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Sample records for forests strong differences

  1. Spatial aspects of tree mortality strongly differ between young and old-growth forests.

    Science.gov (United States)

    Larson, Andrew J; Lutz, James A; Donato, Daniel C; Freund, James A; Swanson, Mark E; HilleRisLambers, Janneke; Sprugel, Douglas G; Franklin, Jerry F

    2015-11-01

    Rates and spatial patterns of tree mortality are predicted to change during forest structural development. In young forests, mortality should be primarily density dependent due to competition for light, leading to an increasingly spatially uniform pattern of surviving trees. In contrast, mortality in old-growth forests should be primarily caused by contagious and spatially autocorrelated agents (e.g., insects, wind), causing spatial aggregation of surviving trees to increase through time. We tested these predictions by contrasting a three-decade record of tree mortality from replicated mapped permanent plots located in young ( 300-year-old) Abies amabilis forests. Trees in young forests died at a rate of 4.42% per year, whereas trees in old-growth forests died at 0.60% per year. Tree mortality in young forests was significantly aggregated, strongly density dependent, and caused live tree patterns to become more uniform through time. Mortality in old-growth forests was spatially aggregated, but was density independent and did not change the spatial pattern of surviving trees. These results extend current theory by demonstrating that density-dependent competitive mortality leading to increasingly uniform tree spacing in young forests ultimately transitions late in succession to a more diverse tree mortality regime that maintains spatial heterogeneity through time.

  2. Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions.

    Science.gov (United States)

    Brienen, Roel J W; Zuidema, Pieter A; Martínez-Ramos, Miguel

    2010-06-01

    Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees--those that have not attained the canopy--are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests.

  3. Forest health from different perspectives

    Science.gov (United States)

    T. E. Kolb; M. R. Wagner; W. W. Covington

    1995-01-01

    Forest health is an increasingly important concept in natural resource management. However, definition of forest health is difficult and dependent on human perspective. From a utilitarian perspective, forest health has been defined by the production of forest conditions which directly satisfy human needs. From an ecosystem-centered perspective, forest health has been...

  4. Strong carbon sink of monsoon tropical seasonal forest in Southern Vietnam

    Science.gov (United States)

    Deshcherevskaya, Olga; Anichkin, Alexandr; Avilov, Vitaly; Duy Dinh, Ba; Luu Do, Phong; Huan Tran, Cong; Kurbatova, Julia

    2014-05-01

    EC procedures were applied to the raw 10-Hz data, including time-lag compensation, block average, WPL-correction, planar fit, low- and high-frequency corrections etc. in EddyPro software (LI-COR Inc., USA). Calculated fluxes with bad quality flags (more than 6 of 9) were excluded. Spikes due to rains, instrument malfunction were removed too. Storage of CO2 from the surface to the measurement level which is very significant in tall tropical forest was added to the flux. Then low-turbulence correction was applied with u*-threshold of 0.178 m s-1. After these steps only 43 % of 30-min data of 2012 still presented, so the rate of gaps was 57 % (mainly at night and in rains). Data were gapfilled using on-line tool at the web-site of Max-Plank Institute, Germany and Flux-Analysis Tool, Japan. Different gap-filling procedures (non-linear regressions, look-up tables, model evaluation, artificial gaps-method) as well as u*-threshold shifting from 0 to 0.25 resulted in drift of 2012 net carbon exchange total from -296 to -612 g C m-2 (strong carbon sink still remain). Unfortunately, the situation of more then 50 % of gaps in CO2 flux is usual for tropical EC stations because of frequent calm nights. So, a gap-filling algorithm is extremely important for evaluation of long-term totals. We found for Vietnamese data that even few spikes which were not removed before gap-filling can change all-year total by up to 20-50 g m-2 year-1. Especially 'powerful' are big positive values at night in rare-occurred good turbulence. Possibly these values are physical. But they influence regressions in look-up table method dramatically because amount of data in peak of rainy season in night-time is too small. So, the gap-filling algorithm happened to be very sensitive to spikes. Additionally, striking was the fact that storage of CO2 appeared to be the main factor influencing 1-year totals after gap-filling procedure. Taking storage into account shifted the 2012 sum from +182 to -402 g m-2 year

  5. Climate- and successional-related changes in functional composition of European forests are strongly driven by tree mortality.

    Science.gov (United States)

    Ruiz-Benito, Paloma; Ratcliffe, Sophia; Zavala, Miguel A; Martínez-Vilalta, Jordi; Vilà-Cabrera, Albert; Lloret, Francisco; Madrigal-González, Jaime; Wirth, Christian; Greenwood, Sarah; Kändler, Gerald; Lehtonen, Aleksi; Kattge, Jens; Dahlgren, Jonas; Jump, Alistair S

    2017-10-01

    Intense droughts combined with increased temperatures are one of the major threats to forest persistence in the 21st century. Despite the direct impact of climate change on forest growth and shifts in species abundance, the effect of altered demography on changes in the composition of functional traits is not well known. We sought to (1) quantify the recent changes in functional composition of European forests; (2) identify the relative importance of climate change, mean climate and forest development for changes in functional composition; and (3) analyse the roles of tree mortality and growth underlying any functional changes in different forest types. We quantified changes in functional composition from the 1980s to the 2000s across Europe by two dimensions of functional trait variation: the first dimension was mainly related to changes in leaf mass per area and wood density (partially related to the trait differences between angiosperms and gymnosperms), and the second dimension was related to changes in maximum tree height. Our results indicate that climate change and mean climatic effects strongly interacted with forest development and it was not possible to completely disentangle their effects. Where recent climate change was not too extreme, the patterns of functional change generally followed the expected patterns under secondary succession (e.g. towards late-successional short-statured hardwoods in Mediterranean forests and taller gymnosperms in boreal forests) and latitudinal gradients (e.g. larger proportion of gymnosperm-like strategies at low water availability in forests formerly dominated by broad-leaved deciduous species). Recent climate change generally favoured the dominance of angiosperm-like related traits under increased temperature and intense droughts. Our results show functional composition changes over relatively short time scales in European forests. These changes are largely determined by tree mortality, which should be further

  6. Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient.

    Science.gov (United States)

    Orihuela, Rodrigo L L; Peres, Carlos A; Mendes, Gabriel; Jarenkow, João A; Tabarelli, Marcelo

    2015-01-01

    We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide.

  7. Temporal bird community dynamics are strongly affected by landscape fragmentation in a Central American tropical forest region

    Science.gov (United States)

    Blandón, A.C.; Perelman, S.B.; Ramírez, M.; López, A.; Javier, O.; Robbins, Chandler S.

    2016-01-01

    Habitat loss and fragmentation are considered the main causes of species extinctions, particularly in tropical ecosystems. The objective of this work was to evaluate the temporal dynamics of tropical bird communities in landscapes with different levels of fragmentation in eastern Guatemala. We evaluated five bird community dynamic parameters for forest specialists and generalists: (1) species extinction, (2) species turnover, (3) number of colonizing species, (4) relative species richness, and (5) a homogeneity index. For each of 24 landscapes, community dynamic parameters were estimated from bird point count data, for the 1998–1999 and 2008–2009 periods, accounting for species’ detection probability. Forest specialists had higher extinction rates and a smaller number of colonizing species in landscapes with higher fragmentation, thus having lower species richness in both time periods. Alternatively, forest generalists elicited a completely different pattern, showing a curvilinear association to forest fragmentation for most parameters. Thus, greater community dynamism for forest generalists was shown in landscapes with intermediate levels of fragmentation. Our study supports general theory regarding the expected negative effects of habitat loss and fragmentation on the temporal dynamics of biotic communities, particularly for forest specialists, providing strong evidence from understudied tropical bird communities.

  8. Strong spatial variability in trace gas dynamics following experimental drought in a humid tropical forest

    Science.gov (United States)

    Tana Wood; W. L. Silver

    2012-01-01

    [1] Soil moisture is a key driver of biogeochemical processes in terrestrial ecosystems, strongly affecting carbon (C) and nutrient availability as well as trace gas production and consumption in soils. Models predict increasing drought frequency in tropical forest ecosystems, which could feed back on future climate change directly via effects on trace gasdynamics and...

  9. Atmospheric CO2 observations and models suggest strong carbon uptake by forests in New Zealand

    Science.gov (United States)

    Steinkamp, Kay; Mikaloff Fletcher, Sara E.; Brailsford, Gordon; Smale, Dan; Moore, Stuart; Keller, Elizabeth D.; Baisden, W. Troy; Mukai, Hitoshi; Stephens, Britton B.

    2017-01-01

    A regional atmospheric inversion method has been developed to determine the spatial and temporal distribution of CO2 sinks and sources across New Zealand for 2011-2013. This approach infers net air-sea and air-land CO2 fluxes from measurement records, using back-trajectory simulations from the Numerical Atmospheric dispersion Modelling Environment (NAME) Lagrangian dispersion model, driven by meteorology from the New Zealand Limited Area Model (NZLAM) weather prediction model. The inversion uses in situ measurements from two fixed sites, Baring Head on the southern tip of New Zealand's North Island (41.408° S, 174.871° E) and Lauder from the central South Island (45.038° S, 169.684° E), and ship board data from monthly cruises between Japan, New Zealand, and Australia. A range of scenarios is used to assess the sensitivity of the inversion method to underlying assumptions and to ensure robustness of the results. The results indicate a strong seasonal cycle in terrestrial land fluxes from the South Island of New Zealand, especially in western regions covered by indigenous forest, suggesting higher photosynthetic and respiratory activity than is evident in the current a priori land process model. On the annual scale, the terrestrial biosphere in New Zealand is estimated to be a net CO2 sink, removing 98 (±37) Tg CO2 yr-1 from the atmosphere on average during 2011-2013. This sink is much larger than the reported 27 Tg CO2 yr-1 from the national inventory for the same time period. The difference can be partially reconciled when factors related to forest and agricultural management and exports, fossil fuel emission estimates, hydrologic fluxes, and soil carbon change are considered, but some differences are likely to remain. Baseline uncertainty, model transport uncertainty, and limited sensitivity to the northern half of the North Island are the main contributors to flux uncertainty.

  10. Dynamics of Salix caprea L. populations during forest regeneration after strong herbivore pressure

    Energy Technology Data Exchange (ETDEWEB)

    Falinski, J.B. [Warsaw Univ. (Poland). Bialowieza Geobotanical Station

    1998-02-01

    Broadleaved forest communities degenerated through strong pressure from large herbivores. Relief of this pressure led to regeneration, in particular of Salix caprea and other light/seeded pioneer trees: Populus tremula, Betula pendula and B. pubescens. This regeneration proceeded following conservation protection of degenerate stands in a nature reserve and later in Bialowieza National Park. The emergence and development of the Salix caprea population proceeded following the expansion of Picea abies, which coincided with the period of enhanced animal pressure on the broadleaved forest. Salix caprea filled all the gaps in the tree stand after the destruction of trees and undergrowth by herbivores (in the years 1892-1915). The species also appeared abundantly in old, at the time unforested, clearings and felled areas. Here, S. caprea developed large populations with certain trees in good condition, with a growth form typical of forest trees and attaining considerable heights. The majority of trees were 50/60 years old at the time of death, although some individuals reached 74 years of age. The process of extinction of the Salix population - observed over 19 years on permanent plots with marked trees - proceeded very quickly, especially in the first decade of observation. It led to the almost complete disappearance of S. caprea from the forest communities of Bialowieza National Park. The death of individual trees is preceded by impairment of their health and reduced annual increments in the last 4-9 years of their life. The development of populations of permanent constituents of the forest, notably Carpinus betulus, Tilia cordata, Acer platanoides and Ulmus glabra, under the canopy of light-seeded trees, and the absence of a new generation of pioneer trees points to the end of the process of regeneration in the forest communities of Bialowieza National Park 30 refs, 9 figs, 1 tab

  11. Evaluating differences in forest fragmentation and restoration between western natural forests and southeastern plantation forests in the United States.

    Science.gov (United States)

    Ren, Xinyu; Lv, Yingying; Li, Mingshi

    2017-03-01

    Changes in forest ecosystem structure and functions are considered some of the research issues in landscape ecology. In this study, advancing Forman's theory, we considered five spatially explicit processes associated with fragmentation, including perforation, dissection, subdivision, shrinkage, and attrition, and two processes associated with restoration, i.e., increment and expansion processes. Following this theory, a forest fragmentation and restoration process model that can detect the spatially explicit processes and ecological consequences of forest landscape change was developed and tested in the current analysis. Using the National Land Cover Databases (2001, 2006 and 2011), the forest fragmentation and restoration process model was applied to US western natural forests and southeastern plantation forests to quantify and classify forest patch losses into one of the four fragmentation processes (the dissection process was merged into the subdivision process) and to classify the newly gained forest patches based on the two restoration processes. At the same time, the spatio-temporal differences in fragmentation and restoration patterns and trends between natural forests and plantations were further compared. Then, through overlaying the forest fragmentation/restoration processes maps with targeting year land cover data and land ownership vectors, the results from forest fragmentation and the contributors to forest restoration in federal and nonfederal lands were identified. Results showed that, in natural forests, the forest change patches concentrated around the urban/forest, cultivated/forest, and shrubland/forest interfaces, while the patterns of plantation change patches were scattered sparsely and irregularly. The shrinkage process was the most common type in forest fragmentation, and the average size was the smallest. Expansion, the most common restoration process, was observed in both natural forests and plantations and often occurred around the

  12. Declines in populations of Salix caprea L.during forest regeneration after strong herbivore pressure

    Directory of Open Access Journals (Sweden)

    Janusz B. Faliński

    2014-01-01

    Full Text Available Communities of broadleaved forest subject to strong pressure from large herbivores underwent degeneration. The relief of this pressure led to regeneration of the community, in which an important role was played by the sallow Salix caprea and other light-seeded pioneer species of tree (Populus tremula, Betula pendula and B. pubescens. Regeneration involving Salix caprea proceeded following the conservatorial protection of the degenerate stands in a reserve and later in Białowieża National Park. The emergence and development of the population of Salix caprea proceeded following the invasion of spruce, which coincided with the period of enhanced animal pressure on broadleaved forest. Salix caprea filled all the gaps in the tree stand arising as a result of the destruction of trees and undergrowth by herbivores (in the years 1892-1915. It also appeared en masse on old, at that time unforested, clearings and felled areas. In these places, Salix caprea created very abundant populations, with particular trees being in good condition, with a habit typical of forest trees and attaining considerable heights. The majority of trees were 50-60 years old at the time of death, although individuals reached 74 years of age. The process of extinction of the sallow population - observed over 19 years on permanent plots and fixed trees - proceeded very quickly, especially in the first decade of observation. It led to the almost complete disappearance of sallow for the forest communities of Białowieża National Park. The death of individual trees is preceded by impairment of their health and reduced annual increments in the 4-9 last years of life. The extinction of the population is associated with the loss of its primary phenological differentiation and with a change in the sex structure of the population from a prevalence of female trees to a near even distribution of the two sexes. The development of the populations of permanent constituents of the forest

  13. Bird species richness and abundance in different forest types at ...

    African Journals Online (AJOL)

    The avifauna of differently disturbed forest types of Kakamega Afrotropical forest were compared from December 2004 to May 2005. A total of 11 220 individual birds comprising of 129 bird species were recorded. Significant differences in abundance of birds among Psidium guajava, Bischoffia javanica, mixed indigenous, ...

  14. Sustaining forest landscape connectivity under different land cover change scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, L.; Rodriguez-Freire, M.; Mateo-Sanchez, M. C.; Estreguil, C.; Saura, S.

    2012-11-01

    Managing forest landscapes to sustain functional connectivity is considered one of the key strategies to counteract the negative effects of climate and human-induced changes in forest species pools. With this objective, we evaluated whether a robust network of forest connecting elements can be identified so that it remains efficient when facing different types of potential land cover changes that may affect forest habitat networks and ecological fluxes. For this purpose we considered changes both in the forested areas and in the non-forest intervening landscape matrix. We combined some of the most recent developments in graph theory with models of land cover permeability and least-cost analysis through the forest landscape. We focused on a case of study covering the habitat of a forest dwelling bird (nuthatch, Sitta europaea) in the region of Galicia (NW Spain). Seven land-use change scenarios were analysed for their effects on connecting forest elements (patches and links): one was the simplest case in which the landscape is represented as a binary forest/non-forest pattern (and where matrix heterogeneity is disregarded), four scenarios in which forest lands were converted to other cover types (to scrubland due to wildfires, to extensive and intensive agriculture, and to urban areas), and two scenarios that only involved changes in the non-forested matrix (re naturalization and intensification). Our results show that while the network of connecting elements for the species was very robust to the conversion of the forest habitat patches to different cover types, the different change scenarios in the landscape matrix could more significantly weaken its long-term validity and effectiveness. This is particularly the case when most of the key connectivity providers for the nuthatch are located outside the protected areas or public forests in Galicia, where biodiversity-friendly measures might be more easily implemented. We discuss how the methodology can be applied to

  15. The nitrogen budget for different forest types in the central Congo Basin

    Science.gov (United States)

    Bauters, Marijn; Verbeeck, Hans; Cizungu, Landry; Boeckx, Pascal

    2016-04-01

    Characterization of fundamental processes in different forest types is vital to understand the interaction of forests with their changing environment. Recent data analyses, as well as modeling activities have shown that the CO2 uptake by terrestrial ecosystems strongly depends on site fertility, i.e. nutrient availability. Accurate projections of future net forest growth and terrestrial CO2 uptake thus necessitate an improved understanding on nutrient cycles and how these are coupled to the carbon (C) cycle in forests. This holds especially for tropical forests, since they represent about 40-50% of the total carbon that is stored in terrestrial vegetation, with the Amazon basin and the Congo basin being the largest two contiguous blocks. However, due to political instability and reduced accessibility in the central Africa region, there is a strong bias in scientific research towards the Amazon basin. Consequently, central African forests are poorly characterized and their role in global change interactions shows distinct knowledge gaps, which is important bottleneck for all efforts to further optimize Earth system models explicitly including this region. Research in the Congo Basin region should combine assessments of both carbon stocks and the underlying nutrient cycles which directly impact the forest productivity. We set up a monitoring network for carbon stocks and nitrogen fluxes in four different forest types in the Congo Basin, which is now operative. With the preliminary data, we can get a glimpse of the differences in nitrogen budget and biogeochemistry of African mixed lowland rainforest, monodominant lowland forest, mixed montane forest and eucalypt plantations.

  16. Vegetation diversity of the Scots pine stands in different forest sites in the Turawa Forest District

    OpenAIRE

    Stefańska-Krzaczek, Ewa; Pech, Paweł

    2014-01-01

    The utility of phytocenotic indices in the diagnosis and classification of forest sites might be limited because of vegetation degeneration in managed forests. However, even in secondary communities it may be possible to determine indicator species, although these may differ from typical and well known plant indicators. The aim of this work was to assess the vegetation diversity of Scots pine stands in representative forest site types along a moisture and fertility gradient. In total ...

  17. The Effects of Different Forest Loggings on Forest Birds Community Composition in Shastkolateh Forest, Gorgan

    Directory of Open Access Journals (Sweden)

    F. Parsaei

    2014-06-01

    Full Text Available The species composition of a bird community is dependent upon many factors. Within any geographic area, vegetation structure may be the most important factor. The changes of bird community composition based on foraging behavior in relation to 3 different harvesting systems, including strip cutting, group selection logging, and single tree selection logging, was evaluated in a virgin area in this study. Birds and environmental variables were detected within 103 circle sampling plots with 25m radius. Based on the results, 4 groups of birds were observed in treatments based on the foraging behavior. Group 1 was ground foragers, group 2 consisted of foliage gleaning, group 3 included flycatchers, and group 4 represented bark foraging. The first group had the highest abundance in the strip treatment. The second group in group selection treatment, and the third and fourth groups had the highest abundance in the virgin area and then, in single tree selection treatment. The first group showed the highest correlation with shrub and herb or grass layer, stone cover and the number of trees 10-20m in height. The second, third and fourth groups showed the highest correlation with the number of trees>20m in height, basal areas, dead trees number, and the number of fagus trees. The results showed the single cutting treatment had a relatively minor effect on mature forest bird species and were more appropriate and sustainable methods to reduce the negative effects of forest harvesting on the birds.

  18. Conducting tests for statistically significant differences using forest inventory data

    Science.gov (United States)

    James A. Westfall; Scott A. Pugh; John W. Coulston

    2013-01-01

    Many forest inventory and monitoring programs are based on a sample of ground plots from which estimates of forest resources are derived. In addition to evaluating metrics such as number of trees or amount of cubic wood volume, it is often desirable to make comparisons between resource attributes. To properly conduct statistical tests for differences, it is imperative...

  19. Impacts of different land management histories on forest change.

    Science.gov (United States)

    Collins, Brandon M; Fry, Danny L; Lydersen, Jamie M; Everett, Richard; Stephens, Scott L

    2017-12-01

    Many western North American forest types have experienced considerable changes in ecosystem structure, composition, and function as a result of both fire exclusion and timber harvesting. These two influences co-occurred over a large portion of dry forests, making it difficult to know the strength of either one on its own or the potential for an interaction between the two. In this study, we used contemporary remeasurements of a systematic historical forest inventory to investigate forest change in the Sierra Nevada. The historical data opportunistically spanned a significant land management agency boundary, which protected part of the inventory area from timber harvesting. This allowed for a robust comparison of forest change between logged and unlogged areas. In addition, we assessed the effects of recent management activities aimed at forest restoration relative to the same areas historically, and to other areas without recent management. Based on analyses of 22,007 trees (historical, 9,573; contemporary, 12,434), live basal area and tree density significantly increased from 1911 to the early 2000s in both logged and unlogged areas. Both shrub cover and the proportion of live basal area occupied by pine species declined from 1911 to the early 2000s in both areas, but statistical significance was inconsistent. The most notable difference between logged and unlogged areas was in the density of large trees, which declined significantly in logged areas, but was unchanged in unlogged areas. Recent management activities had a varied impact on the forest structure and composition variables analyzed. In general, areas with no recent management activities experienced the greatest change from 1911 to the early 2000s. If approximating historical forest conditions is a land management goal the documented changes in forest structure and composition from 1911 to the early 2000s indicate that active restoration, including fire use and mechanical thinning, is needed in many

  20. Difference in Viewpoints of Coastal Forests in the Urban Areas Adjacent to Coastal Forests in Noshiro and Honjo, Akita

    OpenAIRE

    ITO, Hiromu

    2010-01-01

    Coastal forests, which are an important characteristics of many areas, are regarded differently in different areas. It is said this is due to the ease of recognition. This study aims to clarify the differences in the viewpoints of coastal forests between the urban areas of Noshiro and Honjo, Akita Prefecture. Although the coastal forests have existed since the Edo period, the method of urbanization and the way of the viewpoints formation about coastal forests have been different in each area....

