet season.Nonmetric multidimensional scaling multivariate analysis showed differences in the composition of fungal communities among the sampling sites and the seasons.Analysis of similarity showed that the differences were statistically significant (R =0.85;P =0.0001).Our findings revealed that spatial and temporal heterogeneity,and human activities had significant impacts on the saprobic fungi of V.guianensis leaf litter.

  8. Forest biomass carbon stocks and variation in Tibet's carbon-dense forests from 2001 to 2050.

    Science.gov (United States)

    Sun, Xiangyang; Wang, Genxu; Huang, Mei; Chang, Ruiying; Ran, Fei

    2016-10-05

    Tibet's forests, in contrast to China's other forests, are characterized by primary forests, high carbon (C) density and less anthropogenic disturbance, and they function as an important carbon pool in China. Using the biomass C density data from 413 forest inventory sites and a spatial forest age map, we developed an allometric equation for the forest biomass C density and forest age to assess the spatial biomass C stocks and variation in Tibet's forests from 2001 to 2050. The results indicated that the forest biomass C stock would increase from 831.1 Tg C in 2001 to 969.4 Tg C in 2050, with a net C gain of 3.6 Tg C yr -1 between 2001 and 2010 and a decrease of 1.9 Tg C yr -1 between 2040 and 2050. Carbon tends to allocate more in the roots of fir forests and less in the roots of spruce and pine forests with increasing stand age. The increase of the biomass carbon pool does not promote significant augmentation of the soil carbon pool. Our findings suggest that Tibet's mature forests will remain a persistent C sink until 2050. However, afforestation or reforestation, especially with the larger carbon sink potential forest types, such as fir and spruce, should be carried out to maintain the high C sink capacity.

  9. The relationships between microbiological attributes and soil and litter quality in pure and mixed stands of native tree species in southeastern Bahia, Brazil.

    Science.gov (United States)

    Gama-Rodrigues, Emanuela F; Gama-Rodrigues, Antonio Carlos; Barros, Nairam F; Moço, Maria Kellen S

    2011-11-01

    This study was conducted to link soil and litter microbial biomass and activity with soil and litter quality in the surface layer for different pure and mixed stands of native tree species in southeastern Bahia, Brazil. The purpose of the study was to see how strongly the differences among species and stands affect the microbiological attributes of the soil and to identify how microbial processes can be influenced by soil and litter quality. Soil and litter samples were collected from six pure and mixed stands of six hardwood species (Peltogyne angustifolia, Centrolobium robustum, Arapatiella psilophylla, Sclerolobium chrysophyllum, Cordia trichotoma, Macrolobium latifolium) native to the southeastern region of Bahia, Brazil. In plantations of native tree species in humid tropical regions, the immobilization efficiency of C and N by soil microbial biomass was strongly related to the chemical quality of the litter and to the organic matter quality of the soil. According to the variables analyzed, the mixed stand was similar to the natural forest and dissimilar to the pure stands. Litter microbial biomass represented a greater sink of C and N than soil microbial biomass and is an important contributor of resources to tropical soils having low C and N availability.

  10. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Bonzom, Jean-Marc, E-mail: jean-marc.bonzom@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Hättenschwiler, Stephan [Centre d' Ecologie Fonctionnelle et Evolutive (CEFE UMR 5175, CNRS–Université de Montpellier–Université Paul-Valéry Montpellier–EPHE), 1919 Route de Mende, F-34293 Montpellier (France); Lecomte-Pradines, Catherine [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Chauvet, Eric [EcoLab, Université de Toulouse, CNRS, UPS, INPT, 118 Route de Narbonne, 31062 Toulouse cedex (France); Gaschak, Sergey [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Maksimenko, Andrey [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); and others

    2016-08-15

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22–15 μGy h{sup −1}) and (ii) along a short distance gradient of radioactive contamination (1.2–29 μGy h{sup −1}) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150 μGy h{sup −1}. This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. - Highlights: • The effects of radioactivity on

  11. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

    International Nuclear Information System (INIS)

    Bonzom, Jean-Marc; Hättenschwiler, Stephan; Lecomte-Pradines, Catherine; Chauvet, Eric; Gaschak, Sergey; Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas; Maksimenko, Andrey

    2016-01-01

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22–15 μGy h −1 ) and (ii) along a short distance gradient of radioactive contamination (1.2–29 μGy h −1 ) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150 μGy h −1 . This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. - Highlights: • The effects of radioactivity on ecosystem processes

  12. Assessing changes in biomass, productivity, and C and N stores following Juniperus virginiana forest expansion into tallgrass prairie

    Energy Technology Data Exchange (ETDEWEB)

    Norris, M. D.; Blair, J. M.; Johnson, L. C. [Kansas State Univ., Manhattan, KS (United States); McKane, R. B. [Environmental Protection Agency, Western Ecology Division, Corvallis, OR (United States)

    2001-11-01

    The objective of this study was to assess changes in plant productivity and above-ground plant biomass associated with red cedar forest expansion into areas formerly dominated by tallgrass prairie. Regionally appropriate allometric biomass regression equations were developed for the nondestructive estimation of red cedar biomass in eastern Kansas, followed by quantification of the carbon and nitrogen content of selected biomass components. The equations were applied, along with measurements of leaf litter production, to selected local stands of mature closed-canopy red cedars to estimate above-ground biomass, standing stocks of carbon and nitrogen and annual above-ground net primary productivity. Above-ground plant biomass for these red cedar-dominated sites ranged from 114,100 kg/ha for the youngest stand to 210,700 kg/ha for the oldest. Annual above-ground net primary productivity (ANPP) ranged from 7,250 to 10,440 kg/ha/yr for the oldest and younger red cedar stands respectively. The ANPP in comparable tallgrass prairie sites in this region averages 3,690 k/ha/yr, indicating a large increase in carbon uptake and above-ground storage as a result of the change from prairie to red cedar forests. Comparing these results with similar published data from other sites led to the conclusion that the widespread change from tallgrass to red cedars across the woodland-prairie ecotone has important consequences for regional carbon storage.37 refs., 3 tabs., 3 figs.

  13. ROE Carbon Storage - Forest Biomass

    Science.gov (United States)

    This polygon dataset depicts the density of forest biomass in counties across the United States, in terms of metric tons of carbon per square mile of land area. These data were provided in spreadsheet form by the U.S. Department of Agriculture (USDA) Forest Service. To produce the Web mapping application, EPA joined the spreadsheet with a shapefile of U.S. county (and county equivalent) boundaries downloaded from the U.S. Census Bureau. EPA calculated biomass density based on the area of each county polygon. These data sets were converted into a single polygon feature class inside a file geodatabase.

  14. Biomass and Carbon Stocks of Sofala Bay Mangrove Forests

    Directory of Open Access Journals (Sweden)

    Almeida A. Sitoe

    2014-08-01

    Full Text Available Mangroves could be key ecosystems in strategies addressing the mitigation of climate changes through carbon storage. However, little is known regarding the carbon stocks of these ecosystems, particularly below-ground. This study was carried out in the mangrove forests of Sofala Bay, Central Mozambique, with the aim of quantifying carbon stocks of live and dead plant and soil components. The methods followed the procedures developed by the Center for International Forestry Research (CIFOR for mangrove forests. In this study, we developed a general allometric equation to estimate individual tree biomass and soil carbon content (up to 100 cm depth. We estimated the carbon in the whole mangrove ecosystem of Sofala Bay, including dead trees, wood debris, herbaceous, pneumatophores, litter and soil. The general allometric equation for live trees derived was [Above-ground tree dry weight (kg = 3.254 × exp(0.065 × DBH], root mean square error (RMSE = 4.244, and coefficient of determination (R2 = 0.89. The average total carbon storage of Sofala Bay mangrove was 218.5 Mg·ha−1, of which around 73% are stored in the soil. Mangrove conservation has the potential for REDD+ programs, especially in regions like Mozambique, which contains extensive mangrove areas with high deforestation and degradation rates.

  15. Effects of Litter and Nutrient Additions on Soil Carbon Cycling in a Tropical Forest

    Science.gov (United States)

    Cusack, D. F.; Halterman, S.; Turner, B. L.; Tanner, E.; Wright, S. J.

    2014-12-01

    Soil carbon (C) dynamics present one of the largest sources of uncertainty in global C cycle models, with tropical forest soils containing some of the largest terrestrial C stocks. Drastic changes in soil C storage and loss are likely to occur if global change alters plant net primary production (NPP) and/or nutrient availability in these ecosystems. We assessed the effects of litter removal and addition, as well as fertilization with nitrogen (N), phosphorus (P), and/or potassium (K), on soil C stocks in a tropical seasonal forest in Panama after ten and sixteen years, respectively. We used a density fractionation scheme to assess manipulation effects on rapidly and slowly cycling pools of C. Soil samples were collected in the wet and dry seasons from 0-5 cm and 5-10 cm depths in 15- 45x45 m plots with litter removal, 2x litter addition, and control (n=5), and from 32- 40x40 m fertilization plots with factorial additions of N, P, and K. We hypothesized that litter addition would increase all soil C fractions, but that the magnitude of the effect on rapidly-cycling C would be dampened by a fertilization effect. Results for the dry season show that the "free light" C fraction, or rapidly cycling soil C pool, was significantly different among the three litter treatments, comprising 5.1 ± 0.9 % of total soil mass in the litter addition plots, 2.7 ± 0.3 % in control plots, and 1.0 ± 0.1 % in litter removal plots at the 0-5cm depth (means ± one standard error, p < 0.05). Bulk soil C results are similar to observed changes in the rapidly cycling C pool for the litter addition and removal. Fertilization treatments on average diminished this C pool size relative to control plots, although there was substantial variability among fertilization treatments. In particular, addition of N and P together did not significantly alter rapidly cycling C pool sizes (4.1 ± 1.2 % of total soil mass) relative to controls (3.5 ± 0.4 %), whereas addition of P alone resulted in

  16. Loss of aboveground forest biomass and landscape biomass variability in Missouri, US

    Science.gov (United States)

    Brice B. Hanberry; Hong S. He; Stephen R. Shifley

    2016-01-01

    Disturbance regimes and forests have changed over time in the eastern United States. We examined effects of historical disturbance (circa 1813 to 1850) compared to current disturbance (circa 2004 to 2008) on aboveground, live tree biomass (for trees with diameters ≥13 cm) and landscape variation of biomass in forests of the Ozarks and Plains landscapes in Missouri, USA...

  17. Demographic controls of aboveground forest biomass across North America.

    Science.gov (United States)

    Vanderwel, Mark C; Zeng, Hongcheng; Caspersen, John P; Kunstler, Georges; Lichstein, Jeremy W

    2016-04-01

    Ecologists have limited understanding of how geographic variation in forest biomass arises from differences in growth and mortality at continental to global scales. Using forest inventories from across North America, we partitioned continental-scale variation in biomass growth and mortality rates of 49 tree species groups into (1) species-independent spatial effects and (2) inherent differences in demographic performance among species. Spatial factors that were separable from species composition explained 83% and 51% of the respective variation in growth and mortality. Moderate additional variation in mortality (26%) was attributable to differences in species composition. Age-dependent biomass models showed that variation in forest biomass can be explained primarily by spatial gradients in growth that were unrelated to species composition. Species-dependent patterns of mortality explained additional variation in biomass, with forests supporting less biomass when dominated by species that are highly susceptible to competition (e.g. Populus spp.) or to biotic disturbances (e.g. Abies balsamea). © 2016 John Wiley & Sons Ltd/CNRS.

  18. Air contaminants and litter fall decomposition in urban forest areas: The case of São Paulo - SP, Brazil.

    Science.gov (United States)

    Lamano Ferreira, Maurício; Portella Ribeiro, Andreza; Rodrigues Albuquerque, Caroline; Ferreira, Ana Paula do Nascimento Lamano; Figueira, Rubens César Lopes; Lafortezza, Raffaele

    2017-05-01

    Urban forests are usually affected by several types of atmospheric contaminants and by abnormal variations in weather conditions, thus facilitating the biotic homogenization and modification of ecosystem processes, such as nutrient cycling. Peri-urban forests and even natural forests that surround metropolitan areas are also subject to anthropogenic effects generated by cities, which may compromise the dynamics of these ecosystems. Hence, this study advances the hypothesis that the forests located at the margins of the Metropolitan Region of São Paulo (MRSP), Brazil, have high concentrations of atmospheric contaminants leading to adverse effects on litter fall stock. The production, stock and decomposition of litter fall in two forests were quantified. The first, known as Guarapiranga forest, lies closer to the urban area and is located within the MRSP, approximately 20km from the city center. The second, Curucutu forest, is located 70km from the urban center. This forest is situated exactly on the border of the largest continuum of vegetation of the Atlantic Forest. To verify the reach of atmospheric pollutants from the urban area, levels of heavy metals (Cd, Pb, Ni, Cu) adsorbed on the litter fall deposited on the soil surface of the forests were also quantified. The stock of litter fall and the levels of heavy metals were generally higher in the Guarapiranga forest in the samples collected during the lower rainfall season (dry season). Non-metric multidimensional scaling multivariate analysis showed a clear distinction of the sample units related to the concentrations of heavy metals in each forest. A subtle difference between the units related to the dry and rainy seasons in the Curucutu forest was also noted. Multivariate Analysis of Variance revealed that both site and season of the year (dry or rainy) were important to differentiate the quantity of heavy metals in litter fall stock, although the analysis did not show the interaction between these two

  19. Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains

    Science.gov (United States)

    Cheng, Fei; Peng, Xiaobang; Zhao, Peng; Yuan, Jie; Zhong, Chonggao; Cheng, Yalong; Cui, Cui; Zhang, Shuoxin

    2013-01-01

    Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features. PMID:23840671

  20. Forest biomass variation in Southernmost Brazil: the impact of Araucaria trees.

    Science.gov (United States)

    Rosenfield, Milena Fermina; Souza, Alexandre F

    2014-03-01

    A variety of environmental and biotic factors determine vegetation growth and affect plant biomass accumulation. From temperature to species composition, aboveground biomass storage in forest ecosystems is influenced by a number of variables and usually presents a high spatial variability. With this focus, the aim of the study was to evaluate the variables affecting live aboveground forest biomass (AGB) in Subtropical Moist Forests of Southern Brazil, and to analyze the spatial distribution of biomass estimates. Data from a forest inventory performed in the State of Rio Grande do Sul, Southern Brazil, was used in the present study. Thirty-eight 1-ha plots were sampled and all trees with DBH > or = 9.5cm were included for biomass estimation. Values for aboveground biomass were obtained using published allometric equations. Environmental and biotic variables (elevation, rainfall, temperature, soils, stem density and species diversity) were obtained from the literature or calculated from the dataset. For the total dataset, mean AGB was 195.2 Mg/ha. Estimates differed between Broadleaf and Mixed Coniferous-Broadleaf forests: mean AGB was lower in Broadleaf Forests (AGB(BF)=118.9 Mg/ha) when compared to Mixed Forests (AGB(MF)=250.3 Mg/ha). There was a high spatial and local variability in our dataset, even within forest types. This condition is normal in tropical forests and is usually attributed to the presence of large trees. The explanatory multiple regressions were influenced mainly by elevation and explained 50.7% of the variation in AGB. Stem density, diversity and organic matter also influenced biomass variation. The results from our study showed a positive relationship between aboveground biomass and elevation. Therefore, higher values of AGB are located at higher elevations and subjected to cooler temperatures and wetter climate. There seems to be an important contribution of the coniferous species Araucaria angustifolia in Mixed Forest plots, as it presented

  1. Large trees drive forest aboveground biomass variation in moist lowland forests across the tropics

    NARCIS (Netherlands)

    Slik, J.W.F.; Paoli, G.; McGuire, K.; Amaral, I.; Barroso, J.; Bongers, F.; Poorter, L.

    2013-01-01

    Aim - Large trees (d.b.h.¿=¿70¿cm) store large amounts of biomass. Several studies suggest that large trees may be vulnerable to changing climate, potentially leading to declining forest biomass storage. Here we determine the importance of large trees for tropical forest biomass storage and explore

  2. Understanding forest-derived biomass supply with GIS modelling

    DEFF Research Database (Denmark)

    Hock, B. K.; Blomqvist, L.; Hall, P.

    2012-01-01

    distribution, and the cost of delivery as forests are frequently remote from energy users. A GIS-based model was developed to predict supply curves of forest biomass material for a site or group of sites, both now and in the future. The GIS biomass supply model was used to assist the New Zealand Energy...... Efficiency and Conservation Authority's development of a national target for biomass use for industrial heat production, to determine potential forest residue volumes for industrial heat and their delivery costs for 19 processing plants of the dairy company Fonterra, and towards investigating options...

  3. Sustainable use of forest biomass for energy

    International Nuclear Information System (INIS)

    Stupak Moeller, Inge

    2005-01-01

    The substitution of biomass for fossil fuels in energy consumption is a measure to mitigate global warming, and political action plans at European and national levels exist for an increased use. The use of forest biomass for energy can imply different economic and environmental advantages and disadvantages for the society, the energy sector and forestry. For the achievement of an increased and sustainable use of forest biomass for energy, the EU 5th Framework project WOOD-EN-MAN aimed at synthesising current knowledge and creating new knowledge within the field

  4. Seasonal Pattern of Decomposition and N, P, and C Dynamics in Leaf litter in a Mongolian Oak Forest and a Korean Pine Plantation

    Directory of Open Access Journals (Sweden)

    Jaeeun Sohng

    2014-10-01

    Full Text Available Distinct seasons and diverse tree species characterize temperate deciduous forests in NE Asia, but large areas of deciduous forests have been converted to conifer plantations. This study was conducted to understand the effects of seasons and tree species on leaf litter decomposition in a temperate forest. Using the litterbag method, the decomposition rate and nitrogen, phosphorous, and carbon dynamics of Mongolian oak (Quercus mongolica, Korean pine (Pinus koraiensis, and their mixed leaf litter were compared for 24 months in a Mongolian oak stand, an adjacent Korean pine plantation, and a Mongolian oak—Korean pine mixed stand. The decomposition rates of all the leaf litter types followed a pattern of distinct seasonal changes: most leaf litter decomposition occurred during the summer. Tree species was less influential on the leaf litter decomposition. The decomposition rates among different leaf litter types within the same stand were not significantly different, indicating no mixed litter effect. The immobilization of leaf litter N and P lasted for 14 months. Mongolian oak leaf litter and Korean pine leaf litter showed different N and P contents and dynamics during the decomposition, and soil P2O5 was highest in the Korean pine plantation, suggesting effects of plantation on soil nutrient budget.

  5. Earthworm effects on the incorporation of litter C and N into soil organic matter in a sugar maple forest.

    Science.gov (United States)

    Fahey, Timothy J; Yavitt, Joseph B; Sherman, Ruth E; Maerz, John C; Groffman, Peter M; Fisk, Melany C; Bohlen, Patrick J

    2013-07-01

    To examine the mechanisms of earthworm effects on forest soil C and N, we double-labeled leaf litter with 13C and 15N, applied it to sugar maple forest plots with and without earthworms, and traced isotopes into soil pools. The experimental design included forest plots with different earthworm community composition (dominated by Lumbricus terrestris or L. rubellus). Soil carbon pools were 37% lower in earthworm-invaded plots largely because of the elimination of the forest floor horizons, and mineral soil C:N was lower in earthworm plots despite the mixing of high C:N organic matter into soil by earthworms. Litter disappearance over the first winter-spring was highest in the L. terrestris (T) plots, but during the warm season, rapid loss of litter was observed in both L. rubellus (R) and T plots. After two years, 22.0% +/- 5.4% of 13C released from litter was recovered in soil with no significant differences among plots. Total recovery of added 13C (decaying litter plus soil) was much higher in no-worm (NW) plots (61-68%) than in R and T plots (20-29%) as much of the litter remained in the former whereas it had disappeared in the latter. Much higher percentage recovery of 15N than 13C was observed, with significantly lower values for T than R and NW plots. Higher overwinter earthworm activity in T plots contributed to lower soil N recovery. In earthworm-invaded plots isotope enrichment was highest in macroaggregates and microaggregates whereas in NW plots silt plus clay fractions were most enriched. The net effect of litter mixing and priming of recalcitrant soil organic matter (SOM), stabilization of SOM in soil aggregates, and alteration of the soil microbial community by earthworm activity results in loss of SOM and lowering of the C:N ratio. We suggest that earthworm stoichiometry plays a fundamental role in regulating C and N dynamics of forest SOM.

  6. Spaceborne Applications of P Band Imaging Radars for Measuring Forest Biomass

    Science.gov (United States)

    Rignot, Eric J.; Zimmermann, Reiner; vanZyl, Jakob J.

    1995-01-01

    In three sites of boreal and temperate forests, P band HH, HV, and VV polarization data combined estimate total aboveground dry woody biomass within 12 to 27% of the values derived from allometric equations, depending on forest complexity. Biomass estimates derived from HV-polarization data only are 2 to 14% less accurate. When the radar operates at circular polarization, the errors exceed 100% over flooded forests, wet or damaged trees and sparse open tall forests because double-bounce reflections of the radar signals yield radar signatures similar to that of tall and massive forests. Circular polarizations, which minimize the effect of Faraday rotation in spaceborne applications, are therefore of limited use for measuring forest biomass. In the tropical rain forest of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 50 kg/sq m in old, undisturbed floodplain stands, the P band horizontal and vertical polarization data combined separate biomass classes in good agreement with forest inventory estimates. The worldwide need for large scale, updated, biomass estimates, achieved with a uniformly applied method, justifies a more in-depth exploration of multi-polarization long wavelength imaging radar applications for tropical forests inventories.

  7. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone.

    Science.gov (United States)

    Bonzom, Jean-Marc; Hättenschwiler, Stephan; Lecomte-Pradines, Catherine; Chauvet, Eric; Gaschak, Sergey; Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas; Maksimenko, Andrey; Garnier-Laplace, Jacqueline; Adam-Guillermin, Christelle

    2016-08-15

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22-15μGyh(-1)) and (ii) along a short distance gradient of radioactive contamination (1.2-29μGyh(-1)) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150μGyh(-1). This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Biomass estimation as a function of vertical forest structure and forest height: potential and limitations for radar remote sensing

    OpenAIRE

    Torano Caicoya, Astor; Kugler, Florian; Papathanassiou, Kostas; Biber, Peter; Pretzsch, Hans

    2010-01-01

    One common method to estimate biomass is measuring forest height and applying allometric equations to get forest biomass. Conditions like changing forest density or changing forest structure bias the allometric relations or biomass estimation fails completely. Remote sensing systems like SAR or LIDAR allow to measure vertical structure of forests. In this paper it is investigated whether vertical structure is sensitive to biomass. For this purpose vertical biomass profiles were calculated usi...

  9. Variations in canopy and litter interception across a forest chronosequence in the southern Appalachian Mountains

    Science.gov (United States)

    Steven T. Brantley; Paul V. Bolstad; Stephanie H. Laseter; A. Christopher Oishi; Kimberly A. Novick; Chelcy F. Miniat

    2016-01-01

    Variations in evapotranspiration (ET) have been well documented across a variety of forest types and climates in recent decades; however, most of these data have focused on mature, secondgrowth stands. Here we present data on two important fluxes of water, canopy interception (Ic) and forest floor litter interception (Iff), across a chronosequence of forest age in the...

  10. Forest biomass carbon stocks and variation in Tibet’s carbon-dense forests from 2001 to 2050

    Science.gov (United States)

    Sun, Xiangyang; Wang, Genxu; Huang, Mei; Chang, Ruiying; Ran, Fei

    2016-01-01

    Tibet’s forests, in contrast to China’s other forests, are characterized by primary forests, high carbon (C) density and less anthropogenic disturbance, and they function as an important carbon pool in China. Using the biomass C density data from 413 forest inventory sites and a spatial forest age map, we developed an allometric equation for the forest biomass C density and forest age to assess the spatial biomass C stocks and variation in Tibet’s forests from 2001 to 2050. The results indicated that the forest biomass C stock would increase from 831.1 Tg C in 2001 to 969.4 Tg C in 2050, with a net C gain of 3.6 Tg C yr−1 between 2001 and 2010 and a decrease of 1.9 Tg C yr−1 between 2040 and 2050. Carbon tends to allocate more in the roots of fir forests and less in the roots of spruce and pine forests with increasing stand age. The increase of the biomass carbon pool does not promote significant augmentation of the soil carbon pool. Our findings suggest that Tibet’s mature forests will remain a persistent C sink until 2050. However, afforestation or reforestation, especially with the larger carbon sink potential forest types, such as fir and spruce, should be carried out to maintain the high C sink capacity. PMID:27703215

  11. LITTER PRODUCTION AND NUTRIENT ADDITION IN ATLANTIC FOREST AREAS IN SANTA MARIA DE JETIBÁ, ES

    Directory of Open Access Journals (Sweden)

    Geângelo Petene Calvi

    2009-09-01

    Full Text Available This study was accomplished on Espíndula Farm, Santa Maria de Jetibá (ES, with the objective of evaluating the litter and nutrients deposition in areas with different succession stadiums. Two areas were selected with different vegetable coverings, defined as: (SF Secondary Forest, with about 25 ha of area, corresponding to an old area of cassava cultivation with about 50 years in process of ecological succession and where today there is a secondary forest and an Old Secondary Forest (OSF corresponding to a forest area that has just been submitted to a selective wood extraction for use of the farm itself. In each one of vegetal areas, approximately 0.1 ha was delimited and in these ten conical collectors were randomized distributed. The litter collections were accomplished monthly from November 2003 to October 2005. After drying, the material was stratified and the total contributed and the contribution of the different fractions, and the nutritious addition were evaluated. It was not verified significant differences among the total of litter deposited among the areas, being the highest production values observed in the summer, 5.70 Mg ha-1 (SF and 5.73 Mg ha-1(OSF, possibly due to the winds and rain mechanical action. The fraction of higher contribution was the foliar, corresponding to 74.62% for the SF area and 69.46% for the OSF area

  12. Earthworms, arthropods and plant litter decomposition in aspen (Populus tremuloides) and lodgepole pine(Pinus contorta) forests in Colorado, USA

    Science.gov (United States)

    Grizelle Gonzalez; Timothy R. Seastedt; Zugeily Donato

    2003-01-01

    We compared the abundance and community composition of earthworms, soil macroarthropods, and litter microarthropods to test faunal effects on plant litter decomposition rates in two forests in the subalpine in Colorado, USA. Litterbags containing recently senesced litter of Populus tremuloides (aspen) and Pinus contorta (lodgepole pine) were placed in aspen and pine...

  13. Dissecting variation in biomass conversion factors across China's forests: implications for biomass and carbon accounting.

    Science.gov (United States)

    Luo, Yunjian; Zhang, Xiaoquan; Wang, Xiaoke; Ren, Yin

    2014-01-01

    Biomass conversion factors (BCFs, defined as the ratios of tree components (i.e. stem, branch, foliage and root), as well as aboveground and whole biomass of trees to growing stock volume, Mg m-3) are considered as important parameters in large-scale forest biomass carbon estimation. To date, knowledge of possible sources of the variation in BCFs is still limited at large scales. Using our compiled forest biomass dataset of China, we presented forest type-specific values of BCFs, and examined the variation in BCFs in relation to forest type, stand development and environmental factors (climate and soil fertility). BCFs exhibited remarkable variation across forest types, and also were significantly related to stand development (especially growing stock volume). BCFs (except Stem BCF) had significant relationships with mean annual temperature (MAT) and mean annual precipitation (MAP) (Pforest carbon estimates, we should apply values of BCFs for a specified forest type, and also consider climatic and edaphic effects, especially climatic effect, in developing predictive models of BCFs (except Stem BCF).

  14. (abstract) Sensitivity to Forest Biomass Based on Analysis of Scattering Mechanism

    Science.gov (United States)

    Way, JoBea; Bachman, Jennifer E.; Paige, David A.

    1993-01-01

    The estimation of forest biomass on a global scale is an important input to global climate and carbon cycle models. Remote sensing using synthetic aperture radar offers a means to obtain such a data set. Although it has been clear for some time that radar signals penetrate forest canopies, only recently has it been demonstrated that these signals are indeed sensitive to biomass. Inasmuch as the majority of a forest's biomass is in the trunks, it is important that the radar is sensing the trunk biomass as opposed to the branch or leaf biomass. In this study we use polarimetric AIRSAR P- and L-band data from a variety of forests to determine if the radar penetrates to the trunk by examining the scattering mechanism as determined using van Zyl's scattering interaction model, and the levels at which saturation occurs with respect to sensitivity of radar backscatter to total biomass. In particular, the added sensitivity of P-band relative to L-band is addressed. Results using data from the Duke Forest in North Carolina, the Bonanza Creek Experimental Forest in Alaska, Shasta Forest in California, the Black Forest in Germany, the temporate/boreal transition forests in northern Michigan, and coastal forests along the Oregon Transect will be presented.

  15. Temperatures below leaf litter during winter prescribed burns: implications for litter-roosting bats

    Science.gov (United States)

    Roger W. Perry; Virginia L. McDaniel

    2015-01-01

    Some bat species, including eastern red bats (Lasiurus borealis), roost for short periods beneath leaf litter on the forest floor during winter in the south-eastern USA, a region subjected to frequent fire. The variability in fuel consumption, the heterogeneous nature of burns, and the effects of litter and duff moisture on forest-floor...

  16. Transfer of radio-cesium from forest soil to woodchips using fungal activities

    Science.gov (United States)

    Kaneko, Nobuhiro; Huang, Yao; Tanaka, Yoichiro; Fujiwara, Yoshihiro; Sasaki, Michiko; Toda, Hiroto; Takahashi, Terumasa; Kobayashi, Tatsuaki; Harada, Naoki; Nonaka, Masahiro

    2014-05-01

    Raido-cesium released to terrestrial ecosystems by nuclear accidents is know to accumulate forest soil and organic layer on the soil. Forests in Japan are not exceptions. Practically it is impossible to decontaminate large area of forests. However, there is a strong demand from local people, who has been using secondary forests (Satoyama) around croplands in hilly areas, to decontaminate radio-cesium, because those people used to collect wild mushrooms and edible plants, and there are active cultures of mushrooms using logs and sawdusts. These natural resource uses consist substantial part of their economical activities, Therefore it is needed to decontaminate some selected part of forests in Japan to local economy. Clear cutting and scraping surface soil and organic matter are common methods of decontamination. However the efficiency of decontamination is up to 30% reduction of aerial radiation, and the cost to preserve contaminated debris is not affordable. In this study we used wood chips as a growth media for saprotrophic fungi which are known to accumulate redio-cesium. There are many studies indicated that mushrooms accumulated redio-cesium from forest soil and organic layer. It is not practical to collect mushrooms to decontaminate redio-cesium, because biomass of mushrooms are not enough to collect total contaminants. Mushrooms are only minor part of saprotrophic fungi. Fungal biomass in forest soil is about 1% of dead organic matter on forest floor. Our previous study to observe Cs accumulation to decomposing leaf litter indicated 18% absorption of total soil radio-Cs to litter during one year field incubation (Kaneko et al., 2013), and Cs concentration was proportional to fungal biomass on litter. This result indicated that fungi transferred radio-cesium around newly supplied leaf litter free of contamination. Therefore effective decontamination will be possible if we can provide large amount of growth media for saprotrophic fungi, and the media can be

  17. Nutrient Cycling in Primary, Secondary Forests and Cocoa ...

    African Journals Online (AJOL)

    USER

    -bolic processes, assimilation, maintenance and reproduction for sustainability. ... The leaf portion was sorted out from the total trapped litter, dried in the oven at 60 oC ..... Comparative productivity and biomass relations of forest ecosystems.

  18. Geographic, environmental and biotic sources of variation in the nutrient relations of tropical montane forests

    Science.gov (United States)

    James W. Dalling; Katherine Heineman; Grizelle Gonzalez; Rebecca Ostertag

    2016-01-01

    Tropicalmontane forests (TMF) are associated with a widely observed suite of characteristics encompassing forest structure, plant traits and biogeochemistry.With respect to nutrient relations, montane forests are characterized by slow decomposition of organic matter, high investment in below-ground biomass and poor litter quality, relative to tropical lowland forests....

  19. Spatial variation and prediction of forest biomass in a heterogeneous landscape

    Institute of Scientific and Technical Information of China (English)

    S.Lamsal; D.M.Rizzo; R.K.Meentemeyer

    2012-01-01

    Large areas assessments of forest biomass distribution are a challenge in heterogeneous landscapes,where variations in tree growth and species composition occur over short distances.In this study,we use statistical and geospatial modeling on densely sampled forest biomass data to analyze the relative importance of ecological and physiographic variables as determinants of spatial variation of forest biomass in the environmentally heterogeneous region of the Big Sur,California.We estimated biomass in 280 forest plots (one plot per 2.85 km2) and measured an array of ecological (vegetation community type,distance to edge,amount of surrounding non-forest vegetation,soil properties,fire history) and physiographic drivers (elevation,potential soil moisture and solar radiation,proximity to the coast) of tree growth at each plot location.Our geostatistical analyses revealed that biomass distribution is spatially structured and autocorrelated up to 3.1 km.Regression tree (RT) models showed that both physiographic and ecological factors influenced biomass distribution.Across randomly selected sample densities (sample size 112 to 280),ecological effects of vegetation community type and distance to forest edge,and physiographic effects of elevation,potentialsoil moisture and solar radiation were the most consistent predictors of biomass.Topographic moisture index and potential solar radiation had a positive effect on biomass,indicating the importance of topographicallymediated energy and moisture on plant growth and biomass accumulation.RT model explained 35% of the variation in biomass and spatially autocorrelated variation were retained in regession residuals.Regression kriging model,developed from RT combined with kriging of regression residuals,was used to map biomass across the Big Sur.This study demonstrates how statistical and geospatial modeling can be used to discriminate the relative importance of physiographic and ecologic effects on forest biomass and develop

  20. Forest biomass and Armington elasticities in Europe

    International Nuclear Information System (INIS)

    Lundmark, Robert; Shahrammehr, Shima

    2011-01-01

    The purpose of this paper is to provide estimated Armington elasticities for selected European countries and for three forest biomass commodities of main interest in many energy models: roundwood, chips and particles and wood residues. The Armington elasticity is based on the assumption that a specific forest biomass commodity is differentiated by its origin. The statistically significant estimated Armington elasticities range from 0.52 for roundwood in Hungary to approximately 4.53 for roundwood in Estonia. On average, the statistically significant Armington elasticity for chips and particles over all countries is 1.7 and for wood residues and roundwood 1.3 and 1.5, respectively. These elasticities can provide benchmark values for simulation models trying to assess trade patterns of forest biomass commodities and energy policy effects for European countries or for the EU as a whole.

  1. Simulation of the biomass dynamics of Masson pine forest under different management

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gui-lian; WANG Kai-yun; LIU Xin-wei; PENG Shao-lin

    2006-01-01

    TREE submodel affiliated with TREEDYN was used to simulate biomass dynamics of Masson pine (Pinus massoniana) forest under different managements (including thinning, clear cutting, combining thinning with clear cutting). The purpose was to represent biomass dynamics involved in its development, which can provide scientific arguments for management of Masson pine forest. The results showed the scenario that 10% or 20% of biomass of the previous year was thinned every five years from 15 to 40 years made total biomass of pine forest increase slowly and it took more time to reach a mature community; If clear cutting and thinning were combined, the case C (clear cutting at 20 years of forest age, thinning 50% of remaining biomass at 30 years of forest age, and thinning 50% of remaining biomass again at 40 years of forest age) was the best scenario which can accelerate speed of development of Masson pine forest and gained better economic values.

  2. Mercury distribution in two Sierran forest and one desert sagebrush steppe ecosystems and the effects of fire

    International Nuclear Information System (INIS)

    Engle, Mark A.; Sexauer Gustin, Mae; Johnson, Dale W.; Murphy, James F.; Miller, Wally W.; Walker, Roger F.; Wright, Joan; Markee, Melissa

    2006-01-01

    Mercury (Hg) concentration, reservoir mass, and Hg reservoir size were determined for vegetation components, litter, and mineral soil for two Sierran forest sites and one desert sagebrush steppe site. Mercury was found to be held primarily in the mineral soil (maximum depth of 60 to 100 cm), which contained more than 90% of the total ecosystem reservoir. However, Hg in foliage, bark, and litter plays a more dominant role in Hg cycling than the mineral soil. Mercury partitioning into ecosystem components at the Sierran forest sites was similar to that observed for other US forest sites. Vegetation and litter Hg reservoirs were significantly smaller in the sagebrush steppe system because of lower biomass. Data collected from these ecosystems after wildfire and prescribed burns showed a significant decrease in the Hg pool from certain reservoirs. No loss from mineral soil was observed for the study areas but data from fire severity points suggested that Hg in the upper few millimeters of surface soil may be volatilized due to exposure to elevated temperatures. Comparison of data from burned and unburned plots suggested that the only significant source of atmospheric Hg from the prescribed burn was combustion of litter. Differences in unburned versus burned Hg reservoirs at the forest wildfire site demonstrated that drastic reduction in the litter and above ground live biomass Hg reservoirs after burning had occurred. Sagebrush and litter were absent in the burned plots after a wildfire suggesting that both reservoirs were released during the fire. Mercury emissions due to fire from the forest prescribed burn, forest wildfire, and sagebrush steppe wildfire sites were roughly estimated at 2.0 to 5.1, 2.2 to 4.9, and 0.36 ± 0.13 g ha -1 , respectively, with litter and vegetation being the most important sources

  3. A dataset of forest biomass structure for Eurasia.

    Science.gov (United States)

    Schepaschenko, Dmitry; Shvidenko, Anatoly; Usoltsev, Vladimir; Lakyda, Petro; Luo, Yunjian; Vasylyshyn, Roman; Lakyda, Ivan; Myklush, Yuriy; See, Linda; McCallum, Ian; Fritz, Steffen; Kraxner, Florian; Obersteiner, Michael

    2017-05-16

    The most comprehensive dataset of in situ destructive sampling measurements of forest biomass in Eurasia have been compiled from a combination of experiments undertaken by the authors and from scientific publications. Biomass is reported as four components: live trees (stem, bark, branches, foliage, roots); understory (above- and below ground); green forest floor (above- and below ground); and coarse woody debris (snags, logs, dead branches of living trees and dead roots), consisting of 10,351 unique records of sample plots and 9,613 sample trees from ca 1,200 experiments for the period 1930-2014 where there is overlap between these two datasets. The dataset also contains other forest stand parameters such as tree species composition, average age, tree height, growing stock volume, etc., when available. Such a dataset can be used for the development of models of biomass structure, biomass extension factors, change detection in biomass structure, investigations into biodiversity and species distribution and the biodiversity-productivity relationship, as well as the assessment of the carbon pool and its dynamics, among many others.

  4. Litter processing and population food intake of the mangrove crab Ucides cordatus in a high intertidal forest in northern Brazil

    Science.gov (United States)

    Nordhaus, Inga; Wolff, Matthias; Diele, Karen

    2006-03-01

    This study provides the first quantification of the population food intake of the litter-consuming mangrove crab Ucides cordatus (Ocypodidae, L. 1763) in a New World mangrove forest. Diet, feeding periodicity, gastric evacuation rates and size-dependent consumption were determined for this intensively exploited semi-terrestrial crab in different types of mangrove forest. Unlike many other crabs Ucides cordatus is a continuous feeder, as shown by gastrointestinal contents over a day's cycle. Starvation experiments revealed that most gastric evacuation occurs during the first 12 h after feeding, following an exponential decay function. Evacuation rates (0.35 h -1 and 0.31 h -1) for small (carapace width CW 2.5-3.5 cm) and large (CW 6.5-7.5 cm) crabs, respectively, and the mean daily gastrointestinal contents were used to calculate the daily food intake (DFI) of U. cordatus for both sexes and different size classes. DFI was strongly correlated to body size and ranged from 19.8 to 6.0% of body dry weight in small and large crabs, respectively. The daily energy intake of U. cordatus (37.6 kJ for a 65 g wet weight specimen) was high when compared to other leaf-eating crabs. Litter fall and propagule production were calculated as 16.38 t ha -1 y -1, corresponding to a daily mean of 4.49 g m -2 in a high intertidal Rhizophora mangle forest stand. The estimated population food intake of Ucides cordatus (4.1 g dw m -2 d -1) corresponds to 81.3% of this production. This high litter removal rate, a low litter quantity in burrows and high consumption rates during field experiments suggest that the local crab population is food-limited in many parts of the study area. The very efficient coupling of forest litter production and crab litter consumption is possible due to the high crab density and the low inundation frequency of the mangrove forests, allowing for prolonged foraging periods. By processing the major part of the litter, U. cordatus helps to retain nutrients and energy

  5. Forest biomass as an energy source

    Science.gov (United States)

    P.E. Laks; R.W. Hemingway; A. Conner

    1979-01-01

    The Task Force on Forest Biomass as an Energy Source was chartered by the Society of American Foresters on September 26, 1977, and took its present form following an amendment to the charter on October 5, 1977. It built upon the findings of two previous task forces, the Task Force on Energy and Forest Resources and the Task Force for Evaluation of the CORRIM Report (...

  6. A Synthesis of Sierran Forest Biomass Management Studies and Potential Effects on Water Quality

    Directory of Open Access Journals (Sweden)

    Peter J. Weisberg

    2010-09-01

    Full Text Available The Lake Tahoe basin, located along the California and Nevada border between the Carson and Sierra Nevada mountain ranges, represents a complex forested ecosystem consisting of numerous sub-watersheds and tributaries that discharge directly to Lake Tahoe. This synthesis focuses on historical and current nutrient pools and the effects of biomass management in watersheds of the basin relative to their potential impacts on nutrient (N, P related discharge water quality. An accumulating forest floor as a result of fire suppression has resulted in the build-up of large nutrient pools that now provide a “natural” source of long term nutrient availability to surface waters. As a consequence, stand and forest floor replacing wildfire may cause a large magnitude nutrient mobilization impact on runoff water quality. Hence, mechanical harvest and controlled burning have become popular management strategies. The most ecologically significant long-term effects of controlled fire appear to be the loss of C and N from the forest floor. Although the application of controlled fire may have some initial impact on overland/litter interflow nutrient loading, controlled burning in conjunction with mechanical harvest has the potential to improve runoff water quality by reducing N and P discharge and improving the overall health of forest ecosystems without the danger of a high intensity wildfire.

  7. Re-evaluation of forest biomass carbon stocks and lessons from the world's most carbon-dense forests.

    Science.gov (United States)

    Keith, Heather; Mackey, Brendan G; Lindenmayer, David B

    2009-07-14

    From analysis of published global site biomass data (n = 136) from primary forests, we discovered (i) the world's highest known total biomass carbon density (living plus dead) of 1,867 tonnes carbon per ha (average value from 13 sites) occurs in Australian temperate moist Eucalyptus regnans forests, and (ii) average values of the global site biomass data were higher for sampled temperate moist forests (n = 44) than for sampled tropical (n = 36) and boreal (n = 52) forests (n is number of sites per forest biome). Spatially averaged Intergovernmental Panel on Climate Change biome default values are lower than our average site values for temperate moist forests, because the temperate biome contains a diversity of forest ecosystem types that support a range of mature carbon stocks or have a long land-use history with reduced carbon stocks. We describe a framework for identifying forests important for carbon storage based on the factors that account for high biomass carbon densities, including (i) relatively cool temperatures and moderately high precipitation producing rates of fast growth but slow decomposition, and (ii) older forests that are often multiaged and multilayered and have experienced minimal human disturbance. Our results are relevant to negotiations under the United Nations Framework Convention on Climate Change regarding forest conservation, management, and restoration. Conserving forests with large stocks of biomass from deforestation and degradation avoids significant carbon emissions to the atmosphere, irrespective of the source country, and should be among allowable mitigation activities. Similarly, management that allows restoration of a forest's carbon sequestration potential also should be recognized.

  8. Re-evaluation of forest biomass carbon stocks and lessons from the world's most carbon-dense forests

    Science.gov (United States)

    Keith, Heather; Mackey, Brendan G.; Lindenmayer, David B.

    2009-01-01

    From analysis of published global site biomass data (n = 136) from primary forests, we discovered (i) the world's highest known total biomass carbon density (living plus dead) of 1,867 tonnes carbon per ha (average value from 13 sites) occurs in Australian temperate moist Eucalyptus regnans forests, and (ii) average values of the global site biomass data were higher for sampled temperate moist forests (n = 44) than for sampled tropical (n = 36) and boreal (n = 52) forests (n is number of sites per forest biome). Spatially averaged Intergovernmental Panel on Climate Change biome default values are lower than our average site values for temperate moist forests, because the temperate biome contains a diversity of forest ecosystem types that support a range of mature carbon stocks or have a long land-use history with reduced carbon stocks. We describe a framework for identifying forests important for carbon storage based on the factors that account for high biomass carbon densities, including (i) relatively cool temperatures and moderately high precipitation producing rates of fast growth but slow decomposition, and (ii) older forests that are often multiaged and multilayered and have experienced minimal human disturbance. Our results are relevant to negotiations under the United Nations Framework Convention on Climate Change regarding forest conservation, management, and restoration. Conserving forests with large stocks of biomass from deforestation and degradation avoids significant carbon emissions to the atmosphere, irrespective of the source country, and should be among allowable mitigation activities. Similarly, management that allows restoration of a forest's carbon sequestration potential also should be recognized. PMID:19553199

  9. Production and standing crop of litter and humus in a forest exposed to chronic gamma irradiation for twelve years

    International Nuclear Information System (INIS)

    Armentano, T.V.; Woodwell, G.M.

    1976-01-01

    Continuous exposure since 1961 of an oak-pine forest at Brookhaven National Laboratory to chronic gamma irradiation has shown: (1) progressive reduction in litter production from the first year through 1965; (2) greater litter production in 1973 compared to 1965 at exposure rates below 9 R/day primarily because of the prolific sprouting of the oaks, especially Quercus alba; (3) further reduction in litter production in intermediate zones (14-49 R/day) from 1965 to 1973 as a result of replacement of the forest by a Carex pensylvanica mat; (4) increased litter production in the high exposure zone (125 R/day) in 1973 as a result of colonization by adventive species; (5) reduction in the standing crop of litter by 1973 at the lowest exposure rate studied (3.5 R/day) although in 1965 there was no reduction at exposure rates up to 15 R/day; (6) decline in humus content at 4.6 R/day and above with the standing crop in the Carex zone exceeding that of the shrub and damaged forest zones of lower exposures. Both further losses and partial recovery in the production and storage of organic matter have occurred since 1965. These changes constitute a portion of the long-term response of the forest to chronic disturbance. The pattern of response is the result of ecosystem processes that are still not in equilibrium with the chronic disturbance and which were not predictable from short-term studies, even those spanning as much as 4 yr

  10. The total amounts of radioactively contaminated materials in forests in Fukushima, Japan

    Science.gov (United States)

    Hashimoto, Shoji; Ugawa, Shin; Nanko, Kazuki; Shichi, Koji

    2012-01-01

    There has been leakage of radioactive materials from the Fukushima Daiichi Nuclear Power Plant. A heavily contaminated area (≥ 134, 137Cs 1000 kBq m−2) has been identified in the area northwest of the plant. The majority of the land in the contaminated area is forest. Here we report the amounts of biomass, litter (small organic matter on the surface of the soil), coarse woody litter, and soil in the contaminated forest area. The estimated overall volume and weight were 33 Mm3 (branches, leaves, litter, and coarse woody litter are not included) and 21 Tg (dry matter), respectively. Our results suggest that removing litter is an efficient method of decontamination. However, litter is being continuously decomposed, and contaminated leaves will continue to fall on the soil surface for several years; hence, the litter should be removed promptly but continuously before more radioactive elements are transferred into the soil. PMID:22639724

  11. Stakeholder perspectives on converting forest biomass to energy in Oregon, USA

    Energy Technology Data Exchange (ETDEWEB)

    Stidham, Melanie; Simon-Brown, Viviane [Department of Forest Ecosystems and Society, College of Forestry, Oregon State University, 321 Richardson Hall, Corvallis, OR 97331 (United States)

    2011-01-15

    Within the state of Oregon, USA, there is considerable interest in the possibility of converting forest biomass to energy. A number of studies have assessed the technical feasibility of forest biomass energy, but few have focused on social aspects, an important consideration in projects involving public forests. This study explores the social context of converting forest biomass to energy, using qualitative research methods. Semi-structured interviews were conducted with forty individuals representing nine different stakeholder groups. Information gained through interviews was used to understand stakeholder views on forest biomass energy, including their perspectives on potential barriers and opportunities in Oregon. Findings indicate the most challenging barrier will be access to long-term, consistent supply. A related challenge is the long history of contention between parties over forest products coming from public lands. However, findings also show that there are many areas of common ground between these groups that have historically been at odds, such as agreement on the necessity of restoration treatments in certain forest types, the by-product of which could be used for biomass generation. Potential conflicts still exist, for instance over projects in mixed conifer forests. Development of policies and projects through inclusive, collaborative approaches could alleviate controversies, potentially allowing more activities to move forward. Information provided by this research creates a foundation for discussions as forest biomass energy becomes an increasingly prominent issue in Oregon, the western USA, and other regions of the world. (author)

  12. Comparison Between Ground Ant (Hymenoptera: Formicidae) Communities Foraging in the Straw Mulch of Sugarcane Crops and in the Leaf Litter of Neighboring Forests.

    Science.gov (United States)

    Silva, N S; Saad, L P; Souza-Campana, D R; Bueno, O C; Morini, M S C

    2017-02-01

    In many sugarcane plantations in Brazil, the straw is left on the soil after harvesting, and vinasse, a by-product of the production of sugar and ethanol, is used for fertigation. Our goal was to compare ant community composition and species richness in the straw mulch of sugarcane crops with the leaf litter of neighboring forests. We tested the hypothesis that ant communities in the straw mulch of vinasse-irrigated sugarcane crops and in the forest leaf litter were similar, because the combination of straw mulching and vinasse irrigation has a positive effect on soil fauna. Straw mulch and leaf litter were collected from 21 sites and placed in Berlese funnels. In total, 61 species were found in the forest leaf litter, whereas 34 and 28 species were found in the straw mulch of sugarcane fields with and without vinasse, respectively. Ant communities differed between forest and crop fields, but the species in the sugarcane straw mulch were a subset of the species found in the forest leaf litter. Although vinasse is rich in organic matter, it did not increase ant diversity. Seven feeding and/or foraging types were identified and, among the different types, surface-foraging omnivorous ants were the most prevalent in all habitats. Vinasse-irrigated sugarcane straw mulch had more predatory species than mulch from vinasse-free fields, but fewer than forest leaf litter. However, this positive effect of vinasse irrigation should be carefully evaluated because vinasse has negative effects on the environment. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. ROOT BIOMASS ALLOCATION IN THE WORLD'S UPLAND FORESTS

    Science.gov (United States)

    Because the world's forests play a major role in regulating nutrient and carbon cycles, there is much interest in estimating their biomass. Estimates of aboveground biomass based on well-established methods are relatively abundant; estimates of root biomass based on standard meth...

  14. Tree height and tropical forest biomass estimation

    Science.gov (United States)

    M.O. Hunter; M. Keller; D. Vitoria; D.C. Morton

    2013-01-01

    Tropical forests account for approximately half of above-ground carbon stored in global vegetation. However, uncertainties in tropical forest carbon stocks remain high because it is costly and laborious to quantify standing carbon stocks. Carbon stocks of tropical forests are determined using allometric relations between tree stem diameter and height and biomass....

  15. ROE Carbon Storage - Forest Biomass

    Data.gov (United States)

    U.S. Environmental Protection Agency — This polygon dataset depicts the density of forest biomass in counties across the United States, in terms of metric tons of carbon per square mile of land area....

  16. Biogeographical patterns of biomass allocation in leaves, stems, and roots in China's forests.

    Science.gov (United States)

    Zhang, Hao; Wang, Kelin; Xu, Xianli; Song, Tongqing; Xu, Yanfang; Zeng, Fuping

    2015-11-03

    To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China's forests using both the national forest inventory data (2004-2008) and our field measurements (2011-2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass. Based on the constraints of stand biomass, biomass allocation was also influenced by forest type, origin, stand age, stand density, mean annual temperature, precipitation, and maximum temperature in the growing season. Therefore, after stand biomass was accounted for, the residual variation in biomass allocation could be partially explained by stand characteristics and environmental factors, which may aid in quantifying carbon cycling in forest ecosystems and assessing the impacts of climate change on forest carbon dynamics in China.

  17. Landscape-level effects on aboveground biomass of tropical forests: A conceptual framework.

    Science.gov (United States)

    Melito, Melina; Metzger, Jean Paul; de Oliveira, Alexandre A

    2018-02-01

    Despite the general recognition that fragmentation can reduce forest biomass through edge effects, a systematic review of the literature does not reveal a clear role of edges in modulating biomass loss. Additionally, the edge effects appear to be constrained by matrix type, suggesting that landscape composition has an influence on biomass stocks. The lack of empirical evidence of pervasive edge-related biomass losses across tropical forests highlights the necessity for a general framework linking landscape structure with aboveground biomass. Here, we propose a conceptual model in which landscape composition and configuration mediate the magnitude of edge effects and seed-flux among forest patches, which ultimately has an influence on biomass. Our model hypothesizes that a rapid reduction of biomass can occur below a threshold of forest cover loss. Just below this threshold, we predict that changes in landscape configuration can strongly influence the patch's isolation, thus enhancing biomass loss. Moreover, we expect a synergism between landscape composition and patch attributes, where matrix type mediates the effects of edges on species decline, particularly for shade-tolerant species. To test our conceptual framework, we propose a sampling protocol where the effects of edges, forest amount, forest isolation, fragment size, and matrix type on biomass stocks can be assessed both collectively and individually. The proposed model unifies the combined effects of landscape and patch structure on biomass into a single framework, providing a new set of main drivers of biomass loss in human-modified landscapes. We argue that carbon trading agendas (e.g., REDD+) and carbon-conservation initiatives must go beyond the effects of forest loss and edges on biomass, considering the whole set of effects on biomass related to changes in landscape composition and configuration. © 2017 John Wiley & Sons Ltd.

  18. Effects of model choice and forest structure on inventory-based estimations of Puerto Rican forest biomass

    Science.gov (United States)

    Thomas J. Brandeis; Maria Del Rocio; Suarez Rozo

    2005-01-01

    Total aboveground live tree biomass in Puerto Rican lower montane wet, subtropical wet, subtropical moist and subtropical dry forests was estimated using data from two forest inventories and published regression equations. Multiple potentially-applicable published biomass models existed for some forested life zones, and their estimates tended to diverge with increasing...

  19. Opinions of Forest Managers, Loggers, and Forest Landowners in North Carolina regarding Biomass Harvesting Guidelines

    Directory of Open Access Journals (Sweden)

    Diane Fielding

    2012-01-01

    Full Text Available Woody biomass has been identified as an important renewable energy source capable of offsetting fossil fuel use. The potential environmental impacts associated with using woody biomass for energy have spurred development of biomass harvesting guidelines (BHGs in some states and proposals for BHGs in others. We examined stakeholder opinions about BHGs through 60 semistructured interviews with key participants in the North Carolina, USA, forest business sector—forest managers, loggers, and forest landowners. Respondents generally opposed requirements for new BHGs because guidelines added to best management practices (BMPs. Most respondents believed North Carolina’s current BMPs have been successful and sufficient in protecting forest health; biomass harvesting is only an additional component to harvesting with little or no modification to conventional harvesting operations; and scientific research does not support claims that biomass harvesting negatively impacts soil, water quality, timber productivity, or wildlife habitat. Some respondents recognized possible benefits from the implementation of BHGs, which included reduced site preparation costs and increases in proactive forest management, soil quality, and wildlife habitat. Some scientific literature suggests that biomass harvests may have adverse site impacts that require amelioration. The results suggest BHGs will need to be better justified for practitioners based on the scientific literature or linked to demand from new profitable uses or subsidies to offset stakeholder perceptions that they create unnecessary costs.

  20. Forest biomass carbon sinks in East Asia, with special reference to the relative contributions of forest expansion and forest growth.

    Science.gov (United States)

    Fang, Jingyun; Guo, Zhaodi; Hu, Huifeng; Kato, Tomomichi; Muraoka, Hiroyuki; Son, Yowhan

    2014-06-01

    Forests play an important role in regional and global carbon (C) cycles. With extensive afforestation and reforestation efforts over the last several decades, forests in East Asia have largely expanded, but the dynamics of their C stocks have not been fully assessed. We estimated biomass C stocks of the forests in all five East Asian countries (China, Japan, North Korea, South Korea, and Mongolia) between the 1970s and the 2000s, using the biomass expansion factor method and forest inventory data. Forest area and biomass C density in the whole region increased from 179.78 × 10(6) ha and 38.6 Mg C ha(-1) in the 1970s to 196.65 × 10(6) ha and 45.5 Mg C ha(-1) in the 2000s, respectively. The C stock increased from 6.9 Pg C to 8.9 Pg C, with an averaged sequestration rate of 66.9 Tg C yr(-1). Among the five countries, China and Japan were two major contributors to the total region's forest C sink, with respective contributions of 71.1% and 32.9%. In China, the areal expansion of forest land was a larger contributor to C sinks than increased biomass density for all forests (60.0% vs. 40.0%) and for planted forests (58.1% vs. 41.9%), while the latter contributed more than the former for natural forests (87.0% vs. 13.0%). In Japan, increased biomass density dominated the C sink for all (101.5%), planted (91.1%), and natural (123.8%) forests. Forests in South Korea also acted as a C sink, contributing 9.4% of the total region's sink because of increased forest growth (98.6%). Compared to these countries, the reduction in forest land in both North Korea and Mongolia caused a C loss at an average rate of 9.0 Tg C yr(-1), equal to 13.4% of the total region's C sink. Over the last four decades, the biomass C sequestration by East Asia's forests offset 5.8% of its contemporary fossil-fuel CO2 emissions. © 2014 John Wiley & Sons Ltd.

  1. Upland Forest Linkages to Seasonal Wetlands: Litter Flux, Processing, and Food Quality

    Science.gov (United States)

    Brian J. Palik; Darold P. Batzer; Christel Kern

    2005-01-01

    The flux of materials across ecosystem boundaries has significant effects on recipient systems. Because of edge effects, seasonal wetlands in upland forest are good systems to explore these linkages. The purpose of this study was to examine flux of coarse particulate organic matter as litter fall into seasonal wetlands in Minnesota, and the relationship of this flux to...

  2. LBA-ECO CD-04 Leaf Litter Data, km 83 Tower Site, Tapajos National Forest, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Above-ground litter productivity was measured in a 18 ha plot adjacent to the eddy flux tower at the logged forest tower site, km 83, Tapajos National...

  3. Drift and transmission FT-IR spectroscopy of forest soils: an approach to determine decomposition processes of forest litter

    International Nuclear Information System (INIS)

    Haberhauer, G.; Gerzabek, M.H.

    1999-06-01

    A method is described to characterize organic soil layers using Fourier transformed infrared spectroscopy. The applicability of FT-IR, either dispersive or transmission, to investigate decomposition processes of spruce litter in soil originating from three different forest sites in two climatic regions was studied. Spectral information of transmission and diffuse reflection FT-IR spectra was analyzed and compared. For data evaluation Kubelka Munk (KM) transformation was applied to the DRIFT spectra. Sample preparation for DRIFT is simpler and less time consuming in comparison to transmission FT-IR, which uses KBr pellets. A variety of bands characteristics of molecular structures and functional groups has been identified for these complex samples. Analysis of both transmission FT-IR and DRIFT, showed that the intensity of distinct bands is a measure of the decomposition of forest litter. Interferences due to water adsorption spectra were reduced by DRIFT measurement in comparison to transmission FT-IR spectroscopy. However, data analysis revealed that intensity changes of several bands of DRIFT and transmission FT-IR were significantly correlated with soil horizons. The application of regression models enables identification and differentiation of organic forest soil horizons and allows to determine the decomposition status of soil organic matter in distinct layers. On the basis of the data presented in this study, it may be concluded that FT-IR spectroscopy is a powerful tool for the investigation of decomposition dynamics in forest soils. (author)

  4. Handbook for inventorying surface fuels and biomass in the Interior West

    Science.gov (United States)

    James K. Brown; Rick D. Oberheu; Cameron M. Johnston

    1982-01-01

    Presents comprehensive procedures for inventorying weight per unit area of living and dead surface vegetation, to facilitate estimation of biomass and appraisal of fuels. Provides instructions for conducting fieldwork and calculating estimates of downed woody material, forest floor litter and duff, herbaceous vegetation, shrubs, and small conifers. Procedures produce...

  5. The trophic role of a forest salamander: impacts on invertebrates, leaf litter retention, and the humification process

    Science.gov (United States)

    M. L. Best; H. H. Welsh

    2014-01-01

    Woodland (Plethodontid) salamanders are the most abundant vertebrates in North American forests, functioning as predators on invertebrates and prey for higher trophic levels. We investigated the role of Ensatina (Ensatina eschscholtzii) in regulating invertebrate numbers and leaf litter retention in a northern California forest. Our objective was...

  6. Biomass and carbon pools of disturbed riparian forests

    Science.gov (United States)

    Laura A. B. Giese; W. M. Aust; Randall K. Kolka; Carl C. Trettin

    2003-01-01

    Quantification of carbon pools as affected by forest age/development can facilitate riparian restoration and increase awareness of the potential for forests to sequester global carbon. Riparian forest biomass and carbon pools were quantified for four riparian forests representing different seral stages in the South Carolina Upper Coastal Plain. Three of the riparian...

  7. Rates of Litter Decomposition and Soil Respiration in Relation to Soil Temperature and Water in Different-Aged Pinus massoniana Forests in the Three Gorges Reservoir Area, China

    Science.gov (United States)

    Zeng, Lixiong; Huang, Zhilin; Lei, Jingpin; Zhou, Benzhi; Li, Maihe

    2014-01-01

    To better understand the soil carbon dynamics and cycling in terrestrial ecosystems in response to environmental changes, we studied soil respiration, litter decomposition, and their relations to soil temperature and soil water content for 18-months (Aug. 2010–Jan. 2012) in three different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China. Across the experimental period, the mean total soil respiration and litter respiration were 1.94 and 0.81, 2.00 and 0.60, 2.19 and 0.71 µmol CO2 m−2 s−1, and the litter dry mass remaining was 57.6%, 56.2% and 61.3% in the 20-, 30-, and 46-year-old forests, respectively. We found that the temporal variations of soil respiration and litter decomposition rates can be well explained by soil temperature at 5 cm depth. Both the total soil respiration and litter respiration were significantly positively correlated with the litter decomposition rates. The mean contribution of the litter respiration to the total soil respiration was 31.0%–45.9% for the three different-aged forests. The present study found that the total soil respiration was not significantly affected by forest age when P. masonniana stands exceed a certain age (e.g. >20 years old), but it increased significantly with increased soil temperature. Hence, forest management strategies need to protect the understory vegetation to limit soil warming, in order to reduce the CO2 emission under the currently rapid global warming. The contribution of litter decomposition to the total soil respiration varies across spatial and temporal scales. This indicates the need for separate consideration of soil and litter respiration when assessing the climate impacts on forest carbon cycling. PMID:25004164

  8. Net aboveground biomass declines of four major forest types with forest ageing and climate change in western Canada's boreal forests.

    Science.gov (United States)

    Chen, Han Y H; Luo, Yong

    2015-10-01

    Biomass change of the world's forests is critical to the global carbon cycle. Despite storing nearly half of global forest carbon, the boreal biome of diverse forest types and ages is a poorly understood component of the carbon cycle. Using data from 871 permanent plots in the western boreal forest of Canada, we examined net annual aboveground biomass change (ΔAGB) of four major forest types between 1958 and 2011. We found that ΔAGB was higher for deciduous broadleaf (DEC) (1.44 Mg ha(-1)  year(-1) , 95% Bayesian confidence interval (CI), 1.22-1.68) and early-successional coniferous forests (ESC) (1.42, CI, 1.30-1.56) than mixed forests (MIX) (0.80, CI, 0.50-1.11) and late-successional coniferous (LSC) forests (0.62, CI, 0.39-0.88). ΔAGB declined with forest age as well as calendar year. After accounting for the effects of forest age, ΔAGB declined by 0.035, 0.021, 0.032 and 0.069 Mg ha(-1)  year(-1) per calendar year in DEC, ESC, MIX and LSC forests, respectively. The ΔAGB declines resulted from increased tree mortality and reduced growth in all forest types except DEC, in which a large biomass loss from mortality was accompanied with a small increase in growth. With every degree of annual temperature increase, ΔAGB decreased by 1.00, 0.20, 0.55 and 1.07 Mg ha(-1)  year(-1) in DEC, ESC, MIX and LSC forests, respectively. With every cm decrease of annual climatic moisture availability, ΔAGB decreased 0.030, 0.045 and 0.17 Mg ha(-1)  year(-1) in ESC, MIX and LSC forests, but changed little in DEC forests. Our results suggest that persistent warming and decreasing water availability have profound negative effects on forest biomass in the boreal forests of western Canada. Furthermore, our results indicate that forest responses to climate change are strongly dependent on forest composition with late-successional coniferous forests being most vulnerable to climate changes in terms of aboveground biomass. © 2015 John Wiley & Sons Ltd.

  9. Spatio-temporal changes in biomass carbon sinks in China's forests from 1977 to 2008.

    Science.gov (United States)

    Guo, Zhaodi; Hu, Huifeng; Li, Pin; Li, Nuyun; Fang, Jingyun

    2013-07-01

    Forests play a leading role in regional and global carbon (C) cycles. Detailed assessment of the temporal and spatial changes in C sinks/sources of China's forests is critical to the estimation of the national C budget and can help to constitute sustainable forest management policies for climate change. In this study, we explored the spatio-temporal changes in forest biomass C stocks in China between 1977 and 2008, using six periods of the national forest inventory data. According to the definition of the forest inventory, China's forest was categorized into three groups: forest stand, economic forest, and bamboo forest. We estimated forest biomass C stocks for each inventory period by using continuous biomass expansion factor (BEF) method for forest stands, and the mean biomass density method for economic and bamboo forests. As a result, China's forests have accumulated biomass C (i.e., biomass C sink) of 1896 Tg (1 Tg=10(12) g) during the study period, with 1710, 108 and 78 Tg C in forest stands, and economic and bamboo forests, respectively. Annual forest biomass C sink was 70.2 Tg C a(-1), offsetting 7.8% of the contemporary fossil CO2 emissions in the country. The results also showed that planted forests have functioned as a persistent C sink, sequestrating 818 Tg C and accounting for 47.8% of total C sink in forest stands, and that the old-, mid- and young-aged forests have sequestrated 930, 391 and 388 Tg C from 1977 to 2008. Our results suggest that China's forests have a big potential as biomass C sink in the future because of its large area of planted forests with young-aged growth and low C density.

  10. The relative contributions of forest growth and areal expansion to forest biomass carbon

    Science.gov (United States)

    P. Li; J. Zhu; H. Hu; Z. Guo; Y. Pan; R. Birdsey; J. Fang

    2016-01-01

    Forests play a leading role in regional and global terrestrial carbon (C) cycles. Changes in C sequestration within forests can be attributed to areal expansion (increase in forest area) and forest growth (increase in biomass density). Detailed assessment of the relative contributions of areal expansion and forest growth to C sinks is crucial to reveal the mechanisms...

  11. Boreal forest biomass classification with TanDEM-X

    OpenAIRE

    Torano Caicoya, Astor; Kugler, Florian; Papathanassiou, Kostas; Hajnsek, Irena

    2013-01-01

    High spatial resolution X-band interferometric SAR data from the TanDEM-X, in the operational DEM generation mode, are sensitive to forest structure and can therefore be used for thematic boreal forest classification of forest environments. The interferometric coherence in absence of temporal decorrelation depends strongly on forest height and structure. Due to the rather homogenous structure of boreal forest, forest biomass can be derived from forest height, on the basis of allometric equati...

  12. Tree biomass in the Swiss landscape: nationwide modelling for improved accounting for forest and non-forest trees.

    Science.gov (United States)

    Price, B; Gomez, A; Mathys, L; Gardi, O; Schellenberger, A; Ginzler, C; Thürig, E

    2017-03-01

    Trees outside forest (TOF) can perform a variety of social, economic and ecological functions including carbon sequestration. However, detailed quantification of tree biomass is usually limited to forest areas. Taking advantage of structural information available from stereo aerial imagery and airborne laser scanning (ALS), this research models tree biomass using national forest inventory data and linear least-square regression and applies the model both inside and outside of forest to create a nationwide model for tree biomass (above ground and below ground). Validation of the tree biomass model against TOF data within settlement areas shows relatively low model performance (R 2 of 0.44) but still a considerable improvement on current biomass estimates used for greenhouse gas inventory and carbon accounting. We demonstrate an efficient and easily implementable approach to modelling tree biomass across a large heterogeneous nationwide area. The model offers significant opportunity for improved estimates on land use combination categories (CC) where tree biomass has either not been included or only roughly estimated until now. The ALS biomass model also offers the advantage of providing greater spatial resolution and greater within CC spatial variability compared to the current nationwide estimates.

  13. Bringing Together Users and Developers of Forest Biomass Maps

    Science.gov (United States)

    Brown, Molly Elizabeth; Macauley, Molly K.

    2012-01-01

    Forests store carbon and thus represent important sinks for atmospheric carbon dioxide. Reducing uncertainty in current estimates of the amount of carbon in standing forests will improve precision of estimates of anthropogenic contributions to carbon dioxide in the atmosphere due to deforestation. Although satellite remote sensing has long been an important tool for mapping land cover, until recently aboveground forest biomass estimates have relied mostly on systematic ground sampling of forests. In alignment with fiscal year 2010 congressional direction, NASA has initiated work toward a carbon monitoring system (CMS) that includes both maps of forest biomass and total carbon flux estimates. A goal of the project is to ensure that the products are useful to a wide community of scientists, managers, and policy makers, as well as to carbon cycle scientists. Understanding the needs and requirements of these data users is helpful not just to the NASA CMS program but also to the entire community working on carbon-related activities. To that end, this meeting brought together a small group of natural resource managers and policy makers who use information on forests in their work with NASA scientists who are working to create aboveground forest biomass maps. These maps, derived from combining remote sensing and ground plots, aim to be more accurate than current inventory approaches when applied at local and regional scales. Meeting participants agreed that users of biomass information will look to the CMS effort not only to provide basic data for carbon or biomass measurements but also to provide data to help serve a broad range of goals, such as forest watershed management for water quality, habitat management for biodiversity and ecosystem services, and potential use for developing payments for ecosystem service projects. Participants also reminded the CMS group that potential users include not only public sector agencies and nongovernmental organizations but also the

  14. Tropical forest plantation biomass estimation using RADARSAT-SAR and TM data of south china

    Science.gov (United States)

    Wang, Chenli; Niu, Zheng; Gu, Xiaoping; Guo, Zhixing; Cong, Pifu

    2005-10-01

    Forest biomass is one of the most important parameters for global carbon stock model yet can only be estimated with great uncertainties. Remote sensing, especially SAR data can offers the possibility of providing relatively accurate forest biomass estimations at a lower cost than inventory in study tropical forest. The goal of this research was to compare the sensitivity of forest biomass to Landsat TM and RADARSAT-SAR data and to assess the efficiency of NDVI, EVI and other vegetation indices in study forest biomass based on the field survey date and GIS in south china. Based on vegetation indices and factor analysis, multiple regression and neural networks were developed for biomass estimation for each species of the plantation. For each species, the better relationships between the biomass predicted and that measured from field survey was obtained with a neural network developed for the species. The relationship between predicted and measured biomass derived from vegetation indices differed between species. This study concludes that single band and many vegetation indices are weakly correlated with selected forest biomass. RADARSAT-SAR Backscatter coefficient has a relatively good logarithmic correlation with forest biomass, but neither TM spectral bands nor vegetation indices alone are sufficient to establish an efficient model for biomass estimation due to the saturation of bands and vegetation indices, multiple regression models that consist of spectral and environment variables improve biomass estimation performance. Comparing with TM, a relatively well estimation result can be achieved by RADARSAT-SAR, but all had limitations in tropical forest biomass estimation. The estimation results obtained are not accurate enough for forest management purposes at the forest stand level. However, the approximate volume estimates derived by the method can be useful in areas where no other forest information is available. Therefore, this paper provides a better

  15. Effects of gamma radiation on the biomass structure of the arboreal stratum in a northern forest

    International Nuclear Information System (INIS)

    Crow, T.R.

    1977-01-01

    In 1972 an area within the Enterprise Radiation Forest was subjected to a growing-season exposure of gamma radiation from a 10,000-Ci 137 Cs source. Structural changes in woody vegetation caused by ionizing radiation were quantified by measuring changes in the amounts and distribution of biomass. Measurable effects immediately after irradiation were confined to an area within 10 to 15 m from the source; this represented an exposure rate greater than 200 r/day and cumulative exposure in excess of 20 kr. These effects included total shrub mortality at 5 m, 70 to 90 percent reductions in shrub biomass at 10 m, very slight reductions in shrub biomass at 15 m, and an early release of tree and shrub leaf litter within 15 m of the source. Responses to the treatment were more definitive in 1973 and 1974. Ionizing radiation reduced the biomass of low shrubs within 15 m from the source (greater than 135 r/day), but this reduction did not continue beyond 1973 because of ingrowth. Declines in biomass of high shrubs continued into 1974 out to a distance of 30 m (greater than 40 r/day). The result was the spatial and temporal development of a shrub community with a lower profile in response to radiation. Although gross changes in the biomass structure of the tree stratum did not occur until 1973 and 1974, radiation-induced changes in productivity were immediate

  16. Separating the effects of forest type and elevation on the diversity of litter invertebrate communities in a humid tropical forest in Puerto Rico.

    Science.gov (United States)

    BARBARA A. RICHARDSON; MICHAEL J. RICHARDSON; FELIPE N. SOTO-ADAMES

    2005-01-01

    1. The primary effects of climatic conditions on invertebrate litter communities, and the secondary effects of different forest types, were distinguished by using the sierra palm as a control in a natural experiment along an elevational gradient in the Luquillo Mountains. These mountains have three well-defined forest types along the gradient, with the palm occurring...

  17. High-biomass forests of the Pacific Northwest: who manages them and how much is protected?

    Science.gov (United States)

    Krankina, Olga N; DellaSala, Dominick A; Leonard, Jessica; Yatskov, Mikhail

    2014-07-01

    To examine ownership and protection status of forests with high-biomass stores (>200 Mg/ha) in the Pacific Northwest (PNW) region of the United States, we used the latest versions of publicly available datasets. Overlay, aggregation, and GIS-based computation of forest area in broad biomass classes in the PNW showed that the National Forests contained the largest area of high-biomass forests (48.4 % of regional total), but the area of high-biomass forest on private lands was important as well (22.8 %). Between 2000 and 2008, the loss of high-biomass forests to fire on the National Forests was 7.6 % (236,000 ha), while the loss of high-biomass forest to logging on private lands (364,000 ha) exceeded the losses to fire across all ownerships. Many remaining high-biomass forest stands are vulnerable to future harvest as only 20 % are strictly protected from logging, while 26 % are not protected at all. The level of protection for high-biomass forests varies by state, for example, 31 % of all high-biomass federal forests in Washington are in high-protection status compared to only 9 % in Oregon. Across the conterminous US, high-biomass forest covers forest land and the PNW region holds 56.8 % of this area or 5.87 million ha. Forests with high-biomass stores are important to document and monitor as they are scarce, often threatened by harvest and development, and their disturbance including timber harvest results in net C losses to the atmosphere that can take a new generation of trees many decades or centuries to offset.

  18. BIOMASS AND MICROBIAL ACTIVITY UNDER DIFFERENT FOREST COVERS

    Directory of Open Access Journals (Sweden)

    Rafael Malfitano Braga

    2016-06-01

    Full Text Available This study evaluated the soil fertility, biomass and microbial activity of the soil under forest cover of Eucalyptus grandis, Eucalyptus pilularis, Eucalyptus cloeziana and Corymbia maculata; Pinus Caribbean var. hondurensis, 40 years old, and a fragment of Semideciduous Forest, located on the campus of the Federal University of Lavras. In soil samples collected in the 0-5 cm layer were determined fertility parameters, basal respiration and microbial biomass carbon. The results showed that for the species E. grandis and E. cloeziana the carbon of biomass microbial content was higher than for any other ecosystem evaluated, and equal to those observed under native forest. In contrast, the ground under Pinus had the lowest microbiological indexes. Under C. maculata and E. pilularis the contents were intermediate for this parameter. The basal respiration of all ecosystems was equal. The fertility level was very low in all types of evaluated vegetation.

  19. Biomass estimation in forest ecosystems - a review | Wakawa ...

    African Journals Online (AJOL)

    Forest ecosystems plays an important role in global warming serving as both sink and source of one of the prominent green house gases, carbon dioxide (CO2). Biomass estimation in forest ecosystems is an important aspect of forest management processes aimed at ensuring sustainability. The choice of appropriate ...

  20. Economic approach to assess the forest carbon implications of biomass energy.

    Science.gov (United States)

    Daigneault, Adam; Sohngen, Brent; Sedjo, Roger

    2012-06-05

    There is widespread concern that biomass energy policy that promotes forests as a supply source will cause net carbon emissions. Most of the analyses that have been done to date, however, are biological, ignoring the effects of market adaptations through substitution, net imports, and timber investments. This paper uses a dynamic model of forest and land use management to estimate the impact of United States energy policies that emphasize the utilization of forest biomass on global timber production and carbon stocks over the next 50 years. We show that when market factors are included in the analysis, expanded demand for biomass energy increases timber prices and harvests, but reduces net global carbon emissions because higher wood prices lead to new investments in forest stocks. Estimates are sensitive to assumptions about whether harvest residues and new forestland can be used for biomass energy and the demand for biomass. Restricting biomass energy to being sourced only from roundwood on existing forestland can transform the policy from a net sink to a net source of emissions. These results illustrate the importance of capturing market adjustments and a large geographic scope when measuring the carbon implications of biomass energy policies.

  1. Decomposition and nitrogen dynamics of 15N-labeled leaf, root, and twig litter in temperate coniferous forests

    Science.gov (United States)

    van Huysen, Tiff L.; Harmon, Mark E.; Perakis, Steven S.; Chen, Hua

    2013-01-01

    Litter nutrient dynamics contribute significantly to biogeochemical cycling in forest ecosystems. We examined how site environment and initial substrate quality influence decomposition and nitrogen (N) dynamics of multiple litter types. A 2.5-year decomposition study was installed in the Oregon Coast Range and West Cascades using 15N-labeled litter from Acer macrophyllum, Picea sitchensis, and Pseudotsuga menziesii. Mass loss for leaf litter was similar between the two sites, while root and twig litter exhibited greater mass loss in the Coast Range. Mass loss was greatest from leaves and roots, and species differences in mass loss were more prominent in the Coast Range. All litter types and species mineralized N early in the decomposition process; only A. macrophyllum leaves exhibited a net N immobilization phase. There were no site differences with respect to litter N dynamics despite differences in site N availability, and litter N mineralization patterns were species-specific. For multiple litter × species combinations, the difference between gross and net N mineralization was significant, and gross mineralization was 7–20 % greater than net mineralization. The mineralization results suggest that initial litter chemistry may be an important driver of litter N dynamics. Our study demonstrates that greater amounts of N are cycling through these systems than may be quantified by only measuring net mineralization and challenges current leaf-based biogeochemical theory regarding patterns of N immobilization and mineralization.

  2. Decomposition and nitrogen dynamics of (15)N-labeled leaf, root, and twig litter in temperate coniferous forests.

    Science.gov (United States)

    van Huysen, Tiff L; Harmon, Mark E; Perakis, Steven S; Chen, Hua

    2013-12-01

    Litter nutrient dynamics contribute significantly to biogeochemical cycling in forest ecosystems. We examined how site environment and initial substrate quality influence decomposition and nitrogen (N) dynamics of multiple litter types. A 2.5-year decomposition study was installed in the Oregon Coast Range and West Cascades using (15)N-labeled litter from Acer macrophyllum, Picea sitchensis, and Pseudotsuga menziesii. Mass loss for leaf litter was similar between the two sites, while root and twig litter exhibited greater mass loss in the Coast Range. Mass loss was greatest from leaves and roots, and species differences in mass loss were more prominent in the Coast Range. All litter types and species mineralized N early in the decomposition process; only A. macrophyllum leaves exhibited a net N immobilization phase. There were no site differences with respect to litter N dynamics despite differences in site N availability, and litter N mineralization patterns were species-specific. For multiple litter × species combinations, the difference between gross and net N mineralization was significant, and gross mineralization was 7-20 % greater than net mineralization. The mineralization results suggest that initial litter chemistry may be an important driver of litter N dynamics. Our study demonstrates that greater amounts of N are cycling through these systems than may be quantified by only measuring net mineralization and challenges current leaf-based biogeochemical theory regarding patterns of N immobilization and mineralization.

  3. Biogeographical patterns of biomass allocation in leaves, stems, and roots in China’s forests

    Science.gov (United States)

    Zhang, Hao; Wang, Kelin; Xu, Xianli; Song, Tongqing; Xu, Yanfang; Zeng, Fuping

    2015-01-01

    To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China’s forests using both the national forest inventory data (2004–2008) and our field measurements (2011–2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass. Based on the constraints of stand biomass, biomass allocation was also influenced by forest type, origin, stand age, stand density, mean annual temperature, precipitation, and maximum temperature in the growing season. Therefore, after stand biomass was accounted for, the residual variation in biomass allocation could be partially explained by stand characteristics and environmental factors, which may aid in quantifying carbon cycling in forest ecosystems and assessing the impacts of climate change on forest carbon dynamics in China. PMID:26525117

  4. Estimating forest biomass and volume using airborne laser data

    Science.gov (United States)

    Nelson, Ross; Krabill, William; Tonelli, John

    1988-01-01

    An airborne pulsed laser system was used to obtain canopy height data over a southern pine forest in Georgia in order to predict ground-measured forest biomass and timber volume. Although biomass and volume estimates obtained from the laser data were variable when compared with the corresponding ground measurements site by site, the present models are found to predict mean total tree volume within 2.6 percent of the ground value, and mean biomass within 2.0 percent. The results indicate that species stratification did not consistently improve regression relationships for four southern pine species.

  5. Silica uptake and release in live and decaying biomass in a northern hardwood forest.

    Science.gov (United States)

    Clymans, Wim; Conley, Daniel J; Battles, John J; Frings, Patrick J; Koppers, Mary Margaret; Likens, Gene E; Johnson, Chris E

    2016-11-01

    In terrestrial ecosystems, a large portion (20-80%) of the dissolved Si (DSi) in soil solution has passed through vegetation. While the importance of this "terrestrial Si filter" is generally accepted, few data exist on the pools and fluxes of Si in forest vegetation and the rate of release of Si from decomposing plant tissues. We quantified the pools and fluxes of Si through vegetation and coarse woody debris (CWD) in a northern hardwood forest ecosystem (Watershed 6, W6) at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire, USA. Previous work suggested that the decomposition of CWD may have significantly contributed to an excess of DSi reported in stream-waters following experimental deforestation of Watershed 2 (W2) at the HBEF. We found that woody biomass (wood + bark) and foliage account for approximately 65% and 31%, respectively, of the total Si in biomass at the HBEF. During the decay of American beech (Fagus grandifolia) boles, Si loss tracked the whole-bole mass loss, while yellow birch (Betula alleghaniensis) and sugar maple (Acer saccharum) decomposition resulted in a preferential Si retention of up to 30% after 16 yr. A power-law model for the changes in wood and bark Si concentrations during decomposition, in combination with an exponential model for whole-bole mass loss, successfully reproduced Si dynamics in decaying boles. Our data suggest that a minimum of 50% of the DSi annually produced in the soil of a biogeochemical reference watershed (W6) derives from biogenic Si (BSi) dissolution. The major source is fresh litter, whereas only ~2% comes from the decay of CWD. Decay of tree boles could only account for 9% of the excess DSi release observed following the experimental deforestation of W2. Therefore, elevated DSi concentrations after forest disturbance are largely derived from other sources (e.g., dissolution of BSi from forest floor soils and/or mineral weathering). © 2016 The Authors. Ecology, published by Wiley Periodicals

  6. Litter and dead wood dynamics in ponderosa pine forests along a 160-year chronosequence.

    Science.gov (United States)

    Hall, S A; Burke, I C; Hobbs, N T

    2006-12-01

    Disturbances such as fire play a key role in controlling ecosystem structure. In fire-prone forests, organic detritus comprises a large pool of carbon and can control the frequency and intensity of fire. The ponderosa pine forests of the Colorado Front Range, USA, where fire has been suppressed for a century, provide an ideal system for studying the long-term dynamics of detrital pools. Our objectives were (1) to quantify the long-term temporal dynamics of detrital pools; and (2) to determine to what extent present stand structure, topography, and soils constrain these dynamics. We collected data on downed dead wood, litter, duff (partially decomposed litter on the forest floor), stand structure, topographic position, and soils for 31 sites along a 160-year chronosequence. We developed a compartment model and parameterized it to describe the temporal trends in the detrital pools. We then developed four sets of statistical models, quantifying the hypothesized relationship between pool size and (1) stand structure, (2) topography, (3) soils variables, and (4) time since fire. We contrasted how much support each hypothesis had in the data using Akaike's Information Criterion (AIC). Time since fire explained 39-80% of the variability in dead wood of different size classes. Pool size increased to a peak as material killed by the fire fell, then decomposed rapidly to a minimum (61-85 years after fire for the different pools). It then increased, presumably as new detritus was produced by the regenerating stand. Litter was most strongly related to canopy cover (r2 = 77%), suggesting that litter fall, rather than decomposition, controls its dynamics. The temporal dynamics of duff were the hardest to predict. Detrital pool sizes were more strongly related to time since fire than to environmental variables. Woody debris peak-to-minimum time was 46-67 years, overlapping the range of historical fire return intervals (1 to > 100 years). Fires may therefore have burned under a

  7. Uncertainty of Forest Biomass Estimates in North Temperate Forests Due to Allometry: Implications for Remote Sensing

    Directory of Open Access Journals (Sweden)

    Razi Ahmed

    2013-06-01

    Full Text Available Estimates of above ground biomass density in forests are crucial for refining global climate models and understanding climate change. Although data from field studies can be aggregated to estimate carbon stocks on global scales, the sparsity of such field data, temporal heterogeneity and methodological variations introduce large errors. Remote sensing measurements from spaceborne sensors are a realistic alternative for global carbon accounting; however, the uncertainty of such measurements is not well known and remains an active area of research. This article describes an effort to collect field data at the Harvard and Howland Forest sites, set in the temperate forests of the Northeastern United States in an attempt to establish ground truth forest biomass for calibration of remote sensing measurements. We present an assessment of the quality of ground truth biomass estimates derived from three different sets of diameter-based allometric equations over the Harvard and Howland Forests to establish the contribution of errors in ground truth data to the error in biomass estimates from remote sensing measurements.

  8. Assessing biomass accumulation in second growth forests of Puerto Rico using airborne lidar

    Science.gov (United States)

    Martinuzzi, S.; Cook, B.; Corp, L. A.; Morton, D. C.; Helmer, E.; Keller, M.

    2017-12-01

    Degraded and second growth tropical forests provide important ecosystem services, such as carbon sequestration and soil stabilization. Lidar data measure the three-dimensional structure of forest canopies and are commonly used to quantify aboveground biomass in temperate forest landscapes. However, the ability of lidar data to quantify second growth forest biomass in complex, tropical landscapes is less understood. Our goal was to evaluate the use of airborne lidar data to quantify aboveground biomass in a complex tropical landscape, the Caribbean island of Puerto Rico. Puerto Rico provides an ideal place for studying biomass accumulation because of the abundance of second growth forests in different stages of recovery, and the high ecological heterogeneity. Puerto Rico was almost entirely deforested for agriculture until the 1930s. Thereafter, agricultural abandonment resulted in a mosaic of second growth forests that have recovered naturally under different types of climate, land use, topography, and soil fertility. We integrated forest plot data from the US Forest Service, Forest Inventory and Analysis (FIA) Program with recent lidar data from NASA Goddard's Lidar, Hyperspectral, and Thermal (G-LiHT) airborne imager to quantify forest biomass across the island's landscape. The G-LiHT data consisted on targeted acquisitions over the FIA plots and other forested areas representing the environmental heterogeneity of the island. To fully assess the potential of the lidar data, we compared the ability of lidar-derived canopy metrics to quantify biomass alone, and in combination with intensity and topographic metrics. The results presented here are a key step for improving our understanding of the patterns and drivers of biomass accumulation in tropical forests.

  9. Forest biomass resources and utilization in China

    African Journals Online (AJOL)

    user

    environmental benefits may result from using forest biomass for energy rather than fossil fuels. ... nuclear energy. Therefore, one of the most urgent pro- blems the Chinese government faces is to build a safe, economic, clean and sustainable energy supply system, ... Forest bioenergy is the use of renewable forestry.

  10. Growth and mycorrhizal community structure of Pinus sylvestris seedlings following the addition of forest litter.

    Science.gov (United States)

    Aucina, Algis; Rudawska, Maria; Leski, Tomasz; Skridaila, Audrius; Riepsas, Edvardas; Iwanski, Michal

    2007-08-01

    We report the effects of pine and oak litter on species composition and diversity of mycorrhizal fungi colonizing 2-year-old Pinus sylvestris L. seedlings grown in a bare-root nursery in Lithuania. A layer of pine or oak litter was placed on the surface of the nursery bed soil to mimic natural litter cover. Oak litter amendment appeared to be most favorable for seedling survival, with a 73% survival rate, in contrast to the untreated mineral bed soil (44%). The concentrations of total N, P, K, Ca, and Mg were higher in oak growth medium than in pine growth medium. Relative to the control (pH 6.1), the pH was lower in pine growth medium (5.8) and higher in oak growth medium (6.3). There were also twofold and threefold increases in the C content of growth medium with the addition of pine and oak litter, respectively. Among seven mycorrhizal morphotypes, eight different mycorrhizal taxa were identified: Suillus luteus, Suillus variegatus, Wilcoxina mikolae, a Tuber sp., a Tomentella sp., Cenococcum geophilum, Amphinema byssoides, and one unidentified ectomycorrhizal symbiont. Forest litter addition affected the relative abundance of mycorrhizal symbionts more than their overall representation. This was more pronounced for pine litter than for oak litter, with 40% and 25% increases in the abundance of suilloid mycorrhizae, respectively. Our findings provide preliminary evidence that changes in the supply of organic matter through litter manipulation may have far-reaching effects on the chemistry of soil, thus influencing the growth and survival of Scots pine seedlings and their mycorrhizal communities.

  11. Forest biomass and wood waste resources

    Science.gov (United States)

    K. Skog; P. Lebow; D.. Dykstra; P.. Miles; B.J. Stokes; R.D. Perlack; M. Buford; J. Barbour; D. McKeever

    2011-01-01

    This chapter provides estimates of forest biomass and wood waste quantities, as well as roadside costs (i.e., supply curves) for each county in the contiguous United States. Roadside price is the price a buyer pays for wood chips at a roadside in the forest, at a processing mill location in the case of mill residue, or at a landfill for urban wood wastes prior to any...

  12. Exploration of factors limiting biomass estimation by polarimetric radar in tropical forests

    NARCIS (Netherlands)

    Quiñones Fernández, M.J.; Hoekman, D.H.

    2004-01-01

    Direct inversion of radar return signals for forest biomass estimation is limited by signal saturation at medium biomass levels (roughly 150 ton/ha for P-band). Disturbing factors such as forest structural differences-and, notably, at low biomass levels, terrain roughness, and soil moisture

  13. Uptake and distribution of nitrogen from acidic fog within a ponderosa pine (Pinus ponderosa Laws.)/litter/soil system

    Energy Technology Data Exchange (ETDEWEB)

    Fenn, M.E.; Leininger, T.D.

    1995-11-01

    The magnitude and importance of wet deposition of N in forests of the South Coast (Los Angeles) Air Basin have not been well characterized. We exposed 3-yr-old ponderosa pine (Pinus ponderosa Laws.) seedlings growing in native forest soil to acidic fog treatments (pH 3.1) simulating fog chemistry from a pine forest near Los Angeles, California. Fog solutions contained either {sup 15}NH{sub 4}{sup +}, {sup 15}NO{sub 3}{sup {minus}}, or unlabeled N. The fog treatments were applied in open-top chambers in six 5-hr exposures. Soil treatments within each of the fog exposures were bare soil, soil overlain with L- and F-litter, and soil covered with plastic during the fog events to prevent fogwater from contacting soil. Seedlings were harvested and samples were collected 15 wk after the fog treatments. Uptake of {sup 15}N by roots was by far the dominant pathway for plant assimilation of fog-deposited {sup 15}N. Deposition of N in fog supplied 9.4% and 8.7% of the total N in current-year crown biomass in the litter-overlay and bare-soil treatments, respectively. Total N concentrations in every plant fraction except current-year stems were significantly higher in the bare-soil treatment than in the plastic-covered soil treatment. Less than 5% of the {sup 15}N deposited directly to the seedling crowns was retained by the plants in the covered-soil treatment, whereas 57% of the {sup 15}N deposited to the seedling/litter/soil systems was incorporated into plant biomass. The litter layers retained {sup 15}NH{sub 4}{sup +} more effectively than {sup 15}NH{sub 4}{sup +} more effectively than {sup 15}NO{sub 3}. Data from this study suggest that N deposited from fog may be an important source of N for plant growth in forests of the SCAB where fog occurrence and pollution exposure coincide. 5 refs., 5 figs., 3 tabs.

  14. Litter quality mediated nitrogen effect on plant litter decomposition regardless of soil fauna presence.

    Science.gov (United States)

    Zhang, Weidong; Chao, Lin; Yang, Qingpeng; Wang, Qingkui; Fang, Yunting; Wang, Silong

    2016-10-01

    Nitrogen addition has been shown to affect plant litter decomposition in terrestrial ecosystems. The way that nitrogen deposition impacts the relationship between plant litter decomposition and altered soil nitrogen availability is unclear, however. This study examined 18 co-occurring litter types in a subtropical forest in China in terms of their decomposition (1 yr of exposure in the field) with nitrogen addition treatment (0, 0.4, 1.6, and 4.0 mol·N·m -2 ·yr -1 ) and soil fauna exclusion (litter bags with 0.1 and 2 cm mesh size). Results showed that the plant litter decomposition rate is significantly reduced because of nitrogen addition; the strength of the nitrogen addition effect is closely related to the nitrogen addition levels. Plant litters with diverse quality responded to nitrogen addition differently. When soil fauna was present, the nitrogen addition effect on medium-quality or high-quality plant litter decomposition rate was -26% ± 5% and -29% ± 4%, respectively; these values are significantly higher than that of low-quality plant litter decomposition. The pattern is similar when soil fauna is absent. In general, the plant litter decomposition rate is decreased by soil fauna exclusion; an average inhibition of -17% ± 1.5% was exhibited across nitrogen addition treatment and litter quality groups. However, this effect is weakly related to nitrogen addition treatment and plant litter quality. We conclude that the variations in plant litter quality, nitrogen deposition, and soil fauna are important factors of decomposition and nutrient cycling in a subtropical forest ecosystem. © 2016 by the Ecological Society of America.

  15. Limited carbon storage in soil and litter of experimental forest plots under increased atmospheric CO2

    International Nuclear Information System (INIS)

    Schlesinger, W.H.; Lichter, J.

    2001-01-01

    The current rise in atmospheric CO 2 concentration is thought to be mitigated in part by carbon sequestration within forest ecosystems, where carbon can be stored in vegetation or soils. The storage of carbon in soils is determined by the fraction that is sequestered in persistent organic materials, such as humus. In experimental forest plots of loblolly pine (Pinus taeda) exposed to high CO 2 concentrations, nearly half of the carbon uptake is allocated to short-lived tissues, largely foliage. These tissues fall to the ground and decompose, normally contributing only a small portion of their carbon content to refractory soil humic materials. Such findings call into question the role of soils as long-term carbon sinks, and show the need for a better understanding of carbon cycling in forest soils. Here we report a significant accumulation of carbon in the litter layer of experimental forest plots after three years of growth at increased CO 2 concentrations (565 μ l 1 ). But fast turnover times of organic carbon in the litter layer (of about three years) appear to constrain the potential size of this carbon sink. Given the observation that carbon accumulation in the deeper mineral soil layers was absent, we suggest that significant, long-term net carbon sequestration in forest soils is unlikely. (author)

  16. Community Structure of Leaf-Litter Ants in a Neotropical Dry Forest: A Biogeographic Approach to Explain Betadiversity

    Directory of Open Access Journals (Sweden)

    Rogério Silvestre

    2012-01-01

    Full Text Available This paper describes habitat and geographic correlates of ant diversity in Serra da Bodoquena, a poorly surveyed region of central-western Brazil. We discuss leaf-litter ant diversity on a regional scale, with emphasis on the contribution of each of the processes that form the evolutionary basis of contemporary beta diversity. The diversity of leaf-litter ants was assessed from a series of 262 Winkler samples conducted in two microbasins within a deciduous forest domain. A total of 170 litter-dwelling ant species in 45 genera and 11 subfamilies was identified. The data showed that the study areas exhibited different arrangements of ant fauna, with a high turnover in species composition between sites, indicating high beta diversity. Our analysis suggests that the biogeographic history of this tropical dry forest in the centre of South America could explain ant assemblage structure more than competitive dominance. The co-occurrence analysis showed that species co-occur less often than expected by chance in only two of the localities, suggesting that, for most of the species, co-occurrences are random. The assessment of the structure of the diversity of litter-dwelling ants is the first step in understanding the beta diversity patterns in this region of great biogeographic importance.

  17. Floristic structure and biomass distribution of a tropical seasonal rain forest in Xishuangbanna, southwest China

    Energy Technology Data Exchange (ETDEWEB)

    Shanmughavel, P.; Zheng Zheng; Sha Liqing; Cao Min [Chinese Academy of Sciences, Kunming (China). Dept. of Forest Ecology

    2001-07-01

    The aim of this research was to study the forest community structure, tree species diversity and biomass production of a tropical seasonal rain forest in Xishuangbanna, southwest China. The community structure showed a diversified species composition and supported many species of economic significance. This tropical rain forest in closely related to Malaysian forests. The biomass and its distribution were studied using standard regression analysis and the clear-cut method for shrubs and herbs. The total biomass was 360.9 t/ha and its allocation in different layers was: tree layer 352.5 t/ha, shrub layer 4.7 t/ha, liana 3.1 t/ha and herb layer 0.5 t/ha. Most of the biomass was concentrated in the trees: stem 241.2 t/ha, root 69.6 t/ha, branch 37.2 t/ha and leaves 4.3 t/ha. The DBH class allocation of the tree biomass was concentrated in the middle DBH class. The biomass of six DBH classes from 20 to 80 cm was 255.4 t/ha. There are twenty-six species with biomass over 0.5% of the total biomass of the tree layer, and three species with biomass over 5%, i.e., Pometia tomentosa, Barringtonia macrostachya (5.4%) and Terminalia myriocarpa (5.2%). Data on stem, branch, leaves and root of the individual tree species were used to develop regression models. D{sup 2}H was found to be the best estimator of the biomass in this tropical rain forest. However, higher biomass figures have been reported from tropical forests elsewhere e.g., 415-520 t/ha in the tropical forests of Cambodia, the tropical moist mixed dipterocarp forests, and the tropical moist logged moist evergreen-high, medium, and low yield forests of Sri Lanka. In some forests, lower accumulation of biomass was reported, e.g., 10-295 t/ha in the tropical moist forests of Bangladesh, the tropical moist dense forest of Cambodia, the tropical dry forests of India, the tropical moist forests of Peninsular-Malaysia, the tropical moist mixed dipterocarp forests of Sarawak-Malaysia, the tropical evergreen forests of

  18. Forest Biomass Mapping From Lidar and Radar Synergies

    Science.gov (United States)

    Sun, Guoqing; Ranson, K. Jon; Guo, Z.; Zhang, Z.; Montesano, P.; Kimes, D.

    2011-01-01

    The use of lidar and radar instruments to measure forest structure attributes such as height and biomass at global scales is being considered for a future Earth Observation satellite mission, DESDynI (Deformation, Ecosystem Structure, and Dynamics of Ice). Large footprint lidar makes a direct measurement of the heights of scatterers in the illuminated footprint and can yield accurate information about the vertical profile of the canopy within lidar footprint samples. Synthetic Aperture Radar (SAR) is known to sense the canopy volume, especially at longer wavelengths and provides image data. Methods for biomass mapping by a combination of lidar sampling and radar mapping need to be developed. In this study, several issues in this respect were investigated using aircraft borne lidar and SAR data in Howland, Maine, USA. The stepwise regression selected the height indices rh50 and rh75 of the Laser Vegetation Imaging Sensor (LVIS) data for predicting field measured biomass with a R(exp 2) of 0.71 and RMSE of 31.33 Mg/ha. The above-ground biomass map generated from this regression model was considered to represent the true biomass of the area and used as a reference map since no better biomass map exists for the area. Random samples were taken from the biomass map and the correlation between the sampled biomass and co-located SAR signature was studied. The best models were used to extend the biomass from lidar samples into all forested areas in the study area, which mimics a procedure that could be used for the future DESDYnI Mission. It was found that depending on the data types used (quad-pol or dual-pol) the SAR data can predict the lidar biomass samples with R2 of 0.63-0.71, RMSE of 32.0-28.2 Mg/ha up to biomass levels of 200-250 Mg/ha. The mean biomass of the study area calculated from the biomass maps generated by lidar- SAR synergy 63 was within 10% of the reference biomass map derived from LVIS data. The results from this study are preliminary, but do show the

  19. Successional and seasonal variations in soil and litter microbial community structure and function during tropical postagricultural forest regeneration: a multiyear study.

    Science.gov (United States)

    Smith, A Peyton; Marín-Spiotta, Erika; Balser, Teri

    2015-09-01

    Soil microorganisms regulate fundamental biochemical processes in plant litter decomposition and soil organic matter (SOM) transformations. Understanding how microbial communities respond to changes in vegetation is critical for improving predictions of how land-cover change affects belowground carbon storage and nutrient availability. We measured intra- and interannual variability in soil and forest litter microbial community composition and activity via phospholipid fatty acid analysis (PLFA) and extracellular enzyme activity across a well-replicated, long-term chronosequence of secondary forests growing on abandoned pastures in the wet subtropical forest life zone of Puerto Rico. Microbial community PLFA structure differed between young secondary forests and older secondary and primary forests, following successional shifts in tree species composition. These successional patterns held across seasons, but the microbial groups driving these patterns differed over time. Microbial community composition from the forest litter differed greatly from those in the soil, but did not show the same successional trends. Extracellular enzyme activity did not differ with forest succession, but varied by season with greater rates of potential activity in the dry seasons. We found few robust significant relationships among microbial community parameters and soil pH, moisture, carbon, and nitrogen concentrations. Observed inter- and intrannual variability in microbial community structure and activity reveal the importance of a multiple, temporal sampling strategy when investigating microbial community dynamics with land-use change. Successional control over microbial composition with forest recovery suggests strong links between above and belowground communities. © 2015 John Wiley & Sons Ltd.

  20. Annual and Seasonal Changes in the Structure of Litter-Dwelling Ant Assemblages (Hymenoptera: Formicidae in Atlantic Semideciduous Forests

    Directory of Open Access Journals (Sweden)

    Flávio Siqueira de Castro

    2012-01-01

    Full Text Available We surveyed ant fauna in the leaf litter in an Atlantic Semideciduous forest in the State Park of Rio Doce (PERD. The work aimed to produce basic information about habitat effects on diversity, as well as about how the ant fauna in a such buffered forest habitat, as the litter layer, could respond the climate variation in a short and long term. We sampled two years in two distinct forest physiognomies, which respond to different geomorphologic backgrounds, in dry and rainy seasons. Species composition, richness and abundance of these forests were distinct. However, both forests hosted similar numbers of rare and specialized, habitat demanding species, thus suggesting both are similarly well preserved, despite distinct physiognomies. However, the lower and more open forest was, more susceptible to dry season effects, showing a steeper decline in species numbers in such season, but similar numbers in the wet seasons. The pattern varied between years, which corroborates the hypothesis of a strongly variable community in response to subtle climatic variation among years. The present results are baselines for future long term monitoring projects, and could support protocols for early warnings of global climatic changes effects on biodiversity.

  1. A spatial evaluation of forest biomass usage using GIS

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Tsuguki; Yamagata, Yoshiki [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba-shi, Ibaraki-ken 305-8506 (Japan); Inoue, Keisuke; Kagemoto, Hiroshi [The University of Tokyo (Japan); Iwao, Koki [National Institute of Advanced Industrial Science and Technology (Japan)

    2009-01-15

    We conducted a spatial evaluation of forest biomass usage using a geographic information system (GIS) for the Japanese town of Yusuhara. In Japan, over 60% of the land is covered with forest, of which at least 40% is artificial forest. However, because of high labor costs, the profitability of forestry is decreasing, so timber cultivation is not done to the extent that it could be, and thinning has to be subsidized. Under these circumstances, much of the forest is deteriorating. Most of the thinning is accounted for by throwaway thinning, in which the resulting wood is not used. However, with the steep rise in oil prices and the intensification of global warming concerns, expectations are rising for the use of biomass energy from thinned timber that has previously been discarded. If thinned timber, logging residues, and offcuts are utilized for biomass energy and their economic value becomes apparent, profitability will improve for both final cutting and thinning. And in addition to forestry activities being invigorated, it will be possible for some of the deteriorating forests (which have associated dangers such as landslides) to recover. However, using thinned timber and logging residues is problematic in that profitability is affected by harvesting costs. Harvesting costs are largely determined by geographic factors and are higher for more distant stands. Accordingly, in this article, operational costs for different stands are calculated using GIS and matched with total demand in the subject region. In addition, stands with lower operational costs are identified and an investigation of a highly feasible use of forest biomass is carried out. (author)

  2. Interaction of initial litter quality and thinning intensity on litter decomposition rate, nitrogen accumulation and release in a pine plantation

    Science.gov (United States)

    Xiao Chen; Deborah Page-Dumroese; Ruiheng Lv; Weiwei Wang; Guolei Li; Yong. Liu

    2014-01-01

    Thinning alters litter quality and microclimate under forests. Both of these two changes after thinning induce alterations of litter decomposition rates and nutrient cycling. However, a possible interaction between these two changes remains unclear. We placed two types of litter (LN, low N concentration litter; HN, high N concentration litter) in a Chinese pine (Pinus...

  3. Accumulation of policyclic aromatic hydrocarbons (PAHs) in surface litter and soils in four forests in the United States

    Science.gov (United States)

    Obrist, D.; Perlinger, J. A.; Zielinska, B.

    2014-12-01

    Polycyclic aromatic hydrocarbons (PAHs) are toxic environmental pollutants originating from the incomplete combustion of organic material, both from natural or anthropogenic sources. Once emitted, they can be transported across thousands of kilometers impacting remote environments. Here, we characterize the distribution of 23 PAHs and 9 oxygenated PAHs (Σ32PAH) in litter and soils in four remote forests in the United States. Concentrations of Σ32PAH in fresh surface litter (Oi layers) showed very low levels in three of the four forests (mixed coniferous forest in Maine, deciduous blue oak forest in California, and a coniferous forest in Washington State), with PAHs levels much lower than those reported in previous studies from Europe. The analysis showed that PAHs represented a mix of regional background sources. Highest PAH levels were observed in a coniferous forest floor in Florida, attributable to frequent prescribed burning of understory vegetation at this site, and supported by high contributions of retene (>7%; compared to atmospheric deposition. Within mineral soils, Σ32PAH:OC ratios increased with depth (Ah horizons: 750±198 ng g-1; B horizons: 1,202±97 ng g-1), indicating that vertical transfer in mineral soils leads to significant accumulation of PAH in subsoils. ΣPAH:OC increases observed in deeper soil layers may be attributed to slower mineralization rates of PAHs compared to OC, plus vertical transport as indicated by preferential enrichment of PAHs with low Kow (i.e., more water-soluble PAHs). Finally, percentage of potentially biologically produced PAH (Σ Naph+Phen+Pery) were low and consistent across the litter/soil horizons, suggesting that biological production is minor or absent at our sites.

  4. Feedstock quality : an important consideration in forest biomass supply

    Energy Technology Data Exchange (ETDEWEB)

    Ryans, M. [FP Innovations, Vancouver, BC (Canada). FERIC

    2009-07-01

    The move to forest-based sources of biomass requires an emphasis on the quality of forest residues. Customers set the feedstock requirements, and demand homogeneous and predictable quality. The top quality factors are appropriate moisture content, consistent particle size, chlorine content, and clean material. The seasonal variability of the resource means that suppliers must determine how to deliver a year-round supply with appropriate moisture content. Methods such as pre-piling and covering with a tarp are being tested. Although mills tailored for biomass deliveries have modernized boilers capable of burning a variety of biomass feedstocks at varying moisture contents, a 10 per cent reduction in moisture content can offer a good return on investment because suppliers could transports more energy content and less water per tonne of biomass. This presentation also discussed the range of equipment choices available for delivering the right-sized biomass, and outlined the right and wrong practices that influence biomass quality along the supply chain. figs.

  5. Rain-induced changes in soil CO2 flux and microbial community composition in a tropical forest of China.

    Science.gov (United States)

    Deng, Qi; Hui, Dafeng; Chu, Guowei; Han, Xi; Zhang, Quanfa

    2017-07-17

    Rain-induced soil CO 2 pulse, a rapid excitation in soil CO 2 flux after rain, is ubiquitously observed in terrestrial ecosystems, yet the underlying mechanisms in tropical forests are still not clear. We conducted a rain simulation experiment to quantify rain-induced changes in soil CO 2 flux and microbial community composition in a tropical forest. Soil CO 2 flux rapidly increased by ~83% after rains, accompanied by increases in both bacterial (~51%) and fungal (~58%) Phospholipid Fatty Acids (PLFA) biomass. However, soil CO 2 flux and microbial community in the plots without litters showed limited response to rains. Direct releases of CO 2 from litter layer only accounted for ~19% increases in soil CO 2 flux, suggesting that the leaching of dissolved organic carbon (DOC) from litter layer to the topsoil is the major cause of rain-induced soil CO 2 pulse. In addition, rain-induced changes in soil CO 2 flux and microbial PLFA biomass decreased with increasing rain sizes, but they were positively correlated with litter-leached DOC concentration rather than total DOC flux. Our findings reveal an important role of litter-leached DOC input in regulating rain-induced soil CO 2 pulses and microbial community composition, and may have significant implications for CO 2 losses from tropical forest soils under future rainfall changes.

  6. Amazonian landscapes and the bias in field studies of forest structure and biomass.

    Science.gov (United States)

    Marvin, David C; Asner, Gregory P; Knapp, David E; Anderson, Christopher B; Martin, Roberta E; Sinca, Felipe; Tupayachi, Raul

    2014-12-02

    Tropical forests convert more atmospheric carbon into biomass each year than any terrestrial ecosystem on Earth, underscoring the importance of accurate tropical forest structure and biomass maps for the understanding and management of the global carbon cycle. Ecologists have long used field inventory plots as the main tool for understanding forest structure and biomass at landscape-to-regional scales, under the implicit assumption that these plots accurately represent their surrounding landscape. However, no study has used continuous, high-spatial-resolution data to test whether field plots meet this assumption in tropical forests. Using airborne LiDAR (light detection and ranging) acquired over three regions in Peru, we assessed how representative a typical set of field plots are relative to their surrounding host landscapes. We uncovered substantial mean biases (9-98%) in forest canopy structure (height, gaps, and layers) and aboveground biomass in both lowland Amazonian and montane Andean landscapes. Moreover, simulations reveal that an impractical number of 1-ha field plots (from 10 to more than 100 per landscape) are needed to develop accurate estimates of aboveground biomass at landscape scales. These biases should temper the use of plots for extrapolations of forest dynamics to larger scales, and they demonstrate the need for a fundamental shift to high-resolution active remote sensing techniques as a primary sampling tool in tropical forest biomass studies. The potential decrease in the bias and uncertainty of remotely sensed estimates of forest structure and biomass is a vital step toward successful tropical forest conservation and climate-change mitigation policy.

  7. EXPLAINING FOREST COMPOSITION AND BIOMASS ACROSS MULTIPLE BIOGEOGRAPHIC REGIONS

    Science.gov (United States)

    Current scientific concerns regarding the impacts of global change include the responses of forest composition and biomass to rapid changes in climate, and forest gap models, have often been used to address this issue. These models reflect the concept that forest composition and...

  8. An application of remote sensing data in mapping landscape-level forest biomass for monitoring the effectiveness of forest policies in northeastern China.