  1. Analysis of periods with strong and coherent CO2 advection over a forested hill

    Czech Academy of Sciences Publication Activity Database

    Zeri, M.; Rebmann, C.; Feigenwinter, Ch.; Sedlák, Pavel

    2010-01-01

    Roč. 150, č. 5 (2010), s. 674-683 ISSN 0168-1923 R&D Projects: GA AV ČR IAA300420803 Institutional research plan: CEZ:AV0Z30420517 Keywords : Forest ecosystems * Advection * Net ecosystem exchange * Carbon balance * ADVEX Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.228, year: 2010

  2. DETERMINATION OF DIFFERENT STAKEHOLDER’S THOUGHT REGARDING THE FOREST RESOURCES AND FOREST RESOURCES SUSTAINABLE MANAGEMENT: A Case Study in Maçka State Forest Enterprise

    Directory of Open Access Journals (Sweden)

    Atakan Öztürk

    2005-04-01

    Full Text Available This study aimed to determine thoughts and views of stakeholders regarding the forest resources and management in Turkish Forestry. Maçka State Forest Enterprise under Trabzon Forest Regional Directorate was chosen as research area. Six different groups involving urban, rural, managerial, industrial, and recreational stakeholders as well as non-governmental organizations were determined. Interview and public survey methods and Khi-square test were used to attain the aim of the study. The main results were that the forest enterprise was perceived as the rich one with regard to forest existence and, it was put forward pessimistic though for forest future in the forest enterprise and, non-wood forest values were seen more important than the wood values by the stakeholders. The results of the study taken into account in forest resource planning would provide a contribution to sustainable forest resources management for the Maçka State Forest Enterprise.

  3. Foliar fungal communities strongly differ between habitat patches in a landscape mosaic

    Directory of Open Access Journals (Sweden)

    Thomas Fort

    2016-11-01

    Full Text Available Background Dispersal events between habitat patches in a landscape mosaic can structure ecological communities and influence the functioning of agrosystems. Here we investigated whether short-distance dispersal events between vineyard and forest patches shape foliar fungal communities. We hypothesized that these communities homogenize between habitats over the course of the growing season, particularly along habitat edges, because of aerial dispersal of spores. Methods We monitored the richness and composition of foliar and airborne fungal communities over the season, along transects perpendicular to edges between vineyard and forest patches, using Illumina sequencing of the Internal Transcribed Spacer 2 (ITS2 region. Results In contrast to our expectation, foliar fungal communities in vineyards and forest patches increasingly differentiate over the growing season, even along habitat edges. Moreover, the richness of foliar fungal communities in grapevine drastically decreased over the growing season, in contrast to that of forest trees. The composition of airborne communities did not differ between habitats. The composition of oak foliar fungal communities change between forest edge and centre. Discussion These results suggest that dispersal events between habitat patches are not major drivers of foliar fungal communities at the landscape scale. Selective pressures exerted in each habitat by the host plant, the microclimate and the agricultural practices play a greater role, and might account for the differentiation of foliar fugal communities between habitats.

  4. Nutrient limitation in tropical secondary forests following different management practices.

    Science.gov (United States)

    Nagy, R Chelsea; Rastetter, Edward B; Neill, Christopher; Porder, Stephen

    2017-04-01

    Secondary forests now make up more than one-half of all tropical forests, and constraints on their biomass accumulation will influence the strength of the terrestrial carbon (C) sink in the coming decades. However the variance in secondary tropical forest biomass for a given stand age and climate is high and our understanding of why is limited. We constructed a model of terrestrial C, nitrogen (N), and phosphorus (P) cycling to examine the influence of disturbance and management practices on nutrient limitation and biomass recovery in secondary tropical forests. The model predicted that N limited the rate of forest recovery in the first few decades following harvest, but that this limitation switched to P approximately 30-40 yr after abandonment, consistent with field data on N and P cycling from secondary tropical forest chronosequences. Simulated biomass recovery agreed well with field data of biomass accumulation following harvest (R 2  = 0.80). Model results showed that if all biomass remained on site following a severe disturbance such as blowdown, regrowth approached pre-disturbance biomass in 80-90 yr, and recovery was faster following smaller disturbances such as selective logging. Field data from regrowth on abandoned pastures were consistent with simulated losses of nutrients in soil organic matter, particularly P. Following any forest disturbance that involved the removal of nutrients (i.e., except blowdown), forest regrowth produced reduced biomass relative to the initial state as a result of nutrient loss through harvest, leaching and/or sequestration by secondary minerals. Differences in nutrient availability accounted for 49-94% of the variance in secondary forest biomass C at a given stand age. Management lessons from this study are the importance of strategies that help retain nutrients on site, recognizing the role of coarse woody debris in immobilization and subsequent release of nutrients, and the potential for nutrient additions to enhance

  5. Distribution of Cs-137 in the forest litter taken from different forest types of Latvia

    International Nuclear Information System (INIS)

    Riekstina, D.; Mednis, I.; Veveris, O.; Zalitis, P.

    1995-01-01

    Full text: The radioactive pollution of the environment from the Chernobyl catastrophe has only slightly touched Latvian territory. Nevertheless it has changed the usual radioactive background. After the decay of the short and medium - lived radionuclides, the radioactivity background due to that is mainly created by radionuclide Cs-137. Measurements of this radionuclide in soil, moss and mushrooms show rather different results in various areas of Latvia. That is explained by various meteorological conditions in Latvia at the time of the catastrophe. For our study of the radioactive pollution we chose forest litter. This choice was made because the greatest accumulation of the products of radioactive fission from atmosphere is discernible in forest. We chose two areas where we could expect different levels of radioactive pollution: Rucava and Taurene. Samples were gathered at various depths (5 levels: from 0 to 25 cm) and under various tree species (pine, spruce, birch), as well as in forest openings. Samples were dried and then homogenized in ''runner mill''. Radioactivity was determined using gamma spectrometer with 70 cm 3 Ge detector. Measurements were made shielded by lead, thus minimizing background radioactivity. Results are shown in a table. The statistical error measurements does not exceed 20% of Taurene and 10% Rucava samples. Cs-137 content in soils of Latvia is 5.4-19.6 Bk/kg, which is several times lower than that found in forest litter. We can conclude that determine radioactive pollution forest litter should be used, preferably that found under spruce trees

  6. Caraboidea distribution in different forest stands Chrea National Park, Algeria

    International Nuclear Information System (INIS)

    Belhadid, Z.; Gahdeb, C.; Ghalem, M.; Haddar, L.; Boughrara, H.

    2013-01-01

    T he distribution of the ground beetles in different forests of the national park of Chrea (Blida, Algerie) using pitfall traps was investigated . A total of 29 species of Caraboidea , in seven families, were collected, with the chestnut and holm oak forests were the most diversified sites with 16 species each. The family Pterostichidae is the richest with nine specie s. The distribution of the species of Caraboidea was influenced by the site altitude, since the site vegetation composition and fluctuations are dependent on several ecological parameters. (author)

  7. [Effects of different type urban forest plantations on soil fertility].

    Science.gov (United States)

    Sun, Hui-zhen; Chen, Ming-yue; Cai, Chun-ju; Zhu, Ning

    2009-12-01

    Aimed to study the effects of different urban forest plantations on soil fertility, soil samples were collected from eight mono-cultured plantations (Larix gmelinii, Pinus sylvestris var. mongolica, Pinus tabulaeformis var. mukdensis, Phellodendron amurense, Juglans mandshurica, Fraxinus mandshurica, Betula platyphylla, and Quercus mongolica) and one mixed plantation (P. sylvestris var. mongolica + F. mandshurica + Picea koraiensis + P. amurense + B. platyphylla) established in Northeast Forestry University's Urban Forestry Demonstration Research Base in the 1950s, with two sites of neighboring farmland and abandoned farmland as the control. The soils in broadleaved forest plantations except Q. mongolica were near neutral, those in mixed plantation, L. gmelinii, P. sylvestris var. mongolica, and P. tabulaeformis var. mukdensis were slightly acidic, and that in Q. mongolica was acidic. The contents of soil organic matter, total N and P, available P and K, and hydrolysable N tended to decrease with soil depth. There existed significant differences in the chemical indices of the same soil layers among different plantations. The soil fertility was decreased in the order of F. mandshurica > P. amurense > mixed plantation > J. mandshurica > B. platyphylla > abandoned farmland > farmland > P. sylvestris var. mongolica > L. gmelinii > Q. mongolica > P. tabulaeformis var. mukdensis, suggesting that the soil fertility in broadleaved forest plantations except Q. mongolica and in mixed plantation increased, while that in needle-leaved forest plantations tended to decrease.

  8. Sampling Ozone Exposure of Canadian Forests at Different Scales: Some Case Studies

    Directory of Open Access Journals (Sweden)

    R.M. Cox

    2001-01-01

    Full Text Available The use of passive samplers in extensive monitoring, such as that used in national forest health monitoring plots, indicates that these devices are able to determine both spatial and temporal differences in ozone exposure of the plots. This allows for categorisation of the plots and the potential for cause-effect analysis of certain forest health responses. Forest exposure along a gradient of air pollution deposition demonstrates large variation in accumulated exposures. The efficacy of using passive samplers for in situ monitoring of forest canopy exposure was also demonstrated. The sampler data produced weak relationships with ozone values from the nearest �continuous� monitor, even though data from colocated samplers showed strong relationships. This spatial variation and the apparent effect of elevation on ozone exposure demonstrate the importance of topography and tree canopy characteristics in plant exposure on a regional scale. In addition, passive sampling may identify the effects of local pollutant gases, such as NO, which may scavenge ozone locally only to increase the production of this secondary pollutant downwind, as atmospheric reactions redress the equilibrium between concentrations of this precursor and those of the generated ozone. The use of passive samplers at the stand level is able to resolve vertical profiles within the stand and edge effects that are important in exposure of understorey and ground flora. Recent case studies using passive samplers to determine forest exposure to ozone indicate a great potential for the development of spatial models on a regional, landscape, and stand level scale.

  9. Evaporation and transpiration differences among successional stages of Tropical Dry Forest, Santa Rosa National Park, Costa Rica

    Science.gov (United States)

    Jiménez-Rodríguez, César D.; Calvo-Alvarado, Julio

    2016-04-01

    Seasonal environments in the tropics show strong responses to changes in precipitation regimes. The monthly water availability is the main trigger for ecological responses as flowering, fructification, leaf sprouting and senescence. Among these environments, the tropical dry forests (TDF) depends directly on the soil water availability, defining the forest growing season despite the forest characteristics. However, within the same ecosystem is possible to find differences in the water fluxes due to forest age. The TDF located in Santa Rosa National Park (SRNP) in Costa Rica; shows a particular matrix of secondary forest patches varying in age, structure, and species composition allowing us to evaluate the water fluxes differences among successional stages of TDF. Three permanent plots of 1000.0 m2 were selected from the Tropi-Dry project. Each plot characterized a specific successional stage of this ecosystem varying in forest structure and age. Every location was equipped to measure the hourly soil water content and forest growth, while the meteorological conditions were collected by the meteorological station of the national park. The data was collected from December 2005 to June 2009 however, due to data gaps and quality control the data analysis includes only the hydrological years between 2006 and 2009. The soil water content was measured at three depths in each plot (10, 30 and 40 cm) to determine the real evapotranspiration from the forest. The precipitation along these three years shows strong variations registering 326.5 mm-1yr-1 in the first year up to 3004.0 mm-1yr-1 during the last year, these strong changes are influenced by the ENOS phenomena in the region. Regardless the precipitation amounts the evapotranspiration do not differ strongly on a yearly basis, were 726.7 mm-1yr-1, 675.1 mm-1yr-1 and 751.6 mm-1yr-1 were exported to the atmosphere by the early, intermediate and late stages of TDF secondary forest. The yearly strong differences in

  10. Assessment of Different Remote Sensing Data for Forest Structural Attributes Estimation in the Hyrcanian forests

    Energy Technology Data Exchange (ETDEWEB)

    Nourian, N.; Shataee-Joibary, S.; Mohammadi, J.

    2016-07-01

    Aim of the study: The objective of the study was the comparative assessment of various spatial resolutions of optical satellite imagery including Landsat-TM, ASTER, and Quickbird data to estimate the forest structure attributes of Hyrcanian forests, Golestan province, northernIran. Material and methods: The 112 square plots with area of0.09 ha were measured using a random cluster sampling method and then stand volume, basal area, and tree stem density were computed using measured data. After geometric and atmospheric corrections of images, the spectral attributes from original and different synthetic bands were extracted for modelling. The statistical modelling was performed using CART algorithm. Performance assessment of models was examined using the unused validation plots by RMSE and bias measures. Main Results: The results showed that model of Quickbird data for stand volume, basal area, and tree stem density had a better performance compared to ASTER and TM data. However, estimations by ASTER and TM imagery had slightly similar results for all three parameters. Research highlights: This study exposed that the high-resolution satellite data are more useful for forest structure attributes estimation in the Hyrcanian broadleaves forests compared with medium resolution images without consideration of images costs. However, regarding to be free of the most medium resolution data such as ASTER and TM,ETM+ or OLI images, these data can be used with slightly similar results. (Author)

  11. Different cesium-137 transfers to forest and stream ecosystems.

    Science.gov (United States)

    Sakai, Masaru; Gomi, Takashi; Negishi, Junjiro N; Iwamoto, Aimu; Okada, Kengo

    2016-02-01

    Understanding the mechanisms of (137)Cs movement across different ecosystems is crucial for projecting the environmental impact and management of nuclear contamination events. Here, we report differential movement of (137)Cs in adjacent forest and stream ecosystems. The food webs of the forest and stream ecosystems in our study were similar, in that they were both dominated by detrital-based food webs and the basal energy source was terrestrial litter. However, the concentration of (137)Cs in stream litter was significantly lower than in forest litter, the result of (137)Cs leaching from litter in stream water. The difference in (137)Cs concentrations between the two types of litter was reflected in the (137)Cs concentrations in the animal community. While the importance of (137)Cs fallout and the associated transfer to food webs has been well studied, research has been primarily limited to cases in a single ecosystem. Our results indicate that there are differences in the flow of (137)Cs through terrestrial and aquatic ecosystems, and that (137)Cs concentrations are reduced in both basal food resources and higher trophic animals in aquatic systems, where primary production is subsidized by a neighboring terrestrial ecosystem. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. INVESTIGATION OF POLARIZATION PHASE DIFFERENCE RELATED TO FOREST FIELDS CHARACTERIZATIONS

    Directory of Open Access Journals (Sweden)

    M. Majidi

    2013-09-01

    Full Text Available The information content of Synthetic Aperture Radar (SAR data significantly included in the radiometric polarization channels, hence polarimetric SAR data should be analyzed in relation with target structure. The importance of the phase difference between two co-polarized scattered signals due to the possible association between the biophysical parameters and the measured Polarization Phase Difference (PPD statistics of the backscattered signal recorded components has been recognized in geophysical remote sensing. This paper examines two Radarsat-2 images statistics of the phase difference to describe the feasibility of relationship with the physical properties of scattering targets and tries to understand relevance of PPD statistics with various types of forest fields. As well as variation of incidence angle due to affecting on PPD statistics is investigated. The experimental forest pieces that are used in this research are characterized white pine (Pinus strobus L., red pine (Pinus resinosa Ait., jack pine (Pinus banksiana Lamb., white spruce (Picea glauca (Moench Voss, black spruce (Picea mariana (Mill B.S.P., poplar (Populus L., red oak (Quercus rubra L. , aspen and ground vegetation. The experimental results show that despite of biophysical parameters have a wide diversity, PPD statistics are almost the same. Forest fields distributions as distributed targets have close to zero means regardless of the incidence angle. Also, The PPD distribution are function of both target and sensor parameters, but for more appropriate examination related to PPD statistics the observations should made in the leaf-off season or in bands with lower frequencies.

  13. Earthworms as indicators for different forest management types and human disturbance in Ilam oak forest, Iran

    Directory of Open Access Journals (Sweden)

    Heydari Mehdi

    2014-09-01

    Full Text Available There has been observed widespread destruction of natural ecosystems around the world due to population growth, land use change and clear cutting which have affected soil properties. Different management strategies have been so far implemented to reduce this crisis in various regions of the world, such as e.g. short-term and long-term conservation management in the Zagros region. However, any management approach should be evaluated with appropriate measures to determine how managed areas respond. The main objective of the present study was to evaluate the potential of earthworms as an indicator for different forest management strategies and human disturbances in Zagros oak (Quercus persica Jaub. and Spach forest. The sites selected included undisturbed one as the control (Un, the sites under five-year conservation management (FCM and twenty-year conservation management (TCM as well as the disturbed site (D. The results of principal component analysis (PCA showed that different regions separated into the components: PC1 and PC2. Un and TCM sites gathered together and represented higher values of the factors such as pH, Kavailable, OC, clay content, Pavailable, CEC, overstory tree canopy, Ntot, biomass and abundance of earthworms. The positive direction of the first axis reflected a gradient of EC, BD and Ptot. According to the logistic model, NH4-N and EC played the most important role in earthworm presence and absence in Zagros forest ecosystem. Earthworm abundance and biomass could be a good indicator to evaluate different forest management strategies in the study area.

  14. Assemblages of carabid beetles (Coleoptera, Carabidae in humid forest habitats of different stages of succession in the Puszcza Knyszyńska Forest (northeastern Poland

    Directory of Open Access Journals (Sweden)

    Adam Kwiatkowski

    2011-05-01

    Full Text Available During a period of three years (2006–2008 the carabid fauna in wet and humid forest habitats of different stages of succession was studied at the Puszcza Knyszynska (north-east part of Poland. The aim of this study was to determine how the assemblages of the carabid fauna change in relation to the ongoing process of succession. Using pitfall traps, 24 plots were sampled. The plots were located in stands of different age, from two year old plantations to more than 100 year old forests. Additionally, the stands were ordered in three moisture classes (wet, humid and very humid and two classes of soil richness. As indicators for change in the carabid fauna in relation to age of the stands Mean Individual Biomass (MIB, species diversity and share of forest species were used. By applying multivariate statistics the relation of the different habitat characteristics to changes in the carabid fauna was examined. During the study 8903 individuals belonging to 57 species were collected. Pterostichus niger represented 28% of the total catches and therefore the most common species. Another common species, Pterostichus melanarius, contributed to 13% of the total catch. This species was caught at every plot, even in the old forests. In contrast to the results obtained by Szyszko (1990 for fresh and dry pine stands, in this study the relation of MIB with the age of forest was not significant. Although the number of species was rather constant, the number of individuals belonging to the group of forest species significantly increased with the ageing of the forest. The multivariate analysis showed a relationship with ageing of the stands and soil richness rather than with moisture and size of the forest. According to the present paper, clear cuttings in wet and humid habitats do not cause a strong degradation of the carabid fauna.

  15. Long-term effects of different forest regeneration methods on mature forest birds

    Science.gov (United States)

    Roger W. Perry; Julianna M.A. Jenkins; Ronald E. Thill; Frank R. Thompson

    2018-01-01

    Changes in forest structure that result from silviculture, including timber harvest, can positively or negatively affect bird species that use forests. Because many bird species associated with mature forests are facing population declines, managers need to know how timber harvesting affects species of birds that rely on mature trees or forests for breeding, foraging,...

  16. Strong ion difference in urine: new perspectives in acid-base assessment.

    OpenAIRE

    Gattinoni, L.; Carlesso, E.; Cadringher, P.; Caironi, P.

    2006-01-01

    The plasmatic strong ion difference (SID) is the difference between positively and negatively charged strong ions. At pH 7.4, temperature 37°C and partial carbon dioxide tension 40 mmHg, the ideal value of SID is 42 mEq/l. The buffer base is the sum of negatively charged weak acids ([HCO3 -], [A-], [H2PO4 -]) and its normal value is 42 mEq/l. According to the law of electroneutrality, the amount of positive and negative charges must be equal, and therefore the SID value is equal to the buffer...

  17. Drone based estimation of actual evapotranspiration over different forest types

    Science.gov (United States)

    Marzahn, Philip; Gampe, David; Castro, Saulo; Vega-Araya, Mauricio; Sanchez-Azofeifa, Arturo; Ludwig, Ralf

    2017-04-01

    Actual evapotranspiration (Eta) plays an important role in surface-atmosphere interactions. Traditionally, Eta is measured by means of lysimeters, eddy-covariance systems or fiber optics, providing estimates which are spatially restricted to a footprint from a few square meters up to several hectares . In the past, several methods have been developed to derive Eta by means of multi-spectral remote sensing data using thermal and VIS/NIR satellite imagery of the land surface. As such approaches do have their justification on coarser scales, they do not provide Eta information on the fine resolution plant level over large areas which is mandatory for the detection of water stress or tree mortality. In this study, we present a comparison of a drone based assessment of Eta with eddy-covariance measurements over two different forest types - a deciduous forest in Alberta, Canada and a tropical dry forest in Costa Rica. Drone based estimates of Eta were calculated applying the Triangle-Method proposed by Jiang and Islam (1999). The Triangle-Method estimates actual evapotranspiration (Eta) by means of the Normalized Difference Vegetation Index (NDVI) and land surface temperature (LST) provided by two camera systems (MicaSense RedEdge, FLIR TAU2 640) flown simultaneously on an octocopter. . Results indicate a high transferability of the original approach from Jiang and Islam (1999) developed for coarse to medium resolution satellite imagery tothe high resolution drone data, leading to a deviation in Eta estimates of 10% compared to the eddy-covariance measurements. In addition, the spatial footprint of the eddy-covariance measurement can be detected with this approach, by showing the spatial heterogeneities of Eta due to the spatial distribution of different trees and understory vegetation.

  18. High heterogeneity in soil composition and quality in different mangrove forests of Venezuela.

    Science.gov (United States)

    Otero, X L; Méndez, A; Nóbrega, G N; Ferreira, T O; Meléndez, W; Macías, F

    2017-09-18

    Mangrove forests play an important role in biogeochemical cycles of metals, nutrients, and C in coastal ecosystems. However, these functions could be strongly affected by the mangrove soil degradation. In this study, we performed an intensive sampling characterizing mangrove soils under different types of environment (lagoon/gulf) and vegetation (Rhizophora/Avicennia/dead mangrove) in the Venezuelan coast. To better understand the spatial heterogeneity of the composition and characteristics of the soils, a wide range of the soil attributes were analyzed. In general, the soils were anoxic (Eh mangroves presented a low Fe Pyrite content due to a limitation in the Fe oxyhydroxide contents, especially in soils with higher organic C content (TOC > 15%). Finally, the dead mangrove showed significantly lower amounts of TOC and fibers (in comparison to the well-preserved mangrove forest), which indicates that the C pools in mangrove soils are highly sensitive also to natural impact, such as ENSO.