    Science.gov (United States)

    Wang, Xinchuang; Shao, Guofan; Chen, Hua; Lewis, Bernard J; Qi, Guang; Yu, Dapao; Zhou, Li; Dai, Limin

    2013-09-01

    Monitoring the dynamics of forest biomass at various spatial scales is important for better understanding the terrestrial carbon cycle as well as improving the effectiveness of forest policies and forest management activities. In this article, field data and Landsat image data acquired in 1999 and 2007 were utilized to quantify spatiotemporal changes of forest biomass for Dongsheng Forestry Farm in Changbai Mountain region of northeastern China. We found that Landsat TM band 4 and Difference Vegetation Index with a 3 × 3 window size were the best predictors associated with forest biomass estimations in the study area. The inverse regression model with Landsat TM band 4 predictor was found to be the best model. The total forest biomass in the study area decreased slightly from 2.77 × 10(6) Mg in 1999 to 2.73 × 10(6) Mg in 2007, which agreed closely with field-based model estimates. The area of forested land increased from 17.9 × 10(3) ha in 1999 to 18.1 × 10(3) ha in 2007. The stabilization of forest biomass and the slight increase of forested land occurred in the period following implementations of national forest policies in China in 1999. The pattern of changes in both forest biomass and biomass density was altered due to different management regimes adopted in light of those policies. This study reveals the usefulness of the remote sensing-based approach for detecting and monitoring quantitative changes in forest biomass at a landscape scale.

  9. Forest Biomass for Climate Change Mitigation

    DEFF Research Database (Denmark)

    Nielsen, Anders Tærø

    Awareness of elevated CO2 levels in the atmosphere and resulting climate change has increased focus on renewable energy sources during recent decades. Biomass for energy has been predicted to have the greatest potential for CO2 reductions in the short term and the IPCC assumes that the use...... of biomass for energy is CO2 neutral. Several studies have however criticized this CO2 neutrality assumption and questioned whether CO2 reductions actually are achieved through use of biomass for energy. The purpose of this thesis is to investigate the biomass production potential of poplar plantations...... on southern Scandinavian sites, managed under different systems both in agriculture and in forests. In addition, the objective is to assess the potential of the poplar plantations to mitigate climate change by using poplar biomass for substitution of fossil fuels in comparison to a traditional product...

  10. Community Litter Arthropods Associated cerrado and gallery forest, in the Ecological Station Sierra Das Araras - Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Daniela Cristina Zardo

    2015-12-01

    Full Text Available The litter arthropod fauna distinguishes itself by its importance in nutrient cycling and organic matter degradation. This invertebrate fauna has been emphasized as crucial for the processes that structure ecosystems. This study aims to evaluate and compare the arthropod fauna composition, richness and abundance in litter of two environments: the savanna and the gallery forest at Serra das Araras Ecological Station , Mato Grosso. To collect the arthropods a 120m transects for each habitat was delimited, divided into six points in each environment. For all the litter collection points, we marked a plot measuring 1.0 x 1.0 m, totalizing 6m2 for an environment, where the arthropods found were identified by order level, and the individuals were grouped into morphospecies. The total arthropods richness found in the savanna and in the gallery forest areas was 38 morphospecies, 28 morphospecies were found in the savanna and 20 in the gallery forest, with total abundance of 381 individuals, being 226 individuals collected in the savanna and 155 individuals in the gallery forest. The more abundant morphospecies in the savanna and gallery forest belonged to Hymenoptera and Isoptera orders, with 10 and 4 morphospecies and abundance of 263 and 78 individuals respectively. The greatest organism richness and abundance occurred in the savanna, because it is a tropical environment with the greatest biodiversity, especially regarding its insect fauna, and this diversity is primarily concerned with the variety of habitats that the environment provides , which gives the species shelter, food and reproduction sites.

  11. The Spatial Distribution of Forest Biomass in the Brazilian Amazon: A Comparison of Estimates

    Science.gov (United States)

    Houghton, R. A.; Lawrence, J. L.; Hackler, J. L.; Brown, S.

    2001-01-01

    The amount of carbon released to the atmosphere as a result of deforestation is determined, in part, by the amount of carbon held in the biomass of the forests converted to other uses. Uncertainty in forest biomass is responsible for much of the uncertainty in current estimates of the flux of carbon from land-use change. We compared several estimates of forest biomass for the Brazilian Amazon, based on spatial interpolations of direct measurements, relationships to climatic variables, and remote sensing data. We asked three questions. First, do the methods yield similar estimates? Second, do they yield similar spatial patterns of distribution of biomass? And, third, what factors need most attention if we are to predict more accurately the distribution of forest biomass over large areas? Amazonian forests (including dead and below-ground biomass) vary by more than a factor of two, from a low of 39 PgC to a high of 93 PgC. Furthermore, the estimates disagree as to the regions of high and low biomass. The lack of agreement among estimates confirms the need for reliable determination of aboveground biomass over large areas. Potential methods include direct measurement of biomass through forest inventories with improved allometric regression equations, dynamic modeling of forest recovery following observed stand-replacing disturbances (the approach used in this research), and estimation of aboveground biomass from airborne or satellite-based instruments sensitive to the vertical structure plant canopies.

  12. Sustainable Biofuels from Forests: Woody Biomass

    Directory of Open Access Journals (Sweden)

    Edwin H. White

    2011-11-01

    Full Text Available The use of woody biomass feedstocks for bioenergy and bioproducts involves multiple sources of material that together create year round supplies. The main sources of woody biomass include residues from wood manufacturing industries, low value trees including logging slash in forests that are currently underutilized and dedicated short-rotation woody crops. Conceptually a ton of woody biomass feedstocks can replace a barrel of oil as the wood is processed (refined through a biorefinery. As oil is refined only part of the barrel is used for liquid fuel, e.g., gasoline, while much of the carbon in oil is refined into higher value chemical products-carbon in woody biomass can be refined into the same value-added products.

  13. Relocation of carbon from decomposition of {sup 14}C-labelled needle and fine root litter in peat soil

    Energy Technology Data Exchange (ETDEWEB)

    Domish, T; Laine, J; Laiho, R [Helsinki Univ. (Finland). Dept. of Forest Ecology; Finer, L [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Karsisto, M [Finnish Forest Research Inst. (Finland). Dept. of Forest Ecology

    1997-12-31

    Drainage of peatlands promotes a shift of biomass and production from the ground vegetation to the trees. Thus, the above-ground (e.g. needles) and below-ground (roots) litter production of trees increases. Fine roots in particular are an important factor in the carbon and nutrient cycle in forest ecosystems. A major part of the annual net primary production of trees may be allocated below ground, the relative proportion being smaller on fertile sites than on less fertile ones. For modelling the carbon balance of drained peatlands, it is important to know the fate of carbon from newly introduced and decomposing litter. Newly added and fertilised tree litter material may be decomposed at a rate different than litter from the ground vegetation. The objectives of this study are to study the pathways of decomposing litter carbon in peat soil and to evaluate the use of the litterbag method in a controlled environment. (9 refs.)

  14. Relocation of carbon from decomposition of {sup 14}C-labelled needle and fine root litter in peat soil

    Energy Technology Data Exchange (ETDEWEB)

    Domish, T.; Laine, J.; Laiho, R. [Helsinki Univ. (Finland). Dept. of Forest Ecology; Finer, L. [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Karsisto, M. [Finnish Forest Research Inst. (Finland). Dept. of Forest Ecology

    1996-12-31

    Drainage of peatlands promotes a shift of biomass and production from the ground vegetation to the trees. Thus, the above-ground (e.g. needles) and below-ground (roots) litter production of trees increases. Fine roots in particular are an important factor in the carbon and nutrient cycle in forest ecosystems. A major part of the annual net primary production of trees may be allocated below ground, the relative proportion being smaller on fertile sites than on less fertile ones. For modelling the carbon balance of drained peatlands, it is important to know the fate of carbon from newly introduced and decomposing litter. Newly added and fertilised tree litter material may be decomposed at a rate different than litter from the ground vegetation. The objectives of this study are to study the pathways of decomposing litter carbon in peat soil and to evaluate the use of the litterbag method in a controlled environment. (9 refs.)

  15. Biotic and abiotic controls on the distribution of tropical forest aboveground biomass

    Science.gov (United States)

    Saatchi, S. S.; Schimel, D.; Keller, M. M.; Chambers, J. Q.; Dubayah, R.; Duffy, P.; Yu, Y.; Robinson, C. M.; Chowdhury, D.; Yang, Y.

    2013-12-01

    AUTHOR: Sassan Saatchi1,2, Yan Yang2, Diya Chowdhury2, Yifan Yu2, Chelsea Robinson2, David Schimel1, Paul Duffy3, Michael Keller4, Ralph Dubayah5, Jeffery Chambers6 1. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA 2. Institute of Environment and Sustainability, University of California, Los Angeles, CA, USA 3. Neptune and Company, Inc. Denver, CO, USA 4. International Institute of Tropical Forestry & International Programs, USDA Forest Service, Campinas, Brazil 5. Department of Geography, University of Maryland, College Park, MD, USA 6. Department of Geography, University of California, Berkeley, CA, USA ABSTRACT BODY: In recent years, climate change policies and scientific research created a widespread interest in quantify the carbon stock and changes of global tropical forests extending from forest patches to national and regional scales. Using a combination of inventory data from field plots and forest structure from spaceborne Lidar data, we examine the main controls on the distribution of tropical forest biomass. Here, we concentrate on environmental and landscape variables (precipitation, temperature, topography, and soil), and biotic variables such as functional traits (density of large trees, and wood specific gravity). The analysis is performed using global bioclimatic variables for precipitation and temperature, SRTM data for topographical variables (elevation and ruggedness), and global harmonized soil data for soil type and texture. For biotic variables, we use the GLAS Lidar data to quantify the distribution of large trees, a combined field and remote sensing data for distribution of tree wood specific gravity. The results show that climate variables such as precipitation of dry season can explain the heterogeneity of forest biomass over the landscape but cannot predict the biomass variability significantly and particularly for high biomass forests. Topography such as elevation and ruggedness along with temperature can

  16. Dynamics of leaf litter humidity, depth and quantity: two restoration strategies failed to mimic ground microhabitat conditions of a low montane and premontane forest in Costa Rica

    Directory of Open Access Journals (Sweden)

    Zaidett Barrientos

    2012-09-01

    Full Text Available Little is known about how restoration strategies affect aspects like leaf litter’s quantity, depth and humidity. I analyzed leaf litter’s quantity, depth and humidity yearly patterns in a primary tropical lower montane wet forest and two restored areas: a 15 year old secondary forest (unassisted restoration and a 40 year old Cupressus lusitanica plantation (natural understory. The three habitats are located in the Río Macho Forest Reserve, Costa Rica. Twenty litter samples were taken every three months (April 2009-April 2010 in each habitat; humidity was measured in 439g samples (average, depth and quantity were measured in five points inside 50x50cm plots. None of the restoration strategies reproduced the primary forest leaf litter humidity, depth and quantity yearly patterns. Primary forest leaf litter humidity was higher and more stable (x=73.2, followed by secondary forest (x=63.3 and cypress plantation (x=52.9 (Kruskall-Wallis=77.93, n=232, p=0.00. In the primary (Kruskal-Wallis=31.63, n=78, p<0.001 and secondary (Kruskal-Wallis=11.79, n=75, p=0.008 forest litter accumulation was higher during April due to strong winds. In the primary forest (Kruskal-wallis=21.83, n=78, p<0.001 and the cypress plantation (Kruskal-wallis=39.99, n=80, p<0.001 leaf litter depth was shallow in October because heavy rains compacted it. Depth patterns were different from quantity patterns and described the leaf litter’s structure in different ecosystems though the year.

  17. Emissions tradeoffs associated with cofiring forest biomass with coal: A case study in Colorado, USA

    International Nuclear Information System (INIS)

    Loeffler, Dan; Anderson, Nathaniel

    2014-01-01

    Highlights: • Case study using audited fuel consumption and emissions data from a coal mine and power plant. • Model emissions tradeoffs of cofiring forest biomass with coal up to 20% by heat input value. • Substituting forest biomass with coal displaces fossil energy with an otherwise waste material. • Substantially less system emissions overall are generated when cofiring forest biomass. • Cofiring forest biomass has positive global and local greenhouse gas and human health implications. - Abstract: Cofiring forest biomass residues with coal to generate electricity is often cited for its potential to offset fossil fuels and reduce greenhouse gas emissions, but the extent to which cofiring achieves these objectives is highly dependent on case specific variables. This paper uses facility and forest specific data to examine emissions from cofiring forest biomass with coal ranging up to 20% substitution by heat value in southwest Colorado, USA. Calculations for net system emissions include five emissions sources: coal mining, power plant processes, forest biomass processes, boiler emissions, and forest biomass disposal. At the maximum displacement of 20% of heat demand using 120,717 t of forest biomass per year, total system emissions are projected to decrease by 15% for CO 2 , 95% for CH 4 , 18% for NO X , 82% for PM 10 , and 27% for SO X . PM 10 and CH 4 emissions benefits are closely tied to reducing open burning for residue disposal. At maximum displacement, 189,240 t of CO 2 emissions equivalent to the annual CO 2 emissions from 36,200 passenger vehicles, 440,000 barrels of oil, or nearly 990 railcars of coal are avoided. When forest biomass is not cofired, emissions equivalent to144,200 t of CO 2 are emitted from open burning. In addition to exploring the details of this case, we provide a methodology for assessing the emissions tradeoffs related to using forest biomass for cogeneration that incorporates the operational aspects of managing forest

  18. The importance of biotic factors in predicting global change effects on decomposition of temperate forest leaf litter.

    Science.gov (United States)

    Rouifed, Soraya; Handa, I Tanya; David, Jean-François; Hättenschwiler, Stephan

    2010-05-01

    Increasing atmospheric CO(2) and temperature are predicted to alter litter decomposition via changes in litter chemistry and environmental conditions. The extent to which these predictions are influenced by biotic factors such as litter species composition or decomposer activity, and in particular how these different factors interact, is not well understood. In a 5-week laboratory experiment we compared the decomposition of leaf litter from four temperate tree species (Fagus sylvatica, Quercus petraea, Carpinus betulus and Tilia platyphyllos) in response to four interacting factors: elevated CO(2)-induced changes in litter quality, a 3 degrees C warmer environment during decomposition, changes in litter species composition, and presence/absence of a litter-feeding millipede (Glomeris marginata). Elevated CO(2) and temperature had much weaker effects on decomposition than litter species composition and the presence of Glomeris. Mass loss of elevated CO(2)-grown leaf litter was reduced in Fagus and increased in Fagus/Tilia mixtures, but was not affected in any other leaf litter treatment. Warming increased litter mass loss in Carpinus and Tilia, but not in the other two litter species and in none of the mixtures. The CO(2)- and temperature-related differences in decomposition disappeared completely when Glomeris was present. Overall, fauna activity stimulated litter mass loss, but to different degrees depending on litter species composition, with a particularly strong effect on Fagus/Tilia mixtures (+58%). Higher fauna-driven mass loss was not followed by higher C mineralization over the relatively short experimental period. Apart from a strong interaction between litter species composition and fauna, the tested factors had little or no interactive effects on decomposition. We conclude that if global change were to result in substantial shifts in plant community composition and macrofauna abundance in forest ecosystems, these interacting biotic factors could have

  19. Shifts in tree functional composition amplify the response of forest biomass to climate.

    Science.gov (United States)

    Zhang, Tao; Niinemets, Ülo; Sheffield, Justin; Lichstein, Jeremy W

    2018-04-05

    Forests have a key role in global ecosystems, hosting much of the world's terrestrial biodiversity and acting as a net sink for atmospheric carbon. These and other ecosystem services that are provided by forests may be sensitive to climate change as well as climate variability on shorter time scales (for example, annual to decadal). Previous studies have documented responses of forest ecosystems to climate change and climate variability, including drought-induced increases in tree mortality rates. However, relationships between forest biomass, tree species composition and climate variability have not been quantified across a large region using systematically sampled data. Here we use systematic forest inventories from the 1980s and 2000s across the eastern USA to show that forest biomass responds to decadal-scale changes in water deficit, and that this biomass response is amplified by concurrent changes in community-mean drought tolerance, a functionally important aspect of tree species composition. The amplification of the direct effects of water stress on biomass occurs because water stress tends to induce a shift in tree species composition towards species that are more tolerant to drought but are slower growing. These results demonstrate concurrent changes in forest species composition and biomass carbon storage across a large, systematically sampled region, and highlight the potential for climate-induced changes in forest ecosystems across the world, resulting from both direct effects of climate on forest biomass and indirect effects mediated by shifts in species composition.

  20. Shifts in tree functional composition amplify the response of forest biomass to climate

    Science.gov (United States)

    Zhang, Tao; Niinemets, Ülo; Sheffield, Justin; Lichstein, Jeremy W.

    2018-04-01

    Forests have a key role in global ecosystems, hosting much of the world’s terrestrial biodiversity and acting as a net sink for atmospheric carbon. These and other ecosystem services that are provided by forests may be sensitive to climate change as well as climate variability on shorter time scales (for example, annual to decadal). Previous studies have documented responses of forest ecosystems to climate change and climate variability, including drought-induced increases in tree mortality rates. However, relationships between forest biomass, tree species composition and climate variability have not been quantified across a large region using systematically sampled data. Here we use systematic forest inventories from the 1980s and 2000s across the eastern USA to show that forest biomass responds to decadal-scale changes in water deficit, and that this biomass response is amplified by concurrent changes in community-mean drought tolerance, a functionally important aspect of tree species composition. The amplification of the direct effects of water stress on biomass occurs because water stress tends to induce a shift in tree species composition towards species that are more tolerant to drought but are slower growing. These results demonstrate concurrent changes in forest species composition and biomass carbon storage across a large, systematically sampled region, and highlight the potential for climate-induced changes in forest ecosystems across the world, resulting from both direct effects of climate on forest biomass and indirect effects mediated by shifts in species composition.

  1. Measuring and modeling carbon stock change estimates for US forests and uncertainties from apparent inter-annual variability

    Science.gov (United States)

    James E. Smith; Linda S. Heath

    2015-01-01

    Our approach is based on a collection of models that convert or augment the USDA Forest Inventory and Analysis program survey data to estimate all forest carbon component stocks, including live and standing dead tree aboveground and belowground biomass, forest floor (litter), down deadwood, and soil organic carbon, for each inventory plot. The data, which include...

  2. Changes in soil carbon and nutrients following 6 years of litter removal and addition in a tropical semi-evergreen rain forest

    Directory of Open Access Journals (Sweden)

    E. V. J. Tanner

    2016-11-01

    Full Text Available Increasing atmospheric CO2 and temperature may increase forest productivity, including litterfall, but the consequences for soil organic matter remain poorly understood. To address this, we measured soil carbon and nutrient concentrations at nine depths to 2 m after 6 years of continuous litter removal and litter addition in a semi-evergreen rain forest in Panama. Soils in litter addition plots, compared to litter removal plots, had higher pH and contained greater concentrations of KCl-extractable nitrate (both to 30 cm; Mehlich-III extractable phosphorus and total carbon (both to 20 cm; total nitrogen (to 15 cm; Mehlich-III calcium (to 10 cm; and Mehlich-III magnesium and lower bulk density (both to 5 cm. In contrast, litter manipulation did not affect ammonium, manganese, potassium or zinc, and soils deeper than 30 cm did not differ for any nutrient. Comparison with previous analyses in the experiment indicates that the effect of litter manipulation on nutrient concentrations and the depth to which the effects are significant are increasing with time. To allow for changes in bulk density in calculation of changes in carbon stocks, we standardized total carbon and nitrogen on the basis of a constant mineral mass. For 200 kg m−2 of mineral soil (approximately the upper 20 cm of the profile about 0.5 kg C m−2 was “missing” from the litter removal plots, with a similar amount accumulated in the litter addition plots. There was an additional 0.4 kg C m−2 extra in the litter standing crop of the litter addition plots compared to the control. This increase in carbon in surface soil and the litter standing crop can be interpreted as a potential partial mitigation of the effects of increasing CO2 concentrations in the atmosphere.

  3. Litter decomposition in southern Appalachian black locust and pine-hardwood stands: litter quality and nitrogen dynamics

    Science.gov (United States)

    David L. White; Bruce L. Haines

    1988-01-01

    The chemical quality of litter, through its interaction with macroclimate and the litter biota, largely regulates the rate of organic matter (OM) and nitrogen (N) turnover in the forest floor (Cromack 1973; Fogel and Cromack 1977; Meentemeyer 1978; Aber and Melillo 1982; Melillo et al. 1982). Litter quality is thought to be related to the N require-ment and...

  4. The fate of nitrogen mineralized from leaf litter — Initial evidence from 15N-labeled litter

    Science.gov (United States)

    Kathryn B. Piatek

    2011-01-01

    Decomposition of leaf litter includes microbial immobilization of nitrogen (N), followed by N mineralization. The fate of N mineralized from leaf litter is unknown. I hypothesized that N mineralized from leaf litter will be re-immobilized into other forms of organic matter, including downed wood. This mechanism may retain N in some forests. To test this hypothesis, oak...

  5. Tree height integrated into pantropical forest biomass estimates

    NARCIS (Netherlands)

    Feldpausch, T.R.; Lloyd, J.; Lewis, S.L.; Brienen, R.J.W.; Gloor, M.; Montegudo Mendoza, A.; Arets, E.J.M.M.

    2012-01-01

    Aboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer

  6. Retrieval of forest biomass for tropical deciduous mixed forest using ALOS PALSAR mosaic imagery and field plot data

    Science.gov (United States)

    Ningthoujam, Ramesh K.; Joshi, P. K.; Roy, P. S.

    2018-07-01

    Tropical forest is an important ecosystem rich in biodiversity and structural complexity with high woody biomass content. Longer wavelength radar data at L-band sensor provides improved forest biomass (AGB) information due to its higher penetration level and sensitivity to canopy structure. The study presents a regression based woody biomass estimation for tropical deciduous mixed forest dominated by Shorea robusta using ALOS PALSAR mosaic (HH, HV) and field data at the lower Himalayan belt of Northern India. For the purpose of understanding the scattering mechanisms at L-band from this forest type, Michigan Microwave Canopy Scattering model (MIMICS-I) was parameterized with field data to simulate backscatter across polarization and incidence range. Regression analysis between field measured forest biomass and L-band backscatter data from PALSAR mosaic show retrieval of woody biomass up to 100 Mg ha-1 with error between 92 and 94 Mg ha-1 and coefficient of determination (r2) between 0.53 and 0.55 for HH and HH + HV polarized channel at 0.25 ha resolution. This positive relationship could be due to strong volume scattering from ground/trunk interaction at HH-polarized while in combination with direct canopy scattering for HV-polarization at ALOS specific incidence angles as predicted by MIMICS-I model. This study has found that L-band SAR data from currently ALOS-1/-2 and upcoming joint NASA-ISRO SAR (NISAR) are suitable for mapping forest biomass ≤100 Mg ha-1 at 25 m resolution in far incidence range in dense deciduous mixed forest of Northern India.

  7. Distinct responses of soil respiration to experimental litter manipulation in temperate woodland and tropical forest.

    Science.gov (United States)

    Bréchet, Laëtitia M; Lopez-Sangil, Luis; George, Charles; Birkett, Ali J; Baxendale, Catherine; Castro Trujillo, Biancolini; Sayer, Emma J

    2018-04-01

    Global change is affecting primary productivity in forests worldwide, and this, in turn, will alter long-term carbon (C) sequestration in wooded ecosystems. On one hand, increased primary productivity, for example, in response to elevated atmospheric carbon dioxide (CO 2 ), can result in greater inputs of organic matter to the soil, which could increase C sequestration belowground. On other hand, many of the interactions between plants and microorganisms that determine soil C dynamics are poorly characterized, and additional inputs of plant material, such as leaf litter, can result in the mineralization of soil organic matter, and the release of soil C as CO 2 during so-called "priming effects". Until now, very few studies made direct comparison of changes in soil C dynamics in response to altered plant inputs in different wooded ecosystems. We addressed this with a cross-continental study with litter removal and addition treatments in a temperate woodland (Wytham Woods) and lowland tropical forest (Gigante forest) to compare the consequences of increased litterfall on soil respiration in two distinct wooded ecosystems. Mean soil respiration was almost twice as high at Gigante (5.0 μmol CO 2  m -2  s -1 ) than at Wytham (2.7 μmol CO 2  m -2  s -1 ) but surprisingly, litter manipulation treatments had a greater and more immediate effect on soil respiration at Wytham. We measured a 30% increase in soil respiration in response to litter addition treatments at Wytham, compared to a 10% increase at Gigante. Importantly, despite higher soil respiration rates at Gigante, priming effects were stronger and more consistent at Wytham. Our results suggest that in situ priming effects in wooded ecosystems track seasonality in litterfall and soil respiration but the amount of soil C released by priming is not proportional to rates of soil respiration. Instead, priming effects may be promoted by larger inputs of organic matter combined with slower turnover rates.

  8. From a tree to a stand in Finnish boreal forests - biomass estimation and comparison of methods

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chunjiang

    2009-07-01

    There is an increasing need to compare the results obtained with different methods of estimation of tree biomass in order to reduce the uncertainty in the assessment of forest biomass carbon. In this study, tree biomass was investigated in a 30-year-old Scots pine (Pinus sylvestris) (Young-Stand) and a 130-year-old mixed Norway spruce (Picea abies)-Scots pine stand (Mature-Stand) located in southern Finland (61deg50' N, 24deg22' E). In particular, a comparison of the results of different estimation methods was conducted to assess the reliability and suitability of their applications. For the trees in Mature-Stand, annual stem biomass increment fluctuated following a sigmoid equation, and the fitting curves reached a maximum level (from about 1 kg yr-1 for understorey spruce to 7 kg yr-1 for dominant pine) when the trees were 100 years old). Tree biomass was estimated to be about 70 Mg ha-1 in Young-Stand and about 220 Mg ha-1 in Mature-Stand. In the region (58.00-62.13 degN, 14-34 degE, <= 300 m a.s.l.) surrounding the study stands, the tree biomass accumulation in Norway spruce and Scots pine stands followed a sigmoid equation with stand age, with a maximum of 230 Mg ha-1 at the age of 140 years. In Mature-Stand, lichen biomass on the trees was 1.63 Mg ha-1 with more than half of the biomass occurring on dead branches, and the standing crop of litter lichen on the ground was about 0.09 Mg ha-1. There were substantial differences among the results estimated by different methods in the stands. These results imply that a possible estimation error should be taken into account when calculating tree biomass in a stand with an indirect approach. (orig.)

  9. Linking state-and-transition simulation and timber supply models for forest biomass production scenarios

    Science.gov (United States)

    Costanza, Jennifer; Abt, Robert C.; McKerrow, Alexa; Collazo, Jaime

    2015-01-01

    We linked state-and-transition simulation models (STSMs) with an economics-based timber supply model to examine landscape dynamics in North Carolina through 2050 for three scenarios of forest biomass production. Forest biomass could be an important source of renewable energy in the future, but there is currently much uncertainty about how biomass production would impact landscapes. In the southeastern US, if forests become important sources of biomass for bioenergy, we expect increased land-use change and forest management. STSMs are ideal for simulating these landscape changes, but the amounts of change will depend on drivers such as timber prices and demand for forest land, which are best captured with forest economic models. We first developed state-and-transition model pathways in the ST-Sim software platform for 49 vegetation and land-use types that incorporated each expected type of landscape change. Next, for the three biomass production scenarios, the SubRegional Timber Supply Model (SRTS) was used to determine the annual areas of thinning and harvest in five broad forest types, as well as annual areas converted among those forest types, agricultural, and urban lands. The SRTS output was used to define area targets for STSMs in ST-Sim under two scenarios of biomass production and one baseline, business-as-usual scenario. We show that ST-Sim output matched SRTS targets in most cases. Landscape dynamics results indicate that, compared with the baseline scenario, forest biomass production leads to more forest and, specifically, more intensively managed forest on the landscape by 2050. Thus, the STSMs, informed by forest economics models, provide important information about potential landscape effects of bioenergy production.

  10. Linking state-and-transition simulation and timber supply models for forest biomass production scenarios

    Directory of Open Access Journals (Sweden)

    Jennifer K. Costanza

    2015-03-01

    Full Text Available We linked state-and-transition simulation models (STSMs with an economics-based timber supply model to examine landscape dynamics in North Carolina through 2050 for three scenarios of forest biomass production. Forest biomass could be an important source of renewable energy in the future, but there is currently much uncertainty about how biomass production would impact landscapes. In the southeastern US, if forests become important sources of biomass for bioenergy, we expect increased land-use change and forest management. STSMs are ideal for simulating these landscape changes, but the amounts of change will depend on drivers such as timber prices and demand for forest land, which are best captured with forest economic models. We first developed state-and-transition model pathways in the ST-Sim software platform for 49 vegetation and land-use types that incorporated each expected type of landscape change. Next, for the three biomass production scenarios, the SubRegional Timber Supply Model (SRTS was used to determine the annual areas of thinning and harvest in five broad forest types, as well as annual areas converted among those forest types, agricultural, and urban lands. The SRTS output was used to define area targets for STSMs in ST-Sim under two scenarios of biomass production and one baseline, business-as-usual scenario. We show that ST-Sim output matched SRTS targets in most cases. Landscape dynamics results indicate that, compared with the baseline scenario, forest biomass production leads to more forest and, specifically, more intensively managed forest on the landscape by 2050. Thus, the STSMs, informed by forest economics models, provide important information about potential landscape effects of bioenergy production.

  11. Evaluating kriging as a tool to improve moderate resolution maps of forest biomass

    Science.gov (United States)

    Elizabeth A. Freeman; Gretchen G. Moisen

    2007-01-01

    The USDA Forest Service, Forest Inventory and Analysis program (FIA) recently produced a nationwide map of forest biomass by modeling biomass collected on forest inventory plots as nonparametric functions of moderate resolution satellite data and other environmental variables using Cubist software. Efforts are underway to develop methods to enhance this initial map. We...

  12. Characterization of biomass burning aerosols from forest fire in Indonesia

    Science.gov (United States)

    Fujii, Y.; Iriana, W.; Okumura, M.; Lestari, P.; Tohno, S.; Akira, M.; Okuda, T.

    2012-12-01

    Biomass burning (forest fire, wild fire) is a major source of pollutants, generating an estimate of 104 Tg per year of aerosol particles worldwide. These particles have adverse human health effects and can affect the radiation budget and climate directly and indirectly. Eighty percent of biomass burning aerosols are generated in the tropics and about thirty percent of them originate in the tropical regions of Asia (Andreae, 1991). Several recent studies have reported on the organic compositions of biomass burning aerosols in the tropical regions of South America and Africa, however, there is little data about forest fire aerosols in the tropical regions of Asia. It is important to characterize biomass burning aerosols in the tropical regions of Asia because the aerosol properties vary between fires depending on type and moisture of wood, combustion phase, wind conditions, and several other variables (Reid et al., 2005). We have characterized PM2.5 fractions of biomass burning aerosols emitted from forest fire in Indonesia. During the dry season in 2012, PM2.5 aerosols from several forest fires occurring in Riau, Sumatra, Indonesia were collected on quartz and teflon filters with two mini-volume samplers. Background aerosols in forest were sampled during transition period of rainy season to dry season (baseline period). Samples were analyzed with several analytical instruments. The carbonaceous content (organic and elemental carbon, OC and EC) of the aerosols was analyzed by a thermal optical reflectance technique using IMPROVE protocol. The metal, inorganic ion and organic components of the aerosols were analyzed by X-ray Fluorescence (XRF), ion chromatography and gas chromatography-mass spectrometry, respectively. There was a great difference of chemical composition between forest fire and non-forest fire samples. Smoke aerosols for forest fires events were composed of ~ 45 % OC and ~ 2.5 % EC. On the other hand, background aerosols for baseline periods were

  13. Cerium and cobalt movement with litter leachate in a forest soil

    International Nuclear Information System (INIS)

    Thomas, W.A.

    1975-01-01

    Leachate containing 144 Ce and 60 Co from leaf litter of mockernut hickory (Carya tomentosa Nutt.) and black gum (Nyssa sylvatica Marsh.) trees was applied to a forest soil in three different treatments to estimate the rates at which these elements move downward after release in the litter layer: (a) single application, (b) single application at twice the concentration in (a), and (c) four periodic applications over 1 year. Regression b values describing the distribution of 144 Ce and 60 Co 4 years after the first applications did not differ significantly (P greater than 0.01) among treatments for either element, but movement by 144 Ce significantly exceeded that by 60 Co for all treatments. A combination of chemical and physical phenomena retained cerium and cobalt in the biologically active zones of soil, with the organic layer and upper 3 cm of mineral soil accounting for 68 percent of the 144 Ce and 91 percent of the 60 Co

  14. Evaluating the sensitivity of Eurasian forest biomass to climate change using a dynamic vegetation model

    International Nuclear Information System (INIS)

    Shuman, J K; Shugart, H H

    2009-01-01

    Climate warming could strongly influence the structure and composition of the Eurasian boreal forest. Temperature related changes have occurred, including shifts in treelines and changes in regeneration. Dynamic vegetation models are well suited to the further exploration of the impacts that climate change may have on boreal forests. Using the individual-based gap model FAREAST, forest composition and biomass are simulated at over 2000 sites across Eurasia. Biomass output is compared to detailed forest data from a representative sample of Russian forests and a sensitivity analysis is performed to evaluate the impact that elevated temperatures and modified precipitation will have on forest biomass and composition in Eurasia. Correlations between model and forest inventory biomass are strong for several boreal tree species. A significant relationship is shown between altered precipitation and biomass. This analysis showed that a modest increase in temperature of 2 deg. C across 200 years had no significant effect on biomass; however further exploration with increased warming reflective of values measured within Siberia, or at an increased rate, are warranted. Overall, FAREAST accurately simulates forest biomass and composition at sites throughout a large geographic area with widely varying climatic conditions and produces reasonable biomass responses to simulated climatic shifts. These results indicate that this model is robust and useful in making predictions regarding the effect of future climate change on boreal forest structure across Eurasia.

  15. The role of gap phase processes in the biomass dynamics of tropical forests

    Science.gov (United States)

    Feeley, Kenneth J; Davies, Stuart J; Ashton, Peter S; Bunyavejchewin, Sarayudh; Nur Supardi, M.N; Kassim, Abd Rahman; Tan, Sylvester; Chave, Jérôme

    2007-01-01

    The responses of tropical forests to global anthropogenic disturbances remain poorly understood. Above-ground woody biomass in some tropical forest plots has increased over the past several decades, potentially reflecting a widespread response to increased resource availability, for example, due to elevated atmospheric CO2 and/or nutrient deposition. However, previous studies of biomass dynamics have not accounted for natural patterns of disturbance and gap phase regeneration, making it difficult to quantify the importance of environmental changes. Using spatially explicit census data from large (50 ha) inventory plots, we investigated the influence of gap phase processes on the biomass dynamics of four ‘old-growth’ tropical forests (Barro Colorado Island (BCI), Panama; Pasoh and Lambir, Malaysia; and Huai Kha Khaeng (HKK), Thailand). We show that biomass increases were gradual and concentrated in earlier-phase forest patches, while biomass losses were generally of greater magnitude but concentrated in rarer later-phase patches. We then estimate the rate of biomass change at each site independent of gap phase dynamics using reduced major axis regressions and ANCOVA tests. Above-ground woody biomass increased significantly at Pasoh (+0.72% yr−1) and decreased at HKK (−0.56% yr−1) independent of changes in gap phase but remained stable at both BCI and Lambir. We conclude that gap phase processes play an important role in the biomass dynamics of tropical forests, and that quantifying the role of gap phase processes will help improve our understanding of the factors driving changes in forest biomass as well as their place in the global carbon budget. PMID:17785266

  16. ABOVE GROUND BIOMASS MICRONUTRIENTS IN A SEASONAL SUBTROPICAL FOREST

    Directory of Open Access Journals (Sweden)

    Hamilton Luiz Munari Vogel

    2015-06-01

    Full Text Available In the above ground biomass of a native forest or plantation are stored large quantities of nutrients, with few studies in the literature, especially concerning micronutrients. The present work aimed to quantify the micronutrients in above ground biomass in a Seasonal Subtropical forest in Itaara-RS, Brazil. For the above ground biomass evaluation, 20 trees of five different diameter classes were felled. The above ground biomass was separated in the following compartments: stem wood, stem bark, branches and leaves. The contents of B, Cu, Fe, Mn and Zn in the biomass samples were determined. The stock of micronutrients in the biomass for each component was obtained based on the estimated dry biomass, multiplied by the nutrient content. The total production of above ground biomass was estimated at 210.0 Mg.ha-1. The branches, stem wood, stem bark and leaves corresponded to 48.8, 43.3, 5.4 and 2.4% of the above ground biomass. The lower levels of B, Cu, Fe and Mn are in stem wood, except for Zn; in the branches and trunk wood are the largest stocks of B, Cu, Fe and Mn. In the branches, leaves and trunk bark are stored most micronutrients, pointing to the importance of these to remain on the soil.

  17. Leaf litter and roots as sources of mineral soil organic matter in temperate deciduous forest with and without earthworms

    Science.gov (United States)

    Fahey, T.; Yavitt, J. B.

    2012-12-01

    We labeled sugar maple trees with 13C to quantify the separate contributions of decaying leaf litter and root turnover/rhizosphere C flux to mineral soil organic matter (SOM). Labeled leaf litter was applied to forest plots with and without earthworms and recovery of the label in SOM was quantified over three years. In parallel, label recovery was quantified in soils from the labeling chambers where all label was supplied by belowground C flux. In the absence of earthworms about half of the label added as leaf litter remained in the surface organic horizons after three years, with about 3% recovered in mineral SOM. The label was most enriched on silt + clay surfaces, representing precipitation of DOC derived from litter. Earthworms mixed nearly all the leaf litter into mineral soil within one year, and after two years the label was most enriched in particulate organic matter held within soil aggregates produced by worms. After three years 15-20% of the added label was recovered in mineral SOM. In the labeling chambers over 75% of belowground C allocation (BCA) was used in root and rhizosphere respiration in the first year after labeling. We recovered only 3.8% of estimated BCA in SOM after 3 years; however, expressed as a proportion of fine root production plus rhizosphere C flux, this value is 15.4%, comparable to that for leaf litter in the presence of earthworms. In conclusion, both roots and leaf litter contribute significantly to the formation of stabilized mineral SOM in temperate deciduous forests, and this process is profoundly altered by the invasion of lumbricid earthworms.

  18. Anthropogenic Land-use Change and the Dynamics of Amazon Forest Biomass

    Science.gov (United States)

    Laurance, William F.

    2004-01-01

    This project was focused on assessing the effects of prevailing land uses, such as habitat fragmentation, selective logging, and fire, on biomass and carbon storage in Amazonian forests, and on the dynamics of carbon sequestration in regenerating forests. Ancillary goals included developing GIs models to help predict the future condition of Amazonian forests, and assessing the effects of anthropogenic climate change and ENS0 droughts on intact and fragmented forests. Ground-based studies using networks of permanent plots were linked with remote-sensing data (including Landsat TM and AVHRR) at regional scales, and higher-resolution techniques (IKONOS imagery, videography, LIDAR, aerial photographs) at landscape and local scales. The project s specific goals were quite eclectic and included: Determining the effects of habitat fragmentation on forest dynamics, floristic composition, and the various components of above- and below-ground biomass. Assessing historical and physical factors that affect trajectories of forest regeneration and carbon sequestration on abandoned lands. Extrapolating results from local studies of biomass dynamics in fragmented and regenerating forests to landscape and regional scales in Amazonia, using remote sensing and GIS. Testing the hypothesis that intact Amazonian forests are functioning as a significant carbon sink. Examining destructive synergisms between forest fragmentation and fire. Assessing the short-term impacts of selective logging on aboveground biomass. Developing GIS models that integrate current spatial data on forest cover, deforestation, logging, mining, highway and roads, navigable rivers, vulnerability to wild fires, protected areas, and existing and planned infrastructure projects, in an effort to predict the future condition of Brazilian Amazonian forests over the next 20-25 years. Devising predictive spatial models to assess the influence of varied biophysical and anthropogenic predictors on Amazonian deforestation.

  19. Projecting demand and supply of forest biomass for heating in Norway

    International Nuclear Information System (INIS)

    Tromborg, Erik; Havskjold, Monica; Lislebo, Ole; Rorstad, Per Kristian

    2011-01-01

    This paper assesses the increase in demand and supply for forest biomass for heating in Norway in 2020. By then there is a political aim to double the national production of bioenergy from the level in 2008. The competitiveness of woody biomass in central and district heating is analyzed in a model selecting the least-cost heating technology and scale in municipalities given a set of constraints and under different fuels price scenarios. The supply of forest biomass from roundwood is estimated based on data of forest inventories combined with elasticities regarding price and standing volumes. The supply of biomass from harvesting residues is estimated in an engineering approach based on data from the national forest inventories and roundwood harvest. The results show how the production of bioenergy is affected by changes in energy prices and support schemes for bioenergy. One conclusion from the analyses is that the government target of 14 TWh more bioenergy by 2020 is not likely to be met by current technologies and policy incentives. The contribution of the analysis is the detailed presentation of the heat market potentials and technology choices combined with supply functions for both roundwood and harvesting residues. - Highlights: → This paper accesses the demand and supply for forest biomass for heating in Norway in 2020. → Market share for wood in central and new district heating is analyzed in a cost-minimizing model. → The supply of forest biomass includes wood chips from import, roundwood and harvesting residues. → The production of bioenergy is affected by changes in energy prices and support schemes. → The government target for bioenergy is not met by current technologies and policy incentives.

  20. A meta-analysis of soil microbial biomass responses to forest disturbances

    Directory of Open Access Journals (Sweden)

    Sandra Robin Holden

    2013-06-01

    Full Text Available Climate warming is likely to increase the frequency and severity of forest disturbances, with uncertain consequences for soil microbial communities and their contribution to ecosystem C dynamics. To address this uncertainty, we conducted a meta-analysis of 139 published soil microbial responses to forest disturbances. These disturbances included abiotic (fire, harvesting, storm and biotic (insect, pathogen disturbances. We hypothesized that soil microbial biomass would decline following forest disturbances, but that abiotic disturbances would elicit greater reductions in microbial biomass than biotic disturbances. In support of this hypothesis, across all published studies, disturbances reduced soil microbial biomass by an average of 29.4%. However, microbial responses differed between abiotic and biotic disturbances. Microbial responses were significantly negative following fires, harvest, and storms (48.7%, 19.1%, and 41.7% reductions in microbial biomass, respectively. In contrast, changes in soil microbial biomass following insect infestation and pathogen-induced tree mortality were non-significant, although biotic disturbances were poorly represented in the literature. When measured separately, fungal and bacterial responses to disturbances mirrored the response of the microbial community as a whole. Changes in microbial abundance following disturbance were significantly positively correlated with changes in microbial respiration. We propose that the differential effect of abiotic and biotic disturbances on microbial biomass may be attributable to differences in soil disruption and organic C removal from forests among disturbance types. Altogether, these results suggest that abiotic forest disturbances may significantly decrease soil microbial abundance, with corresponding consequences for microbial respiration. Further studies are needed on the effect of biotic disturbances on forest soil microbial communities and soil C dynamics.

  1. Carbon mineralisation in litter and soil organic matter in forests with different nitrogen status

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Patrik

    2000-07-01

    The objective of this thesis was to investigate the effect of both organic and inorganic nitrogen (N) on carbon (C) mineralisation of litter and soil organic matter, in order to increase the understanding of factors affecting decomposition and, ultimately, soil C sequestration. Fresh recently fallen needle litter with three contrasting total N concentrations were sampled, along with litter, humus and mineral soil layers from coniferous and deciduous forest sites in Europe. The sampled substrates were incubated in the laboratory at constant temperature (15 deg C) and near-optimal moisture. The fresh needles further received additions of ammonium and nitrate. Initial C mineralisation rates were higher in fresh N-rich needles than in fresh N-poor needles. However, after a 559-day incubation at 15 deg C cumulative C mineralisation was lower in the fresh N-rich needles than in the fresh N-poor needles. Negative effects of high N on C mineralisation were also found in litter and humus layers in the European forests and at sites with N-fertilisation trials, where low C mineralisation rates were associated with high total N concentrations. During early stages of decomposition, addition of ammonium and nitrate to fresh needles did not increase cumulative C mineralisation, suggesting that the decomposing organisms were not limited by low N supply even in the low-N needles. The initially higher C mineralisation in N-rich compared with N-poor needles is suggested to be a consequence of higher C quality in the N-rich substrates. In later stages of decomposition, the question why N seemed to have a negative effect on decomposition could not be satisfactorily answered, although there were indications that recalcitrant N-containing compounds were formed in fresh needles with high N concentration. This thesis presents some probable explanations of the negative effect on decomposition of high N.

  2. Forest soil carbon is threatened by intensive biomass harvesting.

    Science.gov (United States)

    Achat, David L; Fortin, Mathieu; Landmann, Guy; Ringeval, Bruno; Augusto, Laurent

    2015-11-04

    Forests play a key role in the carbon cycle as they store huge quantities of organic carbon, most of which is stored in soils, with a smaller part being held in vegetation. While the carbon storage capacity of forests is influenced by forestry, the long-term impacts of forest managers' decisions on soil organic carbon (SOC) remain unclear. Using a meta-analysis approach, we showed that conventional biomass harvests preserved the SOC of forests, unlike intensive harvests where logging residues were harvested to produce fuelwood. Conventional harvests caused a decrease in carbon storage in the forest floor, but when the whole soil profile was taken into account, we found that this loss in the forest floor was compensated by an accumulation of SOC in deeper soil layers. Conversely, we found that intensive harvests led to SOC losses in all layers of forest soils. We assessed the potential impact of intensive harvests on the carbon budget, focusing on managed European forests. Estimated carbon losses from forest soils suggested that intensive biomass harvests could constitute an important source of carbon transfer from forests to the atmosphere (142-497 Tg-C), partly neutralizing the role of a carbon sink played by forest soils.

  3. Litter and nutrient flows in tropical upland forest flooded by a hydropower plant in the Amazonian basin.

    Science.gov (United States)

    Pereira, Guilherme Henrique A; Jordão, Henos Carlos K; Silva, Vanessa Francieli V; Pereira, Marcos Gervasio

    2016-12-01

    Extensive areas in the Brazilian Amazon have been flooded for the construction of hydroelectric dams. However, the water regime of these areas affects the dynamics of igarapés (streams) in adjacent terra firme (upland forests). When the reservoirs are filled, the water levels of streams rise above the normal levels and upland bank forests are flooded. We investigated how this flooding affects the litterfall and nutrient input in the upland forests upstream of a hydroelectric dam reservoir in the Central Amazonia. When the reservoir was filled, the forests were flooded and produced more than twice the litter (8.80Mg·ha -1 yr -1 ), with three times more leaves (6.36Mg·ha -1 yr -1 ) than when they were not flooded (4.20 and 1.92Mg·ha -1 yr -1 , respectively). During flooding, the decomposition rate was four times lower in flooded forests (0.328g·g -1 yr -1 ) than in control forests (1.460g·g -1 yr -1 ). Despite this, the flooding did not favor litter or nutrient accumulation. Therefore, dam construction changes the organic matter and nutrient cycling in upland Amazon rainforests. This may influence the important role that they play in organic matter dynamics and could have consequences for the regional carbon balance and, ultimately, global climate. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Influence of litter diversity on dissolved organic matter release and soil carbon formation in a mixed beech forest.

    Science.gov (United States)

    Scheibe, Andrea; Gleixner, Gerd

    2014-01-01

    We investigated the effect of leaf litter on below ground carbon export and soil carbon formation in order to understand how litter diversity affects carbon cycling in forest ecosystems. 13C labeled and unlabeled leaf litter of beech (Fagus sylvatica) and ash (Fraxinus excelsior), characterized by low and high decomposability, were used in a litter exchange experiment in the Hainich National Park (Thuringia, Germany). Litter was added in pure and mixed treatments with either beech or ash labeled with 13C. We collected soil water in 5 cm mineral soil depth below each treatment biweekly and determined dissolved organic carbon (DOC), δ13C values and anion contents. In addition, we measured carbon concentrations and δ13C values in the organic and mineral soil (collected in 1 cm increments) up to 5 cm soil depth at the end of the experiment. Litter-derived C contributes less than 1% to dissolved organic matter (DOM) collected in 5 cm mineral soil depth. Better decomposable ash litter released significantly more (0.50±0.17%) litter carbon than beech litter (0.17±0.07%). All soil layers held in total around 30% of litter-derived carbon, indicating the large retention potential of litter-derived C in the top soil. Interestingly, in mixed (ash and beech litter) treatments we did not find a higher contribution of better decomposable ash-derived carbon in DOM, O horizon or mineral soil. This suggest that the known selective decomposition of better decomposable litter by soil fauna has no or only minor effects on the release and formation of litter-derived DOM and soil organic matter. Overall our experiment showed that 1) litter-derived carbon is of low importance for dissolved organic carbon release and 2) litter of higher decomposability is faster decomposed, but litter diversity does not influence the carbon flow.

  5. Composite materials from forest biomass : a review of current practices, science, and technology

    Science.gov (United States)

    Roger M. Rowell

    2007-01-01

    Renewable and sustainable composite materials can be produced using forest biomass if we maintain healthy forests. Small diameter trees and other forest biomass can be processed in the forest into small solid wood pieces, sliced veneers, strands, flakes, chips, particles and fiber that can be used to make construction composite products such as glued-laminated lumber,...

  6. Assessment of forest management influences on total live aboveground tree biomass in William B Bankhead National Forest, Alabama

    Science.gov (United States)

    Callie Schweitzer; Dawn Lemke; Wubishet Tadesse; Yong Wang

    2015-01-01

    Forests contain a large amount of carbon (C) stored as tree biomass (above and below ground), detritus, and soil organic material. The aboveground tree biomass is the most rapid change component in this forest C pool. Thus, management of forest resources can influence the net C exchange with the atmosphere by changing the amount of C stored, particularly in landscapes...

  7. Estimating Carbon Dynamics in an Intact Lowland Mixed Dipterocarp Forest Using a Forest Carbon Model

    Directory of Open Access Journals (Sweden)

    Jongyeol Lee

    2017-04-01

    Full Text Available Intact dipterocarp forests in Asia act as crucial carbon (C reservoirs, and it is therefore important to investigate the C dynamics in these forests. We estimated C dynamics, together with net ecosystem production (NEP, in an intact tropical dipterocarp forest of Brunei Darussalam. Fifty-four simulation units (plots; 20 m × 20 m were established and initial C stocks were determined via direct field measurement. The C dynamics were annually simulated with a regression model and the Forest Biomass and Dead organic matter Carbon (FBDC model. The initial C stock (Mg C·ha−1 of biomass, litter, dead wood and mineral soil were 213.1 ± 104.8, 2.0 ± 0.8, 31.3 ± 38.8, and 80.7 ± 15.5, respectively. Their annual changes (Mg C·ha−1·year−1 were 3.2 ± 1.1, 0.2 ± 0.2, −3.7 ± 6.1, and −0.3 ± 1.1, respectively. NEP was −0.6 ± 6.1 Mg C·ha−1·year−1, showing large heterogeneity among the plots. The initial C stocks of biomass and dead wood, biomass turnover rates and dead wood decay rates were elucidated as dominant factors determining NEP in a sensitivity analysis. Accordingly, investigation on those input data can constrain an uncertainty in determining NEP in the intact tropical forests.

  8. Time trends in the levels and patterns of polycyclic aromatic hydrocarbons (PAHs) in pine bark, litter, and soil after a forest fire.

    Science.gov (United States)

    Choi, Sung-Deuk

    2014-02-01

    Forest fires are known as an important natural source of polycyclic aromatic hydrocarbons (PAHs), but time trends of PAH levels and patterns in various environmental compartments after forest fires have not been thoroughly studied yet. In this study, 16 US-EPA priority PAHs were analyzed for pine bark, litter, and soil samples collected one, three, five, and seven months after a forest fire in Pohang, South Korea. At the first sampling event, the highest levels of ∑16 PAHs were measured for the three types of samples (pine bark: 5,920 ng/g, litter: 1,540 ng/g, and soil: 133 ng/g). Thereafter, there were apparent decreasing trends in PAH levels; the control samples showed the lowest levels (pine bark: 124 ng/g, litter: 75 ng/g, and soil: 26 ng/g). The levels of PAHs in the litter and soil samples normalized by organic carbon (OC) fractions also showed decreasing trends, indicating a direct influence of the forest fire. Among the 16 target PAHs, naphthalene was a dominant compound for all types of samples. Light PAHs with 2-4 rings significantly contributed to the total concentration, and their contribution decreased in the course of time. Runoff by heavy precipitation, evaporation, and degradation of PAHs in the summer were probably the main reasons for the observed time trends. The results of principal component analysis (PCA) and diagnostic ratio also supported that the forest fire was indeed an important source of PAHs in the study area. © 2013.

  9. Carbon stocks in urban forest remnants: Atlanta and Baltimore as case studies. Chapter 5.

    Science.gov (United States)

    Ian D. Yesilonis; Richard V. Pouyat

    2012-01-01

    Urban environments influence carbon (C) and nitrogen (N) cycles of forest ecosystems by altering plant biomass, litter mass and chemistry, passive and active pools of C and N, and the occurrence and activity of decomposer organisms. It is difficult to determine the net effect of C storage due to the number of environmental factors exerting stress on urban forests....

  10. Mapping aboveground woody biomass using forest inventory, remote sensing and geostatistical techniques.

    Science.gov (United States)

    Yadav, Bechu K V; Nandy, S

    2015-05-01

    Mapping forest biomass is fundamental for estimating CO₂ emissions, and planning and monitoring of forests and ecosystem productivity. The present study attempted to map aboveground woody biomass (AGWB) integrating forest inventory, remote sensing and geostatistical techniques, viz., direct radiometric relationships (DRR), k-nearest neighbours (k-NN) and cokriging (CoK) and to evaluate their accuracy. A part of the Timli Forest Range of Kalsi Soil and Water Conservation Division, Uttarakhand, India was selected for the present study. Stratified random sampling was used to collect biophysical data from 36 sample plots of 0.1 ha (31.62 m × 31.62 m) size. Species-specific volumetric equations were used for calculating volume and multiplied by specific gravity to get biomass. Three forest-type density classes, viz. 10-40, 40-70 and >70% of Shorea robusta forest and four non-forest classes were delineated using on-screen visual interpretation of IRS P6 LISS-III data of December 2012. The volume in different strata of forest-type density ranged from 189.84 to 484.36 m(3) ha(-1). The total growing stock of the forest was found to be 2,024,652.88 m(3). The AGWB ranged from 143 to 421 Mgha(-1). Spectral bands and vegetation indices were used as independent variables and biomass as dependent variable for DRR, k-NN and CoK. After validation and comparison, k-NN method of Mahalanobis distance (root mean square error (RMSE) = 42.25 Mgha(-1)) was found to be the best method followed by fuzzy distance and Euclidean distance with RMSE of 44.23 and 45.13 Mgha(-1) respectively. DRR was found to be the least accurate method with RMSE of 67.17 Mgha(-1). The study highlighted the potential of integrating of forest inventory, remote sensing and geostatistical techniques for forest biomass mapping.

  11. Temporal dynamics of abiotic and biotic factors on leaf litter of three plant species in relation to decomposition rate along a subalpine elevation gradient.

    Directory of Open Access Journals (Sweden)

    Jianxiao Zhu

    Full Text Available Relationships between abiotic (soil temperature and number of freeze-thaw cycles or biotic factors (chemical elements, microbial biomass, extracellular enzymes, and decomposer communities in litter and litter decomposition rates were investigated over two years in subalpine forests close to the Qinghai-Tibet Plateau in China. Litterbags with senescent birch, fir, and spruce leaves were placed on the forest floor at 2,704 m, 3,023 m, 3,298 m, and 3,582 m elevation. Results showed that the decomposition rate positively correlated with soil mean temperature during the plant growing season, and with the number of soil freeze-thaw cycles during the winter. Concentrations of soluble nitrogen (N, phosphorus (P and potassium (K had positive effects but C:N and lignin:N ratios had negative effects on the decomposition rate (k, especially during the winter. Meanwhile, microbial biomass carbon (MBC, N (MBN, and P (MBP were positively correlated with k values during the first growing season. These biotic factors accounted for 60.0% and 56.4% of the variation in decomposition rate during the winter and the growing season in the first year, respectively. Specifically, litter chemistry (C, N, P, K, lignin, C:N and lignin:N ratio independently explained 29.6% and 13.3%, and the microbe-related factors (MBC, MBN, MBP, bacterial and fungal biomass, sucrase and ACP activity explained 22.9% and 34.9% during the first winter and the first growing season, respectively. We conclude that frequent freeze-thaw cycles and litter chemical properties determine the winter decomposition while microbe-related factors play more important roles in determining decomposition in the subsequent growing season.

  12. Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots.

    Science.gov (United States)

    Reich, Peter B; Luo, Yunjian; Bradford, John B; Poorter, Hendrik; Perry, Charles H; Oleksyn, Jacek

    2014-09-23

    Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (>6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics.

  13. Adequacy assessment of mathematical models in the dynamics of litter decomposition in a tropical forest Mosaic Atlantic, in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    FP. Nunes

    Full Text Available The study of litter decomposition and nutrient cycling is essential to know native forests structure and functioning. Mathematical models can help to understand the local and temporal litter fall variations and their environmental variables relationships. The objective of this study was test the adequacy of mathematical models for leaf litter decomposition in the Atlantic Forest in southeastern Brazil. We study four native forest sites in Parque Estadual do Rio Doce, a Biosphere Reserve of the Atlantic, which were installed 200 bags of litter decomposing with 20×20 cm nylon screen of 2 mm, with 10 grams of litter. Monthly from 09/2007 to 04/2009, 10 litterbags were removed for determination of the mass loss. We compared 3 nonlinear models: 1 – Olson Exponential Model (1963, which considers the constant K, 2 – Model proposed by Fountain and Schowalter (2004, 3 – Model proposed by Coelho and Borges (2005, which considers the variable K through QMR, SQR, SQTC, DMA and Test F. The Fountain and Schowalter (2004 model was inappropriate for this study by overestimating decomposition rate. The decay curve analysis showed that the model with the variable K was more appropriate, although the values of QMR and DMA revealed no significant difference (p> 0.05 between the models. The analysis showed a better adjustment of DMA using K variable, reinforced by the values of the adjustment coefficient (R2. However, convergence problems were observed in this model for estimate study areas outliers, which did not occur with K constant model. This problem can be related to the non-linear fit of mass/time values to K variable generated. The model with K constant shown to be adequate to describe curve decomposition for separately areas and best adjustability without convergence problems. The results demonstrated the adequacy of Olson model to estimate tropical forest litter decomposition. Although use of reduced number of parameters equaling the steps of the

  14. Adequacy assessment of mathematical models in the dynamics of litter decomposition in a tropical forest Mosaic Atlantic, in southeastern Brazil.

    Science.gov (United States)

    Nunes, F P; Garcia, Q S

    2015-05-01

    The study of litter decomposition and nutrient cycling is essential to know native forests structure and functioning. Mathematical models can help to understand the local and temporal litter fall variations and their environmental variables relationships. The objective of this study was test the adequacy of mathematical models for leaf litter decomposition in the Atlantic Forest in southeastern Brazil. We study four native forest sites in Parque Estadual do Rio Doce, a Biosphere Reserve of the Atlantic, which were installed 200 bags of litter decomposing with 20 × 20 cm nylon screen of 2 mm, with 10 grams of litter. Monthly from 09/2007 to 04/2009, 10 litterbags were removed for determination of the mass loss. We compared 3 nonlinear models: 1 - Olson Exponential Model (1963), which considers the constant K, 2 - Model proposed by Fountain and Schowalter (2004), 3 - Model proposed by Coelho and Borges (2005), which considers the variable K through QMR, SQR, SQTC, DMA and Test F. The Fountain and Schowalter (2004) model was inappropriate for this study by overestimating decomposition rate. The decay curve analysis showed that the model with the variable K was more appropriate, although the values of QMR and DMA revealed no significant difference (p > 0.05) between the models. The analysis showed a better adjustment of DMA using K variable, reinforced by the values of the adjustment coefficient (R2). However, convergence problems were observed in this model for estimate study areas outliers, which did not occur with K constant model. This problem can be related to the non-linear fit of mass/time values to K variable generated. The model with K constant shown to be adequate to describe curve decomposition for separately areas and best adjustability without convergence problems. The results demonstrated the adequacy of Olson model to estimate tropical forest litter decomposition. Although use of reduced number of parameters equaling the steps of the decomposition

  15. Relating multifrequency radar backscattering to forest biomass: Modeling and AIRSAR measurement

    Science.gov (United States)

    Sun, Guo-Qing; Ranson, K. Jon

    1992-01-01

    During the last several years, significant efforts in microwave remote sensing were devoted to relating forest parameters to radar backscattering coefficients. These and other studies showed that in most cases, the longer wavelength (i.e. P band) and cross-polarization (HV) backscattering had higher sensitivity and better correlation to forest biomass. This research examines this relationship in a northern forest area through both backscatter modeling and synthetic aperture radar (SAR) data analysis. The field measurements were used to estimate stand biomass from forest weight tables. The backscatter model described by Sun et al. was modified to simulate the backscattering coefficients with respect to stand biomass. The average number of trees per square meter or radar resolution cell, and the average tree height or diameter breast height (dbh) in the forest stand are the driving parameters of the model. The rest of the soil surface, orientation, and size distributions of leaves and branches, remain unchanged in the simulations.

  16. Influence of litter quality and fertilization on microbial nitrogen transformations in short-rotation forests

    Energy Technology Data Exchange (ETDEWEB)

    Slapokas, T

    1991-01-01

    Microbial decomposition of different types of litters in short-rotation forests was studied using the litter-bag technique. The impact of earthworm activity on leaf decomposition was included in one study and fungal succession was recorded in certain willow leaf litters. Soil fertility affected leaf compositions, which in turn influenced decomposition rates. Contents of macroelements, (esp. N), water-soluble and lingnified substances, and tannins (i.e. astringency) were observed during decomposition. Directly after leaf-fall most litters lost 5-27 per cent of their dry weight, mainly trough leaching. Thereafter, the various litters converged regarding their contents of certain leaf constituents, e.g. water-soluble and lignified substances and potassium. Mineral-nutrient loss rates from litters were often positively related to initial nutrient contents; in fact, N was transported into N-poor litters. N-contents increased until net mineralization began. Decomposition and N-transformations in a low-humified peat were followed at a cultivated bog. Mean decomposition in a drained, rotovated, and limed control plot was 2.6 per cent yr{sup -1}. Rates in fertilized plots were not shown to be higher, even though their bulk density and degree of humification had increased. N-mineralization rates in planted plot increase over the years. Pools of ammonium- and nitrate-N were lowest during periods of rapid plant growth. Nitrification occurred in both field and laboratory incubations of peat. In the top 10 cm of peat in plots receiving fixed N only, immobilization in 7-year-old stands was 53 kg N ha{sup -1} yr{sup -1}, whereas it was lower in liquid-N fertilized plots. Much of this fertilizer-N (ca. 1500 kg ha{sup -1} over 7 years) must have been immobilized in deeper peat layers or lost, partly through denitrification. One-year N-budgets are presented for alder stands with and without added fertilizer-N. (au).

  17. Long-term litter decomposition controlled by manganese redox cycling.

    Science.gov (United States)

    Keiluweit, Marco; Nico, Peter; Harmon, Mark E; Mao, Jingdong; Pett-Ridge, Jennifer; Kleber, Markus

    2015-09-22

    Litter decomposition is a keystone ecosystem process impacting nutrient cycling and productivity, soil properties, and the terrestrial carbon (C) balance, but the factors regulating decomposition rate are still poorly understood. Traditional models assume that the rate is controlled by litter quality, relying on parameters such as lignin content as predictors. However, a strong correlation has been observed between the manganese (Mn) content of litter and decomposition rates across a variety of forest ecosystems. Here, we show that long-term litter decomposition in forest ecosystems is tightly coupled to Mn redox cycling. Over 7 years of litter decomposition, microbial transformation of litter was paralleled by variations in Mn oxidation state and concentration. A detailed chemical imaging analysis of the litter revealed that fungi recruit and redistribute unreactive Mn(2+) provided by fresh plant litter to produce oxidative Mn(3+) species at sites of active decay, with Mn eventually accumulating as insoluble Mn(3+/4+) oxides. Formation of reactive Mn(3+) species coincided with the generation of aromatic oxidation products, providing direct proof of the previously posited role of Mn(3+)-based oxidizers in the breakdown of litter. Our results suggest that the litter-decomposing machinery at our coniferous forest site depends on the ability of plants and microbes to supply, accumulate, and regenerate short-lived Mn(3+) species in the litter layer. This observation indicates that biogeochemical constraints on bioavailability, mobility, and reactivity of Mn in the plant-soil system may have a profound impact on litter decomposition rates.

  18. [Effects of litter and root exclusion on soil microbial community composition and function of four plantations in subtropical sandy coastal plain area, China].

    Science.gov (United States)

    Sang, Chang Peng; Wan, Xiao Hua; Yu, Zai Peng; Wang, Min Huang; Lin, Yu; Huang, Zhi Qun

    2017-04-18

    We conducted detritus input and removal treatment (DIRT) to examine the effects of shifting above- and belowground carbon (C) inputs on soil microbial biomass, community composition and function in subtropical Pinus elliottii, Eucalyptus urophylla × Eucalyptus grandis, Acacia aulacocarpa and Casuarina equisetifolia coastal sandy plain forests, and the treatments included: root trenching, litter removal and control. Up to September 2015, one year after the experiment began, we collected the 0-10 cm soil samples from each plot. Phospholipid fatty acid (PLFA) analysis was used to characterize the microbial community composition, and micro-hole enzymatic detection technology was utilized to determine the activity of six kinds of soil enzymes. Results showed that changes in microbial biomass induced by the C input manipulations differed among tree species, and mainly affected by litter and root qualily. In E. urophylla × E. grandis stands, root trenching significantly decreased the contents of total PLFAs, Gram-positive bacteria, Gram-negative bacteria, fungi and actinomycetes by 31%, 30%, 32%, 36% and 26%, respectively. Litter removal reduced the contents of Gram-positive bacteria, fungi and actinomycetes by 24%, 27% and 24%, respectively. However, C input manipulations had no significant effect on soil microbial biomassunder other three plantations. According to the effect of C input manipulations on soil microbial community structure, litter and root exclusion decreased fungi abundance and increased actinomycetes abundance. Different treatments under different plantations resulted in various soil enzyme activities. Litter removal significantly decreased the activities of cellobiohydrolase, β-glucosidase, acid phosphatase and N-acetyl-β-d-glucosaminidase of P. elliottii, A. aulacocarpa and C. equisetifolia, root exclusion only decreased and increased the activities of β-glucosidase in P. elliottii and A. aulacocarpa forest soils, respectively. Litter removal also

  19. Aboveground Biomass and Litterfall Dynamics in Secondary Forest ...

    African Journals Online (AJOL)

    The differences in aboveground biomass, litterfall patterns and the seasonality of litterfall in three secondary forest fields aged 1, 5 and 10 years of age regenerating from degraded abandoned rubber plantation and a mature forest were studied in southern Nigeria. This is with a view to understanding the possibility of ...

  20. Cost structure of and competition for forest-based biomass

    International Nuclear Information System (INIS)

    Lundmark, Robert

    2007-01-01

    Biomass has become a popular alternative to satisfy expanding energy demand and as a substitute for fossil fuels and phased-out nuclear energy in Europe. The European Union White Paper stipulates that the utilization of biomass shall increase to 1566 TWh by 2010. However it is often overlooked that the forest resources are already, to a large extent, used by the forest industries. When promoting biomass for energy generation the consequences for the forest industries also need to be considered. Sweden is an excellent case study, as there are vast quantities of forest resources, nuclear power is starting to be phased out, there are restrictions on expanding hydropower and the political desire exists to 'set an example' with respect to carbon dioxide emissions. This paper attempts to estimate and analyse the supply of two types of forest resource, namely, roundwood and harvesting residues derived from final harvesting and commercial thinnings. Two separate supply curves are estimated: one for roundwood and one for harvesting residues. The cost structure is based on an economic-engineering approach where the separate cost components are constructed from the lowest cost element into aggregates for labour, capital, materials and overhead costs for each forest resource. The results indicate an unutilized economic supply of 12 TWh of harvesting residues in Sweden. However, after these 12 TWh have been recovered it becomes more profitable to use roundwood for energy purposes than to continue extracting further amounts of harvesting residues

  1. Impact of biomass harvesting on forest soil productivity in the northern Rocky Mountains

    Science.gov (United States)

    Woongsoon Jang; Christopher R. Keyes; Deborah Page-Dumroese

    2015-01-01

    Biomass harvesting extracts an increased amount of organic matter from forest ecosystems over conventional harvesting. Since organic matter plays a critical role in forest productivity, concerns of potential negative long-term impacts of biomass harvesting on forest productivity (i.e., changing nutrient/water cycling, aggravating soil properties, and compaction) have...

  2. How does litter quality and site heterogeneity interact on decomposer food webs of a semi-natural forest?

    DEFF Research Database (Denmark)

    Strandmark, Lisa Bjørnlund; Christensen, Søren

    2005-01-01

    The relative importance of litter quality and site heterogeneity on population dynamics of decomposer food webs was investigated in a semi-natural mixed deciduous forest in Denmark. Litterbags containing beech or ash leaves were placed in four plots. Plots were located within gaps and under closed...... at the end of the study period. At the first sampling, where bacterial activity prevailed, the relative abundance of the two dominant bacterial-feeders, Rhabditidae (fast growing) and Plectus spp. (slower growing), depended more on site than litter type. At the second sampling where fungal activity became...... in the decomposer food web, site effects were also detected and nematode functional groups responded more to site than to litter quality early on in the decomposition process....

  3. Forest Biomass Energy Resources in China: Quantity and Distribution

    Directory of Open Access Journals (Sweden)

    Caixia Zhang

    2015-11-01

    Full Text Available As one of the most important renewable and sustainable energy sources, the forest biomass energy resource has always been the focus of attention of scholars and policy makers. However, its potential is still uncertain in China, especially with respect to its spatial distribution. In this paper, the quantity and distribution of Chinese forest biomass energy resources are explored based mainly on forestry statistics data rather than forest resource inventory data used by most previous studies. The results show that the forest biomass energy resource in China was 169 million tons in 2010, of which wood felling and bucking residue (WFBR,wood processing residue (WPR, bamboo processing residue, fuel wood and firewood used by farmers accounted for 38%, 37%, 6%, 4% and 15%, respectively. The highest resource was located in East China, accounting for nearly 39.0% of the national amount, followed by the Southwest and South China regions, which accounted for 17.4% and 16.3%, respectively. At the provincial scale, Shandong has the highest distribution, accounting for 11.9% of total resources, followed by Guangxi and Fujian accounting for 10.3% and 10.2%, respectively. The actual wood-processing residue (AWPR estimated from the actual production of different wood products (considering the wood transferred between regions showed apparent differences from the local wood processing residue (LWPR, which assumes that no wood has been transferredbetween regions. Due to the large contribution of WPR to total forestry bioenergy resources, the estimation of AWPR will provide a more accurate evaluation of the total amount and the spatial distribution of forest biomass energy resources in China.

  4. Species diversity and chemical properties of litter influence non-additive effects of litter mixtures on soil carbon and nitrogen cycling

    OpenAIRE

    Mao, Bing; Mao, Rong; Zeng, De-Hui

    2017-01-01

    Decomposition of litter mixtures generally cannot be predicted from the component species incubated in isolation. Therefore, such non-additive effects of litter mixing on soil C and N dynamics remain poorly understood in terrestrial ecosystems. In this study, litters of Mongolian pine and three dominant understory species and soil were collected from a Mongolian pine plantation in Northeast China. In order to examine the effects of mixed-species litter on soil microbial biomass N, soil net N ...

  5. Soil Warming: Consequences for Foliar Litter Decay in a Spruce-Fir Forest in Maine, USA

    Science.gov (United States)

    Lindsey E. Rustad; Ivan J. Fernandez

    1998-01-01

    Increased rates of litter decay due to projected global warming could substantially alter the balance between C assimilation and release in forest soils, with consequent feedbacks to climate change. This study was conducted to investigate the effects of soil warming on the decomposition of red spruce (Picea rubens Sarg.) and red maple (...

  6. Aboveground Forest Biomass Estimation with Landsat and LiDAR Data and Uncertainty Analysis of the Estimates

    Directory of Open Access Journals (Sweden)

    Dengsheng Lu

    2012-01-01

    Full Text Available Landsat Thematic mapper (TM image has long been the dominate data source, and recently LiDAR has offered an important new structural data stream for forest biomass estimations. On the other hand, forest biomass uncertainty analysis research has only recently obtained sufficient attention due to the difficulty in collecting reference data. This paper provides a brief overview of current forest biomass estimation methods using both TM and LiDAR data. A case study is then presented that demonstrates the forest biomass estimation methods and uncertainty analysis. Results indicate that Landsat TM data can provide adequate biomass estimates for secondary succession but are not suitable for mature forest biomass estimates due to data saturation problems. LiDAR can overcome TM’s shortcoming providing better biomass estimation performance but has not been extensively applied in practice due to data availability constraints. The uncertainty analysis indicates that various sources affect the performance of forest biomass/carbon estimation. With that said, the clear dominate sources of uncertainty are the variation of input sample plot data and data saturation problem related to optical sensors. A possible solution to increasing the confidence in forest biomass estimates is to integrate the strengths of multisensor data.

  7. Decoupling of lignin and total litter decomposition across North American forest soils: a phenomenon to reconcile old and new paradigms of soil organic matter?

    Science.gov (United States)

    Hall, S. J.; Hammel, K.

    2017-12-01

    An "old" paradigm of soil organic matter (SOM) posited that biochemically "recalcitrant" lignin derivatives were a dominant constituent. Over the past decade(s), evidence for a newer paradigm has emerged which suggests that recalcitrance has little long-term impact on the biochemical composition of SOM, and that lignin is relatively unimportant in comparison with dead microbial biomass. Yet, methodological biases have hampered accurate quantification of lignin dynamics in mineral soils, and may have led to systematic underestimates of lignin stocks and turnover. Here, we sought to test this aspect of the "new" SOM paradigm. Synthetic position-specific 13C-labeled lignins provide a robust quantitative method to track the mineralization and fate of lignin moieties in mineral soils. Relatively few microbial taxa are known to depolymerize macromolecular lignin, and lignin derivatives can specifically associate with iron oxide mineral phases. Consequently, we hypothesized that decomposition of lignin is poorly correlated with total litter decomposition across ecosystems, and that lignin may represent a variable but significant component of decadal-cycling SOM. We incubated 10 forest soils spanning diverse North American ecosystems over seven months under laboratory conditions at constant temperature and moisture. Soils were incubated alone, with added C4 grass litter and natural isotope abundance lignin, and with added C4 litter and 13Cß-labeled lignin. These treatments allowed us to partition respiration for each soil from SOM, litter, and the Cß moiety of lignin—which is diagnostic for cleavage of the polymer. Consistent with our hypothesis, we found much greater variability (ten-fold) in cumulative lignin mineralization relative to bulk litter (two-fold) among soils. Multiple-pool first-order decay models implied that mean turnover times for lignin ranged from one to several decades among soils, relative to several years for bulk litter. Our results suggest a

  8. Retrieval of pine forest biomass using JPL AIRSAR data

    Science.gov (United States)

    Beaudoin, A.; Letoan, T.; Zagolski, F.; Hsu, C. C.; Han, H. C.; Kong, J. A.

    1992-01-01

    The analysis of Jet Propulsion Laboratory (JPL) Airborne Synthetic Aperture Radar (AIRSAR) data over the Landes forest in South-West France revealed strong correlation between L- and especially P-band sigma degrees and the pine forest biomass. To explain the physical link of radar backscatter to biomass, a polarimetric backscattering model was developed and validated. Then the model was used in a simulation study to predict sigma degree sensitivity to undesired canopy and environmental parameters. Main results concerning the data analysis, modeling, and simulation at P-band are reported.

  9. Estimation of Boreal Forest Biomass Using Spaceborne SAR Systems

    Science.gov (United States)

    Saatchi, Sassan; Moghaddam, Mahta

    1995-01-01

    In this paper, we report on the use of a semiempirical algorithm derived from a two layer radar backscatter model for forest canopies. The model stratifies the forest canopy into crown and stem layers, separates the structural and biometric attributes of the canopy. The structural parameters are estimated by training the model with polarimetric SAR (synthetic aperture radar) data acquired over homogeneous stands with known above ground biomass. Given the structural parameters, the semi-empirical algorithm has four remaining parameters, crown biomass, stem biomass, surface soil moisture, and surface rms height that can be estimated by at least four independent SAR measurements. The algorithm has been used to generate biomass maps over the entire images acquired by JPL AIRSAR and SIR-C SAR systems. The semi-empirical algorithms are then modified to be used by single frequency radar systems such as ERS-1, JERS-1, and Radarsat. The accuracy. of biomass estimation from single channel radars is compared with the case when the channels are used together in synergism or in a polarimetric system.

  10. Cultivable microflora and endo mycorrhizas obtained in litter forest (Paramo Guerrero - Finca Puente de Tierra) Zipaquira, Colombia

    International Nuclear Information System (INIS)

    Bernal, Eleonora; Celis, Sebastian; Galindez, Ximena; Moratto, Claudia; Sanchez, Jimena; Garcia, Daniel

    2006-01-01

    The count of cultivable microorganisms (bacteria and fungi), cellulolytic microorganisms and endo mycorrhizas present in litter forest (property Puente de Tierra) in the Guerrero's moor, Colombia was made. The most frequently isolated microorganisms belonged to the staphylococcus, bacillus, pseudomonas, micrococcus, penicillium and rhodotorulagenus and cladosporium sp., which is a cellulolytic microorganism, was isolated in carboxymethyl cellulose agar. In addition eight morphotypes of endomycorrhizas were found, species of glomus and acaulospora predominated among them. This study contributes with the knowledge of the cultivable microorganisms of litter that have been little explored in moor ecosystems

  11. Forest biomass mapping from fusion of GEDI Lidar data and TanDEM-X InSAR data

    Science.gov (United States)

    Qi, W.; Hancock, S.; Armston, J.; Marselis, S.; Dubayah, R.

    2017-12-01

    Mapping forest above-ground biomass (hereafter biomass) can significantly improve our ability to assess the role of forest in terrestrial carbon budget and to analyze the ecosystem productivity. Global Ecosystem Dynamic Investigation (GEDI) mission will provide the most complete lidar observations of forest vertical structure and has the potential to provide global-scale forest biomass data at 1-km resolution. However, GEDI is intrinsically a sampling mission and will have a between-track spacing of 600 m. An increase in adjacent-swath distance and the presence of cloud cover may also lead to larger gaps between GEDI tracks. In order to provide wall-to-wall forest biomass maps, fusion algorithms of GEDI lidar data and TanDEM-X InSAR data were explored in this study. Relationship between biomass and lidar RH metrics was firstly developed and used to derive biomass values over GEDI tracks which were simulated using airborne lidar data. These GEDI biomass values were then averaged in each 1-km cell to represent the biomass density within that cell. Whereas for cells without any GEDI observations, regression models developed between GEDI-derived biomass and TDX InSAR variables were applied to predict biomass over those places. Based on these procedures, contiguous biomass maps were finally generated at 1-km resolution over three representative forest types. Uncertainties for these biomass maps were also estimated at 1 km following methods developed in Saarela et al. (2016). Our results indicated great potential of GEDI/TDX fusion for large-scale biomass mapping. Saarela, S., Holm, S., Grafstrom, A., Schnell, S., Naesset, E., Gregoire, T.G., Nelson, R.F., & Stahl, G. (2016). Hierarchical model-based inference for forest inventory utilizing three sources of information. Annals of Forest Science, 73, 895-910

  12. Net soil respiration and greenhouse gas balance along a sequence of forest disturbance to smallholder rubber and oil palm plantations in Sumatra

    Science.gov (United States)

    Khusyu Aini, Fitri; Hergoualc'h, Kristell; Smith, Jo; Verchot, Louis; Martius, Christopher

    2017-04-01

    The rapid increase in demand for land to establish oil palm and rubber plantations has led to the conversion of forests, with potential impacts on greenhouse gas emissions and on climate change. This study evaluates the net greenhouse gas balance following forest change to other land uses, i.e. one year rubber plantation, twenty-year rubber plantation and eight year oil palm plantation on Sumatran mineral soils. None of the plantations had ever been fertilized previously. During this study they were fertilized to provide nitrogen at the recommended rate used by farmers (33.3 kg N ha-1 y-1). The ecosystem stores carbon in litterfall, standing litter biomass (undergrowth vegetation, leaves, twigs, litter on the soil surface), soil organic matter, root biomass, and standing tree biomass. It releases carbon to the atmosphere through soil respiration fluxes, negative values indicating that carbon is stored by the land use change and positive values indicating emissions to the atmosphere. Net soil respiration was assessed using a mass balance approach: standing litter and tree biomass were measured once; the rate of carbon accumulation from standing litter and tree biomass was calculated by dividing the stock by the age of plantation or the time since logging started in the disturbed forest. The carbon accumulation in standing litter, tree biomass in the forest and soil organic matter for all land-uses was estimated from available in the literature. Root biomass for each land-use system was calculated using the root:shoot ratio. The net soil respiration of carbon dioxide from the forest, disturbed forest, one year rubber plantation, twenty-year rubber plantation and oil palm plantation were calculated to be -6 (± 5), 12 (± 6), 11 (± 15), 10 (± 5), 39 (± 7) Mg ha-1 y-1, respectively. Soil nitrous oxide, methane and litterfall were measured for 14 months and respiration fluxes were measured for 5 months across land uses and different seasons. The measured emissions of

  13. Conversion of tropical lowland forest reduces nutrient return through litterfall, and alters nutrient use efficiency and seasonality of net primary production.

    Science.gov (United States)

    Kotowska, Martyna M; Leuschner, Christoph; Triadiati, Triadiati; Hertel, Dietrich

    2016-02-01

    Tropical landscapes are not only rapidly transformed by ongoing land-use change, but are additionally confronted by increasing seasonal climate variation. There is an increasing demand for studies analyzing the effects and feedbacks on ecosystem functioning of large-scale conversions of tropical natural forest into intensively managed cash crop agriculture. We analyzed the seasonality of aboveground litterfall, fine root litter production, and aboveground woody biomass production (ANPP(woody)) in natural lowland forests, rubber agroforests under natural tree cover ("jungle rubber"), rubber and oil palm monocultures along a forest-to-agriculture transformation gradient in Sumatra. We hypothesized that the temporal fluctuation of litter production increases with increasing land-use intensity, while the associated nutrient fluxes and nutrient use efficiency (NUE) decrease. Indeed, the seasonal variation of aboveground litter production and ANPP(woody) increased from the natural forest to the plantations, while aboveground litterfall generally decreased. Nutrient return through aboveground litter was mostly highest in the natural forest; however, it was significantly lower only in rubber plantations. NUE of N, P and K was lowest in the oil palm plantations, with natural forest and the rubber systems showing comparably high values. Root litter production was generally lower than leaf litter production in all systems, while the root-to-leaf ratio of litter C flux increased along the land-use intensity gradient. Our results suggest that nutrient and C cycles are more directly affected by climate seasonality in species-poor agricultural systems than in species-rich forests, and therefore might be more susceptible to inter-annual climate fluctuation and climate change.

  14. Trees as templates for tropical litter arthropod diversity.

    Science.gov (United States)

    Donoso, David A; Johnston, Mary K; Kaspari, Michael

    2010-09-01

    Increased tree species diversity in the tropics is associated with even greater herbivore diversity, but few tests of tree effects on litter arthropod diversity exist. We studied whether tree species influence patchiness in diversity and abundance of three common soil arthropod taxa (ants, gamasid mites, and oribatid mites) in a Panama forest. The tree specialization hypothesis proposes that tree-driven habitat heterogeneity maintains litter arthropod diversity. We tested whether tree species differed in resource quality and quantity of their leaf litter and whether more heterogeneous litter supports more arthropod species. Alternatively, the abundance-extinction hypothesis states that arthropod diversity increases with arthropod abundance, which in turn tracks resource quantity (e.g., litter depth). We found little support for the hypothesis that tropical trees are templates for litter arthropod diversity. Ten tree species differed in litter depth, chemistry, and structural variability. However, the extent of specialization of invertebrates on particular tree taxa was low and the more heterogeneous litter between trees failed to support higher arthropod diversity. Furthermore, arthropod diversity did not track abundance or litter depth. The lack of association between tree species and litter arthropods suggests that factors other than tree species diversity may better explain the high arthropod diversity in tropical forests.

  15. Experts’ Perceptions of the Effects of Forest Biomass Harvesting on Sustainability in the Alpine Region

    Directory of Open Access Journals (Sweden)

    Gianluca Grilli

    2015-06-01

    Full Text Available Background and Purpose: In the EU political agenda, the use of forest biomass for energy has grown rapidly and significantly, in order to mitigate carbon dioxide emissions and reduce the energy dependence on fossil fuels of European member countries. The target of the EU climate and energy package is to raise the share of renewable energy consumption produced from renewable resources to 20% in 2020 (Directive 2009/28/EC. With regards to biomass energy, the supply of forest wood biomass is expected to rise by 45% (reference period: 2006-2020, in response to increasing demand for renewable sources. The increase of forest biomass supply could have both positive and negative effects on several forest ecosystem services (ESs and local development. These effects should be assessed in a proper manner and taken into account when formulating management strategies. The aim of the paper is to assess the environmental, economic and social sustainability of forest biomass harvesting for energy, using the Figure of Merit (FoM approach. Materials and Methods: Sustainability was assessed through a set of four indicators: two focused on experts’ opinions regarding the effects of forest biomass harvesting and the other two focused on the cost-benefit analysis (potential energy obtained and costs for wood chips. The research was developed through four case studies located in the Alpine Region. A semi-structured questionnaire was administered face-to-face to 32 selected experts. The perceived effects of forest biomass harvesting for energy on ESs and local development were evaluated by experts using a 5-point Likert scale (from “quite negative effect” to “quite positive effect”. Results: All experts agree that forest biomass harvesting has a positive effect on forest products provision and local economic development (employment of local workforce, local entrepreneurship and market diversification, while the effects on other ESs are controversial (e

  16. Does species richness affect fine root biomass and production in young forest plantations?

    DEFF Research Database (Denmark)

    Domisch, Timo; Finér, Leena; Dawud, Seid Muhie

    2015-01-01

    Tree species diversity has been reported to increase forest ecosystem above-ground biomass and productivity, but little is known about below-ground biomass and production in diverse mixed forests compared to single-species forests. For testing whether species richness increases below-ground biomass...... and production and thus complementarity between forest tree species in young stands, we determined fine root biomass and production of trees and ground vegetation in two experimental plantations representing gradients in tree species richness. Additionally, we measured tree fine root length and determined...... be that these stands were still young, and canopy closure had not always taken place, i.e. a situation where above- or below-ground competition did not yet exist. Another reason could be that the rooting traits of the tree species did not differ sufficiently to support niche differentiation. Our results suggested...

  17. Aboveground Biomass Variability Across Intact and Degraded Forests in the Brazilian Amazon

    Science.gov (United States)

    Longo, Marcos; Keller, Michael; Dos-Santos, Maiza N.; Leitold, Veronika; Pinage, Ekena R.; Baccini, Alessandro; Saatchi, Sassan; Nogueira, Euler M.; Batistella, Mateus; Morton, Douglas C.

    2016-01-01

    Deforestation rates have declined in the Brazilian Amazon since 2005, yet degradation from logging, re, and fragmentation has continued in frontier forests. In this study we quantified the aboveground carbon density (ACD) in intact and degraded forests using the largest data set of integrated forest inventory plots (n 359) and airborne lidar data (18,000 ha) assembled to date for the Brazilian Amazon. We developed statistical models relating inventory ACD estimates to lidar metrics that explained70 of the variance across forest types. Airborne lidar-ACD estimates for intact forests ranged between 5.0 +/- 2.5 and 31.9 +/- 10.8 kg C m(exp -2). Degradation carbon losses were large and persistent. Sites that burned multiple times within a decade lost up to 15.0 +/- 0.7 kg C m(-2)(94%) of ACD. Forests that burned nearly15 years ago had between 4.1 +/- 0.5 and 6.8 +/- 0.3 kg C m(exp -2) (22-40%) less ACD than intact forests. Even for low-impact logging disturbances, ACD was between 0.7 +/- 0.3 and 4.4 +/- 0.4 kg C m(exp -2)(4-21%) lower than unlogged forests. Comparing biomass estimates from airborne lidar to existing biomass maps, we found that regional and pan-tropical products consistently overestimated ACD in degraded forests, under-estimated ACD in intact forests, and showed little sensitivity to res and logging. Fine-scale heterogeneity in ACD across intact and degraded forests highlights the benefits of airborne lidar for carbon mapping. Differences between airborne lidar and regional biomass maps underscore the need to improve and update biomass estimates for dynamic land use frontiers, to better characterize deforestation and degradation carbon emissions for regional carbon budgets and Reduce Emissions from Deforestation and forest Degradation(REDD+).

  18. Biomass accumulation rates of Amazonian secondary forest and biomass of old-growth forests from Landsat time series and the Geoscience Laser Altimeter System

    Science.gov (United States)

    E. H. Helmer; M. A. Lefsky; D. A. Roberts

    2009-01-01

    We estimate the age of humid lowland tropical forests in Rondônia, Brazil, from a somewhat densely spaced time series of Landsat images (1975–2003) with an automated procedure, the Threshold Age Mapping Algorithm (TAMA), first described here. We then estimate a landscape-level rate of aboveground woody biomass accumulation of secondary forest by combining forest age...

  19. A review of forest and tree plantation biomass equations in Indonesia

    NARCIS (Netherlands)

    Anitha, Kamalakumari; Verchot, Louis V.; Joseph, Shijo; Herold, Martin; Manuri, Solichin; Avitabile, Valerio

    2015-01-01

    Key message: We compiled 2,458 biomass equations from 168 destructive sampling studies in Indonesia. Unpublished academic theses contributed the largest share of the biomass equations. The availability of the biomass equations was skewed to certain regions, forest types, and species. Further

  20. Model Effects on GLAS-Based Regional Estimates of Forest Biomass and Carbon

    Science.gov (United States)

    Nelson, Ross F.

    2010-01-01

    Ice, Cloud, and land Elevation Satellite (ICESat) / Geosciences Laser Altimeter System (GLAS) waveform data are used to estimate biomass and carbon on a 1.27 X 10(exp 6) square km study area in the Province of Quebec, Canada, below the tree line. The same input datasets and sampling design are used in conjunction with four different predictive models to estimate total aboveground dry forest biomass and forest carbon. The four models include non-stratified and stratified versions of a multiple linear model where either biomass or (biomass)(exp 0.5) serves as the dependent variable. The use of different models in Quebec introduces differences in Provincial dry biomass estimates of up to 0.35 G, with a range of 4.94 +/- 0.28 Gt to 5.29 +/-0.36 Gt. The differences among model estimates are statistically non-significant, however, and the results demonstrate the degree to which carbon estimates vary strictly as a function of the model used to estimate regional biomass. Results also indicate that GLAS measurements become problematic with respect to height and biomass retrievals in the boreal forest when biomass values fall below 20 t/ha and when GLAS 75th percentile heights fall below 7 m.

  1. Effects of LiDAR point density and landscape context on the retrieval of urban forest biomass

    Science.gov (United States)

    Singh, K. K.; Chen, G.; McCarter, J. B.; Meentemeyer, R. K.

    2014-12-01

    Light Detection and Ranging (LiDAR), as an alternative to conventional optical remote sensing, is being increasingly used to accurately estimate aboveground forest biomass ranging from individual tree to stand levels. Recent advancements in LiDAR technology have resulted in higher point densities and better data accuracies, which however pose challenges to the procurement and processing of LiDAR data for large-area assessments. Reducing point density cuts data acquisition costs and overcome computational challenges for broad-scale forest management. However, how does that impact the accuracy of biomass estimation in an urban environment containing a great level of anthropogenic disturbances? The main goal of this study is to evaluate the effects of LiDAR point density on the biomass estimation of remnant forests in the rapidly urbanizing regions of Charlotte, North Carolina, USA. We used multiple linear regression to establish the statistical relationship between field-measured biomass and predictor variables (PVs) derived from LiDAR point clouds with varying densities. We compared the estimation accuracies between the general Urban Forest models (no discrimination of forest type) and the Forest Type models (evergreen, deciduous, and mixed), which was followed by quantifying the degree to which landscape context influenced biomass estimation. The explained biomass variance of Urban Forest models, adjusted R2, was fairly consistent across the reduced point densities with the highest difference of 11.5% between the 100% and 1% point densities. The combined estimates of Forest Type biomass models outperformed the Urban Forest models using two representative point densities (100% and 40%). The Urban Forest biomass model with development density of 125 m radius produced the highest adjusted R2 (0.83 and 0.82 at 100% and 40% LiDAR point densities, respectively) and the lowest RMSE values, signifying the distance impact of development on biomass estimation. Our evaluation

  2. [Spatial pattern of forest biomass and its influencing factors in the Great Xing'an Mountains, Heilongjiang Province, China].

    Science.gov (United States)

    Wang, Xiao-Li; Chang, Yu; Chen, Hong-Wei; Hu, Yuan-Man; Jiao, Lin-Lin; Feng, Yu-Ting; Wu, Wen; Wu, Hai-Feng

    2014-04-01

    Based on field inventory data and vegetation index EVI (enhanced vegetation index), the spatial pattern of the forest biomass in the Great Xing'an Mountains, Heilongjiang Province was quantitatively analyzed. Using the spatial analysis and statistics tools in ArcGIS software, the impacts of climatic zone, elevation, slope, aspect and vegetation type on the spatial pattern of forest biomass were explored. The results showed that the forest biomass in the Great Xing'an Mountains was 350 Tg and spatially aggregated with great increasing potentials. Forest biomass density in the cold temperate humid zone (64.02 t x hm(-2)) was higher than that in the temperate humid zone (60.26 t x hm(-2)). The biomass density of each vegetation type was in the order of mixed coniferous forest (65.13 t x hm(-2)) > spruce-fir forest (63.92 t x hm(-2)) > Pinus pumila-Larix gmelinii forest (63.79 t x hm(-2)) > Pinus sylvestris var. mongolica forest (61.97 t x hm(-2)) > Larix gmelinii forest (61.40 t x hm(-2)) > deciduous broadleaf forest (58.96 t x hm(-2)). With the increasing elevation and slope, the forest biomass density first decreased and then increased. The forest biomass density in the shady slopes was greater than that in the sunny slopes. The spatial pattern of forest biomass in the Great Xing' an Mountains exhibited a heterogeneous pattern due to the variation of climatic zone, vegetation type and topographical factor. This spatial heterogeneity needs to be accounted when evaluating forest biomass at regional scales.

  3. The leaf litter ant fauna of an Atlantic Forest area in the Cantareira State Park – São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Andre Soliva Ribeiro

    2005-11-01

    Full Text Available The present work surveys the leaf litter ant fauna of an Atlantic Forest area in Cantareira State Park – SP, Brazil as a complement to the project “Richness and diversity of Hymenoptera and Isoptera along a latitudinal gradient in the Atlantic Forest – the eastern Brazilian rain forest” that forms part of the BIOTA-FAPESP program. The general protocol of the project was to collect 50 leaf litter samples of 1 m2 which were then sifted and submitted to Winkler extractors for 48 hours. Sixty-two species of 25 genera in eight ant subfamilies were collected. Myrmicinae was the richest with 39 species, followed by Ponerinae (14, Ectatomminae, Heteroponerinae and Formicinae (two species each, Amblyoponinae, Proceratiinae and Dolichoderinae (one species each. The richest genera were Solenopsis and Hypoponera (12 morph-species each, and Pheidole (eight. Richness estimators indicated that the total number of species in the area should be between 68 and 85, in a confidence interval of 95%. In comparison, other locations of the evergreen Atlantic Forest have shown a significantly higher richness. Our hypothesis is that the proximity of regions of great urban concentration, allied to the factors that act on a local scale, modifies the structure of the local community of leaf litter ants.

  4. Above Ground Biomass-carbon Partitioning, Storage and Sequestration in a Rehabilitated Forest, Bintulu, Sarawak, Malaysia

    International Nuclear Information System (INIS)

    Kueh, J.H.R.; Majid, N.M.A.; Seca, G.; Ahmed, O.H.

    2013-01-01

    Forest degradation and deforestation are some of the major global concerns as it can reduce forest carbon storage and sequestration capacity. Forest rehabilitation on degraded forest areas has the potential to improve carbon stock, hence mitigate greenhouse gases emission. However, the carbon storage and sequestration potential in a rehabilitated tropical forest remains unclear due to the lack of information. This paper reports an initiative to estimate biomass-carbon partitioning, storage and sequestration in a rehabilitated forest. The study site was at the UPM-Mitsubishi Corporation Forest Rehabilitation Project, UPM Bintulu Sarawak Campus, Bintulu, Sarawak. A plot of 20 x 20 m 2 was established each in site 1991 (Plot 1991), 1999 (Plot 1999) and 2008 (Plot 2008). An adjacent natural regenerating secondary forest plot (Plot NF) was also established for comparison purposes. The results showed that the contribution of tree component biomass/ carbon to total biomass/ carbon was in the order of main stem > branch > leaf. As most of the trees were concentrated in diameter size class = 10 cm for younger rehabilitated forests, the total above ground biomass/ carbon was from this class. These observations suggest that the forests are in the early successional stage. The total above ground biomass obtained for the rehabilitated forest ranged from 4.3 to 4,192.3 kg compared to natural regenerating secondary forest of 3,942.3 kg while total above ground carbon ranged from 1.9 to 1,927.9 kg and 1,820.4 kg, respectively. The mean total above ground biomass accumulated ranged from 1.3 x 10 -2 to 20.5 kg/ 0.04 ha and mean total carbon storage ranged from 5.9 x 10 -3 to 9.4 kg/ 0.04 ha. The total CO 2 sequestrated in rehabilitated forest ranged from 6.9 to 7,069.1 kg CO 2 / 0.04 ha. After 19 years, the rehabilitated forest had total above ground biomass and carbon storage comparable to the natural regeneration secondary forest. The forest rehabilitated activities have the

  5. Green electricity externalities: Forest biomass in an Atlantic European Region

    International Nuclear Information System (INIS)

    Solino, M.; Prada, A.; Vazquez, M.X.

    2009-01-01

    Renewable energy sources are expected to represent a growing proportion of the primary energy sources for the production of electricity. Environmental and social reasons support this tendency. European and Spanish energy plans assign a role of primary importance to biomass in general and, especially, to forest biomass for the period up to 2010. This paper reviews, organises and quantifies the potentials and values of this renewable resource in the foremost Spanish Region in terms of silviculture. The non-market externalities (environmental, economic and social) are classified, and some of them are quantified to present a synthesis of the benefits of a partial substitution of fossil fuels by forest biomass for electricity generation. (author)

  6. Competence of Litter Ants for Rapid Biodiversity Assessments

    Directory of Open Access Journals (Sweden)

    T. H. Saumya E. Silva

    2017-01-01

    Full Text Available Rapid Biodiversity Assessment approaches associated with focusing taxa have overcome many of the problems related to large scale surveys. This study examined the suitability of litter ants as a focusing taxon by checking whether diversity and species assemblages of litter ants reflect the overall picture of arthropod diversity and assemblages in leaf litter in two vegetation types: secondary forest and pine plantation in Upper Hanthana forest reserve, Sri Lanka. In each vegetation type, arthropods were sampled using three sampling methods (Winkler extraction, hand collection, and pitfall traps along three 100 m line transects. From the two sites, 1887 litter ants (34 species and 3488 litter arthropods (52 species were collected. Species assemblages composition of both ants and other arthropods differed significantly between the two sites (ANOSIM, p=0.001 with both groups generating distinct clusters for the two sites (SIMPROF, p=0.001. But there was no significant correlation (p>0.05 between abundance and richness of litter ants and those of other arthropods in both vegetation types. The overall finding suggests that the litter ants do not reflect the holistic picture of arthropod diversity and assemblages in leaf litter, but the quality of the habitat for the survival of all litter arthropods.

  7. Allometric biomass equations for 12 tree species in coniferous and broadleaved mixed forests, Northeastern China.

    Science.gov (United States)

    He, Huaijiang; Zhang, Chunyu; Zhao, Xiuhai; Fousseni, Folega; Wang, Jinsong; Dai, Haijun; Yang, Song; Zuo, Qiang

    2018-01-01

    Understanding forest carbon budget and dynamics for sustainable resource management and ecosystem functions requires quantification of above- and below-ground biomass at individual tree species and stand levels. In this study, a total of 122 trees (9-12 per species) were destructively sampled to determine above- and below-ground biomass of 12 tree species (Acer mandshuricum, Acer mono, Betula platyphylla, Carpinus cordata, Fraxinus mandshurica, Juglans mandshurica, Maackia amurensis, P. koraiensis, Populus ussuriensis, Quercus mongolica, Tilia amurensis and Ulmus japonica) in coniferous and broadleaved mixed forests of Northeastern China, an area of the largest natural forest in the country. Biomass allocation was examined and biomass models were developed using diameter as independent variable for individual tree species and all species combined. The results showed that the largest biomass allocation of all species combined was on stems (57.1%), followed by coarse root (21.3%), branch (18.7%), and foliage (2.9%). The log-transformed model was statistically significant for all biomass components, although predicting power was higher for species-specific models than for all species combined, general biomass models, and higher for stems, roots, above-ground biomass, and total tree biomass than for branch and foliage biomass. These findings supplement the previous studies on this forest type by additional sample trees, species and locations, and support biomass research on forest carbon budget and dynamics by management activities such as thinning and harvesting in the northeastern part of China.

  8. Dominant effect of increasing forest biomass on evapotranspiration: interpretations of movement in Budyko space

    Science.gov (United States)

    Jaramillo, Fernando; Cory, Neil; Arheimer, Berit; Laudon, Hjalmar; van der Velde, Ype; Hasper, Thomas B.; Teutschbein, Claudia; Uddling, Johan

    2018-01-01

    During the last 6 decades, forest biomass has increased in Sweden mainly due to forest management, with a possible increasing effect on evapotranspiration. However, increasing global CO2 concentrations may also trigger physiological water-saving responses in broadleaf tree species, and to a lesser degree in some needleleaf conifer species, inducing an opposite effect. Additionally, changes in other forest attributes may also affect evapotranspiration. In this study, we aimed to detect the dominating effect(s) of forest change on evapotranspiration by studying changes in the ratio of actual evapotranspiration to precipitation, known as the evaporative ratio, during the period 1961-2012. We first used the Budyko framework of water and energy availability at the basin scale to study the hydroclimatic movements in Budyko space of 65 temperate and boreal basins during this period. We found that movements in Budyko space could not be explained by climatic changes in precipitation and potential evapotranspiration in 60 % of these basins, suggesting the existence of other dominant drivers of hydroclimatic change. In both the temperate and boreal basin groups studied, a negative climatic effect on the evaporative ratio was counteracted by a positive residual effect. The positive residual effect occurred along with increasing standing forest biomass in the temperate and boreal basin groups, increasing forest cover in the temperate basin group and no apparent changes in forest species composition in any group. From the three forest attributes, standing forest biomass was the one that could explain most of the variance of the residual effect in both basin groups. These results further suggest that the water-saving response to increasing CO2 in these forests is either negligible or overridden by the opposite effect of the increasing forest biomass. Thus, we conclude that increasing standing forest biomass is the dominant driver of long-term and large-scale evapotranspiration

  9. Login wood. Logistic for the Treatment of Forest Biomass; Loginwood. Logistica para el tratamiento de biomasa forestal

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Sanchez, R.; Ayala Schraemili, F.

    2008-07-01

    This paper is about developing a logistic for the treatment of the forest prunes, including specific machines so far. Collecting, treatment, and transportation of forest biomass residues to valuation energy plant. Key words: collecting, treatment, transportation of forest prunes. (Author)

  10. Detritivores enhance the mobilization of {sup 137}Cs from leaf-litter

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Masashi; Suzuki, Takahiro [Community Ecology Lab., Biology Course, Faculty of Science, Chiba University, Chiba, 263-8522 (Japan); Ishii, Nobuyoshi [National Institute of Radiological Sciences, Chiba, 263-8555 (Japan); Ohte, Nobuhito [Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 (Japan)

    2014-07-01

    A large amount of radioactive material was released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident after the disastrous earthquake and subsequent tsunami of March 2011. Since most of the Japanese land area is covered by forest ecosystems, {sup 137}Cs was mostly deposited and accumulated on the land surface of forest. The fate of radioactive materials accumulated on the leaf litters should be conscientiously monitored to understand the future distribution and the spread to the surrounding landscapes. Because the accident took place on 11 March 2011, just before the bud-break of deciduous trees, the {sup 137}Cs are highly accumulated on the surface of leaf litter on the forest floor. This accumulated {sup 137}Cs had transferred to higher trophic organisms mainly through the detritus food chain. However, on the litter surface, {sup 137}Cs considered to be strongly and immediately fixed and highly immobilized. Decomposition processes in the forest floor can re-mobilise the nutritional elements which are contained within detritus and make them available for the organisms. In the present study, the feeding effect of detritivore soil arthropods on the mobilization of {sup 137}Cs from leaf litter was experimentally examined. Furthermore, the effect of detritivores on the plant uptake of {sup 137}Cs was examined by small-scale nursery experiment. Decomposition experiment in the small microcosms was performed using a larvae of Trypoxylus dichotomus, whichis a detritivores feeding on dead plant materials such as wood debris and leaf litters. Contaminated leaf litters were collected in a forest of the Kami-Oguni River catchment in the northern part of Fukushima Prefecture. The leaf litters at A0 layers which are highly contaminated by {sup 137}Cs were utilized for the experiment. The contaminated leaf litter was fed to the larvae for ten days. The litter with larvae excreta was washed by 2 M KCl and deionized water. The {sup 137}Cs concentration was measured

  11. Regional mapping of forest canopy water content and biomass using AIRSAR images over BOREAS study area

    Science.gov (United States)

    Saatchi, Sasan; Rignot, Eric; Vanzyl, Jakob

    1995-01-01

    In recent years, monitoring vegetation biomass over various climate zones has become the primary focus of several studies interested in assessing the role of the ecosystem responses to climate change and human activities. Airborne and spaceborne Synthetic Aperture Radar (SAR) systems provide a useful tool to directly estimate biomass due to its sensitivity to structural and moisture characteristics of vegetation canopies. Even though the sensitivity of SAR data to total aboveground biomass has been successfully demonstrated in many controlled experiments over boreal forests and forest plantations, so far, no biomass estimation algorithm has been developed. This is mainly due to the fact that the SAR data, even at lowest frequency (P-band) saturates at biomass levels of about 200 tons/ha, and the structure and moisture information in the SAR signal forces the estimation algorithm to be forest type dependent. In this paper, we discuss the development of a hybrid forest biomass algorithm which uses a SAR derived land cover map in conjunction with a forest backscatter model and an inversion algorithm to estimate forest canopy water content. It is shown that unlike the direct biomass estimation from SAR data, the estimation of water content does not depend on the seasonal and/or environmental conditions. The total aboveground biomass can then be derived from canopy water content for each type of forest by incorporating other ecological information. Preliminary results from this technique over several boreal forest stands indicate that (1) the forest biomass can be estimated with reasonable accuracy, and (2) the saturation level of the SAR signal can be enhanced by separating the crown and trunk biomass in the inversion algorithm. We have used the JPL AIRSAR data over BOREAS southern study area to test the algorithm and to generate regional scale water content and biomass maps. The results are compared with ground data and the sources of errors are discussed. Several SAR

  12. The Role of Remote Sensing in Assessing Forest Biomass in Appalachian South Carolina

    Science.gov (United States)

    Shain, W.; Nix, L.

    1982-01-01

    Information is presented on the use of color infrared aerial photographs and ground sampling methods to quantify standing forest biomass in Appalachian South Carolina. Local tree biomass equations are given and subsequent evaluation of stand density and size classes using remote sensing methods is presented. Methods of terrain analysis, environmental hazard rating, and subsequent determination of accessibility of forest biomass are discussed. Computer-based statistical analyses are used to expand individual cover-type specific ground sample data to area-wide cover type inventory figures based on aerial photographic interpretation and area measurement. Forest biomass data are presented for the study area in terms of discriminant size classes, merchantability limits, accessibility (as related to terrain and yield/harvest constraints), and potential environmental impact of harvest.

  13. Evaluation of Sentinel-1A Data For Above Ground Biomass Estimation in Different Forests in India

    Science.gov (United States)

    Vadrevu, Krishna Prasad

    2017-01-01

    Use of remote sensing data for mapping and monitoring of forest biomass across large spatial scales can aid in addressing uncertainties in carbon cycle. Earlier, several researchers reported on the use of Synthetic Aperture Radar (SAR) data for characterizing forest structural parameters and the above ground biomass estimation. However, these studies cannot be generalized and the algorithms cannot be applied to all types of forests without additional information on the forest physiognomy, stand structure and biomass characteristics. The radar backscatter signal also saturates as forest parameters such as biomass and the tree height increase. It is also not clear how different polarizations (VV versus VH) impact the backscatter retrievals in different forested regions. Thus, it is important to evaluate the potential of SAR data in different landscapes for characterizing forest structural parameters. In this study, the SAR data from Sentinel-1A has been used to characterize forest structural parameters including the above ground biomass from tropical forests of India. Ground based data on tree density, basal area and above ground biomass data from thirty-eight different forested sites has been collected to relate to SAR data. After the pre-processing of Sentinel 1-A data for radiometric calibration, geo-correction, terrain correction and speckle filtering, the variability in the backscatter signal in relation tree density, basal area and above biomass density has been investigated. Results from the curve fitting approach suggested exponential model between the Sentinel-1A backscatter versus tree density and above ground biomass whereas the relationship was almost linear with the basal area in the VV polarization mode. Of the different parameters, tree density could explain most of the variations in backscatter. Both VV and VH backscatter signals could explain only thirty and thirty three percent of variation in above biomass in different forest sites of India

  14. Patterns of biomass and carbon distribution across a chronosequence of Chinese pine (Pinus tabulaeformis) forests.

    Science.gov (United States)

    Zhao, Jinlong; Kang, Fengfeng; Wang, Luoxin; Yu, Xiaowen; Zhao, Weihong; Song, Xiaoshuai; Zhang, Yanlei; Chen, Feng; Sun, Yu; He, Tengfei; Han, Hairong

    2014-01-01

    Patterns of biomass and carbon (C) storage distribution across Chinese pine (Pinus tabulaeformis) natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb), and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH) were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0-100 cm) were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha-1 for the young stand to 344.8 Mg·ha-1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha-1 in the middle-aged stand to 3.5 Mg·ha-1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha-1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha-1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale.

  15. Patterns of biomass and carbon distribution across a chronosequence of Chinese pine (Pinus tabulaeformis forests.

    Directory of Open Access Journals (Sweden)

    Jinlong Zhao

    Full Text Available Patterns of biomass and carbon (C storage distribution across Chinese pine (Pinus tabulaeformis natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb, and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0-100 cm were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha-1 for the young stand to 344.8 Mg·ha-1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha-1 in the middle-aged stand to 3.5 Mg·ha-1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha-1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha-1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale.

  16. Contribution of Soil Fauna to Foliar Litter-Mass Loss in Winter in an Ecotone between Dry Valley and Montane Forest in the Upper Reaches of the Minjiang River.

    Science.gov (United States)

    Peng, Yan; Yang, Wanqin; Li, Jun; Wang, Bin; Zhang, Chuan; Yue, Kai; Wu, Fuzhong

    2015-01-01

    Litter decomposition during winter can provide essential nutrients for plant growth in the subsequent growing season, which plays important role in preventing the expansion of dry areas and maintaining the stability of ecotone ecosystems. However, limited information is currently available on the contributions of soil fauna to litter decomposition during winter in such ecosystems. Therefore, a field experiment that included litterbags with two different mesh sizes (0.04 mm and 3 mm) was conducted to investigate the contribution of soil fauna to the loss of foliar litter mass in winter from November 2013 to April 2014 along the upper reaches of the Minjiang River. Two litter types of the dominant species were selected in each ecosystem: cypress (Cupressus chengiana) and oak (Quercus baronii) in ecotone; cypress (Cupressus chengiana) and clovershrub (Campylotropis macrocarpa) in dry valley; and fir (Abies faxoniana) and birch (Betula albosinensis) in montane forest. Over one winter incubation, foliar litter lost 6.0%-16.1%, 11.4%-26.0%, and 6.4%-8.5% of initial mass in the ecotone, dry valley and montane forest, respectively. Soil fauna showed obvious contributions to the loss of foliar litter mass in all of the ecosystems. The highest contribution (48.5%-56.8%) was observed in the ecotone, and the lowest contribution (0.4%-25.8%) was observed in the montane forest. Compared with other winter periods, thawing period exhibited higher soil fauna contributions to litter mass loss in ecotone and dry valley, but both thawing period and freezing period displayed higher soil fauna contributions in montane forest. Statistical analysis demonstrated that the contribution of soil fauna was significantly correlated with temperature and soil moisture during the winter-long incubation. These results suggest that temperature might be the primary control factor in foliar litter decomposition, but more active soil fauna in the ecotone could contribute more in litter decomposition and

  17. Contribution of Soil Fauna to Foliar Litter-Mass Loss in Winter in an Ecotone between Dry Valley and Montane Forest in the Upper Reaches of the Minjiang River.