  19. Forests

    Science.gov (United States)

    Louis R. Iverson; Mark W. Schwartz

    1994-01-01

    Originally diminished by development, forests are coming back: forest biomass is accumulating. Forests are repositories for many threatened species. Even with increased standing timber, however, biodiversity is threatened by increased forest fragmentation and by exotic species.

  20. Tropical Montane Cloud Forests: Hydrometeorological variability in three neighbouring catchments with different forest cover

    Science.gov (United States)

    Ramírez, Beatriz H.; Teuling, Adriaan J.; Ganzeveld, Laurens; Hegger, Zita; Leemans, Rik

    2017-09-01

    Mountain areas are characterized by a large heterogeneity in hydrological and meteorological conditions. This heterogeneity is currently poorly represented by gauging networks and by the coarse scale of global and regional climate and hydrological models. Tropical Montane Cloud Forests (TMCFs) are found in a narrow elevation range and are characterized by persistent fog. Their water balance depends on local and upwind temperatures and moisture, therefore, changes in these parameters will alter TMCF hydrology. Until recently the hydrological functioning of TMCFs was mainly studied in coastal regions, while continental TMCFs were largely ignored. This study contributes to fill this gap by focusing on a TMCF which is located on the northern eastern Andes at an elevation of 1550-2300 m asl, in the Orinoco river basin highlands. In this study, we describe the spatial and seasonal meteorological variability, analyse the corresponding catchment hydrological response to different land cover, and perform a sensitivity analysis on uncertainties related to rainfall interpolation, catchment area estimation and streamflow measurements. Hydro-meteorological measurements, including hourly solar radiation, temperature, relative humidity, wind speed, precipitation, soil moisture and streamflow, were collected from June 2013 to May 2014 at three gauged neighbouring catchments with contrasting TMCF/grassland cover and less than 250 m elevation difference. We found wetter and less seasonally contrasting conditions at higher elevations, indicating a positive relation between elevation and fog or rainfall persistence. This pattern is similar to that of other eastern Andean TMCFs, however, the study site had higher wet season rainfall and lower dry season rainfall suggesting that upwind contrasts in land cover and moisture can influence the meteorological conditions at eastern Andean TMCFs. Contrasting streamflow dynamics between the studied catchments reflect the overall system response

  1. [Soil microbial functional diversity of different altitude Pinus koraiensis forests].

    Science.gov (United States)

    Han, Dong-xue; Wang, Ning; Wang, Nan-nan; Sun, Xue; Feng, Fu-juan

    2015-12-01

    In order to comprehensively understand the soil microbial carbon utilization characteristics of Pinus koraiensis forests, we took the topsoil (0-5 cm and 5-10 cm) along the 700-1100 m altitude in Changbai Mountains and analyzed the vertical distributed characteristics and variation of microbial functional diversity along the elevation gradient by Biolog microplate method. The results showed that there were significant differences in functional diversity of microbial communities at different elevations. AWCD increased with the extension of incubation time and AWCD at the same soil depth gradually decreased along with increasing altitude; Shannon, Simpson and McIntosh diversity index also showed the same trend with AWCD and three different diversity indices were significantly different along the elevation gradient; Species diversity and functional diversity showed the same variation. The utilization intensities of six categories carbon sources had differences while amino acids were constantly the most dominant carbon source. Principal component analysis (PCA) identified that soil microbial carbon utilization at different altitudes had obvious spatial differentiation, as reflected in the use of carbohydrates, amino acids and carboxylic acids. In addition, the cluster of the microbial diversity indexes and AWCD values of different altitudes showed that the composition of vegetation had a significant impact on soil microbial composition and functional activity.

  2. The agony of choice: different empirical mortality models lead to sharply different future forest dynamics.

    Science.gov (United States)

    Bircher, Nicolas; Cailleret, Maxime; Bugmann, Harald

    2015-07-01

    Dynamic models are pivotal for projecting forest dynamics in a changing climate, from the local to the global scale. They encapsulate the processes of tree population dynamics with varying resolution. Yet, almost invariably, tree mortality is modeled based on simple, theoretical assumptions that lack a physiological and/or empirical basis. Although this has been widely criticized and a growing number of empirically derived alternatives are available, they have not been tested systematically in models of forest dynamics. We implemented an inventory-based and a tree-ring-based mortality routine in the forest gap model ForClim v3.0. We combined these routines with a stochastic and a deterministic approach for the determination of tree status (alive vs. dead). We tested the four new model versions for two Norway spruce forests in the Swiss Alps, one of which was managed (inventory time series spanning 72 years) and the other was unmanaged (41 years). Furthermore, we ran long-term simulations (-400 years) into the future under three climate scenarios to test model behavior under changing environmental conditions. The tests against inventory data showed an excellent match of simulated basal area and stem numbers at the managed site and a fair agreement at the unmanaged site for three of the four empirical mortality models, thus rendering the choice of one particular model difficult. However, long-term simulations under current climate revealed very different behavior of the mortality models in terms of simulated changes of basal area and stem numbers, both in timing and magnitude, thus indicating high sensitivity of simulated forest dynamics to assumptions on tree mortality. Our results underpin the potential of using empirical mortality routines in forest gap models. However, further tests are needed that span other climatic conditions and mixed forests. Short-term simulations to benchmark model behavior against empirical data are insufficient; long-term tests are

  3. Evaluating spatial-temporal dynamics of net primary productivity of different forest types in northeastern China based on improved FORCCHN.

    Directory of Open Access Journals (Sweden)

    Junfang Zhao

    Full Text Available An improved individual-based forest ecosystem carbon budget model for China (FORCCHN was applied to investigate the spatial-temporal dynamics of net primary productivity of different forest types in northeastern China. In this study, the forests of northeastern China were categorized into four ecological types according to their habitats and generic characteristics (evergreen broadleaf forest, deciduous broadleaf forest, evergreen needleleaf forest and deciduous needleleaf forest. The results showed that distribution and change of forest NPP in northeastern China were related to the different forest types. From 1981 to 2002, among the forest types in northeastern China, per unit area NPP and total NPP of deciduous broadleaf forest were the highest, with the values of 729.4 gC/(m(2•yr and 106.0 TgC/yr, respectively, followed by mixed broadleaf- needleleaf forest, deciduous needleleaf forest and evergreen needleleaf forest. From 1981 to 2002, per unit area NPP and total NPP of different forest types in northeastern China exhibited significant trends of interannual increase, and rapid increase was found between the 1980s and 1990s. The contribution of the different forest type's NPP to total NPP in northeastern China was clearly different. The greatest was deciduous broadleaf forest, followed by mixed broadleaf- needleleaf forest and deciduous needleleaf forest. The smallest was evergreen needleleaf forest. Spatial difference in NPP between different forest types was remarkable. High NPP values of deciduous needleleaf forest, mixed broadleaf- needleleaf forest and deciduous broadleaf forest were found in the Daxing'anling region, the southeastern of Xiaoxing'anling and Jilin province, and the Changbai Mountain, respectively. However, no regional differences were found for evergreen needleleaf NPP. This study provided not only an estimation NPP of different forest types in northeastern China but also a useful methodology for estimating forest

  4. Modelling moose–forest interactions under different predation scenarios at Isle Royale National Park, USA

    Science.gov (United States)

    DeJager, Nathan R.; Rohweder, Jason; Miranda, Brian R.; Sturtevant, Brian R.; Fox, Timothy J.; Romanski, Mark C.

    2017-01-01

    Loss of top predators may contribute to high ungulate population densities and chronic over-browsing of forest ecosystems. However, spatial and temporal variability in the strength of interactions between predators and ungulates occurs over scales that are much shorter than the scales over which forest communities change, making it difficult to characterize trophic cascades in forest ecosystems. We applied the LANDIS-II forest succession model and a recently developed ungulate browsing extension to model how the moose population could interact with the forest ecosystem of Isle Royale National Park, USA, under three different wolf predation scenarios. We contrasted a 100-yr future without wolves (no predation) with two predation scenarios (weak, long-term average predation rates and strong, higher than average rates). Increasing predation rates led to lower peak moose population densities, lower biomass removal rates, and higher estimates of forage availability and landscape carrying capacity, especially during the first 40 yr of simulations. Thereafter, moose population density was similar for all predation scenarios, but available forage biomass and the carrying capacity of the landscape continued to diverge among predation scenarios. Changes in total aboveground live biomass and species composition were most pronounced in the no predation and weak predation scenarios. Consistent with smaller-scale studies, high browsing rates led to reductions in the biomass of heavily browsed Populus tremuloides, Betula papyrifera, and Abies balsamea, and increases in the biomass of unbrowsed Picea glauca and Picea mariana, especially after the simulation year 2050, when existing boreal hardwood stands at Isle Royale are projected to senesce. As a consequence, lower predation rates corresponded with a landscape that progressively shifted toward dominance by Picea glauca and Picea mariana, and lacking available forage biomass. Consistencies with previously documented

  5. Food preferences of winter bird communities in different forest types.

    Directory of Open Access Journals (Sweden)

    Swen C Renner

    Full Text Available Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech during the months of November 2010 to April 2011 in the Schwäbische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity.

  6. Food preferences of winter bird communities in different forest types.

    Science.gov (United States)

    Renner, Swen C; Baur, Sofia; Possler, Astrid; Winkler, Julia; Kalko, Elisabeth K V; Bates, Paul J J; Mello, Marco A R

    2012-01-01

    Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech) during the months of November 2010 to April 2011 in the Schwäbische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity.

  7. Phosphorus cycling in deciduous forest soil differs between stands dominated by ecto- and arbuscular mycorrhizal trees.

    Science.gov (United States)

    Rosling, Anna; Midgley, Meghan G; Cheeke, Tanya; Urbina, Hector; Fransson, Petra; Phillips, Richard P

    2016-02-01

    Although much is known about how trees and their associated microbes influence nitrogen cycling in temperate forest soils, less is known about biotic controls over phosphorus (P) cycling. Given that mycorrhizal fungi are instrumental for P acquisition and that the two dominant associations - arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi - possess different strategies for acquiring P, we hypothesized that P cycling would differ in stands dominated by trees associated with AM vs ECM fungi. We quantified soil solution P, microbial biomass P, and sequentially extracted inorganic and organic P pools from May to November in plots dominated by trees forming either AM or ECM associations in south-central Indiana, USA. Overall, fungal communities in AM and ECM plots were functionally different and soils exhibited fundamental differences in P cycling. Organic forms of P were more available in ECM plots than in AM plots. Yet inorganic P decreased and organic P accumulated over the growing season in both ECM and AM plots, resulting in increasingly P-limited microbial biomass. Collectively, our results suggest that P cycling in hardwood forests is strongly influenced by biotic processes in soil and that these are driven by plant-associated fungal communities. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  8. Soil Organic Carbon assessment on two different forest management

    Science.gov (United States)

    Fernández Minguillón, Alex; Sauras Yera, Teresa; Vallejo Calzada, Ramón

    2017-04-01

    Soil Organic Carbon assessment on two different forest management. A.F. Minguillón1, T. Sauras1, V.R: Vallejo1. 1 Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Universidad de Barcelona, Avenida Diagonal 643, 03080 Barcelona, Spain. Soils from arid and semiarid zones are characterized by a low organic matter content from scarce plant biomass and it has been proposed that these soils have a big capacity to carbon sequestration. According to IPCC ARS WG2 (2014) report and WG3 draft, increase carbon storage in terrestrial ecosystems has been identified such a potential tool for mitigation and adaptation to climate change. In ecological restoration context improve carbon sequestration is considered a management option with multiple benefits (win-win-win). Our work aims to analyze how the recently developed restoration techniques contributed to increases in terrestial ecosystem carbon storage. Two restoration techniques carried out in the last years have been evaluated. The study was carried out in 6 localities in Valencian Community (E Spain) and organic horizons of two different restoration techniques were evaluated; slash brush and thinning Aleppo pine stands. For each technique, carbon stock and its physical and chemical stability has been analysed. Preliminary results point out restoration zones acts as carbon sink due to (1) the relevant necromass input produced by slash brush increases C stock on the topsoil ;(2) Thinning increase carbon accumulation in vegetation.

  9. [Soil quality assessment of forest stand in different plantation esosystems].

    Science.gov (United States)

    Huang, Yu; Wang, Silong; Feng, Zongwei; Gao, Hong; Wang, Qingkui; Hu, Yalin; Yan, Shaokui

    2004-12-01

    After a clear-cutting of the first generation Cunninghamia lanceolata plantation in 1982, three plantation ecosystems, pure Michelia macclurei stand (PMS), pure Chinese-fir stand (PCS) and their mixed stand, were established in spring 1983, and their effects on soil characteristics were evaluated by measuring some soil physical, chemical, microbiological and biochemical parameters. After 20 years' plantation, all test indices showed differences among different forest management models. Both PMS and MCM had a favorable effect on soil fertility maintenance. Soil quality assessment showed that some soil functions, e.g., water availability, nutrient availability, root suitability and soil quality index were all in a moderate level under the mixed and pure PMS stands, whereas in a relatively lower level under successive PCS stand. The results also showed that there existed close correlations between soil total organic C (TOC), cation exchange capacity (CEC), microbial biomass-C (Cmic) and other soil physical, chemical and biological indices. Therefore, TOC, CEC and Cmic could be used as the indicators in assessing soil quality in this study area. In addition, there were also positive correlations between soil microbial biomass-C and TOC, soil microbial biomass-N and total N, and soil microbial biomass-P and total P in the present study.

  10. Biodiversity differences between managed and unmanaged forests: meta-analysis of species richness in Europe.

    Science.gov (United States)

    Paillet, Yoan; Bergès, Laurent; Hjältén, Joakim; Odor, Péter; Avon, Catherine; Bernhardt-Römermann, Markus; Bijlsma, Rienk-Jan; De Bruyn, Luc; Fuhr, Marc; Grandin, Ulf; Kanka, Robert; Lundin, Lars; Luque, Sandra; Magura, Tibor; Matesanz, Silvia; Mészáros, Ilona; Sebastià, M-Teresa; Schmidt, Wolfgang; Standovár, Tibor; Tóthmérész, Béla; Uotila, Anneli; Valladares, Fernando; Vellak, Kai; Virtanen, Risto

    2010-02-01

    Past and present pressures on forest resources have led to a drastic decrease in the surface area of unmanaged forests in Europe. Changes in forest structure, composition, and dynamics inevitably lead to changes in the biodiversity of forest-dwelling species. The possible biodiversity gains and losses due to forest management (i.e., anthropogenic pressures related to direct forest resource use), however, have never been assessed at a pan-European scale. We used meta-analysis to review 49 published papers containing 120 individual comparisons of species richness between unmanaged and managed forests throughout Europe. We explored the response of different taxonomic groups and the variability of their response with respect to time since abandonment and intensity of forest management. Species richness was slightly higher in unmanaged than in managed forests. Species dependent on forest cover continuity, deadwood, and large trees (bryophytes, lichens, fungi, saproxylic beetles) and carabids were negatively affected by forest management. In contrast, vascular plant species were favored. The response for birds was heterogeneous and probably depended more on factors such as landscape patterns. The global difference in species richness between unmanaged and managed forests increased with time since abandonment and indicated a gradual recovery of biodiversity. Clearcut forests in which the composition of tree species changed had the strongest effect on species richness, but the effects of different types of management on taxa could not be assessed in a robust way because of low numbers of replications in the management-intensity classes. Our results show that some taxa are more affected by forestry than others, but there is a need for research into poorly studied species groups in Europe and in particular locations. Our meta-analysis supports the need for a coordinated European research network to study and monitor the biodiversity of different taxa in managed and unmanaged

  11. Different fire-climate relationships on forested and non-forested landscapes in the Sierra Nevada ecoregion

    Science.gov (United States)

    Keeley, Jon E.; Syphard, Alexandra D.

    2015-01-01

    In the California Sierra Nevada region, increased fire activity over the last 50 years has only occurred in the higher-elevation forests on US Forest Service (USFS) lands, and is not characteristic of the lower-elevation grasslands, woodlands and shrublands on state responsibility lands (Cal Fire). Increased fire activity on USFS lands was correlated with warmer and drier springs. Although this is consistent with recent global warming, we found an equally strong relationship between fire activity and climate in the first half of the 20th century. At lower elevations, warmer and drier conditions were not strongly tied to fire activity over the last 90 years, although prior-year precipitation was significant. It is hypothesised that the fire–climate relationship in forests is determined by climatic effects on spring and summer fuel moisture, with hotter and drier springs leading to a longer fire season and more extensive burning. In contrast, future fire activity in the foothills may be more dependent on rainfall patterns and their effect on the herbaceous fuel load. We predict spring and summer warming will have a significant impact on future fire regimes, primarily in higher-elevation forests. Lower elevation ecosystems are likely to be affected as much by global changes that directly involve land-use patterns as by climate change.

  12. Adapting an IPCC-Compliant Full Forest Carbon Accounting Model to Determine the Effects of Different Forest Management Strategies in California

    Science.gov (United States)

    Starrs, C.; Stewart, W.; Potts, M. D.

    2016-12-01

    As California experiences increasing rates of disturbance events such as wildfire, drought, and insect outbreaks, understanding how different management strategies affect long-term forest carbon stock changes in the forest and in harvested wood products used by society will be key to determining strategies to best maximize forest-related carbon sequestration in the future. California's forest area is roughly evenly split across three ownership types: private timberlands, National Forest timberlands, and reserved forests. Forest management strategies in California generally vary by these ownerships; management in reserved lands sequesters carbon within the forest (i.e. leaves wood in the forest), while on private and National Forest timberlands a significant amount of wood is removed from the forest and converted to harvested wood products. The Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) is an IPCC-compliant full forest carbon accounting model developed for use in Canada that has been adapted for use in other countries. Changes in natural disturbances in the forest and technological innovation in the use of harvested wood products could substantially alter future carbon trajectories of forests under different management regimes. A key advantage of the CBM-CFS3 model is that in addition to tracking live tree, dead tree, and dead organic matter (DOM) carbon pools in the forest, it also tracks carbon stock changes in harvested wood products. We calibrated the CBM-CFS3 model with US Forest Service Forest Inventory and Analysis (FIA) data for seven forest types across three ownership types to predict carbon stock changes under different natural disturbance and harvested wood product utilization futures. Our results illustrate the importance of using a tractable model that can integrate future changes in forest carbon cycling to keep pace with our changing climate and usage of wood products.

  13. Influence of different tree-harvesting intensities on forest soil carbon stocks in boreal and northern temperate forest ecosystems

    DEFF Research Database (Denmark)

    Clarke, Nicholas; Gundersen, Per; Jönsson-Belyazid, Ulrika

    2015-01-01

    processes involved, and under which conditions the size of the removals becomes critical. At present, the uncertainty gap between the scientific results and the need for practically useable management guidelines and other governance measures might be bridged by expert opinions given to authorities......Effective forest governance measures are crucial to ensure sustainable management of forests, but so far there has been little specific focus in boreal and northern temperate forests on governance measures in relation to management effects, including harvesting effects, on soil organic carbon (SOC......) stocks. This paper reviews the findings in the scientific literature concerning the effects of harvesting of different intensities on SOC stocks and fluxes in boreal and northern temperate forest ecosystems to evaluate the evidence for significant SOC losses following biomass removal. An overview...

  14. Divergent responses of tropical cyclone genesis factors to strong volcanic eruptions at different latitudes

    Science.gov (United States)

    Yan, Qing; Zhang, Zhongshi; Wang, Huijun

    2018-03-01

    To understand the behaviors of tropical cyclones (TCs), it is very important to explore how TCs respond to anthropogenic greenhouse gases and natural forcings. Volcanic eruptions are a major natural forcing mechanism because they inject sulphate aerosols into the stratosphere, which modulate the global climate by absorbing and scattering solar radiation. The number of Atlantic hurricanes is thought to be reduced following strong tropical eruptions, but whether the response of TCs varies with the locations of the volcanoes and the different ocean basins remains unknown. Here, we use the Community Earth System Model-Last Millennium Ensemble to investigate the response of the large-scale environmental factors that spawn TCs to strong volcanic eruptions at different latitudes. A composite analysis indicates that tropical and northern hemisphere volcanic eruptions lead to significantly unfavorable conditions for TC genesis over the whole Pacific basin and the North Atlantic during the 3 years post-eruption, relative to the preceding 3 years. Southern hemisphere volcanic eruptions result in obviously unfavorable conditions for TC formation over the southwestern Pacific, but more favorable conditions over the North Atlantic. The mean response over the Indian Ocean is generally muted and insignificant. It should be noted that volcanic eruptions impact on environmental conditions through both the direct effect (i.e. on radiative forcing) and the indirect effect (i.e. on El Niño-Southern Oscillation), which is not differentiated in this study. In addition, the spread of the TC genesis response is considerably large for each category of eruptions over each ocean basin, which is also seen in the observational/proxy-based records. This large spread is attributed to the differences in stratospheric aerosol distributions, initial states and eruption intensities, and makes the short-term forecast of TC activity following the next large eruption challenging.

  15. Multiple metrics of diversity have different effects on temperate forest functioning over succession.

    Science.gov (United States)

    Yuan, Zuoqiang; Wang, Shaopeng; Gazol, Antonio; Mellard, Jarad; Lin, Fei; Ye, Ji; Hao, Zhanqing; Wang, Xugao; Loreau, Michel

    2016-12-01

    Biodiversity can be measured by taxonomic, phylogenetic, and functional diversity. How ecosystem functioning depends on these measures of diversity can vary from site to site and depends on successional stage. Here, we measured taxonomic, phylogenetic, and functional diversity, and examined their relationship with biomass in two successional stages of the broad-leaved Korean pine forest in northeastern China. Functional diversity was calculated from six plant traits, and aboveground biomass (AGB) and coarse woody productivity (CWP) were estimated using data from three forest censuses (10 years) in two large fully mapped forest plots (25 and 5 ha). 11 of the 12 regressions between biomass variables (AGB and CWP) and indices of diversity showed significant positive relationships, especially those with phylogenetic diversity. The mean tree diversity-biomass regressions increased from 0.11 in secondary forest to 0.31 in old-growth forest, implying a stronger biodiversity effect in more mature forest. Multi-model selection results showed that models including species richness, phylogenetic diversity, and single functional traits explained more variation in forest biomass than other candidate models. The models with a single functional trait, i.e., leaf area in secondary forest and wood density in mature forest, provided better explanations for forest biomass than models that combined all six functional traits. This finding may reflect different strategies in growth and resource acquisition in secondary and old-growth forests.