    Directory of Open Access Journals (Sweden)

    Yan Peng

    Full Text Available Litter decomposition during winter can provide essential nutrients for plant growth in the subsequent growing season, which plays important role in preventing the expansion of dry areas and maintaining the stability of ecotone ecosystems. However, limited information is currently available on the contributions of soil fauna to litter decomposition during winter in such ecosystems. Therefore, a field experiment that included litterbags with two different mesh sizes (0.04 mm and 3 mm was conducted to investigate the contribution of soil fauna to the loss of foliar litter mass in winter from November 2013 to April 2014 along the upper reaches of the Minjiang River. Two litter types of the dominant species were selected in each ecosystem: cypress (Cupressus chengiana and oak (Quercus baronii in ecotone; cypress (Cupressus chengiana and clovershrub (Campylotropis macrocarpa in dry valley; and fir (Abies faxoniana and birch (Betula albosinensis in montane forest. Over one winter incubation, foliar litter lost 6.0%-16.1%, 11.4%-26.0%, and 6.4%-8.5% of initial mass in the ecotone, dry valley and montane forest, respectively. Soil fauna showed obvious contributions to the loss of foliar litter mass in all of the ecosystems. The highest contribution (48.5%-56.8% was observed in the ecotone, and the lowest contribution (0.4%-25.8% was observed in the montane forest. Compared with other winter periods, thawing period exhibited higher soil fauna contributions to litter mass loss in ecotone and dry valley, but both thawing period and freezing period displayed higher soil fauna contributions in montane forest. Statistical analysis demonstrated that the contribution of soil fauna was significantly correlated with temperature and soil moisture during the winter-long incubation. These results suggest that temperature might be the primary control factor in foliar litter decomposition, but more active soil fauna in the ecotone could contribute more in litter

  18. Regional biomass stores and dynamics in forests of coastal Alaska

    Science.gov (United States)

    Mikhaill A. Yatskov; Mark E. Harmon; Olga N. Krankina; Tara M. Barrett; Kevin R. Dobelbower; Andrew N. Gray; Becky Fasth; Lori Trummer; Toni L. Hoyman; Chana M. Dudoit

    2015-01-01

    Coastal Alaska is a vast forested region (6.2 million ha) with the potential to store large amounts of carbon in live and dead biomass thus influencing continental and global carbon dynamics. The main objectives of this study were to assess regional biomass stores, examine the biomass partitioning between live and dead pools, and evaluate the effect of disturbance on...

  19. Assessing impacts of intensified biomass production and biodiversity protection on ecosystem services provided by European forests

    NARCIS (Netherlands)

    Verkerk, P.J.; Mavsar, R.; Giergiczny, M.; Lindner, M.; Edwards, D.; Schelhaas, M.J.

    2014-01-01

    To develop viable strategies for intensifying the use of forest biomass and for increasing forest protection, impacts on ecosystem services need to be assessed. We investigated the biophysical and economic impacts of increased forest biomass production and biodiversity protection on forest ecosystem

  20. Woody biomass utilization trends, barriers, and strategies: Perspectives of U.S. Forest Service managers

    Science.gov (United States)

    Shiloh Sundstrom; Max Nielsen-Pincus; Cassandra Moseley; Sarah. McCaffrey

    2012-01-01

    The use of woody biomass is being promoted across the United States as a means of increasing energy independence, mitigating climate change, and reducing the cost of hazardous fuels reduction treatments and forest restoration projects. The opportunities and challenges for woody biomass use on the national forest system are unique. In addition to making woody biomass...

  1. Does species richness affect fine root biomass and production in young forest plantations?

    Science.gov (United States)

    Domisch, Timo; Finér, Leena; Dawud, Seid Muhie; Vesterdal, Lars; Raulund-Rasmussen, Karsten

    2015-02-01

    Tree species diversity has been reported to increase forest ecosystem above-ground biomass and productivity, but little is known about below-ground biomass and production in diverse mixed forests compared to single-species forests. For testing whether species richness increases below-ground biomass and production and thus complementarity between forest tree species in young stands, we determined fine root biomass and production of trees and ground vegetation in two experimental plantations representing gradients in tree species richness. Additionally, we measured tree fine root length and determined species composition from fine root biomass samples with the near-infrared reflectance spectroscopy method. We did not observe higher biomass or production in mixed stands compared to monocultures. Neither did we observe any differences in tree root length or fine root turnover. One reason for this could be that these stands were still young, and canopy closure had not always taken place, i.e. a situation where above- or below-ground competition did not yet exist. Another reason could be that the rooting traits of the tree species did not differ sufficiently to support niche differentiation. Our results suggested that functional group identity (i.e. conifers vs. broadleaved species) can be more important for below-ground biomass and production than the species richness itself, as conifers seemed to be more competitive in colonising the soil volume, compared to broadleaved species.

  2. Regional Distribution of Forest Height and Biomass from Multisensor Data Fusion

    Science.gov (United States)

    Yu, Yifan; Saatchi, Sassan; Heath, Linda S.; LaPoint, Elizabeth; Myneni, Ranga; Knyazikhin, Yuri

    2010-01-01

    Elevation data acquired from radar interferometry at C-band from SRTM are used in data fusion techniques to estimate regional scale forest height and aboveground live biomass (AGLB) over the state of Maine. Two fusion techniques have been developed to perform post-processing and parameter estimations from four data sets: 1 arc sec National Elevation Data (NED), SRTM derived elevation (30 m), Landsat Enhanced Thematic Mapper (ETM) bands (30 m), derived vegetation index (VI) and NLCD2001 land cover map. The first fusion algorithm corrects for missing or erroneous NED data using an iterative interpolation approach and produces distribution of scattering phase centers from SRTM-NED in three dominant forest types of evergreen conifers, deciduous, and mixed stands. The second fusion technique integrates the USDA Forest Service, Forest Inventory and Analysis (FIA) ground-based plot data to develop an algorithm to transform the scattering phase centers into mean forest height and aboveground biomass. Height estimates over evergreen (R2 = 0.86, P forests (R2 = 0.93, P forests were less accurate because of the winter acquisition of SRTM data and loss of scattering phase center from tree ]surface interaction. We used two methods to estimate AGLB; algorithms based on direct estimation from the scattering phase center produced higher precision (R2 = 0.79, RMSE = 25 Mg/ha) than those estimated from forest height (R2 = 0.25, RMSE = 66 Mg/ha). We discuss sources of uncertainty and implications of the results in the context of mapping regional and continental scale forest biomass distribution.

  3. Forest above Ground Biomass Inversion by Fusing GLAS with Optical Remote Sensing Data

    Directory of Open Access Journals (Sweden)

    Xiaohuan Xi

    2016-03-01

    Full Text Available Forest biomass is an important parameter for quantifying and understanding biological and physical processes on the Earth’s surface. Rapid, reliable, and objective estimations of forest biomass are essential to terrestrial ecosystem research. The Geoscience Laser Altimeter System (GLAS produced substantial scientific data for detecting the vegetation structure at the footprint level. This study combined GLAS data with MODIS/BRDF (Bidirectional Reflectance Distribution Function and ASTER GDEM data to estimate forest aboveground biomass (AGB in Xishuangbanna, Yunnan Province, China. The GLAS waveform characteristic parameters were extracted using the wavelet method. The ASTER DEM was used to compute the terrain index for reducing the topographic influence on the GLAS canopy height estimation. A neural network method was applied to assimilate the MODIS BRDF data with the canopy heights for estimating continuous forest heights. Forest leaf area indices (LAIs were derived from Landsat TM imagery. A series of biomass estimation models were developed and validated using regression analyses between field-estimated biomass, canopy height, and LAI. The GLAS-derived canopy heights in Xishuangbanna correlated well with the field-estimated AGB (R2 = 0.61, RMSE = 52.79 Mg/ha. Combining the GLAS estimated canopy heights and LAI yielded a stronger correlation with the field-estimated AGB (R2 = 0.73, RMSE = 38.20 Mg/ha, which indicates that the accuracy of the estimated biomass in complex terrains can be improved significantly by integrating GLAS and optical remote sensing data.

  4. Nitrogen fertilization decreases forest soil fungal and bacterial biomass in three long-term experiments

    Science.gov (United States)

    Matthew D. Wallenstein; Steven McNulty; Ivan J. Fernandez; Johnny Boggs; William H. Schlesinger

    2006-01-01

    We examined the effects of N fertilization on forest soil fungal and bacterial biomass at three long-term experiments in New England (Harvard Forest, MA; Mt. Ascutney, VT; Bear Brook, ME). At Harvard Forest, chronic N fertilization has decreased organic soil microbial biomass C (MBC) by an average of 54% and substrate induced respiration (SIR) was decreased by an...

  5. Ecological restoration of litter in mined areas

    Science.gov (United States)

    Teresinha Gonçalves Bizuti, Denise; Nino Diniz, Najara; Schweizer, Daniella; de Marchi Soares, Thaís; Casagrande, José Carlos; Henrique Santin Brancalion, Pedro

    2016-04-01

    The success of ecological restoration projects depends on going monitoring of key ecological variables to determine if a desired trajectory has been established and, in the case of mining sites, nutrient cycling recovery plays an utmost importance. This study aimed to quantify and compare the annual litter production in native forests, and in restoration sites established in bauxite mines. We collected samples in 6 native forest remnants and 6 year-old restoration sites every month for a period of one year, in the city of Poços de Caldas/MG, SE Brazil. 120 wire collectors were used (0,6x0,6) and suspended 30cm above the soil surface. The material was dried until constant weight, weighed and fractionated in leaves, branches and reproductive material. The average annual litter production was 2,6 Mg ha-1 in native forests and 2,1 in forest in restoration sites, differing statistically. Litter production was higher in the rainy season, especially in September. Among the litter components, the largest contributor to total production was the fraction leaves, with 55,4% of the total dry weight of material collected, followed by reproductive material which contributed 24,5% and branches, with 20%. We conclude that the young areas in restoration process already restored important part, but still below the production observed in native areas.

  6. Forest biomass, canopy structure, and species composition relationships with multipolarization L-band synthetic aperture radar data

    Science.gov (United States)

    Sader, Steven A.

    1987-01-01

    The effect of forest biomass, canopy structure, and species composition on L-band synthetic aperature radar data at 44 southern Mississippi bottomland hardwood and pine-hardwood forest sites was investigated. Cross-polarization mean digital values for pine forests were significantly correlated with green weight biomass and stand structure. Multiple linear regression with five forest structure variables provided a better integrated measure of canopy roughness and produced highly significant correlation coefficients for hardwood forests using HV/VV ratio only. Differences in biomass levels and canopy structure, including branching patterns and vertical canopy stratification, were important sources of volume scatter affecting multipolarization radar data. Standardized correction techniques and calibration of aircraft data, in addition to development of canopy models, are recommended for future investigations of forest biomass and structure using synthetic aperture radar.

  7. Impact of biogas interventions on forest biomass and regeneration in southern India

    Directory of Open Access Journals (Sweden)

    M. Agarwala

    2017-07-01

    Full Text Available Programs to provide alternative energy sources such as biogas improve indoor air quality and potentially reduce pressure on forests from fuelwood collection. This study tests whether biogas intervention is associated with higher forest biomass and forest regeneration in degraded forests in Chikkaballapur district in Southern India. Using propensity score matching, we find that forest plots in proximity to villages with biogas interventions (treatment had greater forest biomass than comparable plots around villages without biogas (control. We also found significantly higher sapling abundance and diversity in treatment than control plots despite no significant difference in seedling abundances and diversity in treatment forests, suggesting that plants have a higher probability of reaching sapling stage. These results indicate the potential for alternative energy sources that reduce dependence on fuelwood to promote regeneration of degraded forests. However, forest regrowth is not uniform across treatments and is limited by soil nutrients and biased towards species that are light demanding, fire-resistant and can thrive in poor soil conditions.

  8. Demonstration of a Small Modular BioPower System Using Poultry Litter

    Energy Technology Data Exchange (ETDEWEB)

    John P. Reardon; Art Lilley; Jim Wimberly; Kingsbury Browne; Kelly Beard; Jack Avens

    2002-05-22

    The purpose of this project was to assess poultry grower residue, or litter (manure plus absorbent biomass), as a fuel source for Community Power Corporation's small modular biopower system (SMB). A second objective was to assess the poultry industry to identify potential ''on-site'' applications of the SMB system using poultry litter residue as a fuel source, and to adapt CPC's existing SMB to generate electricity and heat from the poultry litter biomass fuel. Bench-scale testing and pilot testing were used to gain design information for the SMB retrofit. System design approach for the Phase II application of the SMB was the goal of Phase I testing. Cost estimates for an onsite poultry litter SMB were prepared. Finally, a market estimate was prepared for implementation of the on-farm SMB using poultry litter.

  9. Tropical forest biomass and successional age class relationships to a vegetation index derived from Landsat TM data

    Science.gov (United States)

    Sader, Steven A.; Waide, Robert B.; Lawrence, William T.; Joyce, Armond T.

    1989-01-01

    Forest stand structure and biomass data were collected using conventional forest inventory techniques in tropical, subtropical, and warm temperate forest biomes. The feasibility of detecting tropical forest successional age class and total biomass differences using Landsat-Thematic mapper (TM) data, was evaluated. The Normalized Difference Vegetation Index (NDVI) calculated from Landsat-TM data were not significantly correlated with forest regeneration age classes in the mountain terrain of the Luquillo Experimental Forest, Puerto Rico. The low sun angle and shadows cast on steep north and west facing slopes reduced spectral reflectance values recorded by TM orbital altitude. The NDVI, calculated from low altitude aircraft scanner data, was significatly correlated with forest age classes. However, analysis of variance suggested that NDVI differences were not detectable for successional forests older than approximately 15-20 years. Also, biomass differences in young successional tropical forest were not detectable using the NDVI. The vegetation index does not appear to be a good predictor of stand structure variables (e.g., height, diameter of main stem) or total biomass in uneven age, mixed broadleaf forest. Good correlation between the vegetation index and low biomass in even age pine plantations were achieved for a warm temperate study site. The implications of the study for the use of NDVI for forest structure and biomass estimation are discussed.

  10. Forest harvesting reduces the soil metagenomic potential for biomass decomposition.

    Science.gov (United States)

    Cardenas, Erick; Kranabetter, J M; Hope, Graeme; Maas, Kendra R; Hallam, Steven; Mohn, William W

    2015-11-01

    Soil is the key resource that must be managed to ensure sustainable forest productivity. Soil microbial communities mediate numerous essential ecosystem functions, and recent studies show that forest harvesting alters soil community composition. From a long-term soil productivity study site in a temperate coniferous forest in British Columbia, 21 forest soil shotgun metagenomes were generated, totaling 187 Gb. A method to analyze unassembled metagenome reads from the complex community was optimized and validated. The subsequent metagenome analysis revealed that, 12 years after forest harvesting, there were 16% and 8% reductions in relative abundances of biomass decomposition genes in the organic and mineral soil layers, respectively. Organic and mineral soil layers differed markedly in genetic potential for biomass degradation, with the organic layer having greater potential and being more strongly affected by harvesting. Gene families were disproportionately affected, and we identified 41 gene families consistently affected by harvesting, including families involved in lignin, cellulose, hemicellulose and pectin degradation. The results strongly suggest that harvesting profoundly altered below-ground cycling of carbon and other nutrients at this site, with potentially important consequences for forest regeneration. Thus, it is important to determine whether these changes foreshadow long-term changes in forest productivity or resilience and whether these changes are broadly characteristic of harvested forests.

  11. Input and turnover of forest tree litter in the Forsmark and Oskarshamn areas

    Energy Technology Data Exchange (ETDEWEB)

    Mjoefors, Kristina; Johansson, Maj-Britt; Nilsson, Aake [Dept. of Forest Soi ls, Swedish Univ. of Agricultural Sciences (Sweden); Hyvoenen, Riitta [Dept. of Eco logy, Swedish Univ. of Agricultural Sciences (Sweden)

    2007-04-15

    The site investigations reported here were conducted to provide data for the comprehensive descriptive ecosystem model that is being constructed. This report provides estimates of annual inputs of aboveground litter from trees (dry mass and amounts of C and N), litter decomposition rates and changes in organic and inorganic components in litter during decomposition. The study in the Forsmark area comprised two Norway spruce (Picea abies (L.) Karst) stands (sites F1 and F3), and a mixed stand of Norway spruce and alder (Alnus glutinosa (L.) Gaertn.) (site F2). The study in the Oskarshamn area comprised one common oak stand (Quercus robur L.) (site O1), one Scots pine stand (Pinus silvestris L.) (site O2) and one Norway spruce stand (site O3). In the Forsmark area, the aboveground litterfall from trees was of similar magnitude at sites F1 and F2, but considerably lower at site F3. At the former sites the average annual litterfall amounted to 195 and 231 gdw/m{sup 2} respectively, whereas the latter site received only 136 gdw/m{sup 2}. There was also a large variation in annual litterfall between stands in the Oskarshamn area. The spruce stand at site O3 exhibited the highest litterfall (almost 400 gdw/m{sup 2}), followed by the oak stand at site O1 (with almost 300 gdw/m{sup 2}), whereas the pine stand at site O2 had the lowest (less than 150 gdw/m{sup 2}). The proportion of needles/leaves in the total litterfall varied between 65% and 75% for the stands. The amount of carbon (C) returned in aboveground litterfall amounted to between 60 and 110 gdw/m{sup 2}/yr at the forest sites within the Forsmark area. The corresponding range for the sites in the Oskarshamn area was 70 to 190 gdw/m{sup 2}/yr. At sites O1 and O2 in Oskarshamn, about 3.6 gdw/m{sup 2}/yr of nitrogen (N) were returned annually to the forest floor by the aboveground litterfall. This was over four times the N amount deposited in the Scots pine stand in the same area (about 0.8 gdw/m{sup 2}/yr). At the

  12. Input and turnover of forest tree litter in the Forsmark and Oskarshamn areas

    International Nuclear Information System (INIS)

    Mjoefors, Kristina; Johansson, Maj-Britt; Nilsson, Aake; Hyvoenen, Riitta

    2007-04-01

    The site investigations reported here were conducted to provide data for the comprehensive descriptive ecosystem model that is being constructed. This report provides estimates of annual inputs of aboveground litter from trees (dry mass and amounts of C and N), litter decomposition rates and changes in organic and inorganic components in litter during decomposition. The study in the Forsmark area comprised two Norway spruce (Picea abies (L.) Karst) stands (sites F1 and F3), and a mixed stand of Norway spruce and alder (Alnus glutinosa (L.) Gaertn.) (site F2). The study in the Oskarshamn area comprised one common oak stand (Quercus robur L.) (site O1), one Scots pine stand (Pinus silvestris L.) (site O2) and one Norway spruce stand (site O3). In the Forsmark area, the aboveground litterfall from trees was of similar magnitude at sites F1 and F2, but considerably lower at site F3. At the former sites the average annual litterfall amounted to 195 and 231 gdw/m 2 respectively, whereas the latter site received only 136 gdw/m 2 . There was also a large variation in annual litterfall between stands in the Oskarshamn area. The spruce stand at site O3 exhibited the highest litterfall (almost 400 gdw/m 2 ), followed by the oak stand at site O1 (with almost 300 gdw/m 2 ), whereas the pine stand at site O2 had the lowest (less than 150 gdw/m 2 ). The proportion of needles/leaves in the total litterfall varied between 65% and 75% for the stands. The amount of carbon (C) returned in aboveground litterfall amounted to between 60 and 110 gdw/m 2 /yr at the forest sites within the Forsmark area. The corresponding range for the sites in the Oskarshamn area was 70 to 190 gdw/m 2 /yr. At sites O1 and O2 in Oskarshamn, about 3.6 gdw/m 2 /yr of nitrogen (N) were returned annually to the forest floor by the aboveground litterfall. This was over four times the N amount deposited in the Scots pine stand in the same area (about 0.8 gdw/m 2 /yr). At the Forsmark sites, the N return in

  13. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    Directory of Open Access Journals (Sweden)

    Antônio Ocimar Manzi

    2011-04-01

    Full Text Available Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and groundwater chemistry and soil CO2 respiration were studied in forests on sandy soils, whereas drought sensitivity of poorly-drained valley soils was investigated in an artificial drainage experiment. Slightly changes in litter decomposition or water chemistry were observed as a consequence of artificial drainage. Riparian plots did experience higher litter decomposition rates than campina forest. In response to a permanent lowering of the groundwater level from 0.1 m to 0.3 m depth in the drainage plot, topsoil carbon and nitrogen contents decreased substantially. Soil CO2 respiration decreased from 3.7±0.6 µmol m-2 s-1 before drainage to 2.5±0.2 and 0.8±0.1 µmol m-2 s-1 eight and 11 months after drainage, respectively. Soil respiration in the control plot remained constant at 3.7±0.6 µmol m-2 s-1. The above suggests that more frequent droughts may affect topsoil carbon and nitrogen content and soil respiration rates in the riparian ecosystem, and may induce a transition to less diverse campinarana or short-statured campina forest that covers areas with strongly-leached sandy soil.

  14. Are double trailers cost effective for transporting forest biomass on steep terrain?

    Directory of Open Access Journals (Sweden)

    Rene Zamora-Cristales

    2015-07-01

    Full Text Available Transportation of forest biomass on steep terrain involves logistical challenges. Trucks with large single trailers are often unable to travel on forest roads due to their narrowness, tight curves, adverse grades and limited areas to turn around. A shorter trailer must be used but then transportation capacity is limited by the trailer volume due to the low bulk density of the processed biomass, particularly when the biomass is dry. With double trailers, transportation capacity can be limited by allowable legal weight based on axle number and spacing. We developed a simulation model that explores the economic feasibility of using double-trailer configurations to transport forest biomass to a bioenergy facility from the grinder at a landing or from a centralized yard in Washington, Oregon and California. Results show that double trailers can be a cost effective alternative to single trailers under limited conditions in Oregon and Washington, but they are not a competitive option in California due to the state's transportation regulations.

  15. Use of GIS for estimating potential and actual forest biomass for continental South and Southeast Asia.

    Science.gov (United States)

    L. R. Iverson; S. Brown; A. Prasad; H. Mitasova; A. J. R. Gillespie; A. E. Lugo

    1994-01-01

    A geographic information system (GIS) was used to estimate total biomass and biomass density of the tropical forest in south and southeast Asia because available data from forest inventories were insufficient to extrapolate biomass-density estimates across the region.

  16. Tropical forest biomass estimation from truncated stand tables.

    Science.gov (United States)

    A. J. R. Gillespie; S. Brown; A. E. Lugo

    1992-01-01

    Total aboveground forest biomass may be estimated through a variety of techniques based on commercial inventory stand and stock tables. Stand and stock tables from tropical countries commonly omit trees bellow a certain commercial limit.

  17. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS (CFB AND CLB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Ben Thein; Gengsheng Wei; Soyuz Priyadarsan; Senthil Arumugam; Kevin Heflin

    2003-08-28

    Intensive animal feeding operations create large amounts of animal waste that must be safely disposed of in order to avoid environmental degradation. Cattle feedlots and chicken houses are two examples. In feedlots, cattle are confined to small pens and fed a high calorie grain-diet diet in preparation for slaughter. In chicken houses, thousands of chickens are kept in close proximity. In both of these operations, millions of tons of manure are produced every year. The manure could be used as a fuel by mixing it with coal in a 90:10 blend and firing it in an existing coal suspension fired combustion systems. This technique is known as co-firing, and the high temperatures produced by the coal will allow the biomass to be completely combusted. Reburn is a process where a small percentage of fuel called reburn fuel is injected above the NO{sub x} producing, conventional coal fired burners in order to reduce NO{sub x}. The manure could also be used as reburn fuel for reducing NO{sub x} in coal fired plants. An alternate approach of using animal waste is to adopt the gasification process using a fixed bed gasifier and then use the gases for firing in gas turbine combustors. In this report, the cattle manure is referred to as feedlot biomass (FB) and chicken manure as litter biomass (LB). The report generates data on FB and LB fuel characteristics. Co-firing, reburn, and gasification tests of coal, FB, LB, coal: FB blends, and coal: LB blends and modeling on cofiring, reburn systems and economics of use of FB and LB have also been conducted. The biomass fuels are higher in ash, lower in heat content, higher in moisture, and higher in nitrogen and sulfur (which can cause air pollution) compared to coal. Small-scale cofiring experiments revealed that the biomass blends can be successfully fired, and NO{sub x} emissions will be similar to or lower than pollutant emissions when firing coal. Further experiments showed that biomass is twice or more effective than coal when

  18. Production of bio-oil from underutilized forest biomass using an auger reactor

    Science.gov (United States)

    H. Ravindran; S. Thangalzhy-Gopakumar; S. Adhikari; O. Fasina; M. Tu; B. Via; E. Carter; S. Taylor

    2015-01-01

    Conversion of underutilized forest biomass to bio-oil could be a niche market for energy production. In this work, bio-oil was produced from underutilized forest biomass at selected temperatures between 425–500°C using an auger reactor. Physical properties of bio-oil, such as pH, density, heating value, ash, and water, were analyzed and compared with an ASTM standard...

  19. Demonstration of a Small Modular BioPower System Using Poultry Litter; FINAL

    International Nuclear Information System (INIS)

    John P. Reardon; Art Lilley; Jim Wimberly; Kingsbury Browne; Kelly Beard; Jack Avens

    2002-01-01

    The purpose of this project was to assess poultry grower residue, or litter (manure plus absorbent biomass), as a fuel source for Community Power Corporation's small modular biopower system (SMB). A second objective was to assess the poultry industry to identify potential ''on-site'' applications of the SMB system using poultry litter residue as a fuel source, and to adapt CPC's existing SMB to generate electricty and heat from the poultry litter biomass fuel. Bench-scale testing and pilot testing were used to gain design information for the SMB retrofit. System design approach for the Phase II application of the SMB was the goal of Phase I testing. Cost estimates for an onsite poultry litter SMB were prepared. Finally, a market estimate was prepared for implementation of the on-farm SMB using poultry litter

  20. Regional supply, demand and utilization of forest biomass in South-East Finland; Metsaeenergian kaeytoen kasvun liiketoimintamahdollisuudet Kaakkois-Suomessa

    Energy Technology Data Exchange (ETDEWEB)

    Laihanen, M.; Karhunen, A.; Ranta, T.

    2011-07-01

    Rising demand of forest biomass in South-East Finland has created need to evaluate the impact for different energy users and producers. The aim of this study is to settle the current demand and availability of forest biomass and to evaluate the opportunities the growth offers. Initial data of study base on current structure of energy supply and on current energy demand. The information can be used as a guideline when evaluating local sufficiency of energy wood and business opportunities for local actors such as energy producers and forest fuel suppliers. Main aim of the study is to create prosperity and entrepreneurship to South-East Finland. Analysis included following tasks: gathering data about the current and potential use and users of forest biomass (logging residues, stumps and small diameter energy wood), settling local availability of forest fuels, creating forest biomass balance to indicate the sufficiency of local resources and to identify the effects of current business opportunities around forest biomass sector. Results of the study illustrate local balance between use and availability of energy wood, need for labor and revenue of forest biomass supply in South-East Finland. Evaluation analysis constructed for regional and local needs combine the current and potential use of forest biomass with local availability. Analysis represents model for evaluating local possibilities of utilization of forest biomass. Co-operation with Forestry Centre of South-East Finland was productive through entire study. (orig.)

  1. Dominant effect of increasing forest biomass on evapotranspiration: interpretations of movement in Budyko space

    Directory of Open Access Journals (Sweden)

    F. Jaramillo

    2018-01-01

    Full Text Available During the last 6 decades, forest biomass has increased in Sweden mainly due to forest management, with a possible increasing effect on evapotranspiration. However, increasing global CO2 concentrations may also trigger physiological water-saving responses in broadleaf tree species, and to a lesser degree in some needleleaf conifer species, inducing an opposite effect. Additionally, changes in other forest attributes may also affect evapotranspiration. In this study, we aimed to detect the dominating effect(s of forest change on evapotranspiration by studying changes in the ratio of actual evapotranspiration to precipitation, known as the evaporative ratio, during the period 1961–2012. We first used the Budyko framework of water and energy availability at the basin scale to study the hydroclimatic movements in Budyko space of 65 temperate and boreal basins during this period. We found that movements in Budyko space could not be explained by climatic changes in precipitation and potential evapotranspiration in 60 % of these basins, suggesting the existence of other dominant drivers of hydroclimatic change. In both the temperate and boreal basin groups studied, a negative climatic effect on the evaporative ratio was counteracted by a positive residual effect. The positive residual effect occurred along with increasing standing forest biomass in the temperate and boreal basin groups, increasing forest cover in the temperate basin group and no apparent changes in forest species composition in any group. From the three forest attributes, standing forest biomass was the one that could explain most of the variance of the residual effect in both basin groups. These results further suggest that the water-saving response to increasing CO2 in these forests is either negligible or overridden by the opposite effect of the increasing forest biomass. Thus, we conclude that increasing standing forest biomass is the dominant driver of long-term and large

  2. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants

    Science.gov (United States)

    Woodcock, Paul; Edwards, David P.; Fayle, Tom M.; Newton, Rob J.; Khen, Chey Vun; Bottrell, Simon H.; Hamer, Keith C.

    2011-01-01

    South East Asia is widely regarded as a centre of threatened biodiversity owing to extensive logging and forest conversion to agriculture. In particular, forests degraded by repeated rounds of intensive logging are viewed as having little conservation value and are afforded meagre protection from conversion to oil palm. Here, we determine the biological value of such heavily degraded forests by comparing leaf-litter ant communities in unlogged (natural) and twice-logged forests in Sabah, Borneo. We accounted for impacts of logging on habitat heterogeneity by comparing species richness and composition at four nested spatial scales, and examining how species richness was partitioned across the landscape in each habitat. We found that twice-logged forest had fewer species occurrences, lower species richness at small spatial scales and altered species composition compared with natural forests. However, over 80 per cent of species found in unlogged forest were detected within twice-logged forest. Moreover, greater species turnover among sites in twice-logged forest resulted in identical species richness between habitats at the largest spatial scale. While two intensive logging cycles have negative impacts on ant communities, these degraded forests clearly provide important habitat for numerous species and preventing their conversion to oil palm and other crops should be a conservation priority. PMID:22006966

  3. [A comparative study on soil fauna in native secondary evergreen broad-leaved forest and Chinese fir plantation forests in subtropics].

    Science.gov (United States)

    Yan, Shaokui; Wang, Silong; Hu, Yalin; Gao, Hong; Zhang, Xiuyong

    2004-10-01

    In this study, we investigated the response of soil animal communities to the replacement of native secondary forest by Chinese fir plantation forest and successive rotation of Chinese fir in subtropics. Three adjacent forest stands, i.e., native secondary evergreen broad-leaved forest stand (control) and Chinese fir plantation stands of first (20 yr) and second (20 yr) rotations were selected for the comparison of soil fauna. All animals were extracted from the floor litter and 0-15 cm soil layer of the stands in Summer, 2003 by using Tullgren method, wet funnel method and hand-sorting method. Compared to two Chinese fir plantation forests, the native secondary evergreen broad-leaved forest had a higher abundance and a higher taxonomic diversity of animals in soil and litter, but there were no significant differences in the biomass and productivity of soil fauna between all study stands. The abundance or diversity did not differ significantly between the first rotation and second rotation stands, too. The results supported that vegetation cover might be one of the main forces driving the development of soil animal communities, and the effect of successive rotation of Chinese fir on the development of soil fauna was a slow-running process.

  4. Toxicity of iron oxide nanoparticles to grass litter decomposition in a sandy soil

    Science.gov (United States)

    Rashid, Muhammad Imtiaz; Shahzad, Tanvir; Shahid, Muhammad; Imran, Muhammad; Dhavamani, Jeyakumar; Ismail, Iqbal M. I.; Basahi, Jalal M.; Almeelbi, Talal

    2017-02-01

    We examined time-dependent effect of iron oxide nanoparticles (IONPs) at a rate of 2000 mg kg-1 soil on Cynodon dactylon litter (3 g kg-1) decomposition in an arid sandy soil. Overall, heterotrophic cultivable bacterial and fungal colonies, and microbial biomass carbon were significantly decreased in litter-amended soil by the application of nanoparticles after 90 and 180 days of incubation. Time dependent effect of nanoparticles was significant for microbial biomass in litter-amended soil where nanoparticles decreased this variable from 27% after 90 days to 49% after 180 days. IONPs decreased CO2 emission by 28 and 30% from litter-amended soil after 90 and 180 days, respectively. These observations indicated that time-dependent effect was not significant on grass-litter carbon mineralization efficiency. Alternatively, nanoparticles application significantly reduced mineral nitrogen content in litter-amended soil in both time intervals. Therefore, nitrogen mineralization efficiency was decreased to 60% after 180 days compared to that after 90 days in nanoparticles grass-litter amended soil. These effects can be explained by the presence of labile Fe in microbial biomass after 180 days in nanoparticles amendment. Hence, our results suggest that toxicity of IONPs to soil functioning should consider before recommending their use in agro-ecosystems.

  5. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Sathre, Roger [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Gustavsson, Leif [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

    2010-04-15

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

  6. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    International Nuclear Information System (INIS)

    Sathre, Roger; Gustavsson, Leif; Bergh, Johan

    2010-01-01

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO 2equiv if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

  7. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Sathre, Roger; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

    2010-04-15

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission. (author)

  8. Forest-Observation-System.net - towards a global in-situ data repository for biomass datasets validation

    Science.gov (United States)

    Shchepashchenko, D.; Chave, J.; Phillips, O. L.; Davies, S. J.; Lewis, S. L.; Perger, C.; Dresel, C.; Fritz, S.; Scipal, K.

    2017-12-01

    Forest monitoring is high on the scientific and political agenda. Global measurements of forest height, biomass and how they change with time are urgently needed as essential climate and ecosystem variables. The Forest Observation System - FOS (http://forest-observation-system.net/) is an international cooperation to establish a global in-situ forest biomass database to support earth observation and to encourage investment in relevant field-based observations and science. FOS aims to link the Remote Sensing (RS) community with ecologists who measure forest biomass and estimating biodiversity in the field for a common benefit. The benefit of FOS for the RS community is the partnering of the most established teams and networks that manage permanent forest plots globally; to overcome data sharing issues and introduce a standard biomass data flow from tree level measurement to the plot level aggregation served in the most suitable form for the RS community. Ecologists benefit from the FOS with improved access to global biomass information, data standards, gap identification and potential improved funding opportunities to address the known gaps and deficiencies in the data. FOS closely collaborate with the Center for Tropical Forest Science -CTFS-ForestGEO, the ForestPlots.net (incl. RAINFOR, AfriTRON and T-FORCES), AusCover, Tropical managed Forests Observatory and the IIASA network. FOS is an open initiative with other networks and teams most welcome to join. The online database provides open access for both metadata (e.g. who conducted the measurements, where and which parameters) and actual data for a subset of plots where the authors have granted access. A minimum set of database values include: principal investigator and institution, plot coordinates, number of trees, forest type and tree species composition, wood density, canopy height and above ground biomass of trees. Plot size is 0.25 ha or large. The database will be essential for validating and calibrating

  9. Height-diameter allometry and above ground biomass in tropical montane forests: Insights from the Albertine Rift in Africa.

    Science.gov (United States)

    Imani, Gérard; Boyemba, Faustin; Lewis, Simon; Nabahungu, Nsharwasi Léon; Calders, Kim; Zapfack, Louis; Riera, Bernard; Balegamire, Clarisse; Cuni-Sanchez, Aida

    2017-01-01

    Tropical montane forests provide an important natural laboratory to test ecological theory. While it is well-known that some aspects of forest structure change with altitude, little is known on the effects of altitude on above ground biomass (AGB), particularly with regard to changing height-diameter allometry. To address this we investigate (1) the effects of altitude on height-diameter allometry, (2) how different height-diameter allometric models affect above ground biomass estimates; and (3) how other forest structural, taxonomic and environmental attributes affect above ground biomass using 30 permanent sample plots (1-ha; all trees ≥ 10 cm diameter measured) established between 1250 and 2600 m asl in Kahuzi Biega National Park in eastern Democratic Republic of Congo. Forest structure and species composition differed with increasing altitude, with four forest types identified. Different height-diameter allometric models performed better with the different forest types, as trees got smaller with increasing altitude. Above ground biomass ranged from 168 to 290 Mg ha-1, but there were no significant differences in AGB between forests types, as tree size decreased but stem density increased with increasing altitude. Forest structure had greater effects on above ground biomass than forest diversity. Soil attributes (K and acidity, pH) also significantly affected above ground biomass. Results show how forest structural, taxonomic and environmental attributes affect above ground biomass in African tropical montane forests. They particularly highlight that the use of regional height-diameter models introduces significant biases in above ground biomass estimates, and that different height-diameter models might be preferred for different forest types, and these should be considered in future studies.

  10. Remote Sensing of Aboveground Biomass in Tropical Secondary Forests: A Review

    Directory of Open Access Journals (Sweden)

    J. M. Barbosa

    2014-01-01

    Full Text Available Tropical landscapes are, in general, a mosaic of pasture, agriculture, and forest undergoing various stages of succession. Forest succession is comprised of continuous structural changes over time and results in increases in aboveground biomass (AGB. New remote sensing methods, including sensors, image processing, statistical methods, and uncertainty evaluations, are constantly being developed to estimate biophysical forest changes. We review 318 peer-reviewed studies related to the use of remotely sensed AGB estimations in tropical forest succession studies and summarize their geographic distribution, sensors and methods used, and their most frequent ecological inferences. Remotely sensed AGB is broadly used in forest management studies, conservation status evaluations, carbon source and sink investigations, and for studies of the relationships between environmental conditions and forest structure. Uncertainties in AGB estimations were found to be heterogeneous with biases related to sensor type, processing methodology, ground truthing availability, and forest characteristics. Remotely sensed AGB of successional forests is more reliable for the study of spatial patterns of forest succession and over large time scales than that of individual stands. Remote sensing of temporal patterns in biomass requires further study, in particular, as it is critical for understanding forest regrowth at scales useful for regional or global analyses.

  11. Carbon, energy and forest biomass: new opportunities and needs for forest management in Italy

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available Forest biomass provides a relevant fraction of world energy needs, not only in developing Countries. In Italy, several factors are presently contributing to a new interest for this resource, ranging from regulatory quotas for renewables to the increasing price of fossil fuel to the emergence of a European carbon stock exchange. This focus on renewable resources constitutes an important opportunity for the forest sector and for society by and large, but because of the potential dimensions of the emerging market it also requires new planning instruments, in order to avoid a sudden and widespread resumption of coppice management and a reduction of standing carbon stock in forest ecosystems, which would run contrary to the objectives of the Kyoto Protocol. An example of the future demand for biomasses in Central Italy is presented, based on the possible use of fuelwood in new coal-fired power plants by the 'co-firing' technology.

  12. Fate of leaf-litter N in forest and grassland along a pedo-climatic gradient in south-western Siberia: an in situ 15N-labelling experiment

    Science.gov (United States)

    Brédoire, Félix; Zeller, Bernd; Nikitich, Polina; Barsukov, Pavel A.; Rusalimova, Olga; Bakker, Mark R.; Legout, Arnaud; Bashuk, Alexander; Kayler, Zachary E.; Derrien, Delphine

    2017-04-01

    The suitability of Siberia for agriculture is expected to increase in the next decades due to strong and rapid climatic changes, but little is known on the environmental drivers of soil fertility there, especially nitrogen (N). Plant-available N is mainly derived from litter decomposition. South-western (SW) Siberia is located on the transition between several bioclimatic zones that are predicted to shift and extend along with climate change (steppe, forest-steppe, sub-taiga). The soils of this region are formed on a common loess deposit but they are submitted to different climatic conditions and vegetation cover. In the south of the region, typically in steppe/forest-steppe, soil freezes over winter because of a relatively shallow snow-pack, and water shortages are frequent in summer. In the north, typically in sub-taiga, the soil is barely frozen in winter due to a thick snow-pack and sufficient soil moisture in summer. In this study, we characterized the dynamics of leaf litter decomposition and the transfer of N from leaf litter to the soil and back to plants. Four sites were chosen along a climate gradient (temperature, precipitation and snow depth). At each site, we applied 15N-labelled leaf litter on the soil surface in experimental plots in an aspen (Populus tremula L.) forest and in a grassland. Twice a year during three years, we tracked the 15N derived from the decomposing labelled-litter in the organic layers, in the first 15 cm of the soil, and in above-ground vegetation. Soil temperature and moisture were monitored at a daily timestep over three years and soil water budgets were simulated (BILJOU model, Granier et al. 1999). We observed contrasting patterns in the fate of litter-derived 15N between bioclimatic zones. Over three years, along with faster decay rates, the release of leaf litter-N was faster in sub-taiga than in forest-steppe. As such, higher quantities of 15N were transferred into the soil in sub-taiga. The transfer was also deeper there

  13. Multi-decade biomass dynamics in an old-growth hemlock-northern hardwood forest, Michigan, USA

    Directory of Open Access Journals (Sweden)

    Kerry D. Woods

    2014-09-01

    Full Text Available Trends in living aboveground biomass and inputs to the pool of coarse woody debris (CWD in an undisturbed, old-growth hemlock-northern hardwood forest in northern MI were estimated from multi-decade observations of permanent plots. Growth and demographic data from seven plot censuses over 47 years (1962–2009, combined with one-time measurement of CWD pools, help assess biomass/carbon status of this landscape. Are trends consistent with traditional notions of late-successional forests as equilibrial ecosystems? Specifically, do biomass pools and CWD inputs show consistent long-term trends and relationships, and can living and dead biomass pools and trends be related to forest composition and history? Aboveground living biomass densities, estimated using standard allometric relationships, range from 360–450 Mg/ha among sampled stands and types; these values are among the highest recorded for northeastern North American forests. Biomass densities showed significant decade-scale variation, but no consistent trends over the full study period (one stand, originating following an 1830 fire, showed an aggrading trend during the first 25 years of the study. Even though total above-ground biomass pools are neither increasing nor decreasing, they have been increasingly dominated, over the full study period, by very large (>70 cm dbh stems and by the most shade-tolerant species (Acer saccharum and Tsuga canadensis.CWD pools measured in 2007 averaged 151 m3/ha, with highest values in Acer-dominated stands. Snag densities averaged 27/ha, but varied nearly ten-fold with canopy composition (highest in Tsuga-dominated stands, lowest in Acer-dominated; snags constituted 10–50% of CWD biomass. Annualized CWD inputs from tree mortality over the full study period averaged 1.9–3.2 Mg/ha/yr, depending on stand and species composition. CWD input rates tended to increase over the course of the study. Input rates may be expected to increase over longer

  14. Are nitrate exports in stream water linked to nitrogen fluxes in decomposing foliar litter?

    Science.gov (United States)

    Kathryn B. Piatek; Mary Beth. Adams

    2011-01-01

    The central hardwood forest receives some of the highest rates of atmospheric nitrogen (N) deposition, which results in nitrate leaching to surface waters. Immobilization of N in foliar litter during litter decomposition represents a potential mechanism for temporal retention of atmospherically deposited N in forest ecosystems. When litter N dynamics switch to the N-...

  15. Influence of moisture conditions and mineralization of soil solution on structure of litter macrofauna of the deciduous forests of Ukraine steppe zone

    Directory of Open Access Journals (Sweden)

    V. V. Brygadyrenko

    2015-02-01

    Full Text Available The accounting of litter mesofauna was carried out in the territory of Dnipropetrovsk, Zaporizhzhya, Nikolaev,Donetsk regions of Ukrainein the natural forest ecosystems in 2001–2014. 339 forest ecosystems were surveyed; xeromesophilic conditions of moistening were characteristic for 47 trial sites, mesophilic conditions – for 99 sites, hygro-mesophilic conditions – for 50 sites, meso-hygrophilic conditions – for 89 sites, hygrophilic conditions – for 54 sites; trophotope C was represented by 35 trial sites, Dc – by 44, Dac – by 76, Dn – by 128, De – by 37, E – by 19 forest ecosystems, accordingly. The relative number of saprophages reaches maximum values in hygro-mesophilic, meso-hygrophilic and hygrophilic conditions, and minimum values – in mesophilic conditions of moistening. The share of rare species is maximum in hygro-mesophilic conditions of moistening. The minimum quantity of mass species is also observed in conditions of hygro-mesophilic and meso-hygrophilic deciduous forests. With the growth of moistening of the soil, quantity of species of Carabidae, Formicidae and other dominant families remains without significant changes. The relative number of Formicidae is maximum in xeromesophilic and mesophilic conditions of soil moistening. In these hygrotopes, as well as in hygro-mesophilic conditions of moistening the Julidae numbers are maximum. The Isopoda percent in mesofauna significantly grows in meso-hygrophilic and hygrophilic conditions of moistening. The share of other dominant taxonomical groups in the structure of litter mesofauna remains without significant changes in numbers. In the majority of the analysed hygrotopes 7–8 families are withing the structure of dominants. In the conditions of salinization (trophotopes De and E, and also on light sandy loam soils, the numbers of litter mesofauna decrease. Share of saprophages is minimum in trophotopes Dc and E, while it increases in trophotopes C, Dac, Dn

  16. Estimates of Forest Biomass Carbon Storage in Liaoning Province of Northeast China: A Review and Assessment

    Science.gov (United States)

    Yu, Dapao; Wang, Xiaoyu; Yin, You; Zhan, Jinyu; Lewis, Bernard J.; Tian, Jie; Bao, Ye; Zhou, Wangming; Zhou, Li; Dai, Limin

    2014-01-01

    Accurate estimates of forest carbon storage and changes in storage capacity are critical for scientific assessment of the effects of forest management on the role of forests as carbon sinks. Up to now, several studies reported forest biomass carbon (FBC) in Liaoning Province based on data from China's Continuous Forest Inventory, however, their accuracy were still not known. This study compared estimates of FBC in Liaoning Province derived from different methods. We found substantial variation in estimates of FBC storage for young and middle-age forests. For provincial forests with high proportions in these age classes, the continuous biomass expansion factor method (CBM) by forest type with age class is more accurate and therefore more appropriate for estimating forest biomass. Based on the above approach designed for this study, forests in Liaoning Province were found to be a carbon sink, with carbon stocks increasing from 63.0 TgC in 1980 to 120.9 TgC in 2010, reflecting an annual increase of 1.9 TgC. The average carbon density of forest biomass in the province has increased from 26.2 Mg ha−1 in 1980 to 31.0 Mg ha−1 in 2010. While the largest FBC occurred in middle-age forests, the average carbon density decreased in this age class during these three decades. The increase in forest carbon density resulted primarily from the increased area and carbon storage of mature forests. The relatively long age interval in each age class for slow-growing forest types increased the uncertainty of FBC estimates by CBM-forest type with age class, and further studies should devote more attention to the time span of age classes in establishing biomass expansion factors for use in CBM calculations. PMID:24586881

  17. Estimates of forest biomass carbon storage inLiaoning Province of Northeast China: a review and assessment.

    Science.gov (United States)

    Yu, Dapao; Wang, Xiaoyu; Yin, You; Zhan, Jinyu; Lewis, Bernard J; Tian, Jie; Bao, Ye; Zhou, Wangming; Zhou, Li; Dai, Limin

    2014-01-01

    Accurate estimates of forest carbon storage and changes in storage capacity are critical for scientific assessment of the effects of forest management on the role of forests as carbon sinks. Up to now, several studies reported forest biomass carbon (FBC) in Liaoning Province based on data from China's Continuous Forest Inventory, however, their accuracy were still not known. This study compared estimates of FBC in Liaoning Province derived from different methods. We found substantial variation in estimates of FBC storage for young and middle-age forests. For provincial forests with high proportions in these age classes, the continuous biomass expansion factor method (CBM) by forest type with age class is more accurate and therefore more appropriate for estimating forest biomass. Based on the above approach designed for this study, forests in Liaoning Province were found to be a carbon sink, with carbon stocks increasing from 63.0 TgC in 1980 to 120.9 TgC in 2010, reflecting an annual increase of 1.9 TgC. The average carbon density of forest biomass in the province has increased from 26.2 Mg ha(-1) in 1980 to 31.0 Mg ha(-1) in 2010. While the largest FBC occurred in middle-age forests, the average carbon density decreased in this age class during these three decades. The increase in forest carbon density resulted primarily from the increased area and carbon storage of mature forests. The relatively long age interval in each age class for slow-growing forest types increased the uncertainty of FBC estimates by CBM-forest type with age class, and further studies should devote more attention to the time span of age classes in establishing biomass expansion factors for use in CBM calculations.

  18. Composition of fungal and bacterial communities in forest litter and soil is largely determined by dominant trees

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Michaela; Šnajdr, Jaroslav; Baldrian, Petr

    2015-01-01

    Roč. 84, č. 1 (2015), s. 53-64 ISSN 0038-0717 R&D Projects: GA MŠk LD12050; GA ČR GAP504/12/1288; GA ČR GA13-06763S Institutional support: RVO:61388971 Keywords : Litter * Bacteria * Forest soil Subject RIV: EE - Microbiology, Virology Impact factor: 4.152, year: 2015

  19. Effects Of Very Intensive Forest Biomass Harvesting On Short And Long Term Site Productivity

    DEFF Research Database (Denmark)

    Raulund-Rasmussen, Karsten; Stupak, Inge; Clarke, Nicholas

    2008-01-01

    Intensified forest biomass utilisation causes export of substantial amounts of nutrients from the forest ecosystem. Compared to conventional stems-only harvesting, the most intensive biomass sce nario causes increases in nutrient exports of up to 6-7 times whereas the biomass export increases only...... up to 2 times (Stupak et al. 2007a). High concentrations of nutrients in small branches, twigs, and leaves compared to stems are the main reason. The extensive export of nutrients related to intensive biomass extraction have for many years caused concern for the long-term fertility of the system...

  20. Emissions tradeoffs associated with cofiring forest biomass with coal: A case study in Colorado, USA

    Science.gov (United States)

    Dan Loeffler; Nathaniel Anderson

    2014-01-01

    Cofiring forest biomass residues with coal to generate electricity is often cited for its potential to offset fossil fuels and reduce greenhouse gas emissions, but the extent to which cofiring achieves these objectives is highly dependent on case specific variables. This paper uses facility and forest specific data to examine emissions from cofiring forest biomass with...

  1. Achieving Accuracy Requirements for Forest Biomass Mapping: A Data Fusion Method for Estimating Forest Biomass and LiDAR Sampling Error with Spaceborne Data

    Science.gov (United States)

    Montesano, P. M.; Cook, B. D.; Sun, G.; Simard, M.; Zhang, Z.; Nelson, R. F.; Ranson, K. J.; Lutchke, S.; Blair, J. B.

    2012-01-01

    The synergistic use of active and passive remote sensing (i.e., data fusion) demonstrates the ability of spaceborne light detection and ranging (LiDAR), synthetic aperture radar (SAR) and multispectral imagery for achieving the accuracy requirements of a global forest biomass mapping mission. This data fusion approach also provides a means to extend 3D information from discrete spaceborne LiDAR measurements of forest structure across scales much larger than that of the LiDAR footprint. For estimating biomass, these measurements mix a number of errors including those associated with LiDAR footprint sampling over regional - global extents. A general framework for mapping above ground live forest biomass (AGB) with a data fusion approach is presented and verified using data from NASA field campaigns near Howland, ME, USA, to assess AGB and LiDAR sampling errors across a regionally representative landscape. We combined SAR and Landsat-derived optical (passive optical) image data to identify forest patches, and used image and simulated spaceborne LiDAR data to compute AGB and estimate LiDAR sampling error for forest patches and 100m, 250m, 500m, and 1km grid cells. Forest patches were delineated with Landsat-derived data and airborne SAR imagery, and simulated spaceborne LiDAR (SSL) data were derived from orbit and cloud cover simulations and airborne data from NASA's Laser Vegetation Imaging Sensor (L VIS). At both the patch and grid scales, we evaluated differences in AGB estimation and sampling error from the combined use of LiDAR with both SAR and passive optical and with either SAR or passive optical alone. This data fusion approach demonstrates that incorporating forest patches into the AGB mapping framework can provide sub-grid forest information for coarser grid-level AGB reporting, and that combining simulated spaceborne LiDAR with SAR and passive optical data are most useful for estimating AGB when measurements from LiDAR are limited because they minimized

  2. Role of forest biomass energy in developing countries

    International Nuclear Information System (INIS)

    Sattar, M.A.

    1996-01-01

    Forest biomass holds a significant position for energy production in developing countries. Its importance is elucidated through various activities performed by the rural industries. The socio-economic and environmental aspects in utilizing this type of energy are also discussed. (Author)

  3. Spatial and topographic trends in forest expansion and biomass change, from regional to local scales.

    Science.gov (United States)

    Buma, Brian; Barrett, Tara M

    2015-09-01

    Natural forest growth and expansion are important carbon sequestration processes globally. Climate change is likely to increase forest growth in some regions via CO2 fertilization, increased temperatures, and altered precipitation; however, altered disturbance regimes and climate stress (e.g. drought) will act to reduce carbon stocks in forests as well. Observations of asynchrony in forest change is useful in determining current trends in forest carbon stocks, both in terms of forest density (e.g. Mg ha(-1) ) and spatially (extent and location). Monitoring change in natural (unmanaged) areas is particularly useful, as while afforestation and recovery from historic land use are currently large carbon sinks, the long-term viability of those sinks depends on climate change and disturbance dynamics at their particular location. We utilize a large, unmanaged biome (>135 000 km(2) ) which spans a broad latitudinal gradient to explore how variation in location affects forest density and spatial patterning: the forests of the North American temperate rainforests in Alaska, which store >2.8 Pg C in biomass and soil, equivalent to >8% of the C in contiguous US forests. We demonstrate that the regional biome is shifting; gains exceed losses and are located in different spatio-topographic contexts. Forest gains are concentrated on northerly aspects, lower elevations, and higher latitudes, especially in sheltered areas, whereas loss is skewed toward southerly aspects and lower latitudes. Repeat plot-scale biomass data (n = 759) indicate that within-forest biomass gains outpace losses (live trees >12.7 cm diameter, 986 Gg yr(-1) ) on gentler slopes and in higher latitudes. This work demonstrates that while temperate rainforest dynamics occur at fine spatial scales (biomass accumulation suggest the potential for relatively rapid biome shifts and biomass changes. © 2015 John Wiley & Sons Ltd.

  4. Harvesting forest biomass for energy in Minnesota: An assessment of guidelines, costs and logistics

    Science.gov (United States)

    Saleh, Dalia El Sayed Abbas Mohamed

    The emerging market for renewable energy in Minnesota has generated a growing interest in utilizing more forest biomass for energy. However, this growing interest is paralleled with limited knowledge of the environmental impacts and cost effectiveness of utilizing this resource. To address environmental and economic viability concerns, this dissertation has addressed three areas related to biomass harvest: First, existing biomass harvesting guidelines and sustainability considerations are examined. Second, the potential contribution of biomass energy production to reduce the costs of hazardous fuel reduction treatments in these trials is assessed. Third, the logistics of biomass production trials are analyzed. Findings show that: (1) Existing forest related guidelines are not sufficient to allow large-scale production of biomass energy from forest residue sustainably. Biomass energy guidelines need to be based on scientific assessments of how repeated and large scale biomass production is going to affect soil, water and habitat values, in an integrated and individual manner over time. Furthermore, such guidelines would need to recommend production logistics (planning, implementation, and coordination of operations) necessary for a potential supply with the least site and environmental impacts. (2) The costs of biomass production trials were assessed and compared with conventional treatment costs. In these trials, conventional mechanical treatment costs were lower than biomass energy production costs less income from biomass sale. However, a sensitivity analysis indicated that costs reductions are possible under certain site, prescriptions and distance conditions. (3) Semi-structured interviews with forest machine operators indicate that existing fuel reduction prescriptions need to be more realistic in making recommendations that can overcome operational barriers (technical and physical) and planning and coordination concerns (guidelines and communications

  5. Understory biomass from southern pine forests as a fuel source

    Energy Technology Data Exchange (ETDEWEB)

    Ku, T.T. [Univ. of Arkansas, Monticello, AR (United States); Baker, J.B. [USDA Forest Service, Monticello, AR (United States)

    1993-12-31

    The energy crisis in the US in the late 1970s led to accelerated research on renewable energy resources. The use of woody biomass, harvested from pine forests in the southern US, as a renewable energy source would not only provide an efficient energy alternative to forest industries, but its use would also reduce understory competition and accelerate growth of overstory crop trees. This study was initiated in the early 1980s to investigate the feasibility and applicability of the use of understory vegetation as a possible energy fuel resource. All woody understory vegetation [<14 cm (<5.5 in) in dbh], on 0.2 ha (0.5 ac) plots that represented a range of stand/site conditions of pine stands located in twelve southern Arkansas counties and two northern Louisiana parishes were characterized, quantified, and harvested. Based on the biomass yield from 720 subplots nested within 40 main plots, the top five dominant species in the understory, based on number and size were: Red maple, red oaks, pines, sweetgum, and winged elm. Some other species occurring, but in smaller proportions, were flowering dogwood, beautyberry, white oaks, black gum, wax myrtle, hickories, persimmon, and ashes. Most of these species are deciduous hardwoods that provide high BTU output upon burning. The average yield of chipped understory biomass was 23.5 T/ha with no difference occurring between summer and winter harvests. A predictive model of understory biomass production was developed using a step-wise multivariate regression analysis. In relation to forest type, high density pine stands produced 53% more understory biomass than high density pine-hardwood stands. The average moisture content of biomass was significantly lower when harvested in winter than when harvested in summer.

  6. Litter Species Composition and Topographic Effects on Fuels and Modeled Fire Behavior in an Oak-Hickory Forest in the Eastern USA.

    Science.gov (United States)

    Dickinson, Matthew B; Hutchinson, Todd F; Dietenberger, Mark; Matt, Frederick; Peters, Matthew P

    2016-01-01

    Mesophytic species (esp. Acer rubrum) are increasingly replacing oaks (Quercus spp.) in fire-suppressed, deciduous oak-hickory forests of the eastern US. A pivotal hypothesis is that fuel beds derived from mesophytic litter are less likely than beds derived from oak litter to carry a fire and, if they do, are more likely to burn at lower intensities. Species effects, however, are confounded by topographic gradients that affect overstory composition and fuel bed decomposition. To examine the separate and combined effects of litter species composition and topography on surface fuel beds, we conducted a common garden experiment in oak-hickory forests of the Ohio Hills. Each common garden included beds composed of mostly oak and mostly maple litter, representative of oak- and maple-dominated stands, respectively, and a mixture of the two. Beds were replenished each fall for four years. Common gardens (N = 16) were established at four topographic positions (ridges, benches on south- and northeast-facing slopes, and stream terraces) at each of four sites. Litter source and topographic position had largely independent effects on fuel beds and modeled fire dynamics after four years of development. Loading (kg m-2) of the upper litter layer (L), the layer that primarily supports flaming spread, was least in more mesic landscape positions and for maple beds, implying greater decomposition rates for those situations. Bulk density in the L layer (kg m-3) was least for oak beds which, along with higher loading, would promote fire spread and fireline intensity. Loading and bulk density of the combined fermentation and humic (FH) layers were least on stream terrace positions but were not related to species. Litter- and FH-layer moistures during a 5-day dry-down period after a rain event were affected by time and topographic effects while litter source effects were not evident. Characteristics of flaming combustion determined with a cone calorimeter pointed to greater fireline

  7. [Edge effects of forest gap in Pinus massoniana plantations on the decomposition of leaf litter recalcitrant components of Cinnamomum camphora and Toona ciliata.

    Science.gov (United States)

    Zhang, Yan; Zhang, Dan Ju; Li, Xun; Liu, Hua; Zhang, Ming Jin; Yang, Wan Qin; Zhang, Jian

    2016-04-22

    The objective of the study was to evaluate the dynamics of recalcitrant components during foliar litter decomposition under edge effects of forest gap in Pinus massoniana plantations in the low hilly land, Sichuan basin. A field litterbag experiment was conducted in seven forest gaps with different sizes (100, 225, 400, 625, 900, 1225, 1600 m 2 ) which were generated by thinning P. massoniana plantations. The degradation rate of four recalcitrant components, i.e., condensed tannins, total phenol, lignin and cellulose in foliar litter of two native species (Cinnamomum camphora and Toona ciliata) at the gap edge and under the closed canopy were measured. The results showed that the degradation rate of recalcitrant components in T. ciliata litter except for cellulose at the gap edge were significantly higher than that under the closed canopy. For C. camphora litter, only the degradation of lignin at the gap edge was higher than that under the closed canopy. After one-year decomposition, four recalcitrant components in two types of foliar litter exhibited an increment of degradation rate, and the degradation rate of condensed tannin was the fastest, followed by total phenol and cellulose, but the lignin degradation rate was the slowest. With the increase of gap size, except for cellulose, the degradation rate ofthe other three recalcitrant components of the T. ciliata at the edge of medium sized gaps (400 and 625 m 2 ) were significantly higher than at the edge of other gaps. However, lignin in the C. camphora litter at the 625 m 2 gap edge showed the greatest degradation rate. Both temperature and litter initial content were significantly correlated with litter recalcitrant component degradation. Our results suggested that medium sized gaps (400-625 m 2 ) had a more significant edge effect on the degradation of litter recalcitrant components in the two native species in P. massoniana plantations, however, the effect also depended on species.

  8. Aboveground Forest Biomass Estimation with Landsat and LiDAR Data and Uncertainty Analysis of the Estimates

    OpenAIRE

    Dengsheng Lu; Qi Chen; Guangxing Wang; Emilio Moran; Mateus Batistella; Maozhen Zhang; Gaia Vaglio Laurin; David Saah

    2012-01-01

    Landsat Thematic mapper (TM) image has long been the dominate data source, and recently LiDAR has offered an important new structural data stream for forest biomass estimations. On the other hand, forest biomass uncertainty analysis research has only recently obtained sufficient attention due to the difficulty in collecting reference data. This paper provides a brief overview of current forest biomass estimation methods using both TM and LiDAR data. A case study is then presented that demonst...

  9. The influence of fire on the radiocarbon signature and character of soil organic matter in the Siskiyou national forest, Oregon, USA

    Science.gov (United States)

    Katherine Heckman; John L. Campbell; Heath Powers; Beverly E. Law; Chris Swanston

    2013-01-01

    Forest fires contribute a significant amount of CO2 to the atmosphere each year, and CO2 emissions from fires are likely to increase under projected conditions of global climate change. In addition to volatilizing aboveground biomass and litter layers, forest fires have a profound effect on belowground carbon (C) pools and the cycling of soil organic matter as a whole...

  10. Heavy metal concentrations in ground beetles, leaf litter, and soil of a forest ecosystem.

    Science.gov (United States)

    Jelaska, Lucija Serić; Blanusa, Maja; Durbesić, Paula; Jelaska, Sven D

    2007-01-01

    The objective of this study was to quantify the relationships between heavy metal concentrations in soil, leaf litter, and ground beetles at four sampling sites of a forest ecosystem in Medvednica Nature Park, Croatia. Ground beetles were sampled by pitfall trapping. Specimens were dry-ashed and soil and beetle samples digested with nitric acid. Lead, cadmium, copper, zinc, manganese, and iron were analyzed using atomic absorption spectrometry. Statistically significant differences between plots were found for lead, cadmium, and iron in ground beetles. Correlations between ground beetles and soil or leaf litter were positive for lead and cadmium concentrations and negative for iron concentration. Differences in species metal concentrations were recorded. Higher concentrations of all studied metals were found in female beetles. However, a significant difference between sexes was found only for manganese. Significant differences in species metal concentrations were found for species that differ in feeding strategies and age based on breeding season and emergence of young adults.

  11. Feed in summer, rest in winter: microbial carbon utilization in forest topsoil.

    Science.gov (United States)

    Žifčáková, Lucia; Větrovský, Tomáš; Lombard, Vincent; Henrissat, Bernard; Howe, Adina; Baldrian, Petr

    2017-09-18

    Evergreen coniferous forests contain high stocks of organic matter. Significant carbon transformations occur in litter and soil of these ecosystems, making them important for the global carbon cycle. Due to seasonal allocation of photosynthates to roots, carbon availability changes seasonally in the topsoil. The aim of this paper was to describe the seasonal differences in C source utilization and the involvement of various members of soil microbiome in this process. Here, we show that microorganisms in topsoil encode a diverse set of carbohydrate-active enzymes, including glycoside hydrolases and auxiliary enzymes. While the transcription of genes encoding enzymes degrading reserve compounds, such as starch or trehalose, was high in soil in winter, summer was characterized by high transcription of ligninolytic and cellulolytic enzymes produced mainly by fungi. Fungi strongly dominated the transcription in litter and an equal contribution of bacteria and fungi was found in soil. The turnover of fungal biomass appeared to be faster in summer than in winter, due to high activity of enzymes targeting its degradation, indicating fast growth in both litter and soil. In each enzyme family, hundreds to thousands of genes were typically transcribed simultaneously. Seasonal differences in the transcription of glycoside hydrolases and auxiliary enzyme genes are more pronounced in soil than in litter. Our results suggest that mainly fungi are involved in decomposition of recalcitrant biopolymers in summer, while bacteria replace them in this role in winter. Transcripts of genes encoding enzymes targeting plant biomass biopolymers, reserve compounds and fungal cell walls were especially abundant in the coniferous forest topsoil.

  12. Prescribed fire experiences on crop residue removal for biomass exploitations. Application to the maritime pine forests in the Mediterranean Basin.

    Science.gov (United States)

    Molina, Juan Ramón; García, Juan Pedro; Fernández, Juan José; Rodríguez Y Silva, Francisco

    2018-01-15

    Socioeconomic changes, climate change, rural migration and fire exclusion have led to a high woody biomass accumulation increasing potential wildfire severity. Mechanical thinning and prescribed burning practices are commonly used to prevent large fires. The purpose of this study was to assess burning treatment effectiveness following mechanical thinning from biomass harvesting. Prescribed burning to reduce residue removal could help mitigate fire behavior, mainly in strategic management or critical focal points. Field samplings were conducted before and immediately after burnings on different environmental scenarios where fuel load was classified by categories. Prescribed fires reduced available fuel in all fuel categories, mainly in surface litter layer. Total fuel load reduction ranged from 59.07% to 86.18%. In this sense, fuel reduction effects were more pronounced when burns were conducted fewer than 10% on surface litter moisture. The difference in fuel consumption among scenarios was higher for most all woody fuel components and decomposition litter layer than for surface litter layer. Managers can use this information to design technical prescription to achieve the targets while decomposed litter retention maintaining the soil properties and biodiversity. Understanding the most effective "burn window" should help better plan prescribed burning, both in term of fire behavior and fuel consumption, without altering ecosystem properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Test of validity of a dynamic soil carbon model using data from leaf litter decomposition in a West African tropical forest

    Science.gov (United States)

    Guendehou, G. H. S.; Liski, J.; Tuomi, M.; Moudachirou, M.; Sinsin, B.; Mäkipää, R.

    2013-05-01

    We evaluated the applicability of the dynamic soil carbon model Yasso07 in tropical conditions in West Africa by simulating the litter decomposition process using as required input into the model litter mass, litter quality, temperature and precipitation collected during a litterbag experiment. The experiment was conducted over a six-month period on leaf litter of five dominant tree species, namely Afzelia africana, Anogeissus leiocarpa, Ceiba pentandra, Dialium guineense and Diospyros mespiliformis in a semi-deciduous vertisol forest in Southern Benin. Since the predictions of Yasso07 were not consistent with the observations on mass loss and chemical composition of litter, Yasso07 was fitted to the dataset composed of global data and the new experimental data from Benin. The re-parameterized versions of Yasso07 had a good predictive ability and refined the applicability of the model in Benin to estimate soil carbon stocks, its changes and CO2 emissions from heterotrophic respiration as main outputs of the model. The findings of this research support the hypothesis that the high variation of litter quality observed in the tropics is a major driver of the decomposition and needs to be accounted in the model parameterization.

  14. Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam.

    Science.gov (United States)

    Nam, Vu Thanh; van Kuijk, Marijke; Anten, Niels P R

    2016-01-01

    Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB) and root biomass (RB) based on 300 (of 45 species) and 40 (of 25 species) sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH) and tree height (H), wood density (WD) was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam.

  15. Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam.

    Directory of Open Access Journals (Sweden)

    Vu Thanh Nam

    Full Text Available Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB and root biomass (RB based on 300 (of 45 species and 40 (of 25 species sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH and tree height (H, wood density (WD was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam.

  16. Estimation of Forest Biomass Based on Muliti-Source Remote Sensing Data Set - a Case Study of Shangri-La County

    Science.gov (United States)

    Feng, Wanwan; Wang, Leiguang; Xie, Junfeng; Yue, Cairong; Zheng, Yalan; Yu, Longhua

    2018-04-01

    Forest biomass is an important indicator for the structure and function of forest ecosystems, and an accurate assessment of forest biomass is crucial for understanding ecosystem changes. Remote sensing has been widely used for inversion of biomass. However, in mature or over-mature forest areas, spectral saturation is prone to occur. Based on existing research, this paper synthesizes domestic high resolution satellites, ZY3-01 satellites, and GLAS14-level data from space-borne Lidar system, and other data set. Extracting texture and elevation features respectively, for the inversion of forest biomass. This experiment takes Shangri-La as the research area. Firstly, the biomass in the laser spot was calculated based on GLAS data and other auxiliary data, DEM, the second type inventory of forest resources data and the Shangri-La vector boundary data. Then, the regression model was established, that is, the relationship between the texture factors of ZY3-01 and biomass in the laser spot. Finally, by using this model and the forest distribution map in Shangri-La, the biomass of the whole area is obtained, which is 1.3972 × 108t.

  17. Estimating forest and woodland aboveground biomass using active and passive remote sensing

    Science.gov (United States)

    Wu, Zhuoting; Dye, Dennis G.; Vogel, John M.; Middleton, Barry R.

    2016-01-01

    Aboveground biomass was estimated from active and passive remote sensing sources, including airborne lidar and Landsat-8 satellites, in an eastern Arizona (USA) study area comprised of forest and woodland ecosystems. Compared to field measurements, airborne lidar enabled direct estimation of individual tree height with a slope of 0.98 (R2 = 0.98). At the plot-level, lidar-derived height and intensity metrics provided the most robust estimate for aboveground biomass, producing dominant species-based aboveground models with errors ranging from 4 to 14Mg ha –1 across all woodland and forest species. Landsat-8 imagery produced dominant species-based aboveground biomass models with errors ranging from 10 to 28 Mg ha –1. Thus, airborne lidar allowed for estimates for fine-scale aboveground biomass mapping with low uncertainty, while Landsat-8 seems best suited for broader spatial scale products such as a national biomass essential climate variable (ECV) based on land cover types for the United States.

  18. 137Cs dynamics in the forest of Fukushima after the nuclear power plant accident in March 2011

    Science.gov (United States)

    Endo, I.; Ohte, N.; Iseda, K.; Kobayashi, N.; Hirose, A.; Tanoi, K.

    2013-12-01

    The accident of Fukushima Daiichi nuclear power plant after the earthquake and Tsunami in March 11th 2011, caused large amount of radioactive Cesium (137Cs) emission into the environment. In the region of Fukushima Prefecture, forest dominates more than 70 % of the land area. River water from the forest area is used for food production and also for drinking water. Thus, it is important to understand the dynamics of 137Cs deposited in the forest to predict how the radioactive Cs diffuse and discharge from the forest catchments. We measured 137Cs concentration of the tree body, litter fall, throughfall, and stemflow, in order to clarify how 137Cs deposited on the above ground biomass of the forest are transported to the forest floor. We set forest site at the upstream part of Kami-Oguni River catchment, northern part of Fukushima Prefecture. Three plots (2 deciduous stands and 1 Japanese cedar (Cryptomeria japonica) plantation stand) were set in the forest site. Quercus serrata and C. japonica, which are representative tree species, were chosen at each plot and concentration of 137Cs on the bark, sapwood and heartwood were measured every 2 m from the ground to tree top. From each plot, 137Cs concentration of leaf litter was measured among species. Water samples of throughfall and stemflow were filtered and 137Cs concentration in suspended matter was measured. 137Cs was deposited on the bark of Q. serrata at high concentration (9-18 kBq/kg) but there were no clear relationship between tree height and concentration. 137Cs concentration of the sapwood (41 Bq/kg) was relatively higher than that of the heartwood (5 Bq/kg). It was suggested that 137Cs may be absorbed from bark and/or root. The concentration of 137Cs deposited in leaf litter varied from non-detected level to above 30 kBq/kg. The concentration was higher at evergreen tree than deciduous tree. It is considered that the litter of evergreen tree was derived from leaves on the tree canopy at the time of the

  19. An Optimization-Based System Model of Disturbance-Generated Forest Biomass Utilization

    Science.gov (United States)

    Curry, Guy L.; Coulson, Robert N.; Gan, Jianbang; Tchakerian, Maria D.; Smith, C. Tattersall

    2008-01-01

    Disturbance-generated biomass results from endogenous and exogenous natural and cultural disturbances that affect the health and productivity of forest ecosystems. These disturbances can create large quantities of plant biomass on predictable cycles. A systems analysis model has been developed to quantify aspects of system capacities (harvest,…

  20. Modeling population dynamics and woody biomass of Alaska coastal forest

    Science.gov (United States)

    Randy L. Peterson; Jingjing Liang; Tara M. Barrett

    2014-01-01

    Alaska coastal forest, 6.2 million ha in size, has been managed in the past mainly through clearcutting. Declining harvest and dwindling commercial forest resources over the past 2 decades have led to increased interest in management of young-growth stands and utilization of woody biomass for bioenergy. However, existing models to support these new management systems...

  1. A Study on PolInSAR Coherence Based Regression Analysis of Forest Biomass (BARKOT Reserve Forest India), Using RADARSAT-2 Datasets

    Science.gov (United States)

    Singh, J.; Kumar, S.; Kushwaha, S. P. S.

    2015-04-01

    Forests cover 30% of the world's land surface, and are home to around 90% of the world's flora and fauna. They serve as one of the world's largest carbon sinks, absorbing 2.4 million tons of CO2 each year and storing billions more in form of biomass. Around 6 million hectares of forest is lost or changed each year and as much as a fifth of global emissions are estimated to come from deforestation. Hence accurate estimation of forest biophysical variables is necessary as it is a key parameter in determination of forest inventories, vegetation modeling and global carbon cycle. SAR Remote sensing technique is capable of providing accurate and reliable information about forest parameters. The present work aims to explore the potential of C-band Radarsat-2 Polarimetric Interferometric Synthetic Aperture Radar (PolinSAR) technique for developing a relationship between complex coherence and forest aboveground biomass (t/ha). In order to attain our objective Radarsat-2 satellite interferometric pair of 4th March 2013(master image) and 28th March 2013(slave image) were acquired for Barkot Reserve Forest, Dehradun, India. Field inventory was done for 30 plots (31.62m x 31.62m) and tree height and stem diameter were procured for each plot which were later utilized in calculation of aboveground biomass(AGB).Work emphasizes on the application of PolinSAR coherence instead of using SAR backscatter which saturates after a certain value of biomass content. Complex coherence values for different polarization channels were computed with the help of polarimetric interferometric coherence matrix. Retrieved complex coherences were investigated individually and then regression analysis was carried with the field estimated aboveground biomass. R2 value of HV+VH complex coherence component was found to be relatively higher than other polarization channel components

  2. Improved Forest Biomass and Carbon Estimations Using Texture Measures from WorldView-2 Satellite Data

    Directory of Open Access Journals (Sweden)

    Sandra Eckert

    2012-03-01

    Full Text Available Accurate estimation of aboveground biomass and carbon stock has gained importance in the context of the United Nations Framework Convention on Climate Change (UNFCCC and the Kyoto Protocol. In order to develop improved forest stratum–specific aboveground biomass and carbon estimation models for humid rainforest in northeast Madagascar, this study analyzed texture measures derived from WorldView-2 satellite data. A forest inventory was conducted to develop stratum-specific allometric equations for dry biomass. On this basis, carbon was calculated by applying a conversion factor. After satellite data preprocessing, vegetation indices, principal components, and texture measures were calculated. The strength of their relationships with the stratum-specific plot data was analyzed using Pearson’s correlation. Biomass and carbon estimation models were developed by performing stepwise multiple linear regression. Pearson’s correlation coefficients revealed that (a texture measures correlated more with biomass and carbon than spectral parameters, and (b correlations were stronger for degraded forest than for non-degraded forest. For degraded forest, the texture measures of Correlation, Angular Second Moment, and Contrast, derived from the red band, contributed to the best estimation model, which explained 84% of the variability in the field data (relative RMSE = 6.8%. For non-degraded forest, the vegetation index EVI and the texture measures of Variance, Mean, and Correlation, derived from the newly introduced coastal blue band, both NIR bands, and the red band, contributed to the best model, which explained 81% of the variability in the field data (relative RMSE = 11.8%. These results indicate that estimation of tropical rainforest biomass/carbon, based on very high resolution satellite data, can be improved by (a developing and applying forest stratum–specific models, and (b including textural information in addition to spectral information.

  3. Low Tree-Growth Elasticity of Forest Biomass Indicated by an Individual-Based Model

    Directory of Open Access Journals (Sweden)

    Robbie A. Hember

    2018-01-01

    Full Text Available Environmental conditions and silviculture fundamentally alter the metabolism of individual trees and, therefore, need to be studied at that scale. However, changes in forest biomass density (Mg C ha−1 may be decoupled from changes in growth (kg C year−1 when the latter also accelerates the life cycle of trees and strains access to light, nutrients, and water. In this study, we refer to an individual-based model of forest biomass dynamics to constrain the magnitude of system feedbacks associated with ontogeny and competition and estimate the scaling relationship between changes in tree growth and forest biomass density. The model was driven by fitted equations of annual aboveground biomass growth (Gag, probability of recruitment (Pr, and probability of mortality (Pm parameterized against field observations of black spruce (Picea mariana (Mill. BSP, interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn. Franco, and western hemlock (Tsuga heterophylla (Raf. Sarg.. A hypothetical positive step-change in mean tree growth was imposed half way through the simulations and landscape-scale responses were then evaluated by comparing pre- and post-stimulus periods. Imposing a 100% increase in tree growth above calibrated predictions (i.e., contemporary rates only translated into 36% to 41% increases in forest biomass density. This corresponded with a tree-growth elasticity of forest biomass (εG,SB ranging from 0.33 to 0.55. The inelastic nature of stand biomass density was attributed to the dependence of mortality on intensity of competition and tree size, which decreased stand density by 353 to 495 trees ha−1, and decreased biomass residence time by 10 to 23 years. Values of εG,SB depended on the magnitude of the stimulus. For example, a retrospective scenario in which tree growth increased from 50% below contemporary rates up to contemporary rates indicated values of εG,SB ranging from 0.66 to 0.75. We conclude that: (1 effects of

  4. Development of equations for predicting Puerto Rican subtropical dry forest biomass and volume

    Science.gov (United States)

    Thomas J. Brandeis; Matthew Delaney; Bernard R. Parresol; Larry Royer

    2006-01-01

    Carbon accounting, forest health monitoring and sustainable management of the subtropical dry forests of Puerto Rico and other Caribbean Islands require an accurate assessment of forest aboveground biomass (AGB) and stem volume. One means of improving assessment accuracy is the development of predictive equations derived from locally collected data. Forest inventory...

  5. LITTER DEVOLUTION AND DECOMPOSITION IN CERRADÃO AND MATA MESOFÍTICA AREAS IN ECOLOGICAL STATION OF PIRAPITINGA – MG

    Directory of Open Access Journals (Sweden)

    Rômulo Guimarães Giácomo

    2012-12-01

    Full Text Available http://dx.doi.org/10.5902/198050987549This study aimed to quantify the litter and nutrients amount and to estimate the decomposition rate in areas of mesophytic forest and ‘Cerradão’ in the Ecological Station of Pirapitinga. To evaluate litter and nutrients devolution 10 conic litter traps were randomly distributed in an area 0.1 ha in each area of study, with monthly evaluations. The litter decomposition in the areas of study was evaluated by using litter bags. The total production of litter was 2.50 and 2.92 Mg ha-1 yr-1 for mesophytic forest and ‘Cerradão’ areas, respectively. The nutrients devolution importance order was nitrogen> potassium> phosphorus. The mesophytic forest showed more homogeneous distribution of litter fall over the year and higher values of total annual litter and nutrients, the highest values were observed at the dry season. The half-life decomposition of leaf litter was equivalent between areas, about 161 days in the mesophytic forest area and 173 in ‘Cerradão’ area.

  6. Litter-dwelling arthropod abundance peaks near coarse woody debris in loblolly pine forest of the southeastern United States.

    Science.gov (United States)

    Michael D. Ulyshen; J.L. Hanula

    2009-01-01

    Several recent studies have shown that many litter-dwelling arthropod and other invertebrate taxa (e.g., Isopoda, Chilopoda, Diplopoda, Araneae, Pseudo scorpionida, Coleoptera, and Gastropoda) are more numerous near dead wood than away from it in the broad-leaved forests of Europe (Jabin et al. 2004; Topp et al. 2006a, 2006b; Kappes et...

  7. Abiotic and biotic drivers of biomass change in a Neotropical forest

    NARCIS (Netherlands)

    Sande, van der M.T.; Pena Claros, M.; Ascarrunz, Nataly; Arets, E.J.M.M.; Licona, J.C.; Toledo, Marisol; Poorter, L.

    2017-01-01

    Summary
    1. Tropical fores ts play an important role in the global carbon cycle, but the drivers of net forest biomass change (i.e. net carbon sequestration) are poorly understood. Here, we evaluate how abiotic factors (soil co nditions and disturbance) and biotic factors (forest structure,

  8. Forest litter crickets prefer higher substrate moisture for oviposition: Evidence from field and lab experiments.

    Science.gov (United States)

    de Farias-Martins, Fernando; Sperber, Carlos Frankl; Albeny-Simões, Daniel; Breaux, Jennifer Ann; Fianco, Marcos; Szinwelski, Neucir

    2017-01-01

    For insects, choosing a favorable oviposition site is a type of parental care, as far as it increases the fitness of its offspring. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate moisture. However, lab experiments with mole crickets showed a linear oviposition response to substrate moisture. Studies with the house cricket Acheta domesticus also showed a linear juvenile body growth response to water availability, thus adult ovipositing females should respond positively to substrate moisture. We used a field experiment to evaluate the relationship between oviposition preference and substrate moisture in forest litter-dwelling cricket species. We also evaluated oviposition responses to substrate moisture level in Ubiquepuella telytokous, the most abundant litter cricket species in our study area, using a laboratory study. We offered cotton substrate for oviposition which varied in substrate moisture level from zero (i.e., dry) to maximum water absorption capacity. We used two complementary metrics to evaluate oviposition preference: (i) presence or absence of eggs in each sampling unit as binary response variable, and (ii) number of eggs oviposited per sampling unit as count response variable. To test for non-linear responses, we adjusted generalized additive models (GAMM) with mixed effects. We found that both cricket oviposition probability and effort (i.e., number of eggs laid) increased linearly with substrate moisture in the field experiment, and for U. telytokous in the lab experiment. We discarded any non-linear responses. Our results demonstrate the importance of substrate moisture as an ecological niche dimension for litter crickets. This work bolsters knowledge of litter cricket life history association with moisture, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying.

  9. Microbial functional diversity associated with plant litter decomposition along a climatic gradient.

    Science.gov (United States)

    Sherman, Chen; Steinberger, Yosef

    2012-08-01

    Predicted changes in climate associated with increased greenhouse gas emissions can cause increases in global mean temperature and changes in precipitation regimes. These changes may affect key soil processes, e.g., microbial CO(2) evolution and biomass, mineralization rates, primary productivity, biodiversity, and litter decomposition, which play an important role in carbon and nutrient cycling in terrestrial ecosystems. Our study examined the changes in litter microbial communities and decomposition along a climatic gradient, ranging from arid desert to humid Mediterranean regions in Israel. Wheat straw litter bags were placed in arid, semi-arid, Mediterranean, and humid Mediterranean sites. Samples were collected seasonally over a 2-year period in order to evaluate mass loss, litter moisture, C/N ratio, bacterial colony-forming units (CFUs), microbial CO(2) evolution and biomass, microbial functional diversity, and catabolic profile. Decomposition rate was the highest during the first year of the study at the Mediterranean and arid sites. Community-level physiological profile and microbial biomass were the highest in summer, while bacterial CFUs were the highest in winter. Microbial functional diversity was found to be highest at the humid Mediterranean site, whereas substrate utilization increased at the arid site. Our results support the assumption that climatic factors control litter degradation and regulate microbial activity.

  10. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    NARCIS (Netherlands)

    Berton Zanchi, F.; Waterloo, M.J.; Dolman, A.J.; Groenendijk, M.; Kruijt, B.

    2011-01-01

    Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and

  11. Regional contingencies in the relationship between aboveground Bbomass and litter in the world’s grasslands

    Science.gov (United States)

    O’Halloran, Lydia R.; Borer, Elizabeth T.; Seabloom, Eric W.; MacDougall, Andrew S.; Cleland, Elsa E.; McCulley, Rebecca L.; Hobbie, Sarah; Harpole, W. Stan; DeCrappeo, Nicole M.; Chu, Cheng-Jin; Bakker, Jonathan D.; Davies, Kendi F.; Du, Guozhen; Firn, Jennifer; Hagenah, Nicole; Hofmockel, Kirsten S.; Knops, Johannes M.H.; Li, Wei; Melbourne, Brett A.; Morgan, John W.; Orrock, John L.; Prober, Suzanne M.; Stevens, Carly J.

    2013-01-01

    Based on regional-scale studies, aboveground production and litter decomposition are thought to positively covary, because they are driven by shared biotic and climatic factors. Until now we have been unable to test whether production and decomposition are generally coupled across climatically dissimilar regions, because we lacked replicated data collected within a single vegetation type across multiple regions, obfuscating the drivers and generality of the association between production and decomposition. Furthermore, our understanding of the relationships between production and decomposition rests heavily on separate meta-analyses of each response, because no studies have simultaneously measured production and the accumulation or decomposition of litter using consistent methods at globally relevant scales. Here, we use a multi-country grassland dataset collected using a standardized protocol to show that live plant biomass (an estimate of aboveground net primary production) and litter disappearance (represented by mass loss of aboveground litter) do not strongly covary. Live biomass and litter disappearance varied at different spatial scales. There was substantial variation in live biomass among continents, sites and plots whereas among continent differences accounted for most of the variation in litter disappearance rates. Although there were strong associations among aboveground biomass, litter disappearance and climatic factors in some regions (e.g. U.S. Great Plains), these relationships were inconsistent within and among the regions represented by this study. These results highlight the importance of replication among regions and continents when characterizing the correlations between ecosystem processes and interpreting their global-scale implications for carbon flux. We must exercise caution in parameterizing litter decomposition and aboveground production in future regional and global carbon models as their relationship is complex.

  12. CERES: a model of forest stand biomass dynamics for predicting trace contaminant, nutrient, and water effects. I. Model description

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, K R; Luxmoore, R J; Begovich, C L

    1978-06-01

    CERES is a forest stand growth model which incorporates sugar transport in order to predict both short-term effects and long-term accumulation of trace contaminants and/or nutrients when coupled with the soil chemistry model (SCHEM), and models of solute uptake (DIFMAS and DRYADS) of the Unified Transport Model, UTM. An important feature of CERES is its ability to interface with the soil--plant--atmosphere water model (PROSPER) as a means of both predicting and studying the effects of plant water status on growth and solute transport. CERES considers the biomass dynamics of plants, standing dead and litter with plants divided into leaves, stems, roots, and fruits. The plant parts are divided further into sugar substrate, storage, and in the case of stems and roots, heartwood components. Each ecosystem omponent is described by a mass balance equation written as a first-order ordinary differential equation.

  13. Effects of elevated nitrogen deposition on soil microbial biomass carbon in major subtropical forests of southern China

    Institute of Scientific and Technical Information of China (English)

    Hui WANG; Jiangming MO; Xiankai LU; Jinghua XUE; Jiong LI; Yunting FANG

    2009-01-01

    The effects of elevated nitrogen deposition on soil microbial biomass carbon (C) and extractable dissolved organic carbon (DOC) in three types of forest of southern China were studied in November, 2004 and June, 2006. Plots were established in a pine forest (PF), a mixed pine and broad-leaved forest (MF) and monsoon evergreen broad-leaved forest (MEBF) in the Dinghushan Nature Reserve. Nitrogen treatments included a control (no N addition), low N (50 kg N/(hm2.a)), medium N (100 kg N/ (hm2. a)) and high N (150 kg N/(hm2. a)). Microbial biomass C and extractable DOC were determined using a chloro-form fumigation-extraction method. Results indicate that microbial biomass C and extractable DOC were higher in June, 2006 than in November, 2004 and higher in the MEBF than in the PF or the MF. The response of soil microbial biomass C and extractable DOC to nitrogen deposition varied depending on the forest type and the level of nitrogen treatment. In the PF or MF forests, no significantly different effects of nitrogen addition were found on soil microbial biomass C and extractable DOC. In the MEBF, however, the soil microbial biomass C generally decreased with increased nitrogen levels and high nitrogen addition significantly reduced soil microbial biomass C. The response of soil extractable DOC to added nitrogen in the MEBF shows the opposite trend to soil microbial biomass C. These results suggest that nitrogen deposition may increase the accumulation of soil organic carbon in the MEBF in the study region.

  14. Forest biodiversity conservation in the context of increasing woody biomass harvests

    International Nuclear Information System (INIS)

    Bouget, Christophe; Gosselin, Frederic; Gosselin, Marion

    2011-01-01

    After describing peculiarities and stakes in forest biodiversity, we discuss the response of biodiversity to potential habitat changes induced by increasing forest biomass harvesting: decrease in old trees and stands, and in forest areas unmanaged for decades, increase in overall felled areas, in forest road density and in habitat fragmentation, deleterious changes in soil conditions and forest ambience, development of short and very short rotation coppices. Positive or negative effects on several components of forest biodiversity (mainly soil fauna and flora, and dead wood associated species) are explored. Needs are highlighted: biodiversity monitoring, adaptive management and context-based recommendations. (authors)

  15. Spatial distribution of forest aboveground biomass estimated from remote sensing and forest inventory data in New England, USA

    Science.gov (United States)

    Daolan Zheng; Linda S. Heath; Mark J. Ducey

    2008-01-01

    We combined satellite (Landsat 7 and Moderate Resolution Imaging Spectrometer) and U.S. Department of Agriculture forest inventory and analysis (FIA) data to estimate forest aboveground biomass (AGB) across New England, USA. This is practical for large-scale carbon studies and may reduce uncertainty of AGB estimates. We estimate that total regional forest AGB was 1,867...

  16. Impact of a lead mining-smelting complex on the forest-floor litter arthropod fauna in the new lead belt region of southeast Missouri

    Energy Technology Data Exchange (ETDEWEB)

    Watson, A.P.; Van Hook, R.I.; Jackson, D.R.; Reichle, D.E.

    1976-07-01

    Studies of biological activity within the litter horizons of a watershed contaminated by emissions from a lead-ore processing complex focused on the litter-arthropod food chain as a means of detecting perturbations in a heavy-metal contaminated ecosystem. Both point sources (smelter stack emissions) and fugitive sources (ore-handling processes, yard dusts, and exposed concentrate piles) contributed to the Pb, Zn, Cu, and Cd levels in the study area. Arthropod trophic level density, biomass, and heavy metal content were determined by analysis of specimens removed from litter by von Tullgren funnel extraction, taxonomically classified, and segregated into the trophic categories. Changes in litter decomposition were reflected in the dynamics of the litter arthropod community. Food-chain dilution of Pb, Zn, Cu, and Cd from litter to litter consumer was occurring, as indicated by the mean concentration factors. Accumulation of Pb by litter consumers was much less than that found for the other three heavy metals. In contrast, predatory arthropods on Crooked Creek Watershed either concentrated or equilibrated with respect to Pb, Zn, and Cd from their prey, as indicated by mean total predator concentration factors. A significant depression of the Ca, Mg, and K content litter occurred relative to the control within 0.8 km of the stack. Two mechanisms were postulated to explain this result: increased leaching of cations through the litter induced by a loss of cation exchange capacity, a decrease in pH, and a decrease in microbial immobilization of macronutrients; and a decreased uptake of macronutrients due to root damage produced by heavy-metal concentrations.

  17. Effects of litter quality and parent material on organic matter characteristics and N-dynamics in Luxembourg beech and hornbeam forests

    NARCIS (Netherlands)

    Kooijman, A.M.; Martinez-Hernandez, G.B.

    2009-01-01

    To test effects of litter quality and soil conditions on N-dynamics, we selected seven forests in Luxembourg dominated by beech (Fagus sylvatica, L.) and hornbeam (Carpinus betulus L.), and located on acid loam, decalcified marl or limestone, and measured organic matter characteristics, microbial C

  18. Litter Species Composition and Topographic Effects on Fuels and Modeled Fire Behavior in an Oak-Hickory Forest in the Eastern USA.

    Directory of Open Access Journals (Sweden)

    Matthew B Dickinson

    Full Text Available Mesophytic species (esp. Acer rubrum are increasingly replacing oaks (Quercus spp. in fire-suppressed, deciduous oak-hickory forests of the eastern US. A pivotal hypothesis is that fuel beds derived from mesophytic litter are less likely than beds derived from oak litter to carry a fire and, if they do, are more likely to burn at lower intensities. Species effects, however, are confounded by topographic gradients that affect overstory composition and fuel bed decomposition. To examine the separate and combined effects of litter species composition and topography on surface fuel beds, we conducted a common garden experiment in oak-hickory forests of the Ohio Hills. Each common garden included beds composed of mostly oak and mostly maple litter, representative of oak- and maple-dominated stands, respectively, and a mixture of the two. Beds were replenished each fall for four years. Common gardens (N = 16 were established at four topographic positions (ridges, benches on south- and northeast-facing slopes, and stream terraces at each of four sites. Litter source and topographic position had largely independent effects on fuel beds and modeled fire dynamics after four years of development. Loading (kg m-2 of the upper litter layer (L, the layer that primarily supports flaming spread, was least in more mesic landscape positions and for maple beds, implying greater decomposition rates for those situations. Bulk density in the L layer (kg m-3 was least for oak beds which, along with higher loading, would promote fire spread and fireline intensity. Loading and bulk density of the combined fermentation and humic (FH layers were least on stream terrace positions but were not related to species. Litter- and FH-layer moistures during a 5-day dry-down period after a rain event were affected by time and topographic effects while litter source effects were not evident. Characteristics of flaming combustion determined with a cone calorimeter pointed to greater

  19. Foliage biomass qualitative indices of selected forest forming tree species in Ukrainian Steppe

    Directory of Open Access Journals (Sweden)

    Sytnyk Svitlana

    2017-06-01

    Full Text Available Our study objective was research on the assimilation component of aboveground biomass of trees and its correlation with mensurational indices of trees (age, diameter and height in stands of the main forest forming species in the Ukrainian Northern Steppe zone - Pinus sylvestris L. (Scots pine and Robinia pseudoacacia L. (Black locust. The research was carried out in forest stands subordinated to the State Agency of Forest Resources of Ukraine. We used experimental data collected on sample plots established during years 2014-2016. The main research results prove that the foliage share in the tree greenery biomass structure had a wide range of values. For both investigated species, a positive correlation was found between the dry matter content in the tree foliage and the tree age, height and diameter. The foliage share in tree greenery biomass decreased with increasing mensurational index values. Correlation analysis revealed linear relationships between the mensurational indices and the discussed aboveground live biomass parameters. The closest correlation was observed between the stand age, mean stand diameter, mean stand height and dry matter content in the foliage.

  20. Litter-dwelling arthropod abundance peaks near coarse woody debris in loblolly pine forests of the southeastern United States

    Science.gov (United States)

    Michael D. Ulyshen; James L. Hanula

    2009-01-01

    litter-dwelling arthropod and other invertebrate taxa (e.g., Isopoda, Chilopoda, Diplopoda, Araneae, Pseudoscorpionida, Coleoptera, and Gastropoda) are more numerous near dead wood than away from it in the broad-leaved forests of Europe(Jabin et al. 2004; Topp et al. 2006a, 2006b; Kappes et al. 2006; Kappes 2006; Jabin et al. 2007) and...

  1. Organic aerosols from biomass burning in Amazonian rain forest and their impact onto the environment

    International Nuclear Information System (INIS)

    Cecinato, A.; Mabilia, R.; De Castro Vasconcellos, P.

    2001-01-01

    A field campaign performed in Southern Brazilian Amazonia in 1993 has proved that this region is subjected to fallout of particulated exhausts released by fires of forestal biomass. In fact, organic content of aerosols collected at urban sites located on the border of pluvial forest, about 50 km from fires, was similar to that of biomass burning exhausts. Aerosol composition is indicative of dolous origin of fires. However, organic contents seems to be influenced by two additional sources, i. e. motor vehicle and high vegetation emission. Chemical pattern of organic aerosols released by biomass burning of forest seems to promote occurrence of photochemical smog episodes in that region [it

  2. Tactical supply chain planning for a forest biomass power plant under supply uncertainty

    International Nuclear Information System (INIS)

    Shabani, Nazanin; Sowlati, Taraneh; Ouhimmou, Mustapha; Rönnqvist, Mikael

    2014-01-01

    Uncertainty in biomass supply is a critical issue that needs to be considered in the production planning of bioenergy plants. Incorporating uncertainty in supply chain planning models provides improved and stable solutions. In this paper, we first reformulate a previously developed non-linear programming model for optimization of a forest biomass power plant supply chain into a linear programming model. The developed model is a multi-period tactical-level production planning problem and considers the supply and storage of forest biomass as well as the production of electricity. It has a one-year planning horizon with monthly time steps. Next, in order to incorporate uncertainty in monthly available biomass into the planning, we develop a two-stage stochastic programming model. Finally, to balance the risk and profit, we propose a bi-objective model. The results show that uncertainty in availability of biomass has an additional cost of $0.4 million for the power plant. Using the proposed stochastic optimization model could reduce this cost by half. - Highlights: • Developed a two-stage stochastic optimization model to consider supply uncertainty. • Maximized the profit of a forest biomass power plant value chain. • Minimized two risk measures, variability index and downside risk, to manage risks. • Stochastic optimization model provided feasible solution for all scenarios. • Results showed a trade-off between profit and risk management

  3. GASIFICATION BASED BIOMASS CO-FIRING

    Energy Technology Data Exchange (ETDEWEB)

    Babul Patel; Kevin McQuigg; Robert Toerne; John Bick

    2003-01-01

    Biomass gasification offers a practical way to use this widespread fuel source for co-firing traditional large utility boilers. The gasification process converts biomass into a low Btu producer gas that can be used as a supplemental fuel in an existing utility boiler. This strategy of co-firing is compatible with a variety of conventional boilers including natural gas and oil fired boilers, pulverized coal fired conventional and cyclone boilers. Gasification has the potential to address all problems associated with the other types of co-firing with minimum modifications to the existing boiler systems. Gasification can also utilize biomass sources that have been previously unsuitable due to size or processing requirements, facilitating a wider selection of biomass as fuel and providing opportunity in reduction of carbon dioxide emissions to the atmosphere through the commercialization of this technology. This study evaluated two plants: Wester Kentucky Energy Corporation's (WKE's) Reid Plant and TXU Energy's Monticello Plant for technical and economical feasibility. These plants were selected for their proximity to large supply of poultry litter in the area. The Reid plant is located in Henderson County in southwest Kentucky, with a large poultry processing facility nearby. Within a fifty-mile radius of the Reid plant, there are large-scale poultry farms that generate over 75,000 tons/year of poultry litter. The local poultry farmers are actively seeking environmentally more benign alternatives to the current use of the litter as landfill or as a farm spread as fertilizer. The Monticello plant is located in Titus County, TX near the town of Pittsburgh, TX, where again a large poultry processor and poultry farmers in the area generate over 110,000 tons/year of poultry litter. Disposal of this litter in the area is also a concern. This project offers a model opportunity to demonstrate the feasibility of biomass co-firing and at the same time eliminate

  4. Climate change-associated trends in net biomass change are age dependent in western boreal forests of Canada.

    Science.gov (United States)

    Chen, Han Y H; Luo, Yong; Reich, Peter B; Searle, Eric B; Biswas, Shekhar R

    2016-09-01

    The impacts of climate change on forest net biomass change are poorly understood but critical for predicting forest's contribution to the global carbon cycle. Recent studies show climate change-associated net biomass declines in mature forest plots. The representativeness of these plots for regional forests, however, remains uncertain because we lack an assessment of whether climate change impacts differ with forest age. Using data from plots of varying ages from 17 to 210 years, monitored from 1958 to 2011 in western Canada, we found that climate change has little effect on net biomass change in forests ≤ 40 years of age due to increased growth offsetting increased mortality, but has led to large decreases in older forests due to increased mortality accompanying little growth gain. Our analysis highlights the need to incorporate forest age profiles in examining past and projecting future forest responses to climate change. © 2016 John Wiley & Sons Ltd/CNRS.

  5. Uncertainty in the spatial distribution of tropical forest biomass: a comparison of pan-tropical maps.

    Science.gov (United States)

    Mitchard, Edward Ta; Saatchi, Sassan S; Baccini, Alessandro; Asner, Gregory P; Goetz, Scott J; Harris, Nancy L; Brown, Sandra

    2013-10-26

    Mapping the aboveground biomass of tropical forests is essential both for implementing conservation policy and reducing uncertainties in the global carbon cycle. Two medium resolution (500 m - 1000 m) pantropical maps of vegetation biomass have been recently published, and have been widely used by sub-national and national-level activities in relation to Reducing Emissions from Deforestation and forest Degradation (REDD+). Both maps use similar input data layers, and are driven by the same spaceborne LiDAR dataset providing systematic forest height and canopy structure estimates, but use different ground datasets for calibration and different spatial modelling methodologies. Here, we compare these two maps to each other, to the FAO's Forest Resource Assessment (FRA) 2010 country-level data, and to a high resolution (100 m) biomass map generated for a portion of the Colombian Amazon. We find substantial differences between the two maps, in particular in central Amazonia, the Congo basin, the south of Papua New Guinea, the Miombo woodlands of Africa, and the dry forests and savannas of South America. There is little consistency in the direction of the difference. However, when the maps are aggregated to the country or biome scale there is greater agreement, with differences cancelling out to a certain extent. When comparing country level biomass stocks, the two maps agree with each other to a much greater extent than to the FRA 2010 estimates. In the Colombian Amazon, both pantropical maps estimate higher biomass than the independent high resolution map, but show a similar spatial distribution of this biomass. Biomass mapping has progressed enormously over the past decade, to the stage where we can produce globally consistent maps of aboveground biomass. We show that there are still large uncertainties in these maps, in particular in areas with little field data. However, when used at a regional scale, different maps appear to converge, suggesting we can provide

  6. Environmental fate and distribution of technetium-99 in a deciduous forest ecosystem

    International Nuclear Information System (INIS)

    Garten, C.T. Jr.; Tucker, C.S.; Walton, B.T.

    1986-01-01

    The uptake of 99 Tc by trees intercepting contaminated groundwater from a radioactive waste storage site was measured to identify the major 99 Tc pools within the woodland ecosystem and to assess the relative mobility of 99 Tc in the existing element cycle. The highest average 99 Tc concentrations in vegetation were found in herbaceous plants. Tree wood was the major above-ground pool for 99 Tc because of the high concentrations in wood as well as the large amount of wood relative to other biomass at the site. Technetium was not easily leached from the trees by rainfall and was not readily extractable from forest floor leaf litter by water. The relative importance of return pathways for 99 Tc to the forest floor was leaf fall > stemflow > throughfall, indicating that 99 Tc was conserved by the trees. Snails and millipedes from the leaf litter layer concentrated technetium 20- and 16-fold, respectively, above levels found in the soil. Pertechnetate was rendered less bioavailable after ingestion by a leaf litter macroinvertebrate (Porcellio sp.) common to the study site. (author)

  7. Long-term multifactorial climate change impacts on mesofaunal biomass and nitrogen content

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård; Dyrnum, Kristine; Michelsen, Anders

    2015-01-01

    increased at elevated CO2, or tended do so. In contrast, enchytraeid N content decreased at elevated CO2. Soil microbial biomass N pool and litter C:N ratio also increased with elevated CO2, which suggests that mite biomasses are more coupled to microbial biomass, whereas enchytraeid biomass to a larger...... extent is governed by litter nitrogen concentration, i.e. litter quality. Structural equation modelling confirmed the positive coupling between soil microbial N content and oribatid biomass and further between oribatid and mesostigmatic biomass. The SEM also revealed a negative relationship between...... microbial N content and enchytraeid biomass. The biomass of all mesofaunal groups was reduced by spring drought, especially when combined with warming. Enchytraeid and especially collembolan biomass suffered greater drought declines than mite biomasses. We conclude that under long-term elevated CO2 exposure...

  8. ESTIMATION OF FOREST BIOMASS BASED ON MULITI-SOURCE REMOTE SENSING DATA SET – A CASE STUDY OF SHANGRI-LA COUNTY

    Directory of Open Access Journals (Sweden)

    W. Feng

    2018-04-01

    Full Text Available Forest biomass is an important indicator for the structure and function of forest ecosystems, and an accurate assessment of forest biomass is crucial for understanding ecosystem changes. Remote sensing has been widely used for inversion of biomass. However, in mature or over-mature forest areas, spectral saturation is prone to occur. Based on existing research, this paper synthesizes domestic high resolution satellites, ZY3-01 satellites, and GLAS14-level data from space-borne Lidar system, and other data set. Extracting texture and elevation features respectively, for the inversion of forest biomass. This experiment takes Shangri-La as the research area. Firstly, the biomass in the laser spot was calculated based on GLAS data and other auxiliary data, DEM, the second type inventory of forest resources data and the Shangri-La vector boundary data. Then, the regression model was established, that is, the relationship between the texture factors of ZY3-01 and biomass in the laser spot. Finally, by using this model and the forest distribution map in Shangri-La, the biomass of the whole area is obtained, which is 1.3972 × 108t.

  9. Tree Biomass Allocation and Its Model Additivity for Casuarina equisetifolia in a Tropical Forest of Hainan Island, China

    Science.gov (United States)

    Xue, Yang; Yang, Zhongyang; Wang, Xiaoyan; Lin, Zhipan; Li, Dunxi; Su, Shaofeng

    2016-01-01

    Casuarina equisetifolia is commonly planted and used in the construction of coastal shelterbelt protection in Hainan Island. Thus, it is critical to accurately estimate the tree biomass of Casuarina equisetifolia L. for forest managers to evaluate the biomass stock in Hainan. The data for this work consisted of 72 trees, which were divided into three age groups: young forest, middle-aged forest, and mature forest. The proportion of biomass from the trunk significantly increased with age (Pbiomass of the branch and leaf decreased, and the biomass of the root did not change. To test whether the crown radius (CR) can improve biomass estimates of C. equisetifolia, we introduced CR into the biomass models. Here, six models were used to estimate the biomass of each component, including the trunk, the branch, the leaf, and the root. In each group, we selected one model among these six models for each component. The results showed that including the CR greatly improved the model performance and reduced the error, especially for the young and mature forests. In addition, to ensure biomass additivity, the selected equation for each component was fitted as a system of equations using seemingly unrelated regression (SUR). The SUR method not only gave efficient and accurate estimates but also achieved the logical additivity. The results in this study provide a robust estimation of tree biomass components and total biomass over three groups of C. equisetifolia. PMID:27002822

  10. Tree Biomass Allocation and Its Model Additivity for Casuarina equisetifolia in a Tropical Forest of Hainan Island, China.

    Science.gov (United States)

    Xue, Yang; Yang, Zhongyang; Wang, Xiaoyan; Lin, Zhipan; Li, Dunxi; Su, Shaofeng

    2016-01-01

    Casuarina equisetifolia is commonly planted and used in the construction of coastal shelterbelt protection in Hainan Island. Thus, it is critical to accurately estimate the tree biomass of Casuarina equisetifolia L. for forest managers to evaluate the biomass stock in Hainan. The data for this work consisted of 72 trees, which were divided into three age groups: young forest, middle-aged forest, and mature forest. The proportion of biomass from the trunk significantly increased with age (Pbiomass of the branch and leaf decreased, and the biomass of the root did not change. To test whether the crown radius (CR) can improve biomass estimates of C. equisetifolia, we introduced CR into the biomass models. Here, six models were used to estimate the biomass of each component, including the trunk, the branch, the leaf, and the root. In each group, we selected one model among these six models for each component. The results showed that including the CR greatly improved the model performance and reduced the error, especially for the young and mature forests. In addition, to ensure biomass additivity, the selected equation for each component was fitted as a system of equations using seemingly unrelated regression (SUR). The SUR method not only gave efficient and accurate estimates but also achieved the logical additivity. The results in this study provide a robust estimation of tree biomass components and total biomass over three groups of C. equisetifolia.

  11. The limited contribution of large trees to annual biomass production in an old-growth tropical forest.

    Science.gov (United States)

    Ligot, Gauthier; Gourlet-Fleury, Sylvie; Ouédraogo, Dakis-Yaoba; Morin, Xavier; Bauwens, Sébastien; Baya, Fidele; Brostaux, Yves; Doucet, Jean-Louis; Fayolle, Adeline

    2018-04-16

    Although the importance of large trees regarding biodiversity and carbon stock in old-growth forests is undeniable, their annual contribution to biomass production and carbon uptake remains poorly studied at the stand level. To clarify the role of large trees in biomass production, we used data of tree growth, mortality, and recruitment monitored during 20 yr in 10 4-ha plots in a species-rich tropical forest (Central African Republic). Using a random block design, three different silvicultural treatments, control, logged, and logged + thinned, were applied in the 10 plots. Annual biomass gains and losses were analyzed in relation to the relative biomass abundance of large trees and by tree size classes using a spatial bootstrap procedure. Although large trees had high individual growth rates and constituted a substantial amount of biomass, stand-level biomass production decreased with the abundance of large trees in all treatments and plots. The contribution of large trees to annual stand-level biomass production appeared limited in comparison to that of small trees. This pattern did not only originate from differences in abundance of small vs. large trees or differences in initial biomass stocks among tree size classes, but also from a reduced relative growth rate of large trees and a relatively constant mortality rate among tree size classes. In a context in which large trees are increasingly gaining attention as being a valuable and a key structural characteristic of natural forests, the present study brought key insights to better gauge the relatively limited role of large trees in annual stand-level biomass production. In terms of carbon uptake, these results suggest, as already demonstrated, a low net carbon uptake of old-growth forests in comparison to that of logged forests. Tropical forests that reach a successional stage with relatively high density of large trees progressively cease to be carbon sinks as large trees contribute sparsely or even

  12. Carbon storage and emissions offset potential in an African dry forest, the Arabuko-Sokoke Forest, Kenya.

    Science.gov (United States)

    Glenday, Julia

    2008-07-01

    Concerns about rapid tropical deforestation, and its contribution to rising atmospheric concentrations of greenhouse gases, increase the importance of monitoring terrestrial carbon storage in changing landscapes. Emerging markets for carbon emission offsets may offer developing nations needed incentives for reforestation, rehabilitation, and avoided deforestation. However, relatively little empirical data exists regarding carbon storage in African tropical forests, particularly for those in arid or semi-arid regions. Kenya's 416 km(2) Arabuko-Sokoke Forest (ASF) is the largest remaining fragment of East African coastal dry forest and is considered a global biodiversity hotspot (Myers et al. 2000), but has been significantly altered by past commercial logging and ongoing extraction. Forest carbon storage for ASF was estimated using allometric equations for tree biomass, destructive techniques for litter and herbaceous vegetation biomass, and spectroscopy for soils. Satellite imagery was used to assess land cover changes from 1992 to 2004. Forest and thicket types (Cynometra webberi dominated, Brachystegia spiciformis dominated, and mixed species forest) had carbon densities ranging from 58 to 94 Mg C/ha. The ASF area supported a 2.8-3.0 Tg C carbon stock. Although total forested area in ASF did not change over the analyzed time period, ongoing disturbances, quantified by the basal area of cut tree stumps per sample plot, correlated with decreased carbon densities. Madunguni Forest, an adjoining forest patch, lost 86% of its forest cover and at least 76% of its terrestrial carbon stock in the time period. Improved management of wood harvesting in ASF and rehabilitation of Madunguni Forest could substantially increase terrestrial carbon sequestration in the region.