  16. Response of soil respiration to acid rain in forests of different maturity in southern China.

    Directory of Open Access Journals (Sweden)

    Guohua Liang

    Full Text Available The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF, a transitional mixed conifer and broadleaf forest (MF and an old-growth broadleaved forest (BF] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0. Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

  17. Response of soil respiration to acid rain in forests of different maturity in southern China.

    Science.gov (United States)

    Liang, Guohua; Liu, Xingzhao; Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

    2013-01-01

    The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

  18. Strong Gradients in Forest Sensitivity to Climate Change Revealed by Dynamics of Forest Fire Cycles in the Post Little Ice Age Era

    Science.gov (United States)

    Drobyshev, Igor; Bergeron, Yves; Girardin, Martin P.; Gauthier, Sylvie; Ols, Clémentine; Ojal, John

    2017-10-01

    The length of the fire cycle is a critical factor affecting the vegetation cover in boreal and temperate regions. However, its responses to climate change remain poorly understood. We reanalyzed data from earlier studies of forest age structures at the landscape level, in order to map the evolution of regional fire cycles across Eastern North American boreal and temperate forests, following the termination of the Little Ice Age (LIA). We demonstrated a well-defined spatial pattern of post-LIA changes in the length of fire cycles toward lower fire activity during the 1800s and 1900s. The western section of Eastern North America (west of 77°W) experienced a decline in fire activity as early as the first half of the 1800s. By contrast, the eastern section showed these declines as late as the early 1900s. During a regionally fire-prone period of the 1910s-1920s, forests in the western section of Eastern boreal North America burned more than forests in the eastern section. The climate appeared to dominate over vegetation composition and human impacts in shaping the geographical pattern of the post-LIA change in fire activity. Changes in the atmospheric circulation patterns following the termination of the LIA, specifically changes in Arctic Oscillation and the strengthening of the Continental Polar Trough, were likely drivers of the regional fire dynamics.

  19. CpDNA haplotype variation reveals strong human influence on oak stands of the Veluwe forest in the Netherlands

    NARCIS (Netherlands)

    Buiteveld, J.; Koelewijn, H.P.

    2006-01-01

    We examined chloroplast DNA (cpDNA) variation in 78 oak stands of an important forest complex (the Veluwe) in The Netherlands. Based on historical maps and information oak stands were classified as planted or autochthonous. A genetic study by means of cpDNA haplotype characterisation was carried out

  20. Extreme differences in forest degradation in Borneo: comparing practices in Sarawak, Sabah, and Brunei.

    Directory of Open Access Journals (Sweden)

    Jane E Bryan

    Full Text Available The Malaysian states of Sabah and Sarawak are global hotspots of forest loss and degradation due to timber and oil palm industries; however, the rates and patterns of change have remained poorly measured by conventional field or satellite approaches. Using 30 m resolution optical imagery acquired since 1990, forest cover and logging roads were mapped throughout Malaysian Borneo and Brunei using the Carnegie Landsat Analysis System. We uncovered ∼364,000 km of roads constructed through the forests of this region. We estimated that in 2009 there were at most 45,400 km(2 of intact forest ecosystems in Malaysian Borneo and Brunei. Critically, we found that nearly 80% of the land surface of Sabah and Sarawak was impacted by previously undocumented, high-impact logging or clearing operations from 1990 to 2009. This contrasted strongly with neighbouring Brunei, where 54% of the land area remained covered by unlogged forest. Overall, only 8% and 3% of land area in Sabah and Sarawak, respectively, was covered by intact forests under designated protected areas. Our assessment shows that very few forest ecosystems remain intact in Sabah or Sarawak, but that Brunei, by largely excluding industrial logging from its borders, has been comparatively successful in protecting its forests.

  1. Differences in ecosystem carbon distribution and nutrient cycling linked to forest tree species composition in a mid-successional boreal forest

    Science.gov (United States)

    Melvin, April M.; Mack, Michelle C.; Johnstone, Jill F.; McGuire, A. David; Genet, Helene; Schuur, Edward A.G.

    2015-01-01

    In the boreal forest of Alaska, increased fire severity associated with climate change is expanding deciduous forest cover in areas previously dominated by black spruce (Picea mariana). Needle-leaf conifer and broad-leaf deciduous species are commonly associated with differences in tree growth, carbon (C) and nutrient cycling, and C accumulation in soils. Although this suggests that changes in tree species composition in Alaska could impact C and nutrient pools and fluxes, few studies have measured these linkages. We quantified C, nitrogen, phosphorus, and base cation pools and fluxes in three stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a single fire event in 1958. Paper birch consistently displayed characteristics of more rapid C and nutrient cycling, including greater aboveground net primary productivity, higher live foliage and litter nutrient concentrations, and larger ammonium and nitrate pools in the soil organic layer (SOL). Ecosystem C stocks (aboveground + SOL + 0–10 cm mineral soil) were similar for the two species; however, in black spruce, 78% of measured C was found in soil pools, primarily in the SOL, whereas aboveground biomass dominated ecosystem C pools in birch forest. Radiocarbon analysis indicated that approximately one-quarter of the black spruce SOL C accumulated prior to the 1958 fire, whereas no pre-fire C was observed in birch soils. Our findings suggest that tree species exert a strong influence over C and nutrient cycling in boreal forest and forest compositional shifts may have long-term implications for ecosystem C and nutrient dynamics.

  2. Differences among shortleaf pine seed sources on the Ozark and Ouachita National Forests at age ten

    Science.gov (United States)

    Charly Studyvin; David Gwaze

    2012-01-01

    Progeny test planting of shortleaf pine (Pinus echinata Mill.) was started on the National Forests in Arkansas in 1978, and continued through 1990. A series of progeny tests established on the Ouachita and Ozark National Forests were analyzed to determine if significant differences exist between the three seed sources in Arkansas (the East Ouachita,...

  3. Species diversity of polyporoid and corticioid fungi in northern hardwood forests with differing management histories

    Science.gov (United States)

    Daniel L Lindner; Harold H. Burdsall; Glen R. Stanosz

    2006-01-01

    Effects of forest management on fungal diversity were investigated by sampling fruit bodies of polyporoid and corticioid fungi in forest stands that have different management histories. Fruit bodies were sampled in 15 northern hardwood stands in northern Wisconsin and the upper peninsula of Michigan. Sampling was conducted in five old-growth stands, five uneven-age...

  4. Red-Cockaded Woodpecker male/female foraging differences in young forest stands

    Science.gov (United States)

    Kathleen E. Franzreb

    2010-01-01

    The Red-cockaded Woodpecker (Picoides borealis) is an endangered species endemic to pine (Pinusspp.) forests of the southeastern United States. I examined Red-cockaded Woodpecker foraging behavior to learn if there were male/female differences at the Savannah River Site, South Carolina. The study was conducted in largely young forest stands (,50 years of age) in...

  5. Strong influence of long-distance edge effect on herb-layer vegetation in forest fragments in an agricultural landscape

    Czech Academy of Sciences Publication Activity Database

    Hofmeister, J.; Hošek, J.; Brabec, Marek; Hédl, Radim; Modrý, M.

    2013-01-01

    Roč. 15, č. 6 (2013), s. 293-303 ISSN 1433-8319 Grant - others:GA MŽP(CZ) SM/6/69/05; GA MŽP(CZ) SP/2D3/139/07 Institutional support: RVO:67985807 ; RVO:67985939 Keywords : ancient forest * edge effect * habitat fragmentation * light condition * soil nutrients * species richness Subject RIV: BB - Applied Statistics, Operational Research; EH - Ecology, Behaviour (BU-J) Impact factor: 3.324, year: 2013

  6. ATTACHMENT TO FORESTS IN ROMANIA; DOES A HISTORY OF COLLECTIVISM MAKE A DIFFERENCE?

    Directory of Open Access Journals (Sweden)

    Maria ARDELEANU

    2013-12-01

    Full Text Available Forests in Romania are facing significant environmental problems. Due to the large transformations the forestry sector has undergone as a result of the communist period, sustainable forest management is highly relevant. Rural communities, who are dependent on the forests for their daily livelihood, need to be included in discussions regarding sustainable forest management. This paper calls for the need of understanding how these transformations have affected rural people’s attachment to the forests that have been for such a long time taken away from them. Two types of rural communities can be distinguished, those affected by collectivisation of agricultural land and those not. This paper addresses the functional and emotional attachment to the local forests of a former collectivized and of a non-collectivized community. We found that people in both communities are functionally attached to the forest, through a range of social benefits, mostly ‘recreation’ and ‘healthiness’, and economic benefits, especially the use of wood. Attachment was negative thru the economic detriments ‘decrease of wood availability’, ‘high costs of forest management’, ‘wood theft’ and ‘ineffective forest regime’. People in both communities are emotionally attached to the forest through feelings triggered mostly by a sense of kinship with family members. As a final conclusion, in the former collectivized rural areas, people are less attached to the forest compared to people in the non-collectivized rural areas and these differences can be linked to the transformations triggered by the former collectivisation process, but also to the weak regulation of the privatized forests, the limited financial possibilities and access restrictions.

  7. Water balance of different forests types in Kiskunság Sandridge

    Science.gov (United States)

    Bolla, Bence; Kalicz, Péter

    2017-04-01

    Kiskunság Sandridge in central Hungary shows the signs of significant drying caused by anthropogenic (e.g. river regulation and water consumption) and climatic reasons. These factors generated dramatically decreasing of groundwater levels which was an important water supply for forest ecosystems. These worsening in site conditions bring up several questions in forest management and natural protection as well because significant part of forests are in protected areas in Kiskunság. This study aims to give a picture of the characteristic features of Sandridge forests concerning their water balance. Hydrology of forest sites were evaluated throughout measurement of hydrological elements and water balance modelling with the Coup 1D water-balance model. Three forest stands and five control stations in the grasslands were settled and monitored to compare the water consumption of different forests with native grasslands. This case study helps the work of forest managers with the quantification of water consumption of forests in Kiskunság. This research has been partly supported by the Agroclimate.2 VKSZ_12-1-2013-0034 project, and the second author's work was also supported by the János Bolyai Scholarship of the Hungarian Academy of Sciences.

  8. Strong thermal acclimation of photosynthesis in tropical and temperate wet-forest tree species: the importance of altered Rubisco content.

    Science.gov (United States)

    Scafaro, Andrew P; Xiang, Shuang; Long, Benedict M; Bahar, Nur H A; Weerasinghe, Lasantha K; Creek, Danielle; Evans, John R; Reich, Peter B; Atkin, Owen K

    2017-07-01

    Understanding of the extent of acclimation of light-saturated net photosynthesis (A n ) to temperature (T), and associated underlying mechanisms, remains limited. This is a key knowledge gap given the importance of thermal acclimation for plant functioning, both under current and future higher temperatures, limiting the accuracy and realism of Earth system model (ESM) predictions. Given this, we analysed and modelled T-dependent changes in photosynthetic capacity in 10 wet-forest tree species: six from temperate forests and four from tropical forests. Temperate and tropical species were each acclimated to three daytime growth temperatures (T growth ): temperate - 15, 20 and 25 °C; tropical - 25, 30 and 35 °C. CO 2 response curves of A n were used to model maximal rates of RuBP (ribulose-1,5-bisphosphate) carboxylation (V cmax ) and electron transport (J max ) at each treatment's respective T growth and at a common measurement T (25 °C). SDS-PAGE gels were used to determine abundance of the CO 2 -fixing enzyme, Rubisco. Leaf chlorophyll, nitrogen (N) and mass per unit leaf area (LMA) were also determined. For all species and T growth , A n at current atmospheric CO 2 partial pressure was Rubisco-limited. Across all species, LMA decreased with increasing T growth . Similarly, area-based rates of V cmax at a measurement T of 25 °C (V cmax 25 ) linearly declined with increasing T growth , linked to a concomitant decline in total leaf protein per unit leaf area and Rubisco as a percentage of leaf N. The decline in Rubisco constrained V cmax and A n for leaves developed at higher T growth and resulted in poor predictions of photosynthesis by currently widely used models that do not account for T growth -mediated changes in Rubisco abundance that underpin the thermal acclimation response of photosynthesis in wet-forest tree species. A new model is proposed that accounts for the effect of T growth -mediated declines in V cmax 25 on A n , complementing current

  9. PRECIPITATION AND NUTRIENT CONTRIBUTION IN DIFFERENT SUCCESSIONAL STAGES OF ATLANTIC FOREST, PINHEIRAL, RIO DE JANEIRO STATE

    Directory of Open Access Journals (Sweden)

    Anderson Ribeiro Diniz

    2013-08-01

    Full Text Available http://dx.doi.org/10.5902/1980509810550Forest cover has importance within the context of the water balance of a particular site and may alter the mechanism of entry of water and nutrients to the soil surface. The aim of this study was to quantify the net precipitation, interception addition of nutrients in throughfall and stem flow in a forest in different stages of regeneration Mata Atlântica: early-stage secondary forest (ESSF, intermediary stage secondary forest (ISSF and advanced stage secondary forest (AESF. The study was conducted in Pinheiral,  Rio de Janeiro state. The data collection was performed during the period April 2009 to March 2010. The values of incident precipitation,

  10. Different hydraulic traits of woody plants from tropical forests with contrasting soil water availability.

    Science.gov (United States)

    Zhu, Shi-Dan; Chen, Ya-Jun; Fu, Pei-Li; Cao, Kun-Fang

    2017-11-01

    In southwestern China, tropical karst forests (KF) and non-karst rain forests (NKF) have different species composition and forest structure owing to contrasting soil water availability, but with a few species that occur in both forests. Plant hydraulic traits are important for understanding the species' distribution patterns in these two forest types, but related studies are rare. In this study, we investigated hydraulic conductivity, vulnerability to drought-induced cavitation and wood anatomy of 23 abundant and typical woody species from a KF and a neighboring NKF, as well as two Bauhinia liana species common to both forests. We found that the KF species tended to have higher sapwood density, smaller vessel diameter, lower specific hydraulic conductivity (ks) and leaf to sapwood area ratio, and were more resistant to cavitation than NKF species. Across the 23 species distinctly occurring in either KF or NKF, there was a significant tradeoff between hydraulic efficiency and safety, which might be an underlying mechanism for distributions of these species across the two forests. Interestingly, by possessing rather large and long vessels, the two Bauhinia liana species had extremely high ks but were also high resistance to cavitation (escaping hydraulic tradeoff). This might be partially due to their distinctly dimorphic vessels, but contribute to their wide occurrence in both forests. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Analysis on Difference of Forest Phenology Extracted from EVI and LAI Based on PhenoCams

    Science.gov (United States)

    Wang, C.; Jing, L.; Qinhuo, L.

    2017-12-01

    Land surface phenology can make up for the deficiency of field observation with advantages of capturing the continuous expression of phenology on a large scale. However, there are some variability in phenological metrics derived from different satellite time-series data of vegetation parameters. This paper aims at assessing the difference of phenology information extracted from EVI and LAI time series. To achieve this, some web-camera sites were selected to analyze the characteristics between MODIS-EVI and MODIS-LAI time series from 2010 to 2014 for different forest types, including evergreen coniferous forest, evergreen broadleaf forest, deciduous coniferous forest and deciduous broadleaf forest. At the same time, satellite-based phenological metrics were extracted by the Logistics algorithm and compared with camera-based phenological metrics. Results show that the SOS and EOS that are extracted from LAI are close to bud burst and leaf defoliation respectively, while the SOS and EOS that are extracted from EVI is close to leaf unfolding and leaf coloring respectively. Thus the SOS that is extracted from LAI is earlier than that from EVI, while the EOS that is extracted from LAI is later than that from EVI at deciduous forest sites. Although the seasonal variation characteristics of evergreen forests are not apparent, significant discrepancies exist in LAI time series and EVI time series. In addition, Satellite- and camera-based phenological metrics agree well generally, but EVI has higher correlation with the camera-based canopy greenness (green chromatic coordinate, gcc) than LAI.

  12. Habitat differences in dung beetle assemblages in an African savanna-forest ecotone: implications for secondary seed dispersal.

    Science.gov (United States)

    Kunz, Britta K; Krell, Frank-Thorsten

    2011-06-01

    The probability and pattern of secondary seed dispersal by dung beetles (Scarabaeinae) depend on their community structure and composition at the site of primary deposition, which, in turn, seem to be strongly determined by vegetation. Consequently, we expected pronounced differences in secondary seed dispersal between forest and savanna in the northern Ivory Coast, West Africa. We found 99 dung beetle species at experimentally exposed dung piles of the olive baboon (Papio anubis (Lesson, 1827)), an important primary seed disperser in West Africa. Seventy-six species belonged to the roller and tunneler guilds, which are relevant for secondary seed dispersal. Most species showed a clear habitat preference. Contrary to the Neotropics, species number and abundance were much higher in the savanna than in the forest. Rollers and tunnelers each accounted for approximately 50% of the individuals in the savanna, but in the forest rollers made up only 4%. Seeds deposited into the savanna by an omnivorous primary disperser generally have a higher overall probability of being more rapidly dispersed secondarily by dung beetles than seeds in the forest. Also, rollers disperse seeds over larger distances. In contrast to other studies, small rollers were active in dispersal of large seeds, which were seemingly mistaken for dung balls. Our results suggest that rollers can remove seeds from any plant dispersed in primate dung in this ecosystem. © 2011 ISZS, Blackwell Publishing and IOZ/CAS.

  13. Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N2O

    Directory of Open Access Journals (Sweden)

    K. Pilegaard

    2006-01-01

    Full Text Available Soil emissions of NO and N2O were measured continuously at high frequency for more than one year at 15 European forest sites as part of the EU-funded project NOFRETETE. The locations represent different forest types (coniferous/deciduous and different nitrogen loads. Geographically they range from Finland in the north to Italy in the south and from Hungary in the east to Scotland in the west. The highest NO emissions were observed from coniferous forests, whereas the lowest NO emissions were observed from deciduous forests. The NO emissions from coniferous forests were highly correlated with N-deposition. The site with the highest average annual emission (82 μg NO-N m−2 h−1 was a spruce forest in South-Germany (Höglwald receiving an annual N-deposition of 2.9 g m−2. NO emissions close to the detection limit were observed from a pine forest in Finland where the N-deposition was 0.2 g N m−2 a−1. No significant correlation between N2O emission and N-deposition was found. The highest average annual N2O emission (20 μg N2O-N m−2 h−1 was found in an oak forest in the Mátra mountains (Hungary receiving an annual N-deposition of 1.6 g m−2. N2O emission was significantly negatively correlated with the C/N ratio. The difference in N-oxide emissions from soils of coniferous and deciduous forests may partly be explained by differences in N-deposition rates and partly by differences in characteristics of the litter layer and soil. NO was mainly derived from nitrification whereas N2O was mainly derived from denitrification. In general, soil moisture is lower at coniferous sites (at least during spring time and the litter layer of coniferous forests is thick and well aerated favouring nitrification and thus release of NO. Conversely, the higher rates of denitrification in deciduous forests due to a compact and moist litter layer lead to N2O production and NO consumption in the soil. The two factors soil moisture and soil temperature are

  14. [Effects of different forest management alternatives on Sciurus vulgaris habitat].

    Science.gov (United States)

    Jin, Long-Ru; He, Hong-Shi; Zong, Cheng; Zhou, Yu-Fei; Bu, Ren-Cang

    2008-05-01

    A spatially explicit landscape model LANDIS was applied to simulate the forest landscape changes under four management alternatives (no cutting, clear cutting, selective cutting I and II) in Youhao Forestry Bureau located in Small Xing' an Mountain from 2000 to 2200. The outcomes from LANDIS were combined with a landscape-level habitat suitability index (HSI) model in a GIS environment to assess Sciurus vulgaris habitat quality. The results showed that the increase of suitable habitat area and the decrease of marginally suitable area were the fastest under no cutting scenario, and the slowest under clear cutting scenario. Suitable habitat area increased faster while marginally suitable area decreased more slowly under selective cutting I scenario than under selective cutting II. Overall, the optimal management alternative of S. vulgaris habitat was in the sequence of no cutting, selective cutting I, selective cutting II, and clear cutting.

  15. How Similar Are Forest Disturbance Maps Derived from Different Landsat Time Series Algorithms?

    Directory of Open Access Journals (Sweden)

    Warren B. Cohen

    2017-03-01

    Full Text Available Disturbance is a critical ecological process in forested systems, and disturbance maps are important for understanding forest dynamics. Landsat data are a key remote sensing dataset for monitoring forest disturbance and there recently has been major growth in the development of disturbance mapping algorithms. Many of these algorithms take advantage of the high temporal data volume to mine subtle signals in Landsat time series, but as those signals become subtler, they are more likely to be mixed with noise in Landsat data. This study examines the similarity among seven different algorithms in their ability to map the full range of magnitudes of forest disturbance over six different Landsat scenes distributed across the conterminous US. The maps agreed very well in terms of the amount of undisturbed forest over time; however, for the ~30% of forest mapped as disturbed in a given year by at least one algorithm, there was little agreement about which pixels were affected. Algorithms that targeted higher-magnitude disturbances exhibited higher omission errors but lower commission errors than those targeting a broader range of disturbance magnitudes. These results suggest that a user of any given forest disturbance map should understand the map’s strengths and weaknesses (in terms of omission and commission error rates, with respect to the disturbance targets of interest.

  16. Investigation of Different Forest Type’s Structure with Applying Nearest Neighbor Indices (Case Study: Gorazon District, Kheyrud Forest

    Directory of Open Access Journals (Sweden)

    V. Alijani

    2013-07-01

    Full Text Available To implement correct management of forest ecosystems, enough information in relation to the structures of tree species is necessary. In this study, the structures of trees species in Fagus, Fagus-Carpinus, Carpinus-Fagus and Carpinus-Quercus types were investigated and compared in Hyrcanian forest. The data used in this study was collected from 239 plots with an area of 1000 m2 in Gorazbon district of Kheyrud forest, and Crancod (ver. 1.3 software was employed to calculate the uniform angle (Wi, Mingling (DMi, DBH dominance (TDi and Height dominance (THi indices. The result of uniform angle index showed a random positioning for the trees in the studied types. Also, the result of mingling index showed a low mixture for four studied types. The result of this index indicated an intra-specific competition for Fagus orientalis and Carpinus betulus and an inter-specific competition for other species. The average value of DBH and Height dominance indices showed a relative similarity among the studied types. The result of these indices showed that some species such as Acer velutinum,، Tilia begonifolia and Alnus subcordata are dominant and species including Ulmus glabra and Diospyros lotus are dominated. The comparing of similar species structure showed a non significant difference for positioning, DBH and height dominance features in different types. Also, this comparison showed a significant difference in mingling feature of Carpinus betulus, Fagus orientalis, Acer velutinum, Tilia begonifolia, and also deadwoods in the studied types. The utilized indices in this study had a high ability in the description of forest types' structures and also the ecological features of trees species.

  17. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

    Science.gov (United States)

    M. Mazur; C.P.J. Mitchell; C.S. Eckley; S.L. Eggert; R.K. Kolka; S.D. Sebestyen; E.B. Swain

    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...