  13. SOA Formation Potential of Emissions from Soil and Leaf Litter

    Science.gov (United States)

    Faiola, C. L.; Vanderschelden, G. S.; Wen, M.; Cobos, D. R.; Jobson, B. T.; VanReken, T. M.

    2013-12-01

    In the United States, emissions of volatile organic compounds (VOCs) from natural sources exceed all anthropogenic sources combined. VOCs participate in oxidative chemistry in the atmosphere and impact the concentrations of ozone and particulate material. The formation of secondary organic aerosol (SOA) is particularly complex and is frequently underestimated using state-of-the-art modeling techniques. We present findings that suggest emissions of important SOA precursors from soil and leaf litter are higher than current inventories would suggest, particularly under conditions typical of Fall and Spring. Soil and leaf litter samples were collected at Big Meadow Creek from the University of Idaho Experimental Forest. The dominant tree species in this area of the forest are ponderosa pine, Douglas-fir, and western larch. Samples were transported to the laboratory and housed within a 0.9 cubic meter Teflon dynamic chamber where VOC emissions were continuously monitored with a GC-FID-MS and PTR-MS. Aerosol was generated from soil and leaf litter emissions by pumping the emissions into a 7 cubic meter Teflon aerosol growth chamber where they were oxidized with ozone in the absence of light. The evolution of particle microphysical and chemical characteristics was monitored over the following eight hours. Particle size distribution and chemical composition were measured with a SMPS and HR-ToF-AMS respectively. Monoterpenes dominated the emission profile with emission rates up to 283 micrograms carbon per meter squared per hour. The dominant monoterpenes emitted were beta-pinene, alpha-pinene, and delta-3-carene in descending order. The composition of the SOA produced was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and alpha-pinene. Measured soil/litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest that during fall and spring when tree emissions are lower, monoterpene emissions within forests may be

  14. Potential for post-closure radionuclide redistribution due to biotic intrusion: aboveground biomass, litter production rates, and the distribution of root mass with depth at material disposal area G, Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    French, Sean B.; Christensen, Candace; Jennings, Terry L.; Jaros, Christopher L.; Wykoff, David S.; Crowell, Kelly J.; Shuman, Rob

    2008-01-01

    Low-level radioactive waste (LLW) generated at the Los Alamos National Laboratories (LANL) is disposed of at LANL's Technical Area (T A) 54, Material Disposal Area (MDA) G. The ability of MDA G to safely contain radioactive waste during current and post-closure operations is evaluated as part of the facility's ongoing performance assessment (PA) and composite analysis (CA). Due to the potential for uptake and incorporation of radio nuclides into aboveground plant material, the PA and CA project that plant roots penetrating into buried waste may lead to releases of radionuclides into the accessible environment. The potential amount ofcontamination deposited on the ground surface due to plant intrusion into buried waste is a function of the quantity of litter generated by plants, as well as radionuclide concentrations within the litter. Radionuclide concentrations in plant litter is dependent on the distribution of root mass with depth and the efficiency with which radionuclides are extracted from contaminated soils by the plant's roots. In order to reduce uncertainties associated with the PA and CA for MDA G, surveys are being conducted to assess aboveground biomass, plant litter production rates, and root mass with depth for the four prominent vegetation types (grasses, forbs, shrubs and trees). The collection of aboveground biomass for grasses and forbs began in 2007. Additional sampling was conducted in October 2008 to measure root mass with depth and to collect additional aboveground biomass data for the types of grasses, forbs, shrubs, and trees that may become established at MDA G after the facility undergoes final closure, Biomass data will be used to estimate the future potential mass of contaminated plant litter fall, which could act as a latent conduit for radionuclide transport from the closed disposal area. Data collected are expected to reduce uncertainties associated with the PA and CA for MDA G and ultimately aid in the assessment and subsequent

  15. The effects of location, feedstock availability, and supply-chain logistics on the greenhouse gas emissions of forest-biomass energy utilization in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Jappinen, E,

    2013-11-01

    Forest biomass represents a geographically distributed feedstock, and geographical location affects the greenhouse gas (GHG) performance of a given forest-bioenergy system in several ways. For example, biomass availability, forest operations, transportation possibilities and the distances involved, biomass end-use possibilities, fossil reference systems, and forest carbon balances all depend to some extent on location. The overall objective of this thesis was to assess the GHG emissions derived from supply and energy-utilization chains of forest biomass in Finland, with a specific focus on the effect of location in relation to forest biomass's availability and the transportation possibilities. Biomass availability and transportation-network assessments were conducted through utilization of geographical information system methods, and the GHG emissions were assessed by means of lifecycle assessment. The thesis is based on four papers in which forest biomass supply on industrial scale was assessed. The feedstocks assessed in this thesis include harvesting residues, smalldiameter energy wood and stumps. The principal implication of the findings in this thesis is that in Finland, the location and availability of biomass in the proximity of a given energyutilization or energy-conversion plant is not a decisive factor in supply-chain GHG emissions or the possible GHG savings to be achieved with forest-biomass energy use. Therefore, for the greatest GHG reductions with limited forest-biomass resources, energy utilization of forest biomass in Finland should be directed to the locations where most GHG savings are achieved through replacement of fossil fuels. Furthermore, one should prioritize the types of forest biomass with the lowest direct supply-chain GHG emissions (e.g., from transport and comminution) and the lowest indirect ones (in particular, soil carbon-stock losses), regardless of location. In this respect, the best combination is to use harvesting residues

  16. Does Short-term Litter Input Manipulation Affect Soil Respiration and the Carbon-isotopic Signature of Soil Respired CO2

    Science.gov (United States)

    Cheng, X.; Wu, J.

    2016-12-01

    Global change greatly alters the quality and quantity of plant litter inputs to soils, and further impacts soil organic matter (SOM) dynamics and soil respiration. However, the process-based understanding of how soil respiration may change with future shift in litter input is not fully understood. The Detritus Input and Removal Treatment (DIRT) experiment was conducted in coniferous forest (Platycladus orientalis (Linn.) Franco) ecosystem of central China to investigate the impact of above- and belowground litter input on soil respiration and the carbon-isotopic signature of soil respired CO2. Short-term (1-2 years) litter input manipulation significantly affected soil respiration, based on annual flux values, soil respiration was 31.9%, 20.5% and 37.2% lower in no litter (NL), no root (NR) and no input (NRNL), respectively, compared to control (CK). Whereas double litter (DL) treatment increased soil respiration by 9.1% compared to CK. The recalcitrance index of carbon (RIC) and the relative abundance of fungi increased under litter removal or root exclusion treatment (NL, NR and NRNL) compared to CK. Basal soil respiration was positively related to liable C and microbial biomass and negatively related to RIC and fungi to bacteria (F: B) ratio. The carbon-isotopic signature of soil respired CO2 enriched under litter removal and no input treatment, and slightly depleted under litter addition treatment compared to CK. Our results suggest that short-term litter input manipulation can affect the soil respiration by altering substrate availability and microbial community structure, and also impact the carbon-isotopic signature of soil respired CO2 possibly duo to change in the component of soil respiration and soil microclimate.

  17. Environmental parameters affecting the structure of leaf-litter frog (Amphibia: Anura communities in tropical forests: a case study from an Atlantic Rainforest area in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Carla C. Siqueira

    2014-04-01

    Full Text Available Despite a recent increase of information on leaf litter frog communities from Atlantic rainforests, few studies have analyzed the relationship between environmental parameters and community structure of these animals. We analyzed the effects of some environmental factors on a leaf litter frog community at an Atlantic Rainforest area in southeastern Brazil. Data collection lasted ten consecutive days in January 2010, at elevations ranging between 300 and 520 m above sea level. We established 50 quadrats of 5 x 5 m on the forest floor, totaling 1,250 m² of sampled area, and recorded the mean leaf-litter depth and the number of trees within the plot, as well as altitude. We found 307 individuals belonging to ten frog species within the plots. The overall density of leaf-litter frogs estimated from the plots was 24.6 ind/100m², with Euparkerella brasiliensis (Parker, 1926, Ischnocnema guentheri (Steindachner, 1864, Ischnocnema parva (Girard, 1853 and Haddadus binotatus (Spix, 1824 presenting the highest estimated densities. Among the environmental variables analyzed, only altitude influenced the parameters of anuran community. Our results indicate that the study area has a very high density of forest floor leaf litter frogs at altitudes of 300-500 m. Future estimates of litter frog density might benefit from taking the local altitudinal variation into consideration. Neglecting such variation might result in underestimated/overestimated values if they are extrapolated to the whole area.

  18. Dispersal limitation induces long-term biomass collapse in overhunted Amazonian forests.

    Science.gov (United States)

    Peres, Carlos A; Emilio, Thaise; Schietti, Juliana; Desmoulière, Sylvain J M; Levi, Taal

    2016-01-26

    Tropical forests are the global cornerstone of biological diversity, and store 55% of the forest carbon stock globally, yet sustained provisioning of these forest ecosystem services may be threatened by hunting-induced extinctions of plant-animal mutualisms that maintain long-term forest dynamics. Large-bodied Atelinae primates and tapirs in particular offer nonredundant seed-dispersal services for many large-seeded Neotropical tree species, which on average have higher wood density than smaller-seeded and wind-dispersed trees. We used field data and models to project the spatial impact of hunting on large primates by ∼ 1 million rural households throughout the Brazilian Amazon. We then used a unique baseline dataset on 2,345 1-ha tree plots arrayed across the Brazilian Amazon to model changes in aboveground forest biomass under different scenarios of hunting-induced large-bodied frugivore extirpation. We project that defaunation of the most harvest-sensitive species will lead to losses in aboveground biomass of between 2.5-5.8% on average, with some losses as high as 26.5-37.8%. These findings highlight an urgent need to manage the sustainability of game hunting in both protected and unprotected tropical forests, and place full biodiversity integrity, including populations of large frugivorous vertebrates, firmly in the agenda of reducing emissions from deforestation and forest degradation (REDD+) programs.

  19. Litter decomposition, N2-fixer abundance, and microbial dynamics govern tropical dry forest recovery to land use change

    Science.gov (United States)

    Trierweiler, A.; Powers, J. S.; Xu, X.; Gei, M. G.; Medvigy, D.

    2017-12-01

    As one of the most threatened tropical biomes, Seasonal Dry Tropical Forests (TDF) have undergone extensive land-use change. However, some areas are undergoing recovery into secondary forests. Despite their broad distribution (42% of tropical forests), they are under-studied compared to wet tropical forests and our understanding of their biogeochemical cycling and belowground processes are limited. Here, we use models along with field measurements to improve our understanding of nutrient cycling and limitation in secondary TDFs. We ask (1) Is there modeling evidence that tropical dry forests can become nutrient limited? (2) What are the most important mechanisms employed to avoid nutrient limitation? (3) How might climate change alter biogeochemical cycling and nutrient limitation in recovering TDF? We use a new version of the Ecosystem Demography (ED2) model that has been recently parameterized for TDFs and incorporates a range of plant functional groups (including deciduousness and N2-fixation) and multiple resource constraints (carbon, nitrogen, phosphorus, and water). In the model, plants then can dynamically adjust their carbon allocation and nutrient acquisition strategies using N2-fixing bacteria and mycorrhizal fungi according to the nutrient limitation status. We ran the model for a nutrient gradient of field sites in Costa Rica and explored the sensitivity of nutrient limitation to key mechanisms including litter respiration, N resorption, N2-fixation, and overflow respiration. Future runs will evaluate how CO2 and climate change affect recovering TDFs. We found increasing nutrient limitation across the nutrient gradient of sites. Nitrogen limitation dominated the nutrient limitation signal. In the model, forest litter accumulation was negatively correlated with site fertility in Costa Rican forests. Our sensitivity analyses indicate that N2-fixer abundance, decomposition rates, and adding more explicit microbial dynamics are key factors in overcoming

  20. Impacts of Frequent Burning on Live Tree Carbon Biomass and Demography in Post-Harvest Regrowth Forest

    Directory of Open Access Journals (Sweden)

    Luke Collins

    2014-04-01

    Full Text Available The management of forest ecosystems to increase carbon storage is a global concern. Fire frequency has the potential to shift considerably in the future. These shifts may alter demographic processes and growth of tree species, and consequently carbon storage in forests. Examination of the sensitivity of forest carbon to the potential upper and lower extremes of fire frequency will provide crucial insight into the magnitude of possible change in carbon stocks associated with shifts in fire frequency. This study examines how tree biomass and demography of a eucalypt forest regenerating after harvest is affected by two experimentally manipulated extremes in fire frequency (i.e., ~3 year fire intervals vs. unburnt sustained over a 23 year period. The rate of post-harvest biomass recovery of overstorey tree species, which constituted ~90% of total living tree biomass, was lower within frequently burnt plots than unburnt plots, resulting in approximately 20% lower biomass in frequently burnt plots by the end of the study. Significant differences in carbon biomass between the two extremes in frequency were only evident after >15–20 years of sustained treatment. Reduced growth rates and survivorship of smaller trees on the frequently burnt plots compared to unburnt plots appeared to be driving these patterns. The biomass of understorey trees, which constituted ~10% of total living tree biomass, was not affected by frequent burning. These findings suggest that future shifts toward more frequent fire will potentially result in considerable reductions in carbon sequestration across temperate forest ecosystems in Australia.

  1. Developing Biomass Equations for Western Hemlock and Red Alder Trees in Western Oregon Forests

    Science.gov (United States)

    Krishna Poudel; Hailemariam Temesgen

    2016-01-01

    Biomass estimates are required for reporting carbon, assessing feedstock availability, and assessing forest fire threat. We developed diameter- and height-based biomass equations for Western hemlock (Tsuga heterophylla (Raf.) Sarg.) and red alder (Alnus rubra Bong.) trees in Western Oregon. A system of component biomass...

  2. Standing crop and aboveground biomass partitioning of a dwarf mangrove forest in Taylor River Slough, Florida

    Science.gov (United States)

    Coronado-Molina, C.; Day, J.W.; Reyes, E.; Perez, B.C.

    2004-01-01

    The structure and standing crop biomass of a dwarf mangrove forest, located in the salinity transition zone ofTaylor River Slough in the Everglades National Park, were studied. Although the four mangrove species reported for Florida occurred at the study site, dwarf Rhizophora mangle trees dominated the forest. The structural characteristics of the mangrove forest were relatively simple: tree height varied from 0.9 to 1.2 meters, and tree density ranged from 7062 to 23 778 stems haa??1. An allometric relationship was developed to estimate leaf, branch, prop root, and total aboveground biomass of dwarf Rhizophora mangle trees. Total aboveground biomass and their components were best estimated as a power function of the crown area times number of prop roots as an independent variable (Y = B ?? Xa??0.5083). The allometric equation for each tree component was highly significant (pRhizophora mangle contributed 85% of total standing crop biomass. Conocarpus erectus, Laguncularia racemosa, and Avicennia germinans contributed the remaining biomass. Average aboveground biomass allocation was 69% for prop roots, 25% for stem and branches, and 6% for leaves. This aboveground biomass partitioning pattern, which gives a major role to prop roots that have the potential to produce an extensive root system, may be an important biological strategy in response to low phosphorus availability and relatively reduced soils that characterize mangrove forests in South Florida.

  3. Stand density index as a tool to assess the maximization of forest carbon and biomass

    Science.gov (United States)

    Christopher W. Woodall; Anthony W. D’Amato; John B. Bradford; Andrew O. Finley

    2012-01-01

    Given the ability of forests to mitigate greenhouse gas emissions and provide feedstocks to energy utilities, there is an emerging need to assess forest biomass/carbon accretion opportunities over large areas. Techniques for objectively quantifying stand stocking of biomass/carbon are lacking for large areas given the complexity of tree species composition in the U.S....

  4. Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality

    Science.gov (United States)

    Foster, Jane R.; D'Amato, Anthony W.; Bradford, John B.

    2014-01-01

    Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20–30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25–30 % higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics.

  5. Efficacy of generic allometric equations for estimating biomass: a test in Japanese natural forests.

    Science.gov (United States)

    Ishihara, Masae I; Utsugi, Hajime; Tanouchi, Hiroyuki; Aiba, Masahiro; Kurokawa, Hiroko; Onoda, Yusuke; Nagano, Masahiro; Umehara, Toru; Ando, Makoto; Miyata, Rie; Hiura, Tsutom

    2015-07-01

    Accurate estimation of tree and forest biomass is key to evaluating forest ecosystem functions and the global carbon cycle. Allometric equations that estimate tree biomass from a set of predictors, such as stem diameter and tree height, are commonly used. Most allometric equations are site specific, usually developed from a small number of trees harvested in a small area, and are either species specific or ignore interspecific differences in allometry. Due to lack of site-specific allometries, local equations are often applied to sites for which they were not originally developed (foreign sites), sometimes leading to large errors in biomass estimates. In this study, we developed generic allometric equations for aboveground biomass and component (stem, branch, leaf, and root) biomass using large, compiled data sets of 1203 harvested trees belonging to 102 species (60 deciduous angiosperm, 32 evergreen angiosperm, and 10 evergreen gymnosperm species) from 70 boreal, temperate, and subtropical natural forests in Japan. The best generic equations provided better biomass estimates than did local equations that were applied to foreign sites. The best generic equations included explanatory variables that represent interspecific differences in allometry in addition to stem diameter, reducing error by 4-12% compared to the generic equations that did not include the interspecific difference. Different explanatory variables were selected for different components. For aboveground and stem biomass, the best generic equations had species-specific wood specific gravity as an explanatory variable. For branch, leaf, and root biomass, the best equations had functional types (deciduous angiosperm, evergreen angiosperm, and evergreen gymnosperm) instead of functional traits (wood specific gravity or leaf mass per area), suggesting importance of other traits in addition to these traits, such as canopy and root architecture. Inclusion of tree height in addition to stem diameter improved

  6. A supply chain analysis framework for assessing state-level forest biomass utilization policies in the United States

    International Nuclear Information System (INIS)

    Becker, Dennis R.; Moseley, Cassandra; Lee, Christine

    2011-01-01

    The number of state policies aimed at fostering biomass utilization has proliferated in recent years in the United States. Several states aim to increase the use of forest and agriculture biomass through renewable energy production. Several more indirectly encourage utilization by targeting aspects of the supply chain from trees standing in the forest to goods sold. This research classifies 370 state policies from across the United States that provides incentives for forest biomass utilization. We compare those policies by types of incentives relative to the supply chain and geographic clustering. We then develop a framework for policy evaluation building on the supply chain steps, which can be used to assess intended and unintended consequences of policy interactions. These findings may inform policy development and identify synergies at different steps in the supply chain to enhance forest biomass utilization.

  7. Forest biomass diversion in the Sierra Nevada: Energy, economics and emissions

    Science.gov (United States)

    Bruce Springsteen; Thomas Christofk; Robert A. York; Tad Mason; Stephen Baker; Emily Lincoln; Bruce Hartsough; Takuyuki Yoshioka

    2015-01-01

    As an alternative to open pile burning, use of forest wastes from fuel hazard reduction projects at Blodgett Forest Research Station for electricity production was shown to produce energy and emission benefits: energy (diesel fuel) expended for processing and transport was 2.5% of the biomass fuel (energy equivalent); based on measurements from a large pile...

  8. Cost, energy use and GHG emissions for forest biomass harvesting operations

    International Nuclear Information System (INIS)

    Zhang, Fengli; Johnson, Dana M.; Wang, Jinjiang; Yu, Chunxia

    2016-01-01

    For forest-based biomass to become a significant contribution to the United States' energy portfolio, harvesting operations must be physically feasible and economically viable. An assessment of cost, energy and greenhouse gas (GHG) emissions of forest biomass harvesting was conducted. The assessment differentiates harvesting systems by cut-to-length and whole tree; harvest types of 30%, 70%, and 100% cut; and forest types of hardwoods, softwoods, mixed hardwood/softwood, and softwood plantations. Harvesting cost models were developed for economic assessment and life cycle energy and emission assessment was applied to calculate energy and emissions for different harvesting scenarios, considering material and energy inputs (machinery, diesel, etc.) and outputs (GHG emissions) for each harvesting process (felling, forwarding/skidding, etc.). The developed harvesting cost models and the life cycle energy and emission assessment method were applied in Michigan, U.S. using information collected from different sources. A sensitivity analysis was performed for selected input variables for the harvesting operations in order to explore their relative importance. The results indicated that productivity had the largest impact on harvesting cost followed by machinery purchase price, yearly scheduled hours, and expected utilization. Productivity and fuel use, as well as fuel factors, are the most influential environmental impacts of harvesting operations. - Highlights: • Life cycle energy and emissions for forest biomass harvesting operations. • Harvesting cost models were developed for economic assessment. • Productivity had the largest impact on harvesting cost. • Fuel use contributes the most emissions while lubricants contribute the least.

  9. [Biomass allometric equations of nine common tree species in an evergreen broadleaved forest of subtropical China].

    Science.gov (United States)

    Zuo, Shu-di; Ren, Yin; Weng, Xian; Ding, Hong-feng; Luo, Yun-jian

    2015-02-01

    Biomass allometric equation (BAE) considered as a simple and reliable method in the estimation of forest biomass and carbon was used widely. In China, numerous studies focused on the BAEs for coniferous forest and pure broadleaved forest, and generalized BAEs were frequently used to estimate the biomass and carbon of mixed broadleaved forest, although they could induce large uncertainty in the estimates. In this study, we developed the species-specific and generalized BAEs using biomass measurement for 9 common broadleaved trees (Castanopsis fargesii, C. lamontii, C. tibetana, Lithocarpus glaber, Sloanea sinensis, Daphniphyllum oldhami, Alniphyllum fortunei, Manglietia yuyuanensis, and Engelhardtia fenzlii) of subtropical evergreen broadleaved forest, and compared differences in species-specific and generalized BAEs. The results showed that D (diameter at breast height) was a better independent variable in estimating the biomass of branch, leaf, root, aboveground section and total tree than a combined variable (D2 H) of D and H (tree height) , but D2H was better than D in estimating stem biomass. R2 (coefficient of determination) values of BAEs for 6 species decreased when adding H as the second independent variable into D- only BAEs, where R2 value for S. sinensis decreased by 5.6%. Compared with generalized D- and D2H-based BAEs, standard errors of estimate (SEE) of BAEs for 8 tree species decreased, and similar decreasing trend was observed for different components, where SEEs of the branch decreased by 13.0% and 20.3%. Therefore, the biomass carbon storage and its dynamic estimates were influenced largely by tree species and model types. In order to improve the accuracy of the estimates of biomass and carbon, we should consider the differences in tree species and model types.

  10. Implications of floristic and environmental variation for carbon cycle dynamics in boreal forest ecosystems of central Canada

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zicheng; Apps, M.J.; Bhatti, J.S. [Canadan Forest Service, Edmonton (Canada). Northern Forestry Centre

    2002-06-01

    Species composition, detritus, and soil data from 97 boreal forest stands along a transect in central Canada were analysed using Correspondence Analysis to determine the dominant environmental/site variables that differentiate these forest stands. Picea mariana stands were densely clustered together on the understorey DCA plot, suggesting a consistent understorey species composition (feather mosses and Ericaceae), whereas Populus tremuloides stands had the most diverse understorey species composition (ca. 30 species, mostly shrubs and herbs). Pinus banksiana stands had several characteristic species of reindeer lichens (Cladina spp.), but saplings and Pinus seedlings were rare. Although climatic variables showed large variation along the transect, the CCA results indicated that site conditions are more important in determining species composition and differentiating the stand types. Forest floor characteristics (litter and humus layer, woody debris, and drainage) appear to be among the most important site variables. Stands of Picea had significantly higher average carbon (C) densities in the combined litter and humus layer (43,530 kg-C/ha) than either Populus (25,500 kg-C/ha) or Pinus (19,400 kg-C/ha). The thick surface organic layer in lowland Picea stands plays an important role in regulating soil temperature and moisture, and organic-matter decomposition, which in turn affect the ecosystem C-dynamics. During forest succession after a stand-replacing disturbance (e.g. fires), tree biomass and surface organic layer thickness increase in all stand types as forests recover; however, woody biomass detritus first decreases and then increases after ca. 80 yr. Soil C densities show slight decrease with ages in Populus stands, but increase in other stand types. These results indicate the complex C-transfer processes among different components (tree biomass, detritus, forest floor, and soil) of boreal ecosystems at various stages of succession.

  11. Biomass from the Brazilian raining forest; Biomassa das florestas amazonicas brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Fearnside, Philip M [Instituto Nacional de Pesquisas da Amazonia (INPA), Manaus, AM (Brazil)

    1994-12-31

    This work summarizes the existing knowledge about biomass in the Brazilian area of the Amazon jungle and presents a calculation for the average total biomass in virgin forests. The results are presented. The results are higher than those presently accepted. The reasons for the discrepancy in the calculated and presently used value are presented and discussed 64 refs., 8 tabs.

  12. Recovery of Biomass Following Shifting Cultivation in Dry Tropical Forests of the Yucatan

    OpenAIRE

    Read, L; Lawrence, Deborah; Foster, David Russell

    2003-01-01

    Land-use change in the tropics is creating secondary forest at an unprecedented rate. In the tropical Americas, mature dry tropical forest is rapidly being converted to secondary forest during the fallow period of shifting cultivation. This study addresses changes in forest biomass during forest recovery following shifting cultivation of maize (corn) in the Southern Yucatan Peninsular Region (SYPR), Mexico. We sampled stems .1 cm diameter at breast height at 36 study sites in t...

  13. Global patterns and predictions of seafloor biomass using random forests

    Digital Repository Service at National Institute of Oceanography (India)

    Wei, Chih-Lin; Rowe, G.T.; Escobar-Briones, E.; Boetius, A; Soltwedel, T.; Caley, M.J.; Soliman, Y.; Huettmann, F.; Qu, F.; Yu, Z.; Pitcher, C.R.; Haedrich, R.L.; Wicksten, M.K.; Rex, M.A; Baguley, J.G.; Sharma, J.; Danovaro, R.; MacDonald, I.R.; Nunnally, C.C.; Deming, J.W.; Montagna, P.; Levesque, M.; Weslawsk, J.M.; Wlodarska-Kowalczuk, M.; Ingole, B.S.; Bett, B.J.; Billett, D.S.M.; Yool, A; Bluhm, B.A; Iken, K.; Narayanaswamy, B.E.

    A comprehensive seafloor biomass and abundance database has been constructed from 24 oceanographic institutions worldwide within the Census of Marine Life (CoML) field projects. The machine-learning algorithm, Random Forests, was employed to model...

  14. Relasphone—Mobile and Participative In Situ Forest Biomass Measurements Supporting Satellite Image Mapping

    Directory of Open Access Journals (Sweden)

    Matthieu Molinier

    2016-10-01

    Full Text Available Due to the high cost of traditional forest plot measurements, the availability of up-to-date in situ forest inventory data has been a bottleneck for remote sensing image analysis in support of the important global forest biomass mapping. Capitalizing on the proliferation of smartphones, citizen science is a promising approach to increase spatial and temporal coverages of in situ forest observations in a cost-effective way. Digital cameras can be used as a relascope device to measure basal area, a forest density variable that is closely related to biomass. In this paper, we present the Relasphone mobile application with extensive accuracy assessment in two mixed forest sites from different biomes. Basal area measurements in Finland (boreal zone were in good agreement with reference forest inventory plot data on pine ( R 2 = 0 . 75 , R M S E = 5 . 33 m 2 /ha, spruce ( R 2 = 0 . 75 , R M S E = 6 . 73 m 2 /ha and birch ( R 2 = 0 . 71 , R M S E = 4 . 98 m 2 /ha, with total relative R M S E ( % = 29 . 66 % . In Durango, Mexico (temperate zone, Relasphone stem volume measurements were best for pine ( R 2 = 0 . 88 , R M S E = 32 . 46 m 3 /ha and total stem volume ( R 2 = 0 . 87 , R M S E = 35 . 21 m 3 /ha. Relasphone data were then successfully utilized as the only reference data in combination with optical satellite images to produce biomass maps. The Relasphone concept has been validated for future use by citizens in other locations.

  15. Carbon storage in old-growth forests of the Mid-Atlantic: toward better understanding the eastern forest carbon sink.

    Science.gov (United States)

    McGarvey, Jennifer C; Thompson, Jonathan R; Epstein, Howard E; Shugart, Herman H

    2015-02-01

    Few old-growth stands remain in the matrix of secondary forests that dominates the eastern North American landscape. These remnant stands offer insight on the potential carbon (C) storage capacity of now-recovering secondary forests. We surveyed the remaining old-growth forests on sites characteristic of the general Mid-Atlantic United States and estimated the size of multiple components of forest C storage. Within and between old-growth stands, variability in C density is high and related to overstory tree species composition. The sites contain 219 ± 46 Mg C/ha (mean ± SD), including live and dead aboveground biomass, leaf litter, and the soil O horizon, with over 20% stored in downed wood and snags. Stands dominated by tulip poplar (Liriodendron tulipifera) store the most live biomass, while the mixed oak (Quercus spp.) stands overall store more dead wood. Total C density is 30% higher (154 Mg C/ha), and dead wood C density is 1800% higher (46 Mg C/ha) in the old-growth forests than in the surrounding younger forests (120 and 5 Mg C/ha, respectively). The high density of dead wood in old growth relative to secondary forests reflects a stark difference in historical land use and, possibly, the legacy of the local disturbance (e.g., disease) history. Our results demonstrate the potential for dead wood to maintain the sink capacity of secondary forests for many decades to come.

  16. Microbial activities in forest soils exposed to chronic depositions from a lignite power plant

    Energy Technology Data Exchange (ETDEWEB)

    Klose, S.; Wernecke, K.D.; Makeschin, F. [Technical University of Dresden, Tharandt (Germany)

    2004-12-01

    Atmospheric emissions of fly ash and SO{sub 2} from lignite-fired power plants strongly affect large forest areas in Germany. The impact of different deposition loads on the microbial biomass and enzyme activities was studied at three forest sites (Picea abies (L.) Karst.) along an emission gradient of 3, 6, and 15 km downwind of a coal-fired power plant, representing high, moderate and low emission rates. An additional site at a distance of 3 km from the power plant was chosen to study the influence of forest type on microbial parameters in coniferous forest soils under fly ash and SO{sub 2} emissions. Soil microbial biomass C and N, CO{sub 2} evolved and activities of L-asparaginase, L-glutaminase, beta-glucosidase, acid phosphatase and arylsulfatase (expressed on dry soil and organic C basis) were determined in the forest floor (L, Of and Oh horizon) and mineral top soil (0-10 cm). It is concluded that chronic fly ash depositions decrease litter decomposition by influencing specific microbial and enzymatic processes in forest soils.

  17. Estimating and mapping forest biomass using regression models and Spot-6 images (case study: Hyrcanian forests of north of Iran).

    Science.gov (United States)

    Motlagh, Mohadeseh Ghanbari; Kafaky, Sasan Babaie; Mataji, Asadollah; Akhavan, Reza

    2018-05-21

    Hyrcanian forests of North of Iran are of great importance in terms of various economic and environmental aspects. In this study, Spot-6 satellite images and regression models were applied to estimate above-ground biomass in these forests. This research was carried out in six compartments in three climatic (semi-arid to humid) types and two altitude classes. In the first step, ground sampling methods at the compartment level were used to estimate aboveground biomass (Mg/ha). Then, by reviewing the results of other studies, the most appropriate vegetation indices were selected. In this study, three indices of NDVI, RVI, and TVI were calculated. We investigated the relationship between the vegetation indices and aboveground biomass measured at sample-plot level. Based on the results, the relationship between aboveground biomass values and vegetation indices was a linear regression with the highest level of significance for NDVI in all compartments. Since at the compartment level the correlation coefficient between NDVI and aboveground biomass was the highest, NDVI was used for mapping aboveground biomass. According to the results of this study, biomass values were highly different in various climatic and altitudinal classes with the highest biomass value observed in humid climate and high-altitude class.

  18. The Potential of Forest Biomass Inversion Based on Vegetation Indices Using Multi-Angle CHRIS/PROBA Data

    Directory of Open Access Journals (Sweden)

    Qiang Wang

    2016-10-01

    Full Text Available Multi-angle remote sensing can either be regarded as an added source of uncertainty for variable retrieval, or as a source of additional information, which enhances variable retrieval compared to traditional single-angle observation. However, the magnitude of these angular and band effects for forest structure parameters is difficult to quantify. We used the Discrete Anisotropic Radiative Transfer (DART model and the Zelig model to simulate the forest canopy Bidirectional Reflectance Distribution Factor (BRDF in order to build a look-up table, and eight vegetation indices were used to assess the relationship between BRDF and forest biomass in order to find the sensitive angles and bands. Further, the European Space Agency (ESA mission, Compact High Resolution Imaging Spectrometer onboard the Project for On-board Autonomy (CHRIS-PROBA and field sample measurements, were selected to test the angular and band effects on forest biomass retrieval. The results showed that the off-nadir vegetation indices could predict the forest biomass more accurately than the nadir. Additionally, we found that the viewing angle effect is more important, but the band effect could not be ignored, and the sensitive angles for extracting forest biomass are greater viewing angles, especially around the hot and dark spot directions. This work highlighted the combination of angles and bands, and found a new index based on the traditional vegetation index, Atmospherically Resistant Vegetation Index (ARVI, which is calculated by combining sensitive angles and sensitive bands, such as blue band 490 nm/−55°, green band 530 nm/55°, and the red band 697 nm/55°, and the new index was tested to improve the accuracy of forest biomass retrieval. This is a step forward in multi-angle remote sensing applications for mining the hidden relationship between BRDF and forest structure information, in order to increase the utilization efficiency of remote sensing data.

  19. Understanding spatial heterogeneity in soil carbon and nitrogen cycling in regenerating tropical dry forests

    Science.gov (United States)

    Waring, B. G.; Powers, J. S.; Branco, S.; Adams, R.; Schilling, E.

    2015-12-01

    Tropical dry forests (TDFs) currently store significant amounts of carbon in their biomass and soils, but these highly seasonal ecosystems may be uniquely sensitive to altered climates. The ability to quantitatively predict C cycling in TDFs under global change is constrained by tremendous spatial heterogeneity in soil parent material, land-use history, and plant community composition. To explore this variation, we examined soil carbon and nitrogen dynamics in 18 permanent plots spanning orthogonal gradients of stand age and soil fertility. Soil C and N pools, microbial biomass, and microbial extracellular enzyme activities were most variable at small (m2) spatial scales. However, the ratio of organic vs. inorganic N cycling was consistently higher in forest stands dominated by slow-growing, evergreen trees that associate with ectomycorrhizal fungi. Similarly, although bulk litter stocks and turnover rates varied greatly among plots, litter decomposition tended to be slower in ectomycorrhizae-dominated stands. Soil N cycling tended to be more conservative in older plots, although the relationship between stand age and element cycling was weak. Our results emphasize that microscale processes, particularly interactions between mycorrhizal fungi and free-living decomposers, are important controls on ecosystem-scale element cycling.

  20. Towards an ecologically sustainable energy production based on forest biomass - Forest fertilisation with nutrient rich organic waste matter

    Energy Technology Data Exchange (ETDEWEB)

    Roegaard, Pia-Maria; Aakerback, Nina; Sahlen, Kenneth; Sundell, Markus [Swedish Polytechnic, Vasa (Finland)

    2006-07-15

    The project is a collaboration between Swedish Univ. of Agricultural Sciences, Faculty of Forest Sciences in Umeaa, Swedish Polytechnic, Finland in Vaasa and the Finnish Forest Research Institute in Kannus. Today there are pronounced goals within the EU that lead towards an ecologically sustainable community and there is also a global goal to decrease net carbon dioxide emissions. These goals involve among other things efforts to increase the use of renewable biofuel as energy source. This will result in an enlarged demand for biomass for energy production. Therefore, the forest resources in the Nordic countries will be required for energy production to a far greater extent in the future. One way to meet this increased tree biomass demand is to increase forest tree growth through supply of nutrients, of which nitrogen is the most important. Organic nutrient rich waste matter from the society, such as sewage sludge and mink and fox manure compost from fur farms might be used as forest fertilizer. This would result in increased supply of renewable tree biomass, decreased net carbon dioxide emissions, increased forest ecosystem carbon sequestration, decreased methane emissions from sewage sludge landfill and decreased society costs for sludge landfill or incineration. Therefore, the purpose of this project is to develop methods for forest fertilisation with nutrient rich organic waste matter from municipal wastewater, sludge and manure from mink and fox farms. The project may be divided into three main parts. The first part is the chemical composition of the fertiliser with the objective to increase the nitrogen content in sludge-based fertilisers and in compost of mink and fox manure. The second part involves the technique and logistics for forest fertilisation i.e., to develop application equipment that may be integrated in existing forest technical systems. The third part consists of field fertilisation investigations and an environmental impact assessment

  1. Are forestation, bio-char and landfilled biomass adequate offsets for the climate effects of burning fossil fuels?

    NARCIS (Netherlands)

    Reijnders, L.

    2009-01-01

    Forestation and landfilling purpose-grown biomass are not adequate offsets for the CO2 emission from burning fossil fuels. Their permanence is insufficiently guaranteed and landfilling purpose-grown biomass may even be counterproductive. As to permanence, bio-char may do better than forests or

  2. The relationship between species richness and aboveground biomass in a primary Pinus kesiya forest of Yunnan, southwestern China.

    Science.gov (United States)

    Li, Shuaifeng; Lang, Xuedong; Liu, Wande; Ou, Guanglong; Xu, Hui; Su, Jianrong

    2018-01-01

    The relationship between biodiversity and biomass is an essential element of the natural ecosystem functioning. Our research aims at assessing the effects of species richness on the aboveground biomass and the ecological driver of this relationship in a primary Pinus kesiya forest. We sampled 112 plots of the primary P. kesiya forests in Yunnan Province. The general linear model and the structural equation model were used to estimate relative effects of multivariate factors among aboveground biomass, species richness and the other explanatory variables, including climate moisture index, soil nutrient regime and stand age. We found a positive linear regression relationship between the species richness and aboveground biomass using ordinary least squares regressions. The species richness and soil nutrient regime had no direct significant effect on aboveground biomass. However, the climate moisture index and stand age had direct effects on aboveground biomass. The climate moisture index could be a better link to mediate the relationship between species richness and aboveground biomass. The species richness affected aboveground biomass which was mediated by the climate moisture index. Stand age had direct and indirect effects on aboveground biomass through the climate moisture index. Our results revealed that climate moisture index had a positive feedback in the relationship between species richness and aboveground biomass, which played an important role in a link between biodiversity maintenance and ecosystem functioning. Meanwhile, climate moisture index not only affected positively on aboveground biomass, but also indirectly through species richness. The information would be helpful in understanding the biodiversity-aboveground biomass relationship of a primary P. kesiya forest and for forest management.

  3. The contribution of trees outside forests to national tree biomass and carbon stocks--a comparative study across three continents.

    Science.gov (United States)

    Schnell, Sebastian; Altrell, Dan; Ståhl, Göran; Kleinn, Christoph

    2015-01-01

    In contrast to forest trees, trees outside forests (TOF) often are not included in the national monitoring of tree resources. Consequently, data about this particular resource is rare, and available information is typically fragmented across the different institutions and stakeholders that deal with one or more of the various TOF types. Thus, even if information is available, it is difficult to aggregate data into overall national statistics. However, the National Forest Monitoring and Assessment (NFMA) programme of FAO offers a unique possibility to study TOF resources because TOF are integrated by default into the NFMA inventory design. We have analysed NFMA data from 11 countries across three continents. For six countries, we found that more than 10% of the national above-ground tree biomass was actually accumulated outside forests. The highest value (73%) was observed for Bangladesh (total forest cover 8.1%, average biomass per hectare in forest 33.4 t ha(-1)) and the lowest (3%) was observed for Zambia (total forest cover 63.9%, average biomass per hectare in forest 32 t ha(-1)). Average TOF biomass stocks were estimated to be smaller than 10 t ha(-1). However, given the large extent of non-forest areas, these stocks sum up to considerable quantities in many countries. There are good reasons to overcome sectoral boundaries and to extend national forest monitoring programmes on a more systematic basis that includes TOF. Such an approach, for example, would generate a more complete picture of the national tree biomass. In the context of climate change mitigation and adaptation, international climate mitigation programmes (e.g. Clean Development Mechanism and Reduced Emission from Deforestation and Degradation) focus on forest trees without considering the impact of TOF, a consideration this study finds crucial if accurate measurements of national tree biomass and carbon pools are required.

  4. Accounting for biomass carbon stock change due to wildfire in temperate forest landscapes in Australia.

    Science.gov (United States)

    Keith, Heather; Lindenmayer, David B; Mackey, Brendan G; Blair, David; Carter, Lauren; McBurney, Lachlan; Okada, Sachiko; Konishi-Nagano, Tomoko

    2014-01-01

    Carbon stock change due to forest management and disturbance must be accounted for in UNFCCC national inventory reports and for signatories to the Kyoto Protocol. Impacts of disturbance on greenhouse gas (GHG) inventories are important for many countries with large forest estates prone to wildfires. Our objective was to measure changes in carbon stocks due to short-term combustion and to simulate longer-term carbon stock dynamics resulting from redistribution among biomass components following wildfire. We studied the impacts of a wildfire in 2009 that burnt temperate forest of tall, wet eucalypts in south-eastern Australia. Biomass combusted ranged from 40 to 58 tC ha(-1), which represented 6-7% and 9-14% in low- and high-severity fire, respectively, of the pre-fire total biomass carbon stock. Pre-fire total stock ranged from 400 to 1040 tC ha(-1) depending on forest age and disturbance history. An estimated 3.9 TgC was emitted from the 2009 fire within the forest region, representing 8.5% of total biomass carbon stock across the landscape. Carbon losses from combustion were large over hours to days during the wildfire, but from an ecosystem dynamics perspective, the proportion of total carbon stock combusted was relatively small. Furthermore, more than half the stock losses from combustion were derived from biomass components with short lifetimes. Most biomass remained on-site, although redistributed from living to dead components. Decomposition of these components and new regeneration constituted the greatest changes in carbon stocks over ensuing decades. A critical issue for carbon accounting policy arises because the timeframes of ecological processes of carbon stock change are longer than the periods for reporting GHG inventories for national emissions reductions targets. Carbon accounts should be comprehensive of all stock changes, but reporting against targets should be based on human-induced changes in carbon stocks to incentivise mitigation activities.

  5. Variation in Plant Litter Decomposition Rates across Extreme Dry Environments in Qatar

    NARCIS (Netherlands)

    Alsafran, Mohammed; Sarneel, J.M.; Alatalo, Juha

    2017-01-01

    Decomposition of plant litter is a key process for transfer of carbon and nutrients in ecosystems. Carbon contained in decaying biomass is released to the atmosphere as respired CO2, a greenhouse gas that contributes to global warming. To our knowledge, there have been no studies on litter

  6. Undecomposed Twigs in the Leaf Litter as Nest-Building Resources for Ants (Hymenoptera: Formicidae in Areas of the Atlantic Forest in the Southeastern Region of Brazil

    Directory of Open Access Journals (Sweden)

    Tae Tanaami Fernandes

    2012-01-01

    Full Text Available In tropical forests, the leaf-litter stratum exhibits one of the greatest abundances of ant species. This diversity is associated with the variety of available locations for nest building. Ant nests can be found in various microhabitats, including tree trunks and fallen twigs in different stages of decomposition. In this study, we aimed to investigate undecomposed twigs as nest-building resources in the leaf litter of dense ombrophilous forest areas in the southeastern region of Brazil. Demographic data concerning the ant colonies, the physical characteristics of the nests, and the population and structural of the forest were observed. Collections were performed manually over four months in closed canopy locations that did not have trails or flooded areas. A total of 294 nests were collected, and 34 ant species were recorded. Pheidole, Camponotus, and Hypoponera were the richest genera observed; these genera were also among the most populous and exhibited the greatest abundance of nests. We found no association between population size and nest diameter. Only tree cover influenced the nest abundance and species richness. Our data indicate that undecomposed twigs may be part of the life cycle of many species and are important for maintaining ant diversity in the leaf litter.

  7. Leaf litter processing and invertebrate assemblages along a pollution gradient in a Maine (USA) headwater stream

    International Nuclear Information System (INIS)

    Woodcock, Thomas S.; Huryn, Alexander D.

    2005-01-01

    During the autumn of 1997 and 1998, leaf litter processing rates and leaf pack invertebrate assemblages were examined at eight stations along a pollution gradient in Goosefare Brook, a first-order coastal plain stream in southern Maine (USA). There was no significant effect on litter softening rate in 1997, and only the most polluted station showed a decrease in 1998. However, litter loss rates showed decreases in both years. The structure of invertebrate assemblages changed in response to the stresses, showing a decline in EPT richness and an increase in the proportion of collecting taxa. However, total shredder biomass was only weakly affected. Shredder biomass at all stations was dominated by Tipula, and biomass of other shredder taxa showed a serial replacement along the gradient of stress related to their pollution tolerance. Rather than the expected relationship with shredder biomass, litter processing rates were directly related to water and sediment quality. Goosefare Brook demonstrates how variable pollution tolerance of community members enables stress resistance and a consequent preservation of ecosystem function. - Variable pollution tolerance of community members provides stress resistance at the ecosystem level in streams

  8. Soil properties and understory herbaceous biomass in forests of three species of Quercus in Northeast Portugal

    Directory of Open Access Journals (Sweden)

    Marina Castro

    2014-12-01

    Full Text Available Aim of study: This paper aims to characterize some soil properties within the first 25 cm of the soil profile and the herbaceous biomass in Quercus forests, and the possible relationships between soil properties and understory standing biomass.Area of study: Three monoespecific Quercus forests (Q. suber L., Q. ilex subsp. rotundifolia Lam. and Q. pyrenaica Willd in NE Portugal.Material and methods: During 1999 and 2000 soil properties (pH-KCl, total soil nitrogen (N, soil organic carbon (SOC, C/N ratio, available phosphorus (P, and available potassium (K and herbaceous biomass production of three forest types: Quercus suber L., Quercus ilex subsp. rotundifolia Lam. and Quercus pyrenaica Willd were studied.Main results: The results showed a different pattern of soil fertility (N, SOC, P, K in Quercus forests in NE of Portugal. The C/N ratio and the herbaceous biomass confirmed this pattern. Research highlights: There is a pattern of Quercus sp. distribution that correlates with different soil characteristics by soil characteristics in NE Portugal. Q. pyrenaica ecosystems were found in more favoured areas (mesic conditions; Q. rotundifolia developed in nutrient-poor soils (oligotrophic conditions; and Q. suber were found in intermediate zones.Keywords: fertility; biomass; C/N ratio; cork oak; holm oak; pyrenean oak.

  9. Investigating organic matter in Fanno Creek, Oregon, Part 1 of 3: estimating annual foliar biomass for a deciduous-dominant urban riparian corridor

    Science.gov (United States)

    Sobieszczyk, Steven; Keith, Mackenzie K.; Rounds, Stewart A.; Goldman, Jami H.

    2014-01-01

    For this study, we explored the amount, type, and distribution of foliar biomass that is deposited annually as leaf litter to Fanno Creek and its floodplain in Portland, Oregon, USA. Organic matter is a significant contributor to the decreased dissolved oxygen concentrations observed in Fanno Creek each year and leaf litter is amongst the largest sources of organic matter to the stream channel and floodplain. Using a combination of field measurements and light detection and ranging (LiDAR) point cloud data, the annual foliar biomass was estimated for 13 stream reaches along the creek. Biomass estimates were divided into two sets: (1) the annual foliage available from the entire floodplain overstory canopy, and (2) the annual foliage overhanging the stream, which likely contributes leaf litter directly to the creek each year. Based on these computations, an estimated 991 (±22%) metric tons (tonnes, t) of foliar biomass is produced annually above the floodplain, with about 136 t (±24%) of that foliage falling directly into Fanno Creek. The distribution of foliar biomass varies by reach, with between 150 and 640 t/km2 produced along the floodplain and between 400 and 1100 t/km2 available over the channel. Biomass estimates vary by reach based primarily on the density of tree cover, with forest-dominant reaches containing more mature deciduous trees with broader tree canopies than either wetland or urban-dominant reaches, thus supplying more organic material to the creek. By quantifying the foliar biomass along Fanno Creek we have provided a reach-scale assessment of terrestrial organic matter loading, thereby providing land managers useful information for planning future restoration efforts.

  10. Determination of carbon and nitrogen in litter fall of mangrove ecosystem in peninsular Malaysia

    International Nuclear Information System (INIS)

    Hemati, Z.; Hossain, M.

    2017-01-01

    Mangroves in Peninsular Malaysia are typical of tropical forest setting. Nevertheless, the state of the mangrove forests has led to various classifications; natural and degraded mangroves. The study aimed to utilize litter fall (production and standing crop) potential as a means of evaluating the degree of productivity of the mangrove types across seasons, in addition to determining the abundance of carbon and nitrogen in the Peninsular mangrove forest. Leaf litter accounted for more than 70% of the total litter production in both natural and degraded mangroves, and the peak month for such production was December; 82.7% and 82.2%, for Sungai Haji Dorani and Kuala Selangor Nature Park, respectively. The degraded mangrove recorded higher concentration of total N (6.16 mg/g) than the natural mangrove forest (5.60 mg/g) at significant level. However, the organic carbon (CO) content across the litter parts varied with the three seasons. The CO of leaf litter was at the peak during the dry season, however, analysis on the branch and fruit revealed that during the intermediate and wet seasons CO level could be higher than the concentration observed at dry season. Though, the study concluded that both mangrove types in Peninsular Malaysia showed high similarity in the degree of litter production, yet the identified differences suggest that counter measures need to be adopted in order to protect mangroves from degradation and possible productivity loss. (author)

  11. Biomass production from the U.S. forest and agriculture sectors in support of a renewable electricity standard

    International Nuclear Information System (INIS)

    White, Eric M.; Latta, Greg; Alig, Ralph J.; Skog, Kenneth E.; Adams, Darius M.

    2013-01-01

    Production of renewable energy from biomass has been promoted as means to improve greenhouse gas balance in energy production, improve energy security, and provide jobs and income. However, uncertainties remain as to how the agriculture and forest sectors might jointly respond to increased demand for bioelectricity feedstocks and the potential environmental consequences of increased biomass production. We use an economic model to examine how the agriculture and forest sectors might combine to respond to increased demands for bioelectricity under simulated future national-level renewable electricity standards. Both sectors are projected to contribute biomass, although energy crops, like switchgrass, produced on agriculture land are projected to be the primary feedstocks. At the highest targets for bioelectricity production, we project increased conversion of forest to agriculture land in support of agriculture biomass production. Although land conversion takes place in response to renewable electricity mandates, we project only minor increases in forest and agriculture emissions. Similarly, crop prices were projected to generally be stable in the face of increased bioelectricity demand and displacement of traditional agriculture crops. - Highlights: ► We model the response of forest and agriculture to increased bioelectricity demand. ► The agriculture sector, through energy crop production, is the key biomass provider. ► Increased land exchange is projected for the highest bioelectricity demands. ► Land exchange from forest to agriculture yield the greatest changes in GHG flux. ► Agriculture and forestry must be accounted for when considering bioenergy policy

  12. Model Effects on GLAS-Based Regional Estimates of Forest Biomass and Carbon

    Science.gov (United States)

    Nelson, Ross

    2008-01-01

    ICESat/GLAS waveform data are used to estimate biomass and carbon on a 1.27 million sq km study area. the Province of Quebec, Canada, below treeline. The same input data sets and sampling design are used in conjunction with four different predictive models to estimate total aboveground dry forest biomass and forest carbon. The four models include nonstratified and stratified versions of a multiple linear model where either biomass or (square root of) biomass serves as the dependent variable. The use of different models in Quebec introduces differences in Provincial biomass estimates of up to 0.35 Gt (range 4.942+/-0.28 Gt to 5.29+/-0.36 Gt). The results suggest that if different predictive models are used to estimate regional carbon stocks in different epochs, e.g., y2005, y2015, one might mistakenly infer an apparent aboveground carbon "change" of, in this case, 0.18 Gt, or approximately 7% of the aboveground carbon in Quebec, due solely to the use of different predictive models. These findings argue for model consistency in future, LiDAR-based carbon monitoring programs. Regional biomass estimates from the four GLAS models are compared to ground estimates derived from an extensive network of 16,814 ground plots located in southern Quebec. Stratified models proved to be more accurate and precise than either of the two nonstratified models tested.

  13. Unravelling ecosystem functions at the Amazonia-Cerrado transition: II. Carbon stocks and CO2 soil efflux in cerradão forest undergoing ecological succession

    Science.gov (United States)

    Peixoto, Karine S.; Marimon-Junior, Ben Hur; Marimon, Beatriz S.; Elias, Fernando; de Farias, Josenilton; Freitag, Renata; Mews, Henrique A.; das Neves, Eder C.; Prestes, Nayane Cristina C. S.; Malhi, Yadvinder

    2017-07-01

    The transition region between two major South American biomes, the Amazon forest and the Cerrado (Brazilian savanna), has been substantially converted into human-modified ecosystems. Nevertheless, the recovery dynamics of ecosystem functions in this important zone of (ecological) tension (ZOT) remain poorly understood. In this study, we compared two areas of cerradão (a forest-woodland of the Brazilian savanna; Portuguese augmentative of cerrado), one in secondary succession (SC) and one adjacent and well preserved (PC), to test whether the ecosystem functions lost after conversion to pasture were restored after 22 years of regeneration. We tested the hypothesis that the increase in annual aboveground biomass in the SC would be greater than that in the PC because of anticipated successional gains. We also investigated soil CO2 efflux, litter layer content, and fine root biomass in both the SC and PC. In terms of biomass recovery our hypothesis was not supported: the biomass did not increase in the successional area over the study period, which suggested limited capacity for recovery in this key ecosystem compartment. By contrast, the structure and function of the litter layer and root mat were largely reconstituted in the secondary vegetation. Overall, we provide evidence that 22 years of secondary succession were not sufficient for these short and open forests (e.g., cerradão) in the ZOT to recover ecosystem functions to the levels observed in preserved vegetation of identical physiognomy.

  14. A comparison of producer gas, biochar, and activated carbon from two distributed scale thermochemical conversion systems used to process forest biomass

    Science.gov (United States)

    Nathaniel Anderson; J. Greg Jones; Deborah Page-Dumroese; Daniel McCollum; Stephen Baker; Daniel Loeffler; Woodam Chung

    2013-01-01

    Thermochemical biomass conversion systems have the potential to produce heat, power, fuels and other products from forest biomass at distributed scales that meet the needs of some forest industry facilities. However, many of these systems have not been deployed in this sector and the products they produce from forest biomass have not been adequately described or...

  15. Tropical-forest biomass estimation at X-Band from the spaceborne TanDEM-X interferometer

    Science.gov (United States)

    R. Treuhaft; F. Goncalves; J.R. dos Santos; M. Keller; M. Palace; S.N. Madsen; F. Sullivan; P.M.L.A. Graca

    2014-01-01

    This letter reports the sensitivity of X-band interferometric synthetic aperture radar (InSAR) data from the first dual-spacecraft radar interferometer, TanDEM-X, to variations in tropical-forest aboveground biomass (AGB). It also reports the first tropical-forest AGB estimates fromTanDEM-X data. Tropical forests account for...

  16. The partitioning of litter carbon during litter decomposition under different rainfall patterns: a laboratory study

    Science.gov (United States)

    Yang, X.; Szlavecz, K. A.; Langley, J. A.; Pitz, S.; Chang, C. H.

    2017-12-01

    Quantifying litter C into different C fluxes during litter decomposition is necessary to understand carbon cycling under changing climatic conditions. Rainfall patterns are predicted to change in the future, and their effects on the fate of litter carbon are poorly understood. Soils from deciduous forests in Smithsonian Environmental Research Center (SERC) in Maryland, USA were collected to reconstruct soil columns in the lab. 13C labeled tulip poplar leaf litter was used to trace carbon during litter decomposition. Top 1% and the mean of 15-minute historical precipitation data from nearby weather stations were considered as extreme and control rainfall intensity, respectively. Both intensity and frequency of rainfall were manipulated, while the total amount was kept constant. A pulse of CO2 efflux was detected right after each rainfall event in the soil columns with leaf litter. After the first event, CO2 efflux of the control rainfall treatment soils increased to threefold of the CO2 efflux before rain event and that of the extreme treatment soils increased to fivefold. However, in soils without leaf litter, CO2 efflux was suppressed right after rainfall events. After each rainfall event, the leaf litter contribution to CO2 efflux first showed an increase, decreased sharply in the following two days, and then stayed relatively constant. In soil columns with leaf litter, the order of cumulative CO2 efflux was control > extreme > intermediate. The order of cumulative CO2 efflux in the bare soil treatment was extreme > intermediate > control. The order of volume of leachate from different treatments was extreme > intermediate > control. Our initial results suggest that more intense rainfall events result in larger pulses of CO2, which is rarely measured in the field. Additionally, soils with and without leaf litter respond differently to precipitation events. This is important to consider in temperate regions where leaf litter cover changes throughout the year

  17. Airborne laser scanner-assisted estimation of aboveground biomass change in a temperate oak-pine forest

    Science.gov (United States)

    Nicholas S. Skowronski; Kenneth L. Clark; Michael Gallagher; Richard A. Birdsey; John L. Hom

    2014-01-01

    We estimated aboveground tree biomass and change in aboveground tree biomass using repeated airborne laser scanner (ALS) acquisitions and temporally coincident ground observations of forest biomass, for a relatively undisturbed period (2004-2007; ∇07-04), a contrasting period of disturbance (2007-2009; ∇09-07...

  18. Effects of fire frequency on litter decomposition as mediated by changes to litter chemistry and soil environmental conditions.

    Science.gov (United States)

    Ficken, Cari D; Wright, Justin P

    2017-01-01

    Litter quality and soil environmental conditions are well-studied drivers influencing decomposition rates, but the role played by disturbance legacy, such as fire history, in mediating these drivers is not well understood. Fire history may impact decomposition directly, through changes in soil conditions that impact microbial function, or indirectly, through shifts in plant community composition and litter chemistry. Here, we compared early-stage decomposition rates across longleaf pine forest blocks managed with varying fire frequencies (annual burns, triennial burns, fire-suppression). Using a reciprocal transplant design, we examined how litter chemistry and soil characteristics independently and jointly influenced litter decomposition. We found that both litter chemistry and soil environmental conditions influenced decomposition rates, but only the former was affected by historical fire frequency. Litter from annually burned sites had higher nitrogen content than litter from triennially burned and fire suppression sites, but this was correlated with only a modest increase in decomposition rates. Soil environmental conditions had a larger impact on decomposition than litter chemistry. Across the landscape, decomposition differed more along soil moisture gradients than across fire management regimes. These findings suggest that fire frequency has a limited effect on litter decomposition in this ecosystem, and encourage extending current decomposition frameworks into disturbed systems. However, litter from different species lost different masses due to fire, suggesting that fire may impact decomposition through the preferential combustion of some litter types. Overall, our findings also emphasize the important role of spatial variability in soil environmental conditions, which may be tied to fire frequency across large spatial scales, in driving decomposition rates in this system.

  19. Allometric Scaling and Resource Limitations Model of Total Aboveground Biomass in Forest Stands: Site-scale Test of Model

    Science.gov (United States)

    CHOI, S.; Shi, Y.; Ni, X.; Simard, M.; Myneni, R. B.

    2013-12-01

    Sparseness in in-situ observations has precluded the spatially explicit and accurate mapping of forest biomass. The need for large-scale maps has raised various approaches implementing conjugations between forest biomass and geospatial predictors such as climate, forest type, soil property, and topography. Despite the improved modeling techniques (e.g., machine learning and spatial statistics), a common limitation is that biophysical mechanisms governing tree growth are neglected in these black-box type models. The absence of a priori knowledge may lead to false interpretation of modeled results or unexplainable shifts in outputs due to the inconsistent training samples or study sites. Here, we present a gray-box approach combining known biophysical processes and geospatial predictors through parametric optimizations (inversion of reference measures). Total aboveground biomass in forest stands is estimated by incorporating the Forest Inventory and Analysis (FIA) and Parameter-elevation Regressions on Independent Slopes Model (PRISM). Two main premises of this research are: (a) The Allometric Scaling and Resource Limitations (ASRL) theory can provide a relationship between tree geometry and local resource availability constrained by environmental conditions; and (b) The zeroth order theory (size-frequency distribution) can expand individual tree allometry into total aboveground biomass at the forest stand level. In addition to the FIA estimates, two reference maps from the National Biomass and Carbon Dataset (NBCD) and U.S. Forest Service (USFS) were produced to evaluate the model. This research focuses on a site-scale test of the biomass model to explore the robustness of predictors, and to potentially improve models using additional geospatial predictors such as climatic variables, vegetation indices, soil properties, and lidar-/radar-derived altimetry products (or existing forest canopy height maps). As results, the optimized ASRL estimates satisfactorily

  20. Forest operations and woody biomass logistics to improve efficiency, value, and sustainability

    Science.gov (United States)

    Nathaniel Anderson; Dana Mitchell

    2016-01-01

    This paper reviews the most recent work conducted by scientists and engineers of the Forest Service of the US Department of Agriculture (USDA) in the areas of forest operations and woody biomass logistics, with an emphasis on feedstock supply for emerging bioenergy, biofuels, and bioproducts applications. This work is presented in the context of previous...

  1. A canopy trimming experiment in Puerto Rico: the response of litter invertebrate communities to canopy loss and debris deposition in a tropical forest subject to hurricanes

    Science.gov (United States)

    Barbara A. Richardson; Michael J. Richardson; Grizelle Gonzalez; Aaron B. Shiels; Diane S. Srivastava

    2010-01-01

    Hurricanes cause canopy removal and deposition of pulses of litter to the forest floor. A Canopy Trimming Experiment (CTE) was designed to decouple these two factors, and to investigate the separate abiotic and biotic consequences of hurricane-type damage and monitor recovery processes. As part of this experiment, effects on forest floor invertebrate communities were...

  2. Microbial biomass and activity in litter during the initial development of pure and mixed plantations of Eucalyptus grandis and Acacia mangium Biomassa e atividade microbiana da serapilheira durante o desenvolvimento inicial de plantios puros e mistos de Eucalyptus grandis e Acacia mangium

    Directory of Open Access Journals (Sweden)

    Daniel Bini

    2013-02-01

    Full Text Available Studies on microbial activity and biomass in forestry plantations often overlook the role of litter, typically focusing instead on soil nutrient contents to explain plant and microorganism development. However, since the litter is a significant source of recycled nutrients that affect nutrient dynamics in the soil, litter composition may be more strongly correlated with forest growth and development than soil nutrient contents. This study aimed to test this hypothesis by examining correlations between soil C, N, and P; litter C, N, P, lignin content, and polyphenol content; and microbial biomass and activity in pure and mixed second-rotation plantations of Eucalyptus grandis and Acacia mangium before and after senescent leaf drop. The numbers of cultivable fungi and bacteria were also estimated. All properties were correlated with litter C, N, P, lignin and polyphenols, and with soil C and N. We found higher microbial activity (CO2 evolution in litter than in soil. In the E. grandis monoculture before senescent leaf drop, microbial biomass C was 46 % higher in litter than in soil. After leaf drop, this difference decreased to 16 %. In A. mangium plantations, however, microbial biomass C was lower in litter than in soil both before and after leaf drop. Microbial biomass N of litter was approximately 94 % greater than that of the soil in summer and winter in all plantations. The number of cultivable fungi and bacteria increased after leaf drop, especially so in the litter. Fungi were also more abundant in the E. grandis litter. In general, the A. mangium monoculture was associated with higher levels of litter lignin and N, especially after leaf drop. In contrast, the polyphenol and C levels in E. grandis monoculture litter were higher after leaf drop. These properties were negatively correlated with total soil C and N. Litter in the mixed stands had lower C:N and C:P ratios and higher N, P, and C levels in the microbial biomass. This suggests more

  3. Fire-induced Carbon Emissions and Regrowth Uptake in Western U.S. Forests: Documenting Variation Across Forest Types, Fire Severity, and Climate Regions

    Science.gov (United States)

    Ghimire, Bardan; Williams, Christopher A.; Collatz, George James; Vanderhoof, Melanie

    2012-01-01

    The forest area in the western United States that burns annually is increasing with warmer temperatures, more frequent droughts, and higher fuel densities. Studies that examine fire effects for regional carbon balances have tended to either focus on individual fires as examples or adopt generalizations without considering how forest type, fire severity, and regional climate influence carbon legacies. This study provides a more detailed characterization of fire effects and quantifies the full carbon impacts in relation to direct emissions, slow release of fire-killed biomass, and net carbon uptake from forest regrowth. We find important variations in fire-induced mortality and combustion across carbon pools (leaf, live wood, dead wood, litter, and duff) and across low- to high-severity classes. This corresponds to fire-induced direct emissions from 1984 to 2008 averaging 4 TgC/yr and biomass killed averaging 10.5 TgC/yr, with average burn area of 2723 sq km/yr across the western United States. These direct emission and biomass killed rates were 1.4 and 3.7 times higher, respectively, for high-severity fires than those for low-severity fires. The results show that forest regrowth varies greatly by forest type and with severity and that these factors impose a sustained carbon uptake legacy. The western U.S. fires between 1984 and 2008 imposed a net source of 12.3 TgC/yr in 2008, accounting for both direct fire emissions (9.5 TgC/yr) and heterotrophic decomposition of fire-killed biomass (6.1 TgC yr1) as well as contemporary regrowth sinks (3.3 TgC/yr). A sizeable trend exists toward increasing emissions as a larger area burns annually.

  4. Aboveground Biomass and Carbon in a South African Mistbelt Forest and the Relationships with Tree Species Diversity and Forest Structures

    Directory of Open Access Journals (Sweden)

    Sylvanus Mensah

    2016-04-01

    Full Text Available Biomass and carbon stocks are key information criteria to understand the role of forests in regulating global climate. However, for a bio-rich continent like Africa, ground-based measurements for accurate estimation of carbon are scarce, and the variables affecting the forest carbon are not well understood. Here, we present the first biomass study conducted in South Africa Mistbelt forests. Using data from a non-destructive sampling of 59 trees of four species, we (1 evaluated the accuracy of multispecies aboveground biomass (AGB models, using predictors such as diameter at breast height (DBH, total height (H and wood density; (2 estimated the amount of biomass and carbon stored in the aboveground compartment of Mistbelt forests and (3 explored the variation of aboveground carbon (AGC in relation to tree species diversity and structural variables. We found significant effects of species on wood density and AGB. Among the candidate models, the model that incorporated DBH and H as a compound variable (DBH2 × H was the best fitting. AGB and AGC values were highly variable across all plots, with average values of 358.1 Mg·ha−1 and 179.0 Mg·C·ha−1, respectively. Few species contributed 80% of AGC stock, probably as a result of selection effect. Stand basal area, basal area of the ten most important species and basal area of the largest trees were the most influencing variables. Tree species richness was also positively correlated with AGC, but the basal area of smaller trees was not. These results enable insights into the role of biodiversity in maintaining carbon storage and the possibilities for sustainable strategies for timber harvesting without risk of significant biomass decline.

  5. Evaluation of forest management practices through application of a biogeochemical model, PnET-BGC

    Science.gov (United States)

    Valipour, M.; Driscoll, C. T.; Johnson, C. E.; Campbell, J. L.; Fahey, T.; Zeng, T.

    2017-12-01

    Forest ecosystem response to logging disturbance varies significantly, depending on site conditions, species composition, land use history, and the method and frequency of harvesting. The long-term effects of forest cuttings are less clear due to limited information on land use history and long-term time series observations. The hydrochemical model, PnET-BGC was modified and verified using field data from multiple experimentally harvested northern hardwood watersheds at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA, including a commercial whole-tree harvest (Watershed 5), a devegetation experiment (Watershed 2; devegetation and herbicide treatment), a commercial strip-cut (Watershed 4) to simulate the hydrology, biomass accumulation, and soil solution and stream water chemistry responses to clear-cutting. The confirmed model was used to investigate temporal changes in aboveground biomass accumulation and nutrient dynamics under three different harvesting intensities (40%, 60%, 80%) over four varied rotation lengths (20, 40, 60, 80 years) with results compared with a scenario of no forest harvesting. The total ecosystem carbon pool (biomass, soil and litter) was reduced over harvesting events. The greatest decline occurred in litter by 40%-70%, while the pool of carbon stored in aboveground biomass decreased by 30%-60% for 80% cutting levels at 40 and 20 year rotation lengths, respectively. The large pool of soil organic carbon remained relatively stable, with only minor declines over logging regimes. Stream water simulations demonstrated increased loss of major elements over cutting events. Ca+2 and NO3- were the most sensitive elements to leaching over frequent intensive logging. Accumulated leaching of Ca+2 and NO3- varied between 90-520 t Ca/ha and 40-420 t N/ha from conservative (80-year period and 40% cutting) to aggressive (20-year period and 80% cutting) cutting regimes, respectively. Moreover, a reduction in nutrient plant uptake over

  6. Ant-mediated effects on spruce litter decomposition, solution chemistry, and microbial activity

    DEFF Research Database (Denmark)

    Stadler, B.; Schramm, Andreas; Kalbitz, K.

    2006-01-01

    the effects of ants and aphid honeydew on litter solution of Norway spruce, microbial enzyme activities, and needle decomposition in a field and greenhouse experiment during summer 2003. In the field, low ant densities had relatively little effects on litter solution 30 cm away from a tree trunk...... and %N were not affected by ants or honeydew. Our results suggest that ants have a distinct and immediate effect on solution composition and microbial activity in the litter layer indicating accelerated litter decay whereas the effect of honeydew was insignificant. Keywords: Ants; Decomposition; Formica......Forest management practices often generate clear-cut patches, which may be colonized by ants not present in the same densities in mature forests. In addition to the associated changes in abiotic conditions ants can initiate processes, which do not occur in old-growth stands. Here, we analyse...

  7. Litter Decomposition Rate of Avicennia marina and Rhizophora apiculata in Pulau Dua Nature Reserve, Banten

    Directory of Open Access Journals (Sweden)

    Febriana Siska

    2016-05-01

    Full Text Available Litter decomposition rate is useful method to determine forest fertility level. The aims of this study were to measure decomposition rate, and analyze the nutrient content released organic carbon, nitrogen, and phosphor from Avicennia marina and Rhizophora apiculata litters during the decomposition process. The research was conducted in the Pulau Dua Nature Reserve, Serang-Banten on A. marina and R. apiculata forest communities. Litter decomposition rate measurements performed in the field. Litter that has been obtained with the trap system is inserted into litter bag and than tied to the roots or trees to avoid drifting sea water. Litter decomposition rate was measured every 15 days and is accompanied by analysis of the content of organic C , total N and P. Our research results showed decomposition rate of A. marina (k= 0.83 was higher than that of R. apiculata (k= 0.41. Differences of  leaf anatomical structure and sea water salinity  influenced to the rate of litter decomposition. Organic C released was declined with longer of litter decomposition, on the contrary of releasing N and P nutrients.

  8. Generating electricity with forest biomass: Consistency and payment timeframe effects in choice experiments

    International Nuclear Information System (INIS)

    Soliño, Mario; Farizo, Begoña A.; Vázquez, María X.; Prada, Albino

    2012-01-01

    This paper presents a choice experiment analyzing the consumers' preferences towards a policy for replacing conventional electricity with electricity generated from forest biomass. The results show that consumers specially prefer the effects related to the lower risk of forest fires and to the decrease in pressure on non-renewable resources. The article also presents a methodological test in relation to the payment timeframe and its effect on marginal willingness to pay and consistency of responses using choice experiments. The most frequent and realistic payments are associated with lower presence of inconsistent responses. Finally, we cannot reject the null hypothesis of no effects of payment timeframe on marginal willingness to pay. - Highlights: ▶ Analysis of preferences towards electricity generated from forest biomass. ▶ Lowering the risk of forest fires is a high valued external effect. ▶ Less pressure on non-renewable resources is highly valued. ▶ Frequent payments are associated with lower presence of inconsistent responses. ▶ Effects of payment timeframe on marginal willingness to pay.

  9. Uncertainty in the spatial distribution of tropical forest biomass: a comparison of pan-tropical maps

    OpenAIRE

    Mitchard, Edward TA; Saatchi, Sassan S; Baccini, Alessandro; Asner, Gregory P; Goetz, Scott J; Harris, Nancy L; Brown, Sandra

    2013-01-01

    BackgroundMapping the aboveground biomass of tropical forests is essential both for implementing conservation policy and reducing uncertainties in the global carbon cycle. Two medium resolution (500 m – 1000 m) pantropical maps of vegetation biomass have been recently published, and have been widely used by sub-national and national-level activities in relation to Reducing Emissions from Deforestation and forest Degradation (REDD+). Both maps use similar input data layers, and are driven by t...

  10. Community-weighted mean of leaf traits and divergence of wood traits predict aboveground biomass in secondary subtropical forests.

    Science.gov (United States)

    Ali, Arshad; Yan, En-Rong; Chang, Scott X; Cheng, Jun-Yang; Liu, Xiang-Yu

    2017-01-01

    Subtropical forests are globally important in providing ecological goods and services, but it is not clear whether functional diversity and composition can predict aboveground biomass in such forests. We hypothesized that high aboveground biomass is associated with high functional divergence (FDvar, i.e., niche complementarity) and community-weighted mean (CWM, i.e., mass ratio; communities dominated by a single plant strategy) of trait values. Structural equation modeling was employed to determine the direct and indirect effects of stand age and the residual effects of CWM and FDvar on aboveground biomass across 31 plots in secondary forests in subtropical China. The CWM model accounted for 78, 20, 6 and 2% of the variation in aboveground biomass, nitrogen concentration in young leaf, plant height and specific leaf area of young leaf, respectively. The FDvar model explained 74, 13, 7 and 0% of the variation in aboveground biomass, plant height, twig wood density and nitrogen concentration in young leaf, respectively. The variation in aboveground biomass, CWM of leaf nitrogen concentration and specific leaf area, and FDvar of plant height, twig wood density and nitrogen concentration in young leaf explained by the joint model was 86, 20, 13, 7, 2 and 0%, respectively. Stand age had a strong positive direct effect but low indirect positive effects on aboveground biomass. Aboveground biomass was negatively related to CWM of nitrogen concentration in young leaf, but positively related to CWM of specific leaf area of young leaf and plant height, and FDvar of plant height, twig wood density and nitrogen concentration in young leaf. Leaf and wood economics spectra are decoupled in regulating the functionality of forests, communities with diverse species but high nitrogen conservative and light acquisitive strategies result in high aboveground biomass, and hence, supporting both the mass ratio and niche complementarity hypotheses in secondary subtropical forests

  11. An assessment of leaf-litter and epigaeic ants (Hymenoptera: Formicidae living in different landscapes of the Atlantic Forest Biome in the State of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Roberta de Jesus Santos

    2017-11-01

    Full Text Available The Brazilian Atlantic Forest has a rich biodiversity increasingly threatened by human activities. Since the colonial period, the coast of the state of Bahia is among the most affected regions of Brazil by anthropic pressure. Bahia encloses Atlantic Forest remnants distributed in an area reaching 100-200 km along the east-west axis, by 1,000 km along the north-south axis, parallel to the coast of the Atlantic Ocean. We report hereafter the results of an intensive field survey of leaf litter and epigaeic ants realized in forest remnants of the Atlantic Forest landscapes within the original extension of the biome in 11 localities distributed along four degrees of latitude in the state of Bahia. In each site, 16 plots were collected using pitfall and eight using Winkler traps. We identified 391 ant species belonging to 71 genera and nine subfamilies. Among all species recorded, 21 were common to the whole 11 localities, while 98 species were recorded in a single locality. This study highlights the richness and diversity of epigaeic and leaf-litter ants living in the northern part of the Brazilian Atlantic Forest, and is one of the most representative soil ants’ inventories ever done in this biome for a single state of Brazil.

  12. Evaluation of alternative approaches for landscape-scale biomass estimation in a mixed-species northern forest

    Science.gov (United States)

    Coeli M. Hoover; Mark J. Ducey; R. Andy Colter; Mariko Yamasaki

    2018-01-01

    There is growing interest in estimating and mapping biomass and carbon content of forests across large landscapes. LiDAR-based inventory methods are increasingly common and have been successfully implemented in multiple forest types. Asner et al. (2011) developed a simple universal forest carbon estimation method for tropical forests that reduces the amount of required...

  13. Water, Rather than Temperature, Dominantly Impacts How Soil Fauna Affect Dissolved Carbon and Nitrogen Release from Fresh Litter during Early Litter Decomposition

    Directory of Open Access Journals (Sweden)

    Shu Liao

    2016-10-01

    Full Text Available Longstanding observations suggest that dissolved materials are lost from fresh litter through leaching, but the role of soil fauna in controlling this process has been poorly documented. In this study, a litterbag experiment employing litterbags with different mesh sizes (3 mm to permit soil fauna access and 0.04 mm to exclude fauna access was conducted in three habitats (arid valley, ecotone and subalpine forest with changes in climate and vegetation types to evaluate the effects of soil fauna on the concentrations of dissolved organic carbon (DOC and total dissolved nitrogen (TDN during the first year of decomposition. The results showed that the individual density and community abundance of soil fauna greatly varied among these habitats, but Prostigmata, Isotomidae and Oribatida were the dominant soil invertebrates. At the end of the experiment, the mass remaining of foliar litter ranged from 58% for shrub litter to 77% for birch litter, and the DOC and TDN concentrations decreased to 54%–85% and increased to 34%–269%, respectively, when soil fauna were not present. The effects of soil fauna on the concentrations of both DOC and TDN in foliar litter were greater in the subalpine forest (wetter but colder during the winter and in the arid valley (warmer but drier during the growing season, and this effect was positively correlated with water content. Moreover, the effects of fauna on DOC and TDN concentrations were greater for high-quality litter and were related to the C/N ratio. These results suggest that water, rather than temperature, dominates how fauna affect the release of dissolved substances from fresh litter.

  14. Idaho forest growth response to post-thinning energy biomass removal and complementary soil amendments

    Science.gov (United States)

    Lauren A. Sherman; Deborah S. Page-Dumroese; Mark D. Coleman

    2018-01-01

    Utilization of woody biomass for biofuel can help meet the need for renewable energy production. However, there is a concern biomass removal will deplete soil nutrients, having short- and long-term effects on tree growth. This study aimed to develop short-term indicators to assess the impacts of the first three years after small-diameter woody biomass removal on forest...

  15. Measurement and characteristics of microbial biomass in forest soils

    International Nuclear Information System (INIS)

    Vance, E.D.

    1986-01-01

    The soil microbial biomass is the primary agent responsible for the breakdown and mineralization of soil organic matter and plays a major role in regulating nutrient availability to plants. In this study, methods for measuring biomass in soil were compared and tested in forest soils ranging in pH from 3.2 to 7.2. A good relationship between biomass C measured using the chloroform fumigation-incubation method and soil ATP or microbial biomass C by direct microscopy was found in soils at or above pH 4.2. The fumigation-incubation method consistently underestimated biomass C in soils below pH 4.2, however. Hypotheses for the breakdown of the fumigation-incubation method in strongly acid soils were tested by using an alterative fumigant, measuring the proportion of added 14 C labelled fungi and bacteria decomposed in fumigated soils (k/sub C/), and by studying the effect of large, non-fumigated soil inocula on the flush of respiration following fumigation. These studies indicated that the failure of the method in strongly acid soils was due to inhibited decomposition of non-microbial soil organic matter by the microbial recolonizing population following fumigation. A modified method for measuring biomass C by fumigation-incubation in acid soils is proposed

  16. On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests

    Science.gov (United States)

    Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram

    1995-01-01

    In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.

  17. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

    International Nuclear Information System (INIS)

    Mazur, M.; Mitchell, C.P.J.; Eckley, C.S.; Eggert, S.L.; Kolka, R.K.; Sebestyen, S.D.; Swain, E.B.

    2014-01-01

    Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil–air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown. We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg emissions from the forest floor were monitored after two forest harvesting prescriptions, a traditional clear-cut and a clearcut followed by biomass harvest, and compared to an un-harvested reference plot. Gaseous Hg emissions were measured in quadruplicate at four different times between March and November 2012 using Teflon dynamic flux chambers. We also applied enriched Hg isotope tracers and separately monitored their emission in triplicate at the same times as ambient measurements. Clearcut followed by biomass harvesting increased ambient Hg emissions the most. While significant intra-site spatial variability was observed, Hg emissions from the biomass harvested plot (180 ± 170 ng m −2 d −1 ) were significantly greater than both the traditional clearcut plot (− 40 ± 60 ng m −2 d −1 ) and the un-harvested reference plot (− 180 ± 115 ng m −2 d −1 ) during July. This difference was likely a result of enhanced Hg 2+ photoreduction due to canopy removal and less shading from downed woody debris in the biomass harvested plot. Gaseous Hg emissions from more recently deposited Hg, as presumably representative of isotope tracer measurements, were not significantly influenced by harvesting. Most of the Hg tracer applied to the forest floor became sequestered within the ground vegetation and debris, leaf litter, and soil. We observed a dramatic lessening of tracer Hg emissions to near detection levels within 6 months. As post-clearcutting residues are increasingly used as a fuel or fiber resource, our observations suggest that gaseous Hg emissions from forest soils will increase, although it

  18. The stage-classified matrix models project a significant increase in biomass carbon stocks in China's forests between 2005 and 2050.

    Science.gov (United States)

    Hu, Huifeng; Wang, Shaopeng; Guo, Zhaodi; Xu, Bing; Fang, Jingyun

    2015-06-25

    China's forests are characterized by young age, low carbon (C) density and a large plantation area, implying a high potential for increasing C sinks in the future. Using data of provincial forest area and biomass C density from China's forest inventories between 1994 and 2008 and the planned forest coverage of the country by 2050, we developed a stage-classified matrix model to predict biomass C stocks of China's forests from 2005 to 2050. The results showed that total forest biomass C stock would increase from 6.43 Pg C (1 Pg = 10(15) g) in 2005 to 9.97 Pg C (95% confidence interval: 8.98 ~ 11.07 Pg C) in 2050, with an overall net C gain of 78.8 Tg C yr(-1) (56.7 ~ 103.3 Tg C yr(-1); 1 Tg = 10(12) g). Our findings suggest that China's forests will be a large and persistent biomass C sink through 2050.

  19. Fire in the Brazilian Amazon : 3. Dynamics of biomass, C, and nutrient pools in regenerating forests.

    Science.gov (United States)

    Hughes, R F; Kauffman, J B; Cummings, D L

    2000-09-01

    Regenerating forests have become a common land-cover type throughout the Brazilian Amazon. However, the potential for these systems to accumulate and store C and nutrients, and the fluxes resulting from them when they are cut, burned, and converted back to croplands and pastures have not been well quantified. In this study, we quantified pre- and post-fire pools of biomass, C, and nutrients, as well as the emissions of those elements, at a series of second- and third-growth forests located in the states of Pará and Rondônia, Brazil. Total aboveground biomass (TAGB) of second- and third-growth forests averaged 134 and 91 Mg ha -1 , respectively. Rates of aboveground biomass accumulation were rapid in these systems, but were not significantly different between second- and third-growth forests, ranging from 9 to 16 Mg ha -1 year -1 . Residual pools of biomass originating from primary forest vegetation accounted for large portions of TAGB in both forest types and were primarily responsible for TAGB differences between the two forest types. In second-growth forests this pool (82 Mg ha -1 ) represented 58% of TAGB, and in third-growth forests (40 Mg ha -1 ) it represented 40% of TAGB. Amounts of TAGB consumed by burning of second- and third-growth forests averaged 70 and 53 Mg ha -1 , respectively. Aboveground pre-fire pools in second- and third-growth forests averaged 67 and 45 Mg C ha -1 , 821 and 707 kg N ha -1 , 441 and 341 kg P ha -1 , and 46 and 27 kg Ca ha -1 , respectively. While pre-fire pools of C, N, S and K were not significantly different between second- and third-growth forests, pools of both P and Ca were significantly higher in second-growth forests. This suggests that increasing land use has a negative impact on these elemental pools. Site losses of elements resulting from slashing and burning these sites were highly variable: losses of C ranged from 20 to 47 Mg ha -1 ; N losses ranged from 306 to 709 kg ha -1 ; Ca losses ranged from 10 to 145 kg ha -1

  20. Sustainable utilisation of forest biomass for energy - Possibilities and problems

    DEFF Research Database (Denmark)

    Stupak, I.; Asikainen, A.; Jonsell, M.

    2007-01-01

    The substitution of biomass for fossil fuels in energy consumption is a measure to mitigate global warming, as well as having other advantages. Political action plans for increased use exist at both European and national levels. This paper briefly reviews the contents of recommendations. guidelines....... and other synthesis publications on Sustainable use of forest biomass for energy. Topics are listed and an overview of advantages. disadvantages, and trade-offs between them is given, from the viewpoint of society in general and the forestry or the Nordic and Baltic countries, the paper also identifies...

  1. Effects of fire frequency on litter decomposition as mediated by changes to litter chemistry and soil environmental conditions.

    Directory of Open Access Journals (Sweden)

    Cari D Ficken

    Full Text Available Litter quality and soil environmental conditions are well-studied drivers influencing decomposition rates, but the role played by disturbance legacy, such as fire history, in mediating these drivers is not well understood. Fire history may impact decomposition directly, through changes in soil conditions that impact microbial function, or indirectly, through shifts in plant community composition and litter chemistry. Here, we compared early-stage decomposition rates across longleaf pine forest blocks managed with varying fire frequencies (annual burns, triennial burns, fire-suppression. Using a reciprocal transplant design, we examined how litter chemistry and soil characteristics independently and jointly influenced litter decomposition. We found that both litter chemistry and soil environmental conditions influenced decomposition rates, but only the former was affected by historical fire frequency. Litter from annually burned sites had higher nitrogen content than litter from triennially burned and fire suppression sites, but this was correlated with only a modest increase in decomposition rates. Soil environmental conditions had a larger impact on decomposition than litter chemistry. Across the landscape, decomposition differed more along soil moisture gradients than across fire management regimes. These findings suggest that fire frequency has a limited effect on litter decomposition in this ecosystem, and encourage extending current decomposition frameworks into disturbed systems. However, litter from different species lost different masses due to fire, suggesting that fire may impact decomposition through the preferential combustion of some litter types. Overall, our findings also emphasize the important role of spatial variability in soil environmental conditions, which may be tied to fire frequency across large spatial scales, in driving decomposition rates in this system.

  2. Quantifying above- and belowground biomass carbon loss with forest conversion in tropical lowlands of Sumatra (Indonesia).

    Science.gov (United States)

    Kotowska, Martyna M; Leuschner, Christoph; Triadiati, Triadiati; Meriem, Selis; Hertel, Dietrich

    2015-10-01

    Natural forests in South-East Asia have been extensively converted into other land-use systems in the past decades and still show high deforestation rates. Historically, lowland forests have been converted into rubber forests, but more recently, the dominant conversion is into oil palm plantations. While it is expected that the large-scale conversion has strong effects on the carbon cycle, detailed studies quantifying carbon pools and total net primary production (NPPtotal ) in above- and belowground tree biomass in land-use systems replacing rainforest (incl. oil palm plantations) are rare so far. We measured above- and belowground carbon pools in tree biomass together with NPPtotal in natural old-growth forests, 'jungle rubber' agroforests under natural tree cover, and rubber and oil palm monocultures in Sumatra. In total, 32 stands (eight plot replicates per land-use system) were studied in two different regions. Total tree biomass in the natural forest (mean: 384 Mg ha(-1) ) was more than two times higher than in jungle rubber stands (147 Mg ha(-1) ) and >four times higher than in monoculture rubber and oil palm plantations (78 and 50 Mg ha(-1) ). NPPtotal was higher in the natural forest (24 Mg ha(-1)  yr(-1) ) than in the rubber systems (20 and 15 Mg ha(-1)  yr(-1) ), but was highest in the oil palm system (33 Mg ha(-1)  yr(-1) ) due to very high fruit production (15-20 Mg ha(-1)  yr(-1) ). NPPtotal was dominated in all systems by aboveground production, but belowground productivity was significantly higher in the natural forest and jungle rubber than in plantations. We conclude that conversion of natural lowland forest into different agricultural systems leads to a strong reduction not only in the biomass carbon pool (up to 166 Mg C ha(-1) ) but also in carbon sequestration as carbon residence time (i.e. biomass-C:NPP-C) was 3-10 times higher in the natural forest than in rubber and oil palm plantations. © 2015 John Wiley & Sons Ltd.

  3. Accounting for Biomass Carbon Stock Change Due to Wildfire in Temperate Forest Landscapes in Australia

    Science.gov (United States)

    Keith, Heather; Lindenmayer, David B.; Mackey, Brendan G.; Blair, David; Carter, Lauren; McBurney, Lachlan; Okada, Sachiko; Konishi-Nagano, Tomoko

    2014-01-01

    Carbon stock change due to forest management and disturbance must be accounted for in UNFCCC national inventory reports and for signatories to the Kyoto Protocol. Impacts of disturbance on greenhouse gas (GHG) inventories are important for many countries with large forest estates prone to wildfires. Our objective was to measure changes in carbon stocks due to short-term combustion and to simulate longer-term carbon stock dynamics resulting from redistribution among biomass components following wildfire. We studied the impacts of a wildfire in 2009 that burnt temperate forest of tall, wet eucalypts in south-eastern Australia. Biomass combusted ranged from 40 to 58 tC ha−1, which represented 6–7% and 9–14% in low- and high-severity fire, respectively, of the pre-fire total biomass carbon stock. Pre-fire total stock ranged from 400 to 1040 tC ha−1 depending on forest age and disturbance history. An estimated 3.9 TgC was emitted from the 2009 fire within the forest region, representing 8.5% of total biomass carbon stock across the landscape. Carbon losses from combustion were large over hours to days during the wildfire, but from an ecosystem dynamics perspective, the proportion of total carbon stock combusted was relatively small. Furthermore, more than half the stock losses from combustion were derived from biomass components with short lifetimes. Most biomass remained on-site, although redistributed from living to dead components. Decomposition of these components and new regeneration constituted the greatest changes in carbon stocks over ensuing decades. A critical issue for carbon accounting policy arises because the timeframes of ecological processes of carbon stock change are longer than the periods for reporting GHG inventories for national emissions reductions targets. Carbon accounts should be comprehensive of all stock changes, but reporting against targets should be based on human-induced changes in carbon stocks to incentivise mitigation activities

  4. Effects of elevated concentrations of atmospheric CO{sub 2} and tropospheric O{sub 3} on leaf litter production and chemistry in trembling aspen and paper birch communities

    Energy Technology Data Exchange (ETDEWEB)

    Liu, L.; King, J.S. [Michigan Technological Univ., Houghton, MI (United States). School of Forest Resources and Environmental Science; Giardina, C.P. [United States Dept. of Agriculture Forest Service, Houghton, MI (United States)

    2005-12-01

    This study examined the effects of elevated carbon dioxide (CO{sub 2}) and elevated ozone (O{sub 3}) on the quantity and timing of nutrient release to plants and on soil carbon formation rates, and how they are influenced by the combined change in litter quality and quantity. The changes in leaf litter in response to environmental changes was characterized in order to understand the influence of global change on forests. Free-air CO{sub 2} enrichment (FACE) technology was used to examine leaf litter production and biochemical input to soil in response to elevated CO{sub 2} and O{sub 3} treatments. The study involved collecting litter from aspen and birch-aspen communities that had been exposed to FACE and O{sub 3} treatments for 6 years. The hypothesis of growth differentiation balance was used as the basis to develop other hypotheses regarding litter chemistry responses to elevated levels of carbon dioxide and ozone. It was assumed that environmental factors that increase the net balance of plant carbon sources relative to growth sinks will increase the allocation of photosynthate to the production of carbon-based secondary compounds. Litter was analyzed for concentrations of carbon, nitrogen, soluble sugars, lipids, lignin, cellulose, hemicellulose and carbon-based defensive compounds such as soluble phenolics and condensed tannins. The study showed that high levels of ozone greatly increased litter concentrations of soluble sugars, soluble phenolics and condensed tannins, but there were no major effects of elevated carbon dioxide or elevated ozone on the concentrations of individual carbon structural carbon hydrates such as cellulose, hemicellulose and lignin. It was concluded that in the future, the inputs of nitrogen, soluble sugars, condensed tannins, soluble phenolics, cellulose and lignin to forest soils can change as a result of small changes in litter chemistry resulting from elevated CO{sub 2}, tropospheric O{sub 3}, and changes in litter biomass

  5. Inventory-based estimates of forest biomass carbon stocks in China: A comparison of three methods

    Science.gov (United States)

    Zhaodi Guo; Jingyun Fang; Yude Pan; Richard. Birdsey

    2010-01-01

    Several studies have reported different estimates for forest biomass carbon (C) stocks in China. The discrepancy among these estimates may be largely attributed to the methods used. In this study, we used three methods [mean biomass density method (MBM), mean ratio method (MRM), and continuous biomass expansion factor (BEF) method (abbreviated as CBM)] applied to...

  6. Unexpectedly large impact of forest management and grazing on global vegetation biomass

    Science.gov (United States)

    Erb, Karl-Heinz; Kastner, Thomas; Plutzar, Christoph; Bais, Anna Liza S.; Carvalhais, Nuno; Fetzel, Tamara; Gingrich, Simone; Haberl, Helmut; Lauk, Christian; Niedertscheider, Maria; Pongratz, Julia; Thurner, Martin; Luyssaert, Sebastiaan

    2018-01-01

    Carbon stocks in vegetation have a key role in the climate system. However, the magnitude, patterns and uncertainties of carbon stocks and the effect of land use on the stocks remain poorly quantified. Here we show, using state-of-the-art datasets, that vegetation currently stores around 450 petagrams of carbon. In the hypothetical absence of land use, potential vegetation would store around 916 petagrams of carbon, under current climate conditions. This difference highlights the massive effect of land use on biomass stocks. Deforestation and other land-cover changes are responsible for 53-58% of the difference between current and potential biomass stocks. Land management effects (the biomass stock changes induced by land use within the same land cover) contribute 42-47%, but have been underestimated in the literature. Therefore, avoiding deforestation is necessary but not sufficient for mitigation of climate change. Our results imply that trade-offs exist between conserving carbon stocks on managed land and raising the contribution of biomass to raw material and energy supply for the mitigation of climate change. Efforts to raise biomass stocks are currently verifiable only in temperate forests, where their potential is limited. By contrast, large uncertainties hinder verification in the tropical forest, where the largest potential is located, pointing to challenges for the upcoming stocktaking exercises under the Paris agreement.

  7. Unexpectedly large impact of forest management and grazing on global vegetation biomass.

    Science.gov (United States)

    Erb, Karl-Heinz; Kastner, Thomas; Plutzar, Christoph; Bais, Anna Liza S; Carvalhais, Nuno; Fetzel, Tamara; Gingrich, Simone; Haberl, Helmut; Lauk, Christian; Niedertscheider, Maria; Pongratz, Julia; Thurner, Martin; Luyssaert, Sebastiaan

    2018-01-04

    Carbon stocks in vegetation have a key role in the climate system. However, the magnitude, patterns and uncertainties of carbon stocks and the effect of land use on the stocks remain poorly quantified. Here we show, using state-of-the-art datasets, that vegetation currently stores around 450 petagrams of carbon. In the hypothetical absence of land use, potential vegetation would store around 916 petagrams of carbon, under current climate conditions. This difference highlights the massive effect of land use on biomass stocks. Deforestation and other land-cover changes are responsible for 53-58% of the difference between current and potential biomass stocks. Land management effects (the biomass stock changes induced by land use within the same land cover) contribute 42-47%, but have been underestimated in the literature. Therefore, avoiding deforestation is necessary but not sufficient for mitigation of climate change. Our results imply that trade-offs exist between conserving carbon stocks on managed land and raising the contribution of biomass to raw material and energy supply for the mitigation of climate change. Efforts to raise biomass stocks are currently verifiable only in temperate forests, where their potential is limited. By contrast, large uncertainties hinder verification in the tropical forest, where the largest potential is located, pointing to challenges for the upcoming stocktaking exercises under the Paris agreement.

  8. Long-term litter input manipulation effects on production and properties of dissolved organic matter in the forest floor of a Norway spruce stand.

    NARCIS (Netherlands)

    Klotzbücher, T.; Kaiser, K.; Stepper, C.; van Loon, E.; Gerstberger, P.; Kalbitz, K.

    2012-01-01

    Background and aims Environmental factors such as climate and atmospheric CO2 control inputs of plant-derived matter into soils, which then determines properties and decomposition of soil organic matter. We studied how dissolved organic matter (DOM) in forest floors responded to six years of litter

  9. The biotransformation of soil biocenosis by micromycetes under introduction of Fagus sylvatica L. to oak-hornbeam forest

    Science.gov (United States)

    Likhanov, Artur; Bilyera, Nataliya; Sedykh, Olena; Melnychuk, Maksym

    2017-04-01

    Keywords: micromycetes, beech, soil enzymes, illuminance, Penicillium canescens. European beech (Fagus sylvatica L.) is a commercially valuable tree species. As the potential distribution area for beech forest is restricted by Europe, planting of artificial stands is adopted in this region. Beech introduction can alter ecosystem considerably, but the mechanism of this transformation is not clear. We aimed to define abiotic and biotic parameters affecting floor development in beech stands introduced to the oak-hornbeam forest ecosystem ca.50 years ago in Eastern Europe (Ukraine). The daylight illuminace level was similar (2.9-6.5 klx) for both stands. However, grass cover in beech stands did not exceed 0.1-0.5 % even on sites with illuminace level 7.5-8.3 klx. It does not comply with the commonly used suggestion that shading is the main factor causes forest floor absence in the beech stands. We indicated predominantly biotic factors influencing forest floor formation. Thus, particular edaphon represented by micromycetes was able to inhibit plants and microorganisms. We isolated Penicillium canescens strains from soil under beech stands. These fungi utilized beech root exudates and phenol compounds of leaf litter, and produced biologically active substances caused cytostatic and mutagenic effects. They also accelerated (in 2-3.2 times) soil β-glucosidase activity, but had no effect on phosphatase. The biomass of fungi varied under cultivation of Penicillium canescens strains on Czapek medium with the addition of aqueous extracts of beech leaf litter. The biomass of micromycetes increased on 10-15 % at plant phenols concentrations up to 1 mg mL-1. On the contrary, increasing the concentration of phenols up to 4 mg mL-1resulted in a biomass decrease to 40%. The relationship between the concentration of plant phenols and rate of fungal biomass formation indicates that there is probably seasonal regulation of micromycetes activity in the forest biocenosis. The highest

  10. Decadal change of forest biomass carbon stocks and tree demography in the Delaware River Basin

    Science.gov (United States)

    Bing Xu; Yude Pan; Alain F. Plante; Arthur Johnson; Jason Cole; Richard Birdsey

    2016-01-01

    Quantifying forest biomass carbon (C) stock change is important for understanding forest dynamics and their feedbacks with climate change. Forests in the northeastern U.S. have been a net carbon sink in recent decades, but C accumulation in some northern hardwood forests has been halted due to the impact of emerging stresses such as invasive pests, land use change and...

  11. Energy from wood biomass: The experience of the Brazilian forest sector

    Energy Technology Data Exchange (ETDEWEB)

    Couto, L. [Universidade Federal de Vicosa (Brazil); Graca, L.R. [Centro Nacional de Pesquisa de Floresta, Colombo (Brazil); Betters, D.R. [Colorado State Univ., Fort Collins, CO (United States)

    1993-12-31

    Wood biomass is one of the most significant renewable sources of energy in Brazil. Fuelwood and charcoal play a very important role not only for household energy consumption but also for the cement, iron and steel industries. Wood is used as an energy source by the pulp and paper, composite board and other industries of the country, mainly for steam and electricity generation. Ethanol, lignin-based coke and methanol from wood were produced at experimental units in Brazil but were not implemented on a commercial scale. Currently, a new experimental plant using a technology developed in the US is being built in the state of Bahia to generate electricity from Eucalyptus. This technology is a Biomass Integrated Gasification/Gas Turbine process which is expected to make the use of wood biomass economically feasible for electricity generation. Forest plantations are the main source of wood biomass for energy consumption by the Brazilian industrial sector. Fiscal incentives in the 1960s helped the country to begin a massive reforestation program mainly using Eucalyptus and Pinus species. A native species, bracatinga (Mimosa scabrella) has also been used extensively for wood energy plantations in southern Brazil. Technical, economic, social and environmental impacts of these plantation forests are discussed along with a forecast of the future wood energy utilization in Brazil.

  12. Decomposition performance of animals as an indicator of stress acting on beech-forest ecosystems - microcosmos experiments with carbon-14-labelled litter components

    International Nuclear Information System (INIS)

    Schaefer, M.; Wolters, V.

    1988-01-01

    The effect of acid rain and heavy metals on the biotic interactions in the soil of beech forest with mull, must, and limed must was investigated with the aid of close-to-nature microcosmos systems. Parameters made use of were the decomposition of carbon-14-labelled litter components and the turnover of the microflora in C, N, and P. As the results show, increased proton uptake will bear on rearly every stage of the decomposition process in mull soils. As a result, there may be litter accumulation on the ground and first signs of humus disintegration in the mineral soil of mull soils. A direct relation between the acidity of the environment and the extent of decomposition inhibition does not exist. Despite wide-ranging impairment of edaphic animals, the activity of the ground fauna still is to be considered as the most important buffer system of soils rich in bases. Acidic condition of the beech forest soils with the humus form 'must' led to drastic inhibition of litter decomposition, to a change of the effect of edaphic animals, and to an increase in N mineralization. The grazing animals frequently aggravate the decomposition inhibition resulting from acid precipitation. The comparision of the decomposition process in a soil containing must as compared to one containing mull showed acidic soils to be on a lower biological buffer level than soils rich in bases. The main buffer capacity of acidic soils lies in the microflora, which is adapted to sudden increases in acidity and which recovers quickly. In the opinion of the authors, simple liming is not enough to increase the long-term biogenic stability of a forest ecosystem. A stabilizing effect of the fauna, for instance on nitrogen storage, is possible only if forest care measuries are carried out, for instance careful loosening of the mineral soil, which will attract earthworm species penetrating deeply into the soil. (orig./MG) With 12 refs., 6 figs [de

  13. Woody biomass production lags stem-girth increase by over one month in coniferous forests.

    Science.gov (United States)

    Cuny, Henri E; Rathgeber, Cyrille B K; Frank, David; Fonti, Patrick; Mäkinen, Harri; Prislan, Peter; Rossi, Sergio; Del Castillo, Edurne Martinez; Campelo, Filipe; Vavrčík, Hanuš; Camarero, Jesus Julio; Bryukhanova, Marina V; Jyske, Tuula; Gričar, Jožica; Gryc, Vladimír; De Luis, Martin; Vieira, Joana; Čufar, Katarina; Kirdyanov, Alexander V; Oberhuber, Walter; Treml, Vaclav; Huang, Jian-Guo; Li, Xiaoxia; Swidrak, Irene; Deslauriers, Annie; Liang, Eryuan; Nöjd, Pekka; Gruber, Andreas; Nabais, Cristina; Morin, Hubert; Krause, Cornelia; King, Gregory; Fournier, Meriem

    2015-10-26

    Wood is the main terrestrial biotic reservoir for long-term carbon sequestration(1), and its formation in trees consumes around 15% of anthropogenic carbon dioxide emissions each year(2). However, the seasonal dynamics of woody biomass production cannot be quantified from eddy covariance or satellite observations. As such, our understanding of this key carbon cycle component, and its sensitivity to climate, remains limited. Here, we present high-resolution cellular based measurements of wood formation dynamics in three coniferous forest sites in northeastern France, performed over a period of 3 years. We show that stem woody biomass production lags behind stem-girth increase by over 1 month. We also analyse more general phenological observations of xylem tissue formation in Northern Hemisphere forests and find similar time lags in boreal, temperate, subalpine and Mediterranean forests. These time lags question the extension of the equivalence between stem size increase and woody biomass production to intra-annual time scales(3, 4, 5, 6). They also suggest that these two growth processes exhibit differential sensitivities to local environmental conditions. Indeed, in the well-watered French sites the seasonal dynamics of stem-girth increase matched the photoperiod cycle, whereas those of woody biomass production closely followed the seasonal course of temperature. We suggest that forecasted changes in the annual cycle of climatic factors(7) may shift the phase timing of stem size increase and woody biomass production in the future.

  14. Heat storage in forest biomass improves energy balance closure

    Science.gov (United States)

    Lindroth, A.; Mölder, M.; Lagergren, F.

    2010-01-01

    Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and -35 W m-2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m-2 and the minimum was -35 W m-2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation very well. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. -0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy covariance

  15. Stakeholders' perceptions on forest biomass-based bioenergy development in the southern US

    International Nuclear Information System (INIS)

    Dwivedi, Puneet; Alavalapati, Janaki R.R.

    2009-01-01

    This study analyzes perceptions of four stakeholder groups (non-governmental organizations [NGOs], government, industry, and academia) regarding forest biomass-based bioenergy development in the southern US (United States) by combining SWOT (Strength, Weakness, Opportunities, and Threats) framework with AHP (Analytical Hierarchy Process). Results suggest that NGO representatives perceived rural development as an important opportunity. Government stakeholder group noted that less or no competition with food production and promotes energy security were major strength factors. Conversion technologies are still under trial was identified as a major weakness by industry representatives. Representatives of academia felt that the competition from other renewable energy sources could be a major threat. Overall, all stakeholder groups were in favor of forest biomass-based bioenergy development in the southern US.

  16. The radiocesium dynamics in the Fukushima forests at the late stage after deposition

    Science.gov (United States)

    Yoschenko, Vasyl; Takase, Tsugiko; Nanba, Kenji; Konoplev, Alexei; Onda, Yuichi

    2017-04-01

    several experimental sites in the typical Fukushima forests (Japanese cedar, Japanese red pine). We observe the dynamics of the radiocesium concentrations and total inventories in the ecosystem compartments and quantify the biogenic fluxes of radiocesium which will determine its further redistribution between the biomass, soil and litter. Our study also includes characterization of the stable cesium distributions in the forest ecosystems and development of the methods for non-destructive monitoring of the radiocesium concentration in wood. We present the observation results for the period of 2014-2016 (annual and seasonal changes in the aboveground biomass, leaching from the forest litter, downward migration in soil), as well as the estimates of the radiocesium fluxes which will be used later for the modelling of its long-term dynamics in the Fukushima forests.

  17. Production of cellulases by fungal cultures isolated from forest litter soil

    Directory of Open Access Journals (Sweden)

    A. Sri Lakshmi

    2012-06-01

    Full Text Available The aims of this study were the isolation and screening of fungal cultures from forest litter soil for cellulases production. In the present study, four fungal cultures were isolated and identified. Among these fungal cultures, three belonged to the genus Aspergillus and one belonged to the genus Pencillium. These fungal cultures were tested to find their ability to produce cellulases, that catalyze the degradation of cellulose, which is a linear polymer made of glucose subunits linked by beta-1, 4 glycosidic bonds. The fungal isolate 3 (Aspergillus sp. was noticed to show maximum zone of hydrolysis of carboxy-methyl cellulose and produce higher titers of cellulases including exoglucanase, endoglucanase and beta -D-glucosidase. The activities of the cellulases were determined by Filter paper assay (FPA, Carboxy-methly cellulase assay (CMCase and beta -D-glucosidase assay respectively. The total soluble sugar and extracellular protein contents of the fungal filtrates were also determined.

  18. Plant litter decomposition and carbon sequestration for arable soils. Final report of works. April 2005

    International Nuclear Information System (INIS)

    Recous, S.; Barrois, F.; Coppens, F.; Garnier, P.; Grehan, E.; Balesdent, J.; Dambrine, E.; Zeller, B.; Loiseau, P.; Personeni, E.

    2002-01-01

    The general objective of this project was to contribute to the evaluation of land use and management impacts on C sequestration and nitrogen dynamics in soils. The land used through the presence/absence of crops and their species, and the land management through tillage, localisation of crop residues, fertilizer applications,... are important factors that affect the dynamics of organic matters in soils, particularly the mineralization of C and N, the losses to the atmosphere and hydrosphere, the retention of carbon into the soil. This project was conducted by four research groups, three of them having expertise in nutrient cycling of three major agro-ecosystems (arable crops, grasslands, forests) and the fourth one having expertise in modelling long term effects of land use on C storage into the soils. Within this common project one major objective was to better understand the fate of plant litter entering the soil either as above litter or as root litter. The focus was put on two factors that particularly affect decomposition: the initial biochemical quality of plant litter, and the location of the decomposing litter. One innovative aspect of the project was the use of stable isotope as 13 C for carbon, based on the use of enriched or depleted 13 C material, the only option to assess the dynamics of 'new' C entering the soil on the short term, in order to reveal the effects of decomposition factors. Another aspect was the simultaneous study of C and N. The project consisted in experiments relevant for each agro-ecosystem, in forest, grassland and arable soils for which interactions between residue quality and nitrogen availability on the one hand, residue quality and location on the other hand, was investigated. A common experiment was set up to investigate the potential degradability of the various residue used (beech leaf rape straw, young rye, Lolium and dactylic roots) in a their original soils and in a single soil was assessed. Based on these experiments, the

  19. Type of litter determines the formation and properties of charred material during wildfires

    Science.gov (United States)

    Chavez, Bruno; Fonturbel, M. Teresa; Salgado, Josefa; García-Oliva, Felipe; Vega, Jose A.; Merino, Agustin

    2014-05-01

    Wildfire is one of the most important disturbances all over the World, affecting both the amount and composition of forest floor and mineral soils. In comparison with unburnt areas, wildfire-affected forest floor usually shows lower contents of labile C compounds and higher concentrations of recalcitrant aromatic forms. These changes in composition can have important impact on biogeochemical cycles and therefore ecosystem functions. Although burning of different types of litter can lead to different amount and types of pyrogenic compounds, this aspect has not been evaluated yet. The effect of wildfire on SOM composition and stability were evaluated in five major types of non-wood litter in Mediterranean ecosystems: Pinus nigra, E. arborea, P. pinaster, U. europaeus and Eucalyptus globulus. In each of these ecosystems, forest floor samples from different soil burn severities were sampled. Soil burnt severities were based on visual signs of changes in forest floor and deposition of ash. Pyrogenic carbon quality were analysed using elementary analysis, solid-state 13 C nuclear magnetic resonance spectroscopy, Reflectance Infrared Fourier Transform (FTIR) and thermal analysis (simultaneous DSC-TG). The study showed that the different types of litter influenced the formation and characteristics of charred material. They differed in the temperature at which they start to be formed, the amounts of charred compounds and in their chemical composition. The resulting charred materials from the different litter, showed an important variability in the degree of carbonitation/aromatization. Unlike the biochar obtained through pyrolysis of woody sources, which contains exclusively aromatic structures, in the charred material produced in some litter, lignin, cellulose and even cellulose persist even in the high soil burnt severity. Coinciding with increases in aromatic contents, important decreases in atomic H/C and O/C ratios were recorded. However, the values found in some

  20. Effect of the silvicultural treatment on canopy properties, litter and seed production in beech coppices under conversion to high forest.

    Directory of Open Access Journals (Sweden)

    Andrea Cutini

    2010-12-01

    Full Text Available European beech (Fagus sylvatica L. is widely distributed in Italy where it covers 1035103 ha, mainly concentrated in the mountainous areas at altitudes above 900 m. The major part is represented by high forest often issued from the conversion of coppice woods, which in the past was the silvicultural system most widely applied mainly to provide fire wood. The social changes occurred in the second half of the last century –fire wood market crisis and the increasing importance of environmental issues- enhanced the conversion into high forest of large areas previously managed as coppice by means of different silvicultural treatments and practices. Nevertheless, the environmental benefits of this choice were not adequately investigated. Results of annual measurements (1992-2009 made in a beech coppice stand aged 65 are here reported. The study area is located on the Alpe di Catenaia, a pre-Apennine outcrop close to Arezzo (Central Italy. Variables strictly related to stand productivity and dynamics such as annual litter and seed production, leaf area index (LAI and transmittance (PAR were measured in the research area of Buca Zamponi to estimate the effects of two theses, natural evolution (TEST and conversion into high forest (DIR. Three thinnings were undertaken in the latter thesis in 1972, 1987 and 2002. Additional theses of natural evolution (CONTR and advance seed cutting (TS were added in 2002 in a nearby study area (Eremo della Casella. Results showed the high productivity of coppice stands, under conversion to high forest, with mean values of annual total litter, leaf litter and leaf area index of 5 Mg ha-1, 3 Mg ha-1 and 6 m2m-2, respectively. These findings confirm both the prompt response of beech to intensive thinning cycles and the reliability of undertaking coppice conversion into high forest. Furthermore, the positive trend observed in the ecological parameters and the high consistency of leaf fraction, highlight the still juvenile