  18. Water fluxes in forest of different ages in the Colombian amazonia

    International Nuclear Information System (INIS)

    Tellez Guio, Patricia; Boshell, Jose Francisco

    2004-01-01

    Rainfall reaching the canopy of a forest ecosystem may be divided into different fluxes: intercepted water, through fall and stem flow. This partitioning determines the spatial distribution of soil water. This paper describes the fixes and their spatial and temporal variability in a mature forest and three secondary forests of different ages (5, 18 and 30 years old) in the middle Caqueta, in Colombian Amazonia. Results showed that there are no significant differences in the mean rainfall (P) and through fall (TH) among the land uses. However, there were differences in the percentages of TH with respect to different ranges of magnitude of P, mainly for heavy rain showers with more than 20 mm rainfall. The temporal variability of TH was high, while the spatial variability was low. Stem flow (ST) showed significant differences, which were related to the vegetation characteristics. The spatial and temporal variability of ST were high

  19. Aboveground-belowground biodiversity linkages differ in early and late successional temperate forests.

    Science.gov (United States)

    Li, Hui; Wang, Xugao; Liang, Chao; Hao, Zhanqing; Zhou, Lisha; Ma, Sam; Li, Xiaobin; Yang, Shan; Yao, Fei; Jiang, Yong

    2015-07-17

    Understanding ecological linkages between above- and below-ground biota is critical for deepening our knowledge on the maintenance and stability of ecosystem processes. Nevertheless, direct comparisons of plant-microbe diversity at the community level remain scarce due to the knowledge gap between microbial ecology and plant ecology. We compared the α- and β- diversities of plant and soil bacterial communities in two temperate forests that represented early and late successional stages. We documented different patterns of aboveground-belowground diversity relationships in these forests. We observed no linkage between plant and bacterial α-diversity in the early successional forest, and even a negative correlation in the late successional forest, indicating that high bacterial α-diversity is not always linked to high plant α-diversity. Beta-diversity coupling was only found at the late successional stage, while in the early successional forest, the bacterial β-diversity was closely correlated with soil property distances. Additionally, we showed that the dominant competitive tree species in the late successional forest may play key roles in driving forest succession by shaping the soil bacterial community in the early successional stage. This study sheds new light on the potential aboveground-belowground linkage in natural ecosystems, which may help us understand the mechanisms that drive ecosystem succession.

  20. Ecology of cultivable yeasts in pristine forests in northern Patagonia (Argentina) influenced by different environmental factors.

    Science.gov (United States)

    Mestre, María Cecilia; Fontenla, Sonia; Rosa, Carlos A

    2014-06-01

    Environmental factors influencing the occurrence and community structure of soil yeasts in forests are not well studied. There are few studies dedicated to Southern Hemisphere soil yeasts populations and even fewer focused on temperate forests influenced by volcanic activity. The present work aimed to study the ecology of soil yeast communities from pristine forests influenced by different environmental factors (precipitation, physicochemical properties of soil, tree species, soil region, and season). The survey was performed in 4 northern Patagonian forests: 2 dominated by Nothofagus pumilio and 2 by Nothofagus antarctica. Yeast communities were described with ecological indices and species accumulation curves, and their association with environmental characteristics was assessed using multivariate analysis. Each forest site showed a particular arrangement of species as a result of environmental characteristics, such as dominant plant species, nutrient availability, and climatic characteristics. Cryptococcus podzolicus was most frequently isolated in nutrient-rich soils, Trichosporon porosum dominated cold mountain forests with low nutrient and water availability in soil, and capsulated yeasts such as Cryptococcus phenolicus dominated forest sites with low precipitation. The present work suggests that environmental factors affecting yeast communities may not be the current soil characteristics but the result of complex interactions of factors including natural disturbances like volcanic activity.

  1. Differences in Prokaryotic Species Between Primary and Logged-Over Deep Peat Forest in Sarawak, Malaysia

    International Nuclear Information System (INIS)

    Mohd Shawal Thakib Maidin; Sakinah Safari; Nur Aziemah Ghani; Sharifah Azura Syed Ibrahim; Shamsilawani Ahamed Bakeri; Mohamed Mazmira Mohd Masri; Siti Ramlah Ahmad Ali

    2016-01-01

    Peat land has an important role in environmental sustainability which can be used for agricultural purposes. However, deforestation in the logged-over forest may disrupt the diversity of microbial population in peat soil. Therefore, this study focuses on the differences of microbial populations in Maludam primary forest and Cermat Ceria logged-over forest in Sarawak, Malaysia. The prokaryotic 16S rDNA region was amplified followed by denaturing gradient gel electrophoresis (16S PCR-DGGE) analysis. Berger-Parker and Shannon-Weaver Biodiversity Index showed that Maludam (0.11, 7.75) was more diverse compared to Cermat Ceria (0.19, 7.63). Sequence analysis showed that the bacterial community in Maludam and Cermat Ceria were dominated by unclassified bacteria, followed by Acidobacteria, Actinobacteria, Firmicutes and a-Proteobacteria. Based on the findings, the distinct species that can be found in Maludam were Acidobacterium capsulatum, Solibacter sp., Mycobacterium intracellulare, Rhodoplanes sp., Clostridia bacterium, Exiguobacterium sp. and Lysinibacillus fusiformis. While, the distinct species that can be found in Cermat Ceria were Telmatobacter, Mycobacterium tuberculosis and Bacillus tequilensis. Overall, the findings showed that microbial population in the logged-over forest are less diverse compared to primary forest. Higher prokaryotic diversity identified in the primary forest compared to logged-over forest showed that deforestation might cause prokaryotic population changes to both ecosystems. (author)

  2. Throughfall in different forest stands of Iperó, São Paulo

    Directory of Open Access Journals (Sweden)

    Esthevan Augusto Goes Gasparoto

    2014-06-01

    Full Text Available In forestry, throughfall (Pi is that fraction of rainfall that runs directly through the tree canopy and reaches the ground. It is characterized as the main source of water supply in a watershed. This study aimed to analyze the dynamics of throughfall in three types of forest stands, namely Eucalyptus cloeziana, Pinus sp. and seasonal semideciduous forest (FES, all located in Ipanema National Forest, in the municipality of Iperó-SP. In each stand, a 300 m² plot was established in which ten rain gauges were installed for monitoring throughfall, and three rain gauges were installed in an open area adjacent to the stand for measuring gross precipitation (P. At the end of 25 observations, it was observed that, relative to P values, Pi values were 76.2% in semideciduous forest (FES, 85.1% in E.cloeziana forest and 84.0% in Pinus sp forest. In addition, comparing these stands, a larger leaf canopy coverage and consequently greater capability for water retention was noted in the semideciduous forest. However, no statistical differences were observed (P<0.05 between the stands of interest regarding throughfall.

  3. Differences in seed rain composition in small and large fragments in the northeast Brazilian Atlantic Forest.

    Science.gov (United States)

    Knörr, U C; Gottsberger, G

    2012-09-01

    Tropical forests are seriously threatened by fragmentation and habitat loss. The impact of fragment size and forest configuration on the composition of seed rain is insufficiently studied. For the present study, seed rain composition of small and large forest fragments (8-388 ha) was assessed in order to identify variations in seed abundance, species richness, seed size and dispersal mode. Seed rain was documented during a 1-year period in three large and four small Atlantic Forest fragments that are isolated by a sugarcane matrix. Total seed rain included 20,518 seeds of 149 species of trees, shrubs, palms, lianas and herbs. Most species and seeds were animal-dispersed. A significant difference in the proportion of seeds and species within different categories of seed size was found between small and large fragments. Small fragments received significantly more very small-sized seeds (1.5 cm) that were generally very rare, with only one species in small and eight in large fragments. We found a negative correlation between the inflow of small-sized seeds and the percentage of forest cover. Species richness was lower in small than in large fragments, but the difference was not very pronounced. Given our results, we propose changing plant species pools through logging, tree mortality and a high inflow of pioneer species and lianas, especially in small forest fragments and areas with low forest cover. Connecting forest fragments through corridors and reforestation with local large-seeded tree species may facilitate the maintenance of species diversity. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  4. Variation of Annual ET Determined from Water Budgets Across Rural Southeastern Basins Differing in Forest Types

    Science.gov (United States)

    Younger, S. E.; Jackson, C. R.

    2017-12-01

    In the Southeastern United States, evapotranspiration (ET) typically accounts for 60-70% of precipitation. Watershed and plot scale experiments show that evergreen forests have higher ET rates than hardwood forests and pastures. However, some plot experiments indicate that certain hardwood species have higher ET than paired evergreens. The complexity of factors influencing ET in mixed land cover watersheds makes identifying the relative influences difficult. Previous watershed scale studies have relied on regression to understand the influences or low flow analysis to indicate growing season differences among watersheds. Existing studies in the southeast investigating ET rates for watersheds with multiple forest cover types have failed to identify a significant forest type effect, but these studies acknowledge small sample sizes. Trends of decreasing streamflow have been recognized in the region and are generally attributed to five key factors, 1.) influences from multiple droughts, 2.) changes in distribution of precipitation, 3.) reforestation of agricultural land, 4.) increasing consumptive uses, or 5.) a combination of these and other factors. This study attempts to address the influence of forest type on long term average annual streamflow and on stream low flows. Long term annual ET rates were calculated as ET = P-Q for 46 USGS gaged basins with daily data for the 1982 - 2014 water years, >40% forest cover, and no large reservoirs. Land cover data was regressed against ET to describe the relationship between each of the forest types in the National Land Cover Database. Regression analysis indicates evergreen land cover has a positive relationship with ET while deciduous and total forest have a negative relationship with ET. Low flow analysis indicates low flows tend to be lower in watersheds with more evergreen cover, and that low flows increase with increasing deciduous cover, although these relationships are noisy. This work suggests considering forest

  5. Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N2O)

    DEFF Research Database (Denmark)

    Pilegaard, K.; Skiba, U.; Ambus, P.

    2006-01-01

    Soil emissions of NO and N2O were measured continuously at high frequency for more than one year at 15 European forest sites as part of the EU-funded project NOFRETETE. The locations represent different forest types (coniferous/deciduous) and different nitrogen loads. Geoaphically they range from...... with the C/N ratio. The difference in N-oxide emissions from soils of coniferous and deciduous forests may partly be explained by differences in N-deposition rates and partly by differences in characteristics of the litter layer and soil. NO was mainly derived from nitrification whereas N2O was mainly...... to a compact and moist litter layer lead to N2O production and NO consumption in the soil. The two factors soil moisture and soil temperature are often explaining most of the temporal variation within a site. When comparing annual emissions on a regional scale, however, factors such as nitrogen deposition...

  6. Performance and population dynamics of a native understory herb differ between young and old forest stands in the Southern Appalachians

    Science.gov (United States)

    Michelle M. Jackson; Scott M. Pearson; Monica G. Turner

    2013-01-01

    Anthropogenic disturbances (e.g., logging) can strongly affect the composition and structure of forest understory herb communities, with land-use legacies often persisting for decades or even centuries. Many studies of forest plant response to land-use history have focused on species distributions and abundances, and argued broadly for either dispersal or establishment...

  7. Strong but diverging clonality - climate relationships of different plant clades explain weak overall pattern across China

    Science.gov (United States)

    Ye, Duo; Liu, Guofang; Song, Yao-Bin; Cornwell, William K.; Dong, Ming; Cornelissen, Johannes H. C.

    2016-06-01

    The clonal strategy should be relatively important in stressful environments (i.e. of low resource availability or harsh climate), e.g. in cold habitats. However, our understanding of the distribution pattern of clonality along environmental gradients is still far from universal. The weakness and inconsistency of overall clonality-climate relationships across taxa, as reported in previous studies, may be due to different phylogenetic lineages having fundamental differences in functional traits other than clonality determining their climate response. Thus, in this study we compared the clonality-climate relationships along a latitudinal gradient within and between different lineages at several taxonomic levels, including four major angiosperm lineages (Magnoliidae, Monocotyledoneae, Superrosidae and Superasteridae), orders and families. To this aim we used a species clonality dataset for 4015 vascular plant species in 545 terrestrial communities across China. Our results revealed clear predictive patterns of clonality proportion in relation to environmental gradients for the predominant representatives of each of the taxonomic levels above, but the relationships differed in shape and strength between the 4 major angiosperm lineages, between the 12 orders and between the 12 families. These different relationships canceled out one another when all lineages at a certain taxonomic level were pooled. Our findings highlight the importance of explicitly accounting for the functional or taxonomic scale for studying variation in plant ecological strategy across environmental gradients.

  8. Calcium mineralization in the forest floor and surface soil beneath different tree species in the northeastern US

    NARCIS (Netherlands)

    Dijkstra, F.A.

    2003-01-01

    Calcium (Ca) is an important element for neutralizing soil acidity in temperate forests. The immediate availability of Ca in forested acid soils is largely dependent on mineralization of organic Ca, which may differ significantly among tree species. I estimated net Ca mineralization in the forest

  9. Atlantic forest bird communities provide different but not fewer functions after habitat loss.

    Science.gov (United States)

    De Coster, Greet; Banks-Leite, Cristina; Metzger, Jean Paul

    2015-07-22

    Habitat loss often reduces the number of species as well as functional diversity. Dramatic effects to species composition have also been shown, but changes to functional composition have so far been poorly documented, partly owing to a lack of appropriate indices. We here develop three new community indices (i.e. functional integrity, community integrity of ecological groups and community specialization) to investigate how habitat loss affects the diversity and composition of functional traits and species. We used data from more than 5000 individuals of 137 bird species captured in 57 sites in the Brazilian Atlantic Forest, a highly endangered biodiversity hotspot.Results indicate that habitat loss leads to a decrease in functional integrity while measures of functional diversity remain unchanged or are even positively affected. Changes to functional integrity were caused by (i) a decrease in the provisioning of some functions, and an increase in others; (ii) strong within-guild species turnover; and (iii) a replacement of specialists by generalists. Hence, communities from more deforested sites seem to provide different but not fewer functions. We show the importance of investigating changes to both diversity and composition of functional traits and species, as the effects of habitat loss on ecosystem functioning may be more complex than previously thought. Crucially, when only functional diversity is assessed, important changes to ecological functions may remain undetected and negative effects of habitat loss underestimated, thereby imperiling the application of effective conservation actions.

  10. Soc stock in different forest-related land-uses in central Stara planina mountain, Bulgaria

    Directory of Open Access Journals (Sweden)

    Zhiyanski Miglena

    2009-01-01

    Full Text Available Forest conversions may lead to an accumulation of carbon in vegetation, but little is known about changes in soil C storage with establishment of plantation forests. Understanding these effects is important to addressing issues relevant to ecosystem function and productivity, and to global balance of carbon. The study investigated the effects of the created coniferous plantations on former beech and pasture sites on the soil organic carbon storage. The major forest-related land-uses in the high mountainous regions of central Stara Planina Mountain were investigated: mountainous pasture, coniferous plantations (planted on previous pasture and beech forests between four and five decades ago and natural beech forests. The experimental data of soil properties, conducted in 2005, 2006 and 2007, were used in determining the variations in organic carbon storage in forest litter and in mineral soil under different land-use patterns. At each site five representative soil profiles were opened and described giving a total 75 soil samples from the soil layers respectively at 0-10, 10-30 and 30-50 cm depth. A total of 55 samples from forest floor layers (Aol, Aof, Aoh and greensward were collected with 25:25 cm plastic frame. The main soil properties were determined in accordance with the standardized methods in the Laboratory of soil science at the Forest Research Institute - BAS. The IPCC Good Practice Guidance for Land Use, Land Use Change and Forestry was used to estimate the soil organic carbon stock in soil and litter. The results obtained showed that the SOC stock was quite similar among forest land-uses. The conversion of natural beech forests to coniferous plantations in studied region is related with slightly expressed decrease in soil carbon storage. The values of SOC stocks in 0-50 cm soil layer in these sites were 8.5 (±2.1 tones/ha for pine and 11.0 (±1.4 tones/ha for spruce, while under the natural beech forest it was 14.8 (±1.0 tones

  11. Is the Number of Different MRI Findings More Strongly Associated with Low Back Pain Than Single MRI Findings?

    DEFF Research Database (Denmark)

    Hancock, Mark J; Kjaer, Per; Kent, Peter

    2017-01-01

    STUDY DESIGN: A cross-sectional and longitudinal analysis using 2 different data sets OBJECTIVE.: To investigate if the number of different MRI findings present is more strongly associated with low back pain (LBP) than single MRI findings. SUMMARY OF BACKGROUND DATA: Most previous studies have....... The outcome for the cross-sectional study was presence of LBP during the last year. The outcome for the longitudinal study was days to recurrence of activity limiting LBP. In both data sets we created an aggregate score of the number of different MRI findings present in each individual and assessed...... investigated the associations between single MRI findings and back pain rather than investigating combinations of MRI findings. If different individuals have different pathoanatomic sources contributing to their pain, then combinations of MRI findings may be more strongly associated with LBP. METHODS...

  12. 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.

  13. Ecosystemic, climatic and temporal differences in oribatid communities (Acari: Oribatida) from forest soils.

    Science.gov (United States)

    Corral-Hernández, E; Balanzategui, I; Iturrondobeitia, J C

    2016-08-01

    Oribatid mite communities from 18 natural autochthonous forest soils in the Basque Country, belonging to five forest types, distributed along an ombrothermic gradient of five climatic regions were broadly studied. Forest type and climatic region together (45 % of the total variability) were important factors influencing the oribatid community. The local scale variable (forest type, 28 %) was about as determinant a factor as the regional scale (climatic region, 26 %), though together they accounted for just 9 %. By contrast, the influence of spatial distribution (geography) was not significant by itself but played an important role as a co-variable. Differences in community indices were detected only for species abundances, with holm oak showing the highest oribatid density and beech the lowest. The effect of the passage of time on oribatid communities was also analyzed by comparing recent communities to those of 19-26 years ago in the same forests. The community indices are influenced by the course of time when separate periods of time are compared. Although the recently studied forests apparently show the same conservational conditions as those studied in the past, they are less diverse.

  14. Diversity of Ixodes ricinus tick-associated bacterial communities from different forests

    NARCIS (Netherlands)

    Overbeek, van L.S.; Gassner, F.; Lombaers-van der Plas, C.H.; Kastelein, P.; Nunes da Rocha, U.; Takken, W.

    2008-01-01

    Nymphal Ixodes ricinus ticks (n=180) were collected from three different areas in the Netherlands to investigate the effect of forest composition on tick-associated microbial communities. Sampled habitats differed in thickness of leaf litter and humus layers and vegetation associations and were

  15. Carbon Stocks of Fine Woody Debris in Coppice Oak Forests at Different Development Stages

    Directory of Open Access Journals (Sweden)

    Ender Makineci

    2017-06-01

    Full Text Available Dead woody debris is a significant component of the carbon cycle in forest ecosystems. This study was conducted in coppice-originated oak forests to determine carbon stocks of dead woody debris in addition to carbon stocks of different ecosystem compartments from the same area and forests which were formerly elucidated. Weight and carbon stocks of woody debris were determined with recent samplings and compared among development stages (diameter at breast height (DBH, D1.3m, namely small-diameter forests (SDF = 0–8 cm, medium diameter forests (MDF = 8–20 cm, and large-diameter forests (LDF = 20–36 cm. Total woody debris was collected in samplings; as bilateral diameters of all woody debris parts were less than 10 cm, all woody parts were in the “fine woody debris (FWD” class. The carbon concentrations of FWD were about 48% for all stages. Mass (0.78–4.92 Mg·ha−1 and carbon stocks (0.38–2.39 Mg·ha−1 of FWD were significantly (p > 0.05 different among development stages. FWD carbon stocks were observed to have significant correlation with D1.3m, age, basal area, and carbon stocks of aboveground biomass (Spearman rank correlation coefficients; 0.757, 0.735, 0.709, and 0.694, respectively. The most important effects on carbon budgets of fine woody debris were determined to be coppice management and intensive utilization. Also, national forestry management, treatments of traditional former coppice, and conversion to high forest were emphasized as having substantial effects.

  16. Final report of the project CARBOFOR. Carbon sequestration in the big forest ecosystems in France. Quantification, spatialization, vulnerability and impacts of different climatic and forestry scenario

    International Nuclear Information System (INIS)

    Loustau, D.

    2004-06-01

    The main outcomes of the project allowed to revise the carbon stock estimate of the national french forests, to clarify the interactions between climate and sylviculture according to the ecological profile of main species, to describe the changes in species area distribution for forest trees and pathogens. Different approaches for estimating the national carbon stock in forest biomass were investigated such as biomass equations and architectural models. Some conclusions in terms of adaptation scenario can be drawn. The global production potential of the french forest will be changed. This change is rapid and will occur a time interval shorter than average tree life duration. Species substitution and changing practices must be considered from now. The soil water holding capacity and the nutrient availability interact strongly with the climate effects and are therefore target factors for adapting forest stands to future changes. The dramatic change in the potential area distribution of most pathogens over France lead to recommend strong regulations for avoiding dissemination of fungal diseases and to anticipate the pathogen risks through species distribution. (A.L.B.)

  17. Streamflow response of a small forested catchment on different timescales

    Directory of Open Access Journals (Sweden)

    A. Zabaleta

    2013-01-01

    Full Text Available The hydrological response of a catchment to rainfall on different timescales is result of a complex system involving a range of physical processes which may operate simultaneously and have different spatial and temporal influences. This paper presents the analysis of streamflow response of a small humid-temperate catchment (Aixola, 4.8 km2 in the Basque Country on different timescales and discusses the role of the controlling factors. Firstly, daily time series analysis was used to establish a hypothesis on the general functioning of the catchment through the relationship between precipitation and discharge on an annual and multiannual scale (2003–2008. Second, rainfall-runoff relationships and relationships among several hydrological variables, including catchment antecedent conditions, were explored at the event scale (222 events to check and improve the hypothesis. Finally, the evolution of electrical conductivity (EC during some of the monitored storm events (28 events was examined to identify the time origin of waters. Quick response of the catchment to almost all the rainfall events as well as a considerable regulation capacity was deduced from the correlation and spectral analyses. These results agree with runoff event scale data analysis; however, the event analysis revealed the non-linearity of the system, as antecedent conditions play a significant role in this catchment. Further, analysis at the event scale made possible to clarify factors controlling (precipitation, precipitation intensity and initial discharge the different aspects of the runoff response (runoff coefficient and discharge increase for this catchment. Finally, the evolution of EC of the waters enabled the time origin (event or pre-event waters of the quickflow to be established; specifically, the conductivity showed that pre-event waters usually represent a high percentage of the total discharge during runoff peaks. The importance of soil waters in the

  18. Can Carbon Fluxes Explain Differences in Soil Organic Carbon Storage under Aspen and Conifer Forest Overstories?

    Directory of Open Access Journals (Sweden)

    Antra Boča

    2017-04-01

    Full Text Available Climate- and management-induced changes in tree species distributions are raising questions regarding tree species-specific effects on soil organic carbon (SOC storage and stability. Quaking aspen (Populus tremuloides Michx. is the most widespread tree species in North America, but fire exclusion often promotes the succession to conifer dominated forests. Aspen in the Western US have been found to store more SOC in the mineral soil than nearby conifers, but we do not yet fully understand the source of this differential SOC accumulation. We measured total SOC storage (0–50 cm, characterized stable and labile SOC pools, and quantified above- and belowground litter inputs and dissolved organic carbon (DOC fluxes during snowmelt in plots located in N and S Utah, to elucidate the role of foliage vs. root detritus in SOC storage and stabilization in both ecosystems. While leaf litterfall was twice as high under aspen as under conifers, input of litter-derived DOC with snowmelt water was consistently higher under conifers. Fine root (<2 mm biomass, estimated root detritus input, and root-derived DOC fluxes were also higher under conifers. A strong positive relationship between root and light fraction C content suggests that root detritus mostly fueled the labile fraction of SOC. Overall, neither differences in above- and belowground detritus C inputs nor in detritus-derived DOC fluxes could explain the higher and more stable SOC pools under aspen. We hypothesize that root–microbe–soil interactions in the rhizosphere are more likely to drive these SOC pool differences.

  19. Structure of the herb stratum under different light regimes in the Submontane Atlantic Rain Forest.

    Science.gov (United States)

    Lima, R A F; Gandolfi, S

    2009-05-01

    This study aimed to characterize the structure of the herb stratum in relation to light availability in the Submontane Atlantic Rain Forest at the Carlos Botelho State Park, SP, Brazil. Fortyone 10 x10 m plots were established under the closed canopy (18 plots), small and medium canopy gaps (11) and large canopy gaps dominated by Guadua tagoara (Ness) Kunth (12). Inside each plot, the line intercept method was applied to assess soil coverage as an estimate of density of herb stratum vegetation. Hemispherical photographs were taken at the centre of the plots to evaluate the annual light regime. Overall, Calathea communis Wanderley and S. Vieira had the greater mean coverage, followed by woody seedlings, ground ferns and other herbs (mainly, Araceae, Acanthaceae, Amaranthaceae and Cyperaceae). There were strong correlations among several groups of the herb stratum, such as the negative correlations between woody seedlings with the coverage of C. communis and with rocks. The analysis of the hemispherical photographs confirmed the difference among environments that led to significant differences in the soil coverage of the herb stratum vegetation but woody seedlings. For instance, C. communis showed great coverage in large gaps while ferns were more abundant in small and medium gaps and in the understorey. Other herbs, in turn, demonstrated bigger soil coverage in small and medium gaps. Although this study represents a rough assessment of the structure and composition of the herb stratum, the results found here illustrated the evident relation between herb species density and the environmental variation promoted by changes on canopy structure and topography.

  20. Operational efficiency of forest energy supply chains in different operational environments

    Energy Technology Data Exchange (ETDEWEB)

    Roeser, D.

    2012-06-15

    Ambitious international efforts to combat climate change have lead to a large interest about the use of forest biomass for energy in many countries. In order to meet the expected growing demand in the future, it will be necessary to improve operational efficiency of existing forest energy supply chains and support the establishment of efficient supply chains in new operational environments. The thesis applied a three-dimensional approach which examines forest energy supply chains from a technical, social and economic viewpoint. Four case studies in different operational environments have been carried out to investigate the applicability of the three dimensional approach to improve operational efficiency. The technical dimension was investigated in Paper 1 and 2. In Paper 1, the effects of climatic conditions, covering of piles, and partial debarking on drying of roundwood were studied in four experimental trials located in Scotland, Finland and Italy. In Paper 2, the chipping of forest biomass was studied in two different operational environments. The investigation of the social dimension in Paper 3 provides insights into the setup of two different supply chains through business process mapping and simulation. Finally, in paper 4, which investigated the economic dimension, an analysis of the effect of the operational environment on technology selection and design of supply chains, is presented. The thesis demonstrates that the chosen approach was practical to investigate the complex relationships between the chosen technologies and different supply chain actors and stakeholders thereby contributing to maintain or improve operational efficiency of forest energy supply chains. Due to its applicability in different operational environments, the approach is also suitable in a more global context. Furthermore, it captures the effect of different aspects and characteristics of the various operational environments on the setup and organization of supply chains. This will

  1. Sources of errors and uncertainties in the assessment of forest soil carbon stocks at different scales

    DEFF Research Database (Denmark)

    Vanguelova, E. I.; Bonifacio, E.; De Vos, B.

    2016-01-01

    Spatially explicit knowledge of recent and past soil organic carbon (SOC) stocks in forests will improve our understanding of the effect of human- and non-human-induced changes on forest C fluxes. For SOC accounting, a minimum detectable difference must be defined in order to adequately determine...... and temporal distribution (such as soil type, topography, climate and vegetation) are needed to optimise sampling depths and numbers of samples, thereby ensuring that samples accurately reflect the distribution of SOC at a site. Furthermore, the appropriate scales related to the research question need...

  2. The contrasting nature of woody plant species in different neotropical forest biomes reflects differences in ecological stability.

    Science.gov (United States)

    Pennington, R Toby; Lavin, Matt

    2016-04-01

    A fundamental premise of this review is that distinctive phylogenetic and biogeographic patterns in clades endemic to different major biomes illuminate the evolutionary process. In seasonally dry tropical forests (SDTFs), phylogenies are geographically structured and multiple individuals representing single species coalesce. This pattern of monophyletic species, coupled with their old species stem ages, is indicative of maintenance of small effective population sizes over evolutionary timescales, which suggests that SDTF is difficult to immigrate into because of persistent resident lineages adapted to a stable, seasonally dry ecology. By contrast, lack of coalescence in conspecific accessions of abundant and often widespread species is more frequent in rain forests and is likely to reflect large effective population sizes maintained over huge areas by effective seed and pollen flow. Species nonmonophyly, young species stem ages and lack of geographical structure in rain forest phylogenies may reflect more widespread disturbance by drought and landscape evolution causing resident mortality that opens up greater opportunities for immigration and speciation. We recommend full species sampling and inclusion of multiple accessions representing individual species in phylogenies to highlight nonmonophyletic species, which we predict will be frequent in rain forest and savanna, and which represent excellent case studies of incipient speciation. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  3. [Accumulation of soil organic carbon and total nitrogen in Pinus yunnanensis forests at different age stages].

    Science.gov (United States)

    Miao, Juan; Zhou, Chuan-Yan; Li, Shi-Jie; Yan, Jun-Hua

    2014-03-01

    Taking three Pinus yunnanensis forests at different ages (19, 28 and 45 a) in Panxian County of Guizhou Province as test objects, we investigated vertical distributions and accumulation rates of soil organic carbon (SOC) and total nitrogen (TN), as well as their relationships with soil bulk density. For the three forests at different age stages, SOC and TN changed consistently along the soil profile, declining with the soil depth. Both SOC and TN storage increased with the forest age. The SOC and TN storage amounts were 96.24, 121.65 and 148.13 t x hm(-2), and 10.76, 12.96 and 13.08 t x hm(-2) for the forest stands with 19 a, 28 a and 45 a, respectively. SOC had a significant positive correlation with soil TN, while both of them had a significant negative relationship with the soil bulk density. The accumulation rates of both SOC and TN storage at different growth periods were different, and the rate in the period from age 19 to 28 was higher than in the period from age 28 to 45.

  4. Price transmission between products at different stages of manufacturing in forest industries

    Science.gov (United States)

    Mo Zhou; Joseph Buongiorno

    2005-01-01

    The theory of demand and supply implies a positive relationship, or "price transmission" between the prices of products at different stages of manufacturing, This relationship was investigated with quarterly prices of softwood stumpage in the US South, and national prices of forest products, from 1977 to 2002. All prices, net of inflation, were found to be...

  5. Differences in forest plant functional trait distributions across land-use and productivity gradients

    Science.gov (United States)

    Margaret M. Mayfield; John M. Dwyer; Loic Chalmandrier; Jessie A. Wells; Stephen P. Bonser; Carla P. Catterall; Fabrice DeClerck; Yi Ding; Jennifer M. Fraterrigo; Daniel J. Metcalfe; Cibele Queiroz; Peter A. Vesk; John W. Morgan

    2013-01-01

    • Premise of study: Plant functional traits are commonly used as proxies for plant responses to environmental challenges, yet few studies have explored how functional trait distributions differ across gradients of land-use change. By comparing trait distributions in intact forests with those across land-use change gradients, we can improve our understanding of the ways...

  6. Soil organic carbon quality in forested mineral wetlands at different mean annual temperature.

    Science.gov (United States)

    Cinzia Fissore; Christian P. Giardina; Randall K. Kolka; Carl C. Trettin

    2009-01-01

    Forested mineral soil wetlands (FMSW) store large stocks of soil organic carbon (SOC), but little is known on: (i) whether the quality of SOC stored in these soils (proportion of active versus more resistant SOC compounds) differs from SOC in upland soils; (ii) how the quality of SOC in FMSW varies with mean annual temperature (MAT); and (iii) whether SOC decomposition...

  7. Calcium weathering in forested soils and the effedt of different tree species

    NARCIS (Netherlands)

    Dijkstra, F.A.; Breemen, van N.; Jongmans, A.G.; Davies, G.R.; Likens, G.E.

    2003-01-01

    Soil weathering can be an important mechanism to neutralize acidity in forest soils. Tree species may differ in their effect on or response to soil weathering. We used soil mineral data and the natural strontium isotope ratio Sr-87/Sr-86 as a tracer to identify the effect of tree species on the Ca

  8. Variability in estimated runoff in a forested area based on different cartographic data sources

    Energy Technology Data Exchange (ETDEWEB)

    Fragoso, L.; Quirós, E.; Durán-Barroso, P.

    2017-11-01

    Aim of study: The goal of this study is to analyse variations in curve number (CN) values produced by different cartographic data sources in a forested watershed, and determine which of them best fit with measured runoff volumes. Area of study: A forested watershed located in western Spain. Material and methods: Four digital cartographic data sources were used to determine the runoff CN in the watershed. Main results: None of the cartographic sources provided all the information necessary to determine properly the CN values. Our proposed methodology, focused on the tree canopy cover, improves the achieved results. Research highlights: The estimation of the CN value in forested areas should be attained as a function of tree canopy cover and new calibrated tables should be implemented in a local scale.

  9. Resource communication: Variability in estimated runoff in a forested area based on different cartographic data sources

    Directory of Open Access Journals (Sweden)

    Laura Fragoso

    2017-10-01

    Full Text Available Aim of study: The goal of this study is to analyse variations in curve number (CN values produced by different cartographic data sources in a forested watershed, and determine which of them best fit with measured runoff volumes. Area of study: A forested watershed located in western Spain. Material and methods: Four digital cartographic data sources were used to determine the runoff CN in the watershed. Main results: None of the cartographic sources provided all the information necessary to determine properly the CN values. Our proposed methodology, focused on the tree canopy cover, improves the achieved results. Research highlights: The estimation of the CN value in forested areas should be attained as a function of tree canopy cover and new calibrated tables should be implemented in a local scale.

  10. Functional trait strategies of trees in dry and wet tropical forests are similar but differ in their consequences for succession.

    Science.gov (United States)

    Lohbeck, Madelon; Lebrija-Trejos, Edwin; Martínez-Ramos, Miguel; Meave, Jorge A; Poorter, Lourens; Bongers, Frans

    2014-01-01

    Global plant trait studies have revealed fundamental trade-offs in plant resource economics. We evaluated such trait trade-offs during secondary succession in two species-rich tropical ecosystems that contrast in precipitation: dry deciduous and wet evergreen forests of Mexico. Species turnover with succession in dry forest largely relates to increasing water availability and in wet forest to decreasing light availability. We hypothesized that while functional trait trade-offs are similar in the two forest systems, the successful plant strategies in these communities will be different, as contrasting filters affect species turnover. Research was carried out in 15 dry secondary forest sites (5-63 years after abandonment) and in 17 wet secondary forest sites (dry and wet forest and compare trait trade-offs. We evaluated whether multivariate plant strategies changed during succession, by calculating a 'Community-Weighted Mean' plant strategy, based on species scores on the first two PCA-axes. Trait spectra reflected two main trade-off axes that were similar for dry and wet forest species: acquisitive versus conservative species, and drought avoiding species versus evergreen species with large animal-dispersed seeds. These trait associations were consistent when accounting for evolutionary history. Successional changes in the most successful plant strategies reflected different functional trait spectra depending on the forest type. In dry forest the community changed from having drought avoiding strategies early in succession to increased abundance of evergreen strategies with larger seeds late in succession. In wet forest the community changed from species having mainly acquisitive strategies to those with more conservative strategies during succession. These strategy changes were explained by increasing water availability during dry forest succession and increasing light scarcity during wet forest succession. Although similar trait spectra were observed among dry and

  11. Physical Forest Sructure and its Change estimated by means of Multi-Baseline SAR at different Frequencies

    Science.gov (United States)

    Pardini, M.; Papathanassiou, K.

    2016-12-01

    Forest structure is a key forest parameter to assess biodiversity, successional stage and structural degradation / regeneration of forests, as well as for the development of forest biomass estimators. Forest structure changes is furthermore important to characterize the type and intensity of forest disturbance and seasonal / annual forest cycles. However a large scale structure characterization / monitoring of forest ecosystems is today missing; the systematic estimation of forest structure on larger scales is difficult and requires an increased amount of measurements and effort compared to traditional inventories. Space-borne remote sensing configurations are probably the only option to map vertical and horizontal forest structure and its change on a global scale. Today, two remote sensing techniques appear capable to provide forest structure estimates with an adequate spatial resolution and accuracy: Lidar and Synthetic Aperture Radar (SAR) configurations. SAR configurations are able to reconstruct the 3D reflectivity of volume scatterers by means of tomographic techniques on the basis of multi-baseline (i.e. multi-angular) acquisitions. In this paper we are going to discuss the potential of tomographic SAR techniques to reconstruct 3D forest structure and his changes over time. Emphasis will be given on different approaches to link the 3D radar reflectivity at different frequencies and the physical forest structure parameters. Descriptors for vertical and horizontal forest structure will be discussed and their derivation from the reconstructed 3D reflectivity will be assessed at different scales with respect to their performance to distinguish different forest types and different successional stage from each other. A comparison with the reconstruction obtained from Lidar data will be attempted. Finally the performance of tomographic SAR techniques to estimate and track changes in (horizontal & vertical) structure caused by forest management, logging and / or

  12. Effect of different tree mortality patterns on stand development in the forest model SIBYLA

    Directory of Open Access Journals (Sweden)

    Trombik Jiří

    2016-09-01

    Full Text Available Forest mortality critically affects stand structure and the quality of ecosystem services provided by forests. Spruce bark beetle (Ips typographus generates rather complex infestation and mortality patterns, and implementation of such patterns in forest models is challenging. We present here the procedure, which allows to simulate the bark beetle-related tree mortality in the forest dynamics model Sibyla. We explored how sensitive various production and stand structure indicators are to tree mortality patterns, which can be generated by bark beetles. We compared the simulation outputs for three unmanaged forest stands with 40, 70 and 100% proportion of spruce as affected by the disturbance-related mortality that occurred in a random pattern and in a patchy pattern. The used tree species and age class-specific mortality rates were derived from the disturbance-related mortality records from Slovakia. The proposed algorithm was developed in the SQLite using the Python language, and the algorithm allowed us to define the degree of spatial clustering of dead trees ranging from a random distribution to a completely clustered distribution; a number of trees that died in either mode is set to remain equal. We found significant differences between the long-term developments of the three investigated forest stands, but we found very little effect of the tested mortality modes on stand increment, tree species composition and diversity, and tree size diversity. Hence, our hypothesis that the different pattern of dead trees emergence should affect the competitive interactions between trees and regeneration, and thus affect selected productivity and stand structure indicators was not confirmed.

  13. Urban Forests

    Science.gov (United States)

    David Nowak

    2016-01-01

    Urban forests (and trees) constitute the second forest resource considered in this report. We specifically emphasize the fact that agricultural and urban forests exist on a continuum defined by their relationship (and interrelationship) with a given landscape. These two forest types generally serve different purposes, however. Whereas agricultural forests are...

  14. Temporal Trends of Ecosystem Development on Different Site Types in Reclaimed Boreal Forests

    Directory of Open Access Journals (Sweden)

    Bradley D. Pinno

    2015-06-01

    Full Text Available Forest development after land reclamation in the oil sands mining region of northern Alberta, Canada was assessed using long-term monitoring plots from both reclaimed and natural forests. The metrics of ecosystem development analyzed included measures of plant community structure and composition and soil nutrient availability. Early seral reclamation plots were grouped by site type (dry and moist-rich and age categories, and these were compared with mature natural forests. There were few significant differences in ecosystem metrics between reclamation site types, but natural stands showed numerous significant differences between site types. Over time, there were significant changes in most plant community metrics such as species richness and cover of plant community groups (e.g., forbs, shrubs, and non-native species, but these were still substantially different from mature forests 20 years after reclamation. Available soil nitrogen did not change over time or by reclamation site type but available soil phosphorus did, suggesting that phosphorus may be a more suitable indicator of ecosystem development. The significant temporal changes in these reclaimed ecosystems indicate that studies of ecosystem establishment and development on reclaimed areas should be conducted over the long-term, emphasizing the utility of monitoring using long-term plot networks.

  15. Strong Links Between Teleconnections and Ecosystem Exchange Found at a Pacific Northwest Old-Growth Forest from Flux Tower and MODIS EVI Data

    Energy Technology Data Exchange (ETDEWEB)

    Wharton, S; Chasmer, L; Falk, M; Paw U, K T

    2009-03-12

    Variability in three Pacific teleconnection patterns are examined to see if net carbon exchange at a low-elevation, old-growth forest is affected by climatic changes associated with these periodicities. Examined are the Pacific Decadal Oscillation (PDO), Pacific/North American Oscillation (PNA) and El Nino-Southern Oscillation (ENSO). We use nine years of eddy covariance CO{sub 2}, H{sub 2}O and energy fluxes measured at the Wind River AmeriFlux site, Washington, USA and eight years of tower-pixel remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) to address this question. We compute a new Composite Climate Index (CCI) based on the three Pacific Oscillations to divide the measurement period into positive- (2003 and 2005), negative- (1999 and 2000) and neutral-phase climate years (2001, 2002, 2004, 2006 and 2007). The forest transitioned from an annual net carbon sink (NEP = + 217 g C m{sup -2} year{sup -1}, 1999) to a source (NEP = - 100 g C m{sup -2} year{sup -1}, 2003) during two dominant teleconnection patterns. Net ecosystem productivity (NEP), water use efficiency (WUE) and light use efficiency (LUE) were significantly different (P < 0.01) during positive (NEP = -0.27 g C m{sup -2} day{sup -1}, WUE = 4.1 mg C/g H{sub 2}O, LUE = 0.94 g C MJ{sup -1}) and negative (NEP = +0.37 g C m{sup -2} day{sup -1}, WUE = 3.4 mg C/g H{sub 2}O, LUE = 0.83 g C MJ{sup -1}) climate phases. The CCI was linked to variability in the MODIS Enhanced Vegetation Index (EVI) but not to MODIS Fraction of absorbed Photosynthetically Active Radiation (FPAR). EVI was highest during negative climate phases (1999 and 2000) and was positively correlated with NEP and showed potential for using MODIS to estimate teleconnection-driven anomalies in ecosystem CO{sub 2} exchange in old-growth forests. This work suggests that any increase in the strength or frequency of ENSO coinciding with in-phase, low frequency Pacific oscillations (PDO and PNA) will likely increase

  16. Water Repellency, Infiltration and Water Retention Properties of Forest Soils Under Different Management Practices

    Science.gov (United States)

    Wahl, N. A.; Bens, O.; Schäfer, B.; Hüttl, R. F.

    For soils under both agricultural and forest use, management and tillage practice can have significant influence on the hydraulic properties. It is therefore supposed, that management practices are capable of altering surface runoff, water retention and flood- ing risk for river catchments. Soil water repellency (hydrophobicity) can adversely affect soil hydrological properties, e.g. reduce infiltration capacity and induce pref- erential flow, thus enhancing the overall risk of flooding in river catchment areas. Hydrophobic effects are especially pronounced in coniferous forest soils. Investigations were carried out on several study plots in the German Northeastern Lowlands, located app. 50 km NE of Berlin in Brandenburg. Soils found in the area are mainly of glacifluvial origin with a pronounced sandy texture (with medium sized sand dominating). The four stands investigated represent different stages of forest transfor- mation, in a sense of a SfalseT chronosequence and are made up of populations of & cedil;Pinus sylvestris and Fagus sylvatica of different ages. Infiltration was measured with hood infiltrometers, and single infiltration rings at soil surface. Water retention capacity and the influence of soil organic matter on water storage were evaluated with laboratory methods. Water repellency was quantified with the water drop penetration time (WDPT) test, for determining the persistence of water repellency, and the ethanol percentage (EP) test, for measuring the severity/degree of water repellency. Soil samples from the four forest plots and different soil depths (0U160 cm) were used for the measurements. SPotentialT water repellencies were & cedil;determined after 3-day oven-drying at 45 C. The results indicate that for sandy forest soils, the overall infiltration capacity of the plots is low due to the effects of water repellency. The inter-variability of the plots is mainly caused by changes in the textural composition of the soils. For all plots a

  17. Inoculum production of arbuscular mycorrhizal fungi native to soils under different forest covers

    Directory of Open Access Journals (Sweden)

    Renata Soares dos Santos

    Full Text Available ABSTRACT The low natural fertility of Brazilian soils requires the use of inoculants that facilitate the absorption of nutrients by plants. Arbuscular mycorrhizal fungi such as obligatory biotrophics of active roots perform this function, but access to this resource is limited by the difficulty in producing inoculants. The objective of this study was to investigate the production of AMF inoculants native of soils under different forest covers in Vitória da Conquista, BA, by means of spore quantification, colonization rate and species identification. For this purpose, soils were collected from sites under Mata Nativa (native forest and plantations of Madeira Nova (Pterogyne nitens and Eucalyptus, placed into separate 500 mL disposable cups with seeds of Brachiaria sp. and cultivated for five months. Spores were quantified and the AMF species identified in the control soil (without brachiaria and in the cups cultivated with brachiaria at each month. From the first month, the colonization rate of brachiaria roots was evaluated. The inoculants produced showed differences in the number of spores and species, in the AMF species identified, and in the root colonization rate as a function of the forest cover. Thus, considering the increase in the number of spores, species and colonization over time, the inoculant produced from the soil under native forest was more promising for utilization.

  18. Variation in Vegetation Structure and Soil Properties, and the Relation Between Understory Plants and Environmental Variables Under Different Phyllostachys pubescens Forests in Southeastern China

    Science.gov (United States)

    Zhang, Changshun; Xie, Gaodi; Fan, Shaohui; Zhen, Lin

    2010-04-01

    Biodiversity maintenance and soil improvement are key sustainable forestry objectives. Research on the effects of bamboo forest management on plant diversity and soil properties are therefore necessary in bamboo-growing regions, such as southeastern China’s Shunchang County, that have not been studied from this perspective. We analyzed the effects of different Phyllostachys pubescens proportions in managed forests on vegetation structure and soil properties using pure Cunninghamia lanceolata forests as a contrast, and analyzed the relation between understory plants and environmental variables (i.e., topography, stand and soil characteristics) by canonical correspondence analysis (CCA). The forest with 80% P. pubescens and 20% hardwoods (such as Phoebe bournei, Jatropha curcas, Schima superba) maintained the highest plant diversity and best soil properties, with significantly higher plant diversity than the C. lanceolata forest, and better soil physicochemical and biological properties. The distribution of understory plants is highly related to environmental factors. Silvicultural disturbance strongly influenced the ability of different bamboo forests to maintain biodiversity and soil quality under extensive management, and the forest responses to management were consistent with the intermediate-disturbance hypothesis (i.e., diversity and soil properties were best at intermediate disturbance levels). Our results suggest that biodiversity maintenance and soil improvement are important management goals for sustainable bamboo management. To achieve those objectives, managers should balance the inputs and outputs of nutrients and protect understory plants by using appropriate fertilizer (e.g., organic fertilizer), adjusting stand structure, modifying utilization model and the harvest time, and controlling the intensity of culms and shoots harvests.

  19. Microbial diversity during cellulose decomposition in different forest stands: I. microbial communities and environmental conditions.

    Science.gov (United States)

    Kubartová, Ariana; Moukoumi, Judicaël; Béguiristain, Thierry; Ranger, Jacques; Berthelin, Jacques

    2007-10-01

    We studied the effect of forest tree species on a community of decomposers that colonize cellulose strips. Both fungal and bacterial communities were targeted in a native forest dominated by beech and oak and 30-year-old beech and spruce plantations, growing in similar ecological conditions in the Breuil-Chenue experimental forest site in Morvan (France). Microbial ingrowths from the 3rd to 10th month of strip decomposition (May to December 2004) were studied. Community composition was assessed using temperature gradient gel electrophoresis with universal fungal (ITS1F, ITS2) and bacterial (1401r, 968f) primers. Soil temperature and moisture as well as fungal biomass were also measured to give additional information on decomposition processes. Changing the dominant tree species had no significant influence in the number of decomposer species. However, decomposer community composition was clearly different. If compared to the native forest, where community composition highly differed, young monocultures displayed similar species structure for fungi and bacteria. Both species numbers and community composition evolved during the decay process. Time effect was found to be more important than tree species. Nevertheless, the actual environmental conditions and seasonal effect seemed to be even more determining factors for the development of microbial communities. The course and correlations of the explored variables often differed between tree species, although certain general trends were identified. Fungal biomass was high in summer, despite that species richness (SR) decreased and conversely, that high SR did not necessarily mean high biomass values. It can be concluded that the growth and development of the microbiological communities that colonized a model material in situ depended on the combination of physical and biological factors acting collectively and interdependently at the forest soil microsite.

  20. The European forest sector: past and future carbon budget and fluxes under different management scenarios

    Science.gov (United States)

    Pilli, Roberto; Grassi, Giacomo; Kurz, Werner A.; Fiorese, Giulia; Cescatti, Alessandro

    2017-05-01

    increases (+7 %), heterotrophic respiration increases at a greater rate (+13 %) and this leads to a decrease in the sink in the forest pools (-6 %) in 2030 compared to the historical period. By comparing the evolution of the biomass as a function of the NPP (i.e., the turnover time) for each country, we highlighted at least three groups of countries and turnover times. This means that, contrary to the assumptions proposed by other authors, this relationship cannot be assumed as a constant for all the EU countries, but specific conditions, such as the harvest rate, the current age structure and the forest composition, may contribute to the country-specific evolution of biomass stocks. The detailed picture of the C fluxes condensed in this study, and their evolution under different harvest scenarios, may represent both a benchmark for similar studies and a basis for broader analyses (e.g., including substitution effects of wood) on the mitigation potential of the EU forest sector.

  1. Emission of Nitrous Oxide in Temperate Forests with Different Stages of Nitrogen Saturation in Central Japan

    Science.gov (United States)

    Shaoyan, F.

    2015-12-01

    Long-term nitrogen deposition has caused a problem called nitrogen saturation in forest ecosystems globally. Aber et al. (1989) suggested that nitrogen saturation activate soil nitrification in forest systems, which is the main process of N2O production in aerobic condition. Thus, nitrogen saturation may affect significantly the N2O emission from forests, while the impact on flux has not been quantitatively evaluated yet. In the present study, 3-year monitoring of N2O emission was performed in an N-saturated forests (Tama Hill, Tokyo): the emission rate of N2O was measured monthly by a closed chamber method at 12 plots along a slope, and the net nitrification rate of surface soil (0-10 cm) was measured 4 times in situ. In addition, a comparative research was conducted in summer in eight temperate forests with different stages of nitrogen saturation in central Japan; the N2O flux, soil moisture, nitrogen availability and stream water NO3- concentration were measured at each site. In an N-saturated forests, the annual N2O emission was estimated to be 0.88 kg N ha-1year-1 , showing a typical seasonal variation . The seasonal patterns of N2O emission were significantly related to soil moisture and ambient temperature. We also found high spatial variation of N2O flux among 12 plots along the slope, which was generally higher at the bottom. Moreover, a positive correlation was found between the rate of N2O emission and the net nitrification rate with WFPS60% , probably due to the effect of denitrification. In comparison sites, the N2O emission rate ranged nearly 16-fold from 0.13-2.11 g N ha-1day-1 was linearly related to the stream water NO3- concentration ranged 10-fold from 0.14 to 1.4 mg N/L. Our results revealed N enrichment in forest obviously stimulate soil N2O emission. Keywords: Nitrous oxide, nitrogen saturation, nitrification, temperate forest

  2. Mercury, cadmium and lead concentrations in different ecophysiological groups of earthworms in forest soils

    International Nuclear Information System (INIS)

    Ernst, Gregor; Zimmermann, Stefan; Christie, Peter; Frey, Beat

    2008-01-01

    Bioaccumulation of Hg, Cd and Pb by eight ecophysiologically distinct earthworm species was studied in 27 polluted and uncontaminated forest soils. Lowest tissue concentrations of Hg and Cd occurred in epigeic Lumbricus rubellus and highest in endogeic Octolasion cyaneum. Soils dominated by Dendrodrilus rubidus possess a high potential of risk of Pb biomagnification for secondary predators. Bioconcentration factors (soil-earthworm) followed the sequence ranked Cd > Hg > Pb. Ordination plots of redundancy analysis were used to compare HM concentrations in earthworm tissues with soil, leaf litter and root concentrations and with soil pH and CEC. Different ecological categories of earthworms are exposed to Hg, Cd and Pb in the topsoil by atmospheric deposition and accumulate them in their bodies. Species differences in HM concentrations largely reflect differences in food selectivity and niche separation. - Accumulation of non-essential heavy metals by earthworms is species-dependent and is affected by soil characteristics in natural forest soils

  3. Efficiency of different forest types in carbon storage depends on their internal structure

    Directory of Open Access Journals (Sweden)

    Iuliana F. Gheorghe

    2011-01-01

    Full Text Available Forest vegetation is a key factor in the maintenance of global carbon cycle balance under the present climate change conditions. Forest ecosystems are both buffers against extreme climatic events accompanying climate change and carbon sinks diminishing the environmental impact of anthropogenic greenhouse gas emissions. We investigated the influence of stand structure and site characteristics on the productivity and carbon storage capacity of temperate forest types. Predictors of species productivity were parameters such as stand density, age, height, average diameter and wood density. Morus alba (L. was more productive than average both in terms of annual volume increment and annual biomass gain, while Quercus sessiliflora (Matt. Lieb. and Quercus frainetto (Ten. were significantly less productive than average. Differences in stand productivity were explained by stand density, age, height, altitude, type of regeneration and species composition. Statistically significant differences were measured between the productivity of stands dominated by different woody species, with low productive stands dominated by slow growing species with high wood density like Quercus or Fagus, and highly productive stands rich in fast growing species with low wood density like Populus or Salix. Stands with different plant communities in the underlying herbaceous layer also tended to have different levels of productivity.

  4. Study of Tree and Shrub Species Diversity in Forestry Plans with Different Forest Management

    Directory of Open Access Journals (Sweden)

    nooreddin noorian

    2017-12-01

    Full Text Available The aim of this research was to investigate the diversity of tree and shrub species in forestry plan in a watershed and in almost the same ecological conditions but different in forest management plan in the part of Golestan province forest. To this end, the 6675 hectares of the watershed number of 85 in 5 different plans in series one (30-year forestry plan with University Scientific Management, series two Doctor Bahramnia (without implementation and protection, series four Shamoshak, Naharkhoran plan and Sad Abad plan were selected. Inventory grid was designed by a systematic cluster sampling method with 239 circle plots in the study area. In each sample, species composition and diameter at breast height of trees and shrubs were measured. Species diversity in different series, were performed by calculating the heterogeneity indices, species richness and evenness. Statistical analysis of significant differences between the values of biodiversity of woody species among different series was performed by Duncan’s test. The results showed that biodiversity of woody species in the one and two series of Shastkalateh forest under academic management was better than other plans and forestry plan of Naharkhoran is in an unfavorable situation in terms of diversity indices.

  5. Extraction of the strong neutron-proton mass difference from the charge symmetry breaking in pn->dpi{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Filin, A.; Baru, V. [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Theoretical and Experimental Physics, 117218, B. Cheremushkinskaya 25, Moscow (Russian Federation); Epelbaum, E. [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Haidenbauer, J., E-mail: j.haidenbauer@fz-juelich.d [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany); Hanhart, C. [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany); Kudryavtsev, A. [Institute for Theoretical and Experimental Physics, 117218, B. Cheremushkinskaya 25, Moscow (Russian Federation); Meissner, U.-G. [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany)

    2009-11-16

    We perform a complete calculation of charge symmetry breaking effects for the reaction pn->dpi{sup 0} at leading order in chiral perturbation theory. A new leading-order operator is included. From our analysis we extract deltam{sub N}{sup str}, the strong contribution to the neutron-proton mass difference. The value obtained, deltam{sub N}{sup str}=(1.5+-0.8 (exp.)+-0.5 (th.)) MeV, is consistent with the result based on the Cottingham sum rule. This agreement provides a non-trivial test of our current understanding of the chiral structure of QCD.

  6. Investigating Forest Soil Disturbance with Different Timber Harvesting Operations in South Korea

    Science.gov (United States)

    Im, Sangjun; Lee, Eunjai; Eu, Song; Han, Sang-Kyun

    2017-04-01

    Forest operation such as timber harvesting can influence to forest environment by displacing soil particles, compacting surface layers, and destroying soil structures. This results in increased surface runoff and associated soil erosion during rainy season, due to soil disturbance. The extent of soil disturbance depends on the skidding/yarding method, types of machine used, and soil types. In South Korea, cut-to-length (CTL) operation is traditionally used by excavator with grapple in most areas. Recently, whole-tree (WT) harvesting system by swing yarder has gained considerable attention as an alternative traditional extraction method. The objectives of this study were to describe the effects of two different harvesting methods (CTL and WT) on soil disturbance and soil physical properties. After the CTL observation, we found that severe disturbed soils and compacted area were more than WT. Rutting was influenced more than 50% of the deep disturbance classes by the uphill climbing and downhill extraction method, while exposing bare soil was most disturbance in WT operation. Soil physical properties were influenced considerably by the number of excavator passes and slash residual classes in both units. The results from the study would be useful for understanding soil disturbance influence by timber harvesting in Korea. But, more detailed observations are needed to accurately estimate erosion rates and sediment delivery associated with forest management and operation. Acknowledgements. This study was carried out with the support of 'R&D Program for Forestry Technology (Project No. S211316L020110)' provided by Korea Forest Service.

  7. Nitric oxide (NO) emissions from N-saturated subtropical forest soils are strongly affected by spatial and temporal variability in soil moisture

    Science.gov (United States)

    Kang, Ronghua; Dörsch, Peter; Mulder, Jan

    2016-04-01

    Subtropical forests in Southwest China have chronically high nitrogen (N) deposition. This results in high emission rates of N gasses, including N2O, NO and N2. In contrast to N2O, NO emission in subtropical China has received little attention, partly because its quantification is challenging. Here we present NO fluxes in a Masson pine-dominated headwater catchment with acrisols on mesic, well-drained hill slopes at TieShanPing (Chongqing, SW China). Measurements were conducted from July to September in 2015, using a dynamic chamber technique and a portable and highly sensitive chemiluminesence NOx analyzer (LMA-3M, Drummond Technology Inc, Canada). Mean NO fluxes as high as 120 μg N m-2 h-1 (± 56 μg N m-2 h-1) were observed at the foot of the hill slope. Mid-slope positions had intermediate NO emission rates (47 ± 17 μg N m-2 h-1), whereas the top of the hill slope showed the lowest NO fluxes (3 ± 3 μg N m-2 h-1). The magnitude of NO emission seemed to be controlled mainly by site-specific soil moisture, which was on average lower at the foot of the hill slope and in mid-slope positions than at the top of the hill slope. Rainfall episodes caused a pronounced decline in NO emission fluxes in all hill slope positions, whereas the subsequent gradual drying of the soil resulted in an increase. NO fluxes were negatively correlated with soil moisture (r2 = 0.36, p ˂ 0.05). The NO fluxes increased in the early morning, and decreased in the late afternoon, with peak emissions occurring between 2 and 3 pm. The diurnal variation of NO fluxes on mid-slope positions was positively correlated with soil temperature (r2 = 0.9, p ˂ 0.05). Our intensive measurements indicate that NO-N emissions in N-saturated subtropical forests are significant and strongly controlled by local hydrological conditions.

  8. Effects of different land-uses on soil organic carbon pools in the Peruvian tropical forests

    Science.gov (United States)

    Oliver, V.; Kala, J.; Lever, R.; Teh, Y.

    2013-12-01

    Tropical soils are a large carbon reservoir, acting as both a source and a sink of CO2. Changes to these soil environments have major implications for long term carbon storage and rising atmospheric CO2 concentrations. Enhanced CO2 emissions originate, in large part, from the decomposition and loss of soil organic matter (SOM) following anthropogenic disturbances such as deforestation or agricultural conversion. Therefore, quantitative knowledge of the stabilisation and decomposition of SOM is necessary in order to understand, assess and predict the impact of land use change in the tropics. In particular, labile SOM is an early and sensitive indicator of how SOM responds to changes in land use and management practices. The main focus of this study is to explore the relationship between soil respiration, decomposition and soil C pools in order to estimate the turnover times of soil C on a suite of different land uses in the Peruvian tropical forests. Three major C pools (light fractions, occluded light fractions and heavy fractions) were separated using sodium polytungstate in a density fraction technique, soil CO2 flux was measured bimonthly over a year using a closed-chamber technique and decomposition rates were estimated using buried birch wood sticks acting as a common substrate across the sites. Our results showed that CO2 flux ranged from 0.237-7.676 μmol m-2s-1 for the banana plantation, 2.773-11.1 μmol m-2s-1 for the mature forest, 1.718-17.005 μmol m-2s-1 for pasture and 2.931-5.216 μmol m-2s-1 for the secondary forest. On an annual basis, the soil CO2 flux was highest in the pasture ecosystem with an estimated production of 2.3 kg C m-2yr-1 followed by the banana plantation with 1.3 kg C m-2yr-1 and the mature forest site with 1.0 kg C m-2yr-1. Land use affected soil temperature and bulk density, which also showed positive correlations with CO2 flux. The stick decomposition rate was significantly faster on the pasture site in comparison to the forest

  9. Comparison of different methods for the in situ measurement of forest litter moisture content

    OpenAIRE

    C. Schunk; B. Ruth; M. Leuchner; C. Wastl; A. Menzel

    2015-01-01

    Dead fine fuel (e.g. litter) moisture content is an important parameter for both forest fire and ecological applications as it is related to ignitability, fire behavior as well as soil respiration. However, the comprehensive literature review in this paper shows that there is no easy-to-use method for automated measurements available. This study investigates the applicability of four different sensor types (permittivity and electrical resistance measuring pr...

  10. The Italian National Forest Inventory: geographical and positioning aspects in relation to the different phases of the project

    Science.gov (United States)

    Giacomo Colle; Antonio Floris; Gianfranco Scrinzi; Giovanni Tabacchi; Lorenzo Cavini

    2009-01-01

    In this article, we describe in depth the analysis and solutions to manage the multiple coordinates of the sampling objects coming from the three different phases of the second Italian national forest inventory (Inventario Nazionale delle Foreste e dei serbatoi forestali di Carbonio [INFC]). In particular, this article describes the criteria used to determine the...

  11. Global wood production : assessment of industrial round wood supply from forest management systems in different global regions

    NARCIS (Netherlands)

    Arets, E.J.M.M.; Meer, van der P.J.; Verwer, C.C.; Hengeveld, G.M.; Tolkamp, G.W.; Nabuurs, G.J.; Oorschot, van M.

    2011-01-01

    To meet the global demand for wood the old forest management module of the IMAGE integrated assessment model (Bouwman et al. 2006) only applied clear felling. As a consequence in whole gird cells the forest was completely harvested. In reality, however, there many different ways to produce wood,

  12. Evaluation of forest fires in Portugal Mainland during 2016 summer considering different satellite datasets

    Science.gov (United States)

    Teodoro, A. C.; Amaral, A.

    2017-10-01

    Portugal is one of the most affected countries in Europe by forest fires. Every year in the summer, hundreds of hectares burn, destroying goods and forests at an alarming rate. The objective of this work was to analyze the forest areas burned in Portugal in 2016 (summer) using different satellite data with different spatial resolution (Sentinel-2A MSI and Landsat 8 OLI) in two affected areas. Data from spring from 2016 and 2017 were chosen (pre-fire event and post-fire event) in order to maximize the Normalized Difference Vegetation Index (NDVI) values. The QGIS software's plugin - Semi- Automatic Classification Plugin- which allowed to obtain NDVI values for the Landsat 8 OLI and Sentinel- 2A was used. The results showed that the NDVI decreased considerably in Arouca and Vila Nova de Cerveira after de fire event, meaning a marked drop in vegetation level. In Sintra municipality this change was not verified because non forest fire was registered in this area during the study period. The results from the Sentinel-2A and Landsat 8 OLI data analysis are in agreement, however the Sentinel-2A satellite gives results more accurate than Landsat-8 OLI since it has best spatial resolution. This study could help the experts to understand both the causes and consequences of spatial variability of post-fire effects. Other vegetation spectral indices related with fire and burnt areas could also be calculated in order to discriminate burnt areas. Added to the best spatial resolution of Sentinel-2A (10 m), the temporal resolution of Sentinel- 2A (10 days) was increased with the launch of the twin Sentinel-2B (very recently) and therefore the frequency of the combined constellation revisit will be 5 days. However, for historical studies, the Landsat program remains the best option.

  13. Why Do the Boreal Forest Ecosystems of Northwestern Europe Differ from Those of Western North America?

    Science.gov (United States)

    Boonstra, Rudy; Andreassen, Harry P.; Boutin, Stan; Hušek, Jan; Ims, Rolf A.; Krebs, Charles J.; Skarpe, Christina; Wabakken, Petter

    2016-01-01

    Abstract The boreal forest is one of the largest terrestrial biomes on Earth. Conifers normally dominate the tree layer across the biome, but other aspects of ecosystem structure and dynamics vary geographically. The cause of the conspicuous differences in the understory vegetation and the herbivore–predator cycles between northwestern Europe and western North America presents an enigma. Ericaceous dwarf shrubs and 3– to 4-year vole–mustelid cycles characterize the European boreal forests, whereas tall deciduous shrubs and 10-year snowshoe hare–lynx cycles characterize the North American ones. We discuss plausible explanations for this difference and conclude that it is bottom-up: Winter climate is the key determinant of the dominant understory vegetation that then determines the herbivore–predator food-web interactions. The crucial unknown for the twenty-first century is how climate change and increasing instability will affect these forests, both with respect to the dynamics of individual plant and animal species and to their community interactions. PMID:28533563

  14. Acetazolamide-mediated decrease in strong ion difference accounts for the correction of metabolic alkalosis in critically ill patients.

    Science.gov (United States)

    Moviat, Miriam; Pickkers, Peter; van der Voort, Peter H J; van der Hoeven, Johannes G

    2006-02-01

    Metabolic alkalosis is a commonly encountered acid-base derangement in the intensive care unit. Treatment with the carbonic anhydrase inhibitor acetazolamide is indicated in selected cases. According to the quantitative approach described by Stewart, correction of serum pH due to carbonic anhydrase inhibition in the proximal tubule cannot be explained by excretion of bicarbonate. Using the Stewart approach, we studied the mechanism of action of acetazolamide in critically ill patients with a metabolic alkalosis. Fifteen consecutive intensive care unit patients with metabolic alkalosis (pH > or = 7.48 and HCO3- > or = 28 mmol/l) were treated with a single administration of 500 mg acetazolamide intravenously. Serum levels of strong ions, creatinine, lactate, weak acids, pH and partial carbon dioxide tension were measured at 0, 12, 24, 48 and 72 hours. The main strong ions in urine and pH were measured at 0, 3, 6, 12, 24, 48 and 72 hours. Strong ion difference (SID), strong ion gap, sodium-chloride effect, and the urinary SID were calculated. Data (mean +/- standard error were analyzed by comparing baseline variables and time dependent changes by one way analysis of variance for repeated measures. After a single administration of acetazolamide, correction of serum pH (from 7.49 +/- 0.01 to 7.46 +/- 0.01; P = 0.001) was maximal at 24 hours and sustained during the period of observation. The parallel decrease in partial carbon dioxide tension was not significant (from 5.7 +/- 0.2 to 5.3 +/- 0.2 kPa; P = 0.08) and there was no significant change in total concentration of weak acids. Serum SID decreased significantly (from 41.5 +/- 1.3 to 38.0 +/- 1.0 mEq/l; P = 0.03) due to an increase in serum chloride (from 105 +/- 1.2 to 110 +/- 1.2 mmol/l; P metabolic alkalosis in critically ill patients by decreasing the serum SID. This effect is completely explained by the increased renal excretion ratio of sodium to chloride, resulting in an increase in serum chloride.

  15. Individual differences and the characterization of animal models of psychopathology: a strong challenge and a good opportunity

    Directory of Open Access Journals (Sweden)

    Antonio eArmario

    2013-11-01

    Full Text Available Despite the development of valuable new techniques (i.e. genetics, neuroimage for the study of the neurobiological substrate of psychiatric diseases, there are strong limitations in the information that can be gathered from human studies. It is thus critical to develop appropriate animal models of psychiatric diseases to characterize their putative biological bases and the development of new therapeutic strategies. The present review tries to offer a general perspective and several examples of how individual differences in animals can contribute to explain differential susceptibility to develop behavioural alterations, but also emphasizes methodological problems that can lead to inappropriate or over-simplistic interpretations. A critical analysis of the approaches currently used could contribute to obtain more reliable data and allow taking full advantage of new and sophisticated technologies. The discussion is mainly focused on anxiety-like and to a lower extent on depression-like behaviour in rodents.

  16. CARBON STOCK IN SOIL UNDER DIFFERENT FOREST FORMATIONS, CHAPECÓ, SANTA CATARINA STATE

    Directory of Open Access Journals (Sweden)

    Rosiane Berenice Nicoloso Denardin

    2014-03-01

    Full Text Available http://dx.doi.org/10.5902/1980509813323The adoption of management practices that ensure the stability of soil organic matter also maintain the stabilityor quantitative increase of carbon (C in the lithosphere, reducing the amount of CO2 in theatmosphere. You can also minimize the losses of C to the atmosphere by using conservation practices,or using cover crops to keep the soil C stocks, and the forest cover are considered great abductionand forest systems considered large reservoirs of C. This work was performed on a property located inChapecó, Santa Catarina state, where soils were sampled from different forest formations distributedin a homogeneous soil range. The local climate is mesothermal, rainy, and the soil was characterizedas an association Cambissolo Háplico/Neossolo Litólico. The objectives were to estimate the C stocksin soils and estimate the C losses occurred due to the change of soil cover. It was evaluated soils undernatural forest (FN, of secondary stage, with a high degree of preservation; planted forest of eucalyptus(Eucalyptus saligna (PE, with eight years of cultivation, preceded by 17 years under crop conventionaltillage; and a planted forest of herb mate (Ilex paraguariensis (EM, with 25 years of cultivation underconventional system (cutting interval of 18 months, with removal of all waste produced and maintenanceof the ground without cover, with periodic use of herbicide - glyphosate. In each area were opened fourtrenches with 50 cm deep, where soil samples were collected in depths of: 0-5 cm, 5-10 cm, 10-20 cm,20-30 cm, 30-40 cm, and 40-50 cm, with kopeck rings. It was possible to determine the bulk density (Mgm-3, the soil volume per layer (depth and per hectare, and the concentration of soil C in the differentstudied areas. To quantify the C stocks equal amounts of soil were used for each depth evaluated. Itwas observed higher densities of soils and under PE and EM, to FN the lowest density are explained bythe

  17. Modeling carbon dynamics in two adjacent spruce forests with different soil conditions in Russia

    Directory of Open Access Journals (Sweden)

    J. Kurbatova

    2008-07-01

    Full Text Available Net ecosystem carbon exchange (NEE was measured with eddy covariance method for two adjacent forests located at the southern boundary of European taiga in Russia in 1999–2004. The two spruce forests shared similar vegetation composition but differed in soil conditions. The wet spruce forest (WSF possessed a thick peat layer (60 cm with a high water table seasonally close to or above the soil surface. The dry spruce forest (DSF had a relatively thin organic layer (5 cm with a deep water table (>60 cm. The measured multi-year average NEE fluxes (2000 and –1440 kg C ha−1yr−1 for WSF and DSF, respectively indicated that WSF was a source while DSF a sink of atmospheric carbon dioxide (CO2 during the experimental years. A process-based model, Forest-DNDC, was employed in the study to interpret the observations. The modeled multi-year average NEE fluxes were 1800 and –2200 kg C ha−1yr−1 for WSF and DSF, respectively, which were comparable with observations. The modeled data also showed high soil heterotrophic respiration rates at WSF that suggested that the water table fluctuation at WSF could have played a key role in determining the negative carbon balance in the wetland ecosystem. A sensitivity test was conducted by running Forest-DNDC with varied water table scenarios for WSF. The results indicated that the NEE fluxes from WSF were highly sensitive to the water table depth. When the water table was high, the WSF ecosystem maintained as a sink of atmospheric CO2; while along with the drop of the water table the length of the flooded period reduced and more organic matter in the soil profile suffered from rapid decomposition that gradually converted the ecosystem into a source of atmospheric CO2. The general effect of water table variation on wetland carbon balance observed from this modeling study could be applicable for a wide range of wetland ecosystems that

  18. Biodiversity Differences between Managed and Unmanaged Forests: Meta-Analysis of Species Richness in Europe

    NARCIS (Netherlands)

    Paillet, Y.; Bergès, L.; Hjältén, J.; Ódor, P.; Avon, C.; Bernhardt-Römermann, M.; Bijlsma, R.J.; Bruyn, de L.; Fuhr, M.; Grandin, U.; Kanka, R.; Lundin, L.; Luque, S.; Magura, T.; Matesanz, S.; Mészáros, I.; Sebastià, M.T.; Schmidt, W.; Standovár, T.; Tóthmérész, B.; Uotila, A.; Valladares, F.; Vellak, K.; Virtanen, R.

    2010-01-01

    Past and present pressures on forest resources have led to a drastic decrease in the surface area of unmanaged forests in Europe. Changes in forest structure, composition, and dynamics inevitably lead to changes in the biodiversity of forest-dwelling species. The possible biodiversity gains and

  19. Phylogenetic and functional traits of ectomycorrhizal assemblages in top soil from different biogeographic regions and forest types.

    Science.gov (United States)

    Pena, Rodica; Lang, Christa; Lohaus, Gertrud; Boch, Steffen; Schall, Peter; Schöning, Ingo; Ammer, Christian; Fischer, Markus; Polle, Andrea

    2017-04-01

    Ectomycorrhizal (EM) fungal taxonomic, phylogenetic, and trait diversity (exploration types) were analyzed in beech and conifer forests along a north-to-south gradient in three biogeographic regions in Germany. The taxonomic community structures of the ectomycorrhizal assemblages in top soil were influenced by stand density and forest type, by biogeographic environmental factors (soil physical properties, temperature, and precipitation), and by nitrogen forms (amino acids, ammonium, and nitrate). While α-diversity did not differ between forest types, β-diversity increased, leading to higher γ-diversity on the landscape level when both forest types were present. The highest taxonomic diversity of EM was found in forests in cool, moist climate on clay and silty soils and the lowest in the forests in warm, dry climate on sandy soils. In the region with higher taxonomic diversity, phylogenetic clustering was found, but not trait clustering. In the warm region, trait clustering occurred despite neutral phylogenetic effects. These results suggest that different forest types and favorable environmental conditions in forests promote high EM species richness in top soil presumably with both high functional diversity and phylogenetic redundancy, while stressful environmental conditions lead to lower species richness and functional redundancy.

  20. Assessing the risk caused by ground level ozone to European forest trees: A case study in pine, beech and oak across different climate regions

    International Nuclear Information System (INIS)

    Emberson, Lisa D.; Bueker, Patrick; Ashmore, Mike R.

    2007-01-01

    Two different indices have been proposed for estimation of the risk caused to forest trees across Europe by ground-level ozone, (i) the concentration based AOT40 index (Accumulated Over a Threshold of 40 ppb) and (ii) the recently developed flux based AFstY index (Accumulated stomatal Flux above a flux threshold Y). This paper compares the AOT40 and AFstY indices for three forest trees species at different locations in Europe. The AFstY index is estimated using the DO 3 SE (Deposition of Ozone and Stomatal Exchange) model parameterized for Scots pine (Pinus sylvestris), beech (Fagus sylvatica) and holm oak (Quercus ilex). The results show a large difference in the perceived O 3 risk when using AOT40 and AFstY indices both between species and regions. The AOT40 index shows a strong north-south gradient across Europe, whereas there is little difference between regions in the modelled values of AFstY. There are significant differences in modelled AFstY between species, which are predominantly determined by differences in the timing and length of the growing season, the periods during which soil moisture deficit limits stomatal conductance, and adaptation to soil moisture stress. This emphasizes the importance of defining species-specific flux response variables to obtain a more accurate quantification of O 3 risk. - A new flux-based model provides a revised assessment of risks of ozone impacts to European forests

  1. Co-dominance and succession in forest dynamics: the role of interspecific differences in crown transmissivity.

    Science.gov (United States)

    Cammarano, Mario

    2011-09-21

    Forests that are composed of two or more tree species with similar ecological strategies appear to contradict the competitive exclusion principle. Beech-maple communities are a well-known example of such a system. On a local scale, a number of mechanisms have been proposed to explain the coexistence of these two species. These are reciprocal replacement, external factors that favour alternatively one or the other species and demographic stochasticity. This paper presents and analyses a simple mathematical model that shows that external factors are not an essential requirement for coexistence. Rather, coexistence requires interspecific differences in light transmissivity through the crowns of adult trees. However, all the three mechanisms mentioned above can be interpreted within the framework of the model. Furthermore, many models of forest dynamics make use of shade tolerance as a key feature in describing successional dynamics. Despite its importance, however, shade tolerance does not have a commonly accepted quantitative definition. Here, a simple scheme is proposed where the relationship between shade tolerance, individual traits (growth and survival) and successional status is defined. This might have important implications in understanding the overall dynamics. Theoretical results have been compared with a number of studies carried out in North American forests. In particular, coexistence in beech-maple communities and the relation between shade tolerance and successional status in a beech-hemlock-birch community have been discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Proportion of root-derived acid phosphomonoesterase in total soil acid phosphomonoesterase in different forests

    Directory of Open Access Journals (Sweden)

    Ladislav Holík

    2011-01-01

    Full Text Available Enzyme acid phosphomonoesterase (APM plays an important role in phosphorus mineralization in different type of terrestrial ecosystems. This enzyme is of great agronomic significance because it hydrolyses organic phosphorus to different forms of inorganic phosphorus which are assimilable by plants. APM may also indicate changes in the quantity and quality of phosphorylated substrates in soil and is a good indicator of its biological state as well as presence of pollutants. APM may be produced by plant roots and soil microorganisms and both of these sources may play different role in phosphorus mineralization in different ecosystems. The aim of this work was determine acid phosphomonoesterase (APM activity location in soil of different forest ecosystems. The APM activity location determination was performed on the basis of root-derived and soil-derived APM and expression of proportion of those root-derived in total soil APM up to 13 cm depth. The results of this preliminary study showed that root-derived APM formed 21–34 % of total soil APM in pine and oak forest.

  3. Functional trait strategies of trees in dry and wet tropical forests are similar but differ in their consequences for succession.

    Directory of Open Access Journals (Sweden)

    Madelon Lohbeck

    Full Text Available Global plant trait studies have revealed fundamental trade-offs in plant resource economics. We evaluated such trait trade-offs during secondary succession in two species-rich tropical ecosystems that contrast in precipitation: dry deciduous and wet evergreen forests of Mexico. Species turnover with succession in dry forest largely relates to increasing water availability and in wet forest to decreasing light availability. We hypothesized that while functional trait trade-offs are similar in the two forest systems, the successful plant strategies in these communities will be different, as contrasting filters affect species turnover. Research was carried out in 15 dry secondary forest sites (5-63 years after abandonment and in 17 wet secondary forest sites (<1-25 years after abandonment. We used 11 functional traits measured on 132 species to make species-trait PCA biplots for dry and wet forest and compare trait trade-offs. We evaluated whether multivariate plant strategies changed during succession, by calculating a 'Community-Weighted Mean' plant strategy, based on species scores on the first two PCA-axes. Trait spectra reflected two main trade-off axes that were similar for dry and wet forest species: acquisitive versus conservative species, and drought avoiding species versus evergreen species with large animal-dispersed seeds. These trait associations were consistent when accounting for evolutionary history. Successional changes in the most successful plant strategies reflected different functional trait spectra depending on the forest type. In dry forest the community changed from having drought avoiding strategies early in succession to increased abundance of evergreen strategies with larger seeds late in succession. In wet forest the community changed from species having mainly acquisitive strategies to those with more conservative strategies during succession. These strategy changes were explained by increasing water availability during

  4. Assessing risks and uncertainties in forest dynamics under different management scenarios and climate change

    Directory of Open Access Journals (Sweden)

    Matthias Albert

    2015-05-01

    Full Text Available Background Forest management faces a climate induced shift in growth potential and increasing current and emerging new risks. Vulnerability analysis provides decision support based on projections of natural resources taking risks and uncertainties into account. In this paper we (1 characterize differences in forest dynamics under three management scenarios, (2 analyse the effects of the three scenarios on two risk factors, windthrow and drought stress, and (3 quantify the effects and the amount of uncertainty arising from climate projections on height increment and drought stress. Methods In four regions in northern Germany, we apply three contrasting management scenarios and project forest development under climate change until 2070. Three climate runs (minimum, median, maximum based on the emission scenario RCP 8.5 control the site-sensitive forest growth functions. The minimum and maximum climate run define the range of prospective climate development. Results The projections of different management regimes until 2070 show the diverging medium-term effects of thinnings and harvests and long-term effects of species conversion on a regional scale. Examples of windthrow vulnerability and drought stress reveal how adaptation measures depend on the applied management path and the decision-maker’s risk attitude. Uncertainty analysis shows the increasing variability of drought risk projections with time. The effect of climate projections on height growth are quantified and uncertainty analysis reveals that height growth of young trees is dominated by the age-trend whereas the climate signal in height increment of older trees is decisive. Conclusions Drought risk is a serious issue in the eastern regions independent of the applied silvicultural scenario, but adaptation measures are limited as the proportion of the most drought tolerant species Scots pine is already high. Windthrow risk is no serious overall threat in any region, but adequate

  5. Trends over time in tree and seedling phylogenetic diversity indicate regional differences in forest biodiversity change.

    Science.gov (United States)

    Potter, Kevin M; Woodall, Christopher W

    2012-03-01

    Changing climate conditions may impact the short-term ability of forest tree species to regenerate in many locations. In the longer term, tree species may be unable to persist in some locations while they become established in new places. Over both time frames, forest tree biodiversity may change in unexpected ways. Using repeated inventory measurements five years apart from more than 7000 forested plots in the eastern United States, we tested three hypotheses: phylogenetic diversity is substantially different from species richness as a measure of biodiversity; forest communities have undergone recent changes in phylogenetic diversity that differ by size class, region, and seed dispersal strategy; and these patterns are consistent with expected early effects of climate change. Specifically, the magnitude of diversity change across broad regions should be greater among seedlings than in trees, should be associated with latitude and elevation, and should be greater among species with high dispersal capacity. Our analyses demonstrated that phylogenetic diversity and species richness are decoupled at small and medium scales and are imperfectly associated at large scales. This suggests that it is appropriate to apply indicators of biodiversity change based on phylogenetic diversity, which account for evolutionary relationships among species and may better represent community functional diversity. Our results also detected broadscale patterns of forest biodiversity change that are consistent with expected early effects of climate change. First, the statistically significant increase over time in seedling diversity in the South suggests that conditions there have become more favorable for the reproduction and dispersal of a wider variety of species, whereas the significant decrease in northern seedling diversity indicates that northern conditions have become less favorable. Second, we found weak correlations between seedling diversity change and latitude in both zones

  6. Soil compaction during harvest operations in five tropical soils with different textures under eucalyptus forests

    Directory of Open Access Journals (Sweden)

    Paula Cristina Caruana Martins

    Full Text Available ABSTRACT Traffic of farm machinery during harvest and logging operations has been identified as the main source of soil structure degradation in forestry activity. Soil susceptibility to compaction and the amount of compaction caused by each forest harvest operation differs according to a number of factors (such as soil strength, soil texture, kind of equipment, traffic intensity, among many others, what requires the adequate assessment of soil compaction under different traffic conditions. The objectives of this study were to determine the susceptibility to compaction of five soil classes with different textures under eucalyptus forests based on their load bearing capacity models; and to determine, from these models and the precompression stresses obtained after harvest operations, the effect of traffic intensity with different equipment in the occurrence of soil compaction. Undisturbed soil samples were collected before and after harvest operations, being then subjected to uniaxial compression tests to determine their precompression stress. The coarse-textured soils were less resistant and endured greater soil compaction. In the clayey LVd2, traffic intensity below four Forwarder passes limited compaction to a third of the samples, whereas in the sandy loam PVd all samples from the 0-3 cm layer were compacted regardless of traffic intensity. The Feller Buncher and the Clambunk presented a high potential to cause soil compaction even with only one or two passes. The use of soil load bearing capacity models and precompression stress determined after harvest and logging operations allowed insight into the soil compaction process in forestry soils.

  7. Black carbon yields and types in forest and cultivated sandy soils (Landes de Gascogne, France) as determined with different methods: influence of change in land use

    Energy Technology Data Exchange (ETDEWEB)

    Quenea, K. [UMR CNRS, Paris (France). LBCOP; INRA-CNRS-UPMC, Thjiverval (France). BIOEMCO; Derenne, S.; Largeau, C. [UMR CNRS, Paris (France). LBCOP; Rumpel, C.; Mariotti, A. [INRA-CNRS-UPMC, Thjiverval (France). BIOEMCO; Rouzaud, J.-N. [Laboratoire de Geologie, Paris (France); Gustafsson, O. [Stockholm University (Sweden). Dept. of Applied Environmental Science; Carcaillet, C.C. [Institut de Botanique, Montpelier (France)

    2006-09-15

    Black carbon ( BC ) was isolated from sandy soils of a pine forest reference plot and an adjacent plot used maize cropping since forest clearing 22 years ago. This was performed by: (i) isolation of a refractory organic macromolecular fraction (ROM) using strong hydrolysis followed by chemo-thermal oxidation (CTO) and (ii) direct hand-picking of the untreated soils. Much lower BC contents, ca. x 300, were obtained with the ROM-CTO approach. Experiments on reference chars from the ''international BC-ring trial'' and high resolution, transmission electron microscopy (HRTEM) observations showed that this large difference was not due to BC component losses resulting from the strong hydrolysis during ROM isolation but was due primarily to complete removal of char/charcoal upon CTO. BC is heavily dominated by char/charcoal and soot only affords a very low contribution in both soils. Calculations showed that BC accounts for a substantial part, ca 13% , of total ROM and change in land-use resulted in a large loss of BC relative to the forest soil, ca. 60% after 22 years, thus supporting recent questions raised about BC persistence in soil. (Author)

  8. Red-cockaded woodpecker male/female foraging differences in young forest stands.

    Energy Technology Data Exchange (ETDEWEB)

    Franzreb, Kathleen, E.

    2010-07-01

    ABSTRACT The Red-cockaded Woodpecker (Picoides borealis) is an endangered species endemic to pine (Pinus spp.) forests of the southeastern United States. I examined Red-cockaded Woodpecker foraging behavior to learn if there were male/female differences at the Savannah River Site, South Carolina. The study was conducted in largely young forest stands (,50 years of age) in contrast to earlier foraging behavior studies that focused on more mature forest. The Redcockaded Woodpecker at the Savannah River site is intensively managed including monitoring, translocation, and installation of artificial cavity inserts for roosting and nesting. Over a 3-year period, 6,407 foraging observations covering seven woodpecker family groups were recorded during all seasons of the year and all times of day. The most striking differences occurred in foraging method (males usually scaled [45% of observations] and females mostly probed [47%]),substrate used (females had a stronger preference [93%] for the trunk than males [79%]), and foraging height from the ground (mean 6 SE foraging height was higher for males [11.1 6 0.5 m] than females [9.8 6 0.5 m]). Niche overlap between males and females was lowest for substrate (85.6%) and foraging height (87.8%), and highest for tree species (99.0%), tree condition (98.3%), and tree height (96.4%). Both males and females preferred to forage in older, large pine trees. The habitat available at the Savannah River Site was considerably younger than at most other locations, but the pattern of male/female habitat partitioning observed was similar to that documented elsewhere within the range attesting to the species’ ability to adjust behaviorally.

  9. Fallout volume and litter type affect 137Cs concentration difference in litter between forest and stream environments.

    Science.gov (United States)

    Sakai, Masaru; Gomi, Takashi; Negishi, Junjiro N

    2016-11-01

    It is important to understand the changes in the 137 Cs concentration in litter through leaching when considering that 137 Cs is transferred from basal food resources to animals in forested streams. We found that the difference of 137 Cs activity concentration in litter between forest and stream was associated with both litter type and 137 Cs fallout volume around Fukushima, Japan. The 137 Cs activity concentrations in the litter of evergreen conifers tended to be greater than those in the litter of broad-leaved deciduous trees because of the absence of deciduous leaves during the fallout period in March 2011. Moreover, 137 Cs activity concentrations in forest litter were greater with respect to the 137 Cs fallout volume. The 137 Cs activity concentrations in stream litter were much lower than those in forest litter when those in forest litter were higher. The 137 Cs leaching patterns indicated that the differences in 137 Cs activity concentration between forest and stream litter could change with changes in both fallout volume and litter type. Because litter is an important basal food resource in the food webs of both forests and streams, the 137 Cs concentration gradient reflects to possible 137 Cs transfer from lower to higher trophic animals. Our findings will improve our understanding of the spatial heterogeneity and variability of 137 Cs concentrations in animals resident to the contaminated landscape. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Mass-loss rates from decomposition of plant residues in spruce forests near the northern tree line subject to strong air pollution.

    Science.gov (United States)

    Lukina, Natalia V; Orlova, Maria A; Steinnes, Eiliv; Artemkina, Natalia A; Gorbacheva, Tamara T; Smirnov, Vadim E; Belova, Elena A

    2017-08-01

    Mass-loss rates during the early phase of decomposition of plant residues were studied for a period of 3 years in Norway spruce forests subjected to air pollution by Cu-Ni smelters on the Kola Peninsula, northwest Russia. Litterbags were deployed in two main patches of forests at the northern tree line, between and below the crowns of spruce trees older than 100 years. The study results demonstrated the dependence of the decomposition rates on the initial concentrations of nutrients and the C/N and lignin/N ratios in plant residues. Lower rates of mass loss in forests subject to air pollution may be related to low quality of plant residues, i.e. high concentrations of heavy metals, low concentrations of nutrients, and high lignin/N and C/N ratios. The increased losses of Ca, Mg, K, and Mn from plant residues in these forests compared to the reference were, probably, related to leaching of their compounds from the residues. The relatively high rates of heavy metal accumulation in the residues were most likely related to uptake of pollutants from the atmosphere, as well as to the lower mass-loss rates. The present study results demonstrate that the forest patchiness should be taken into account in assessment and predictions of decomposition rates in Norway spruce forests. Mass-loss rates of plant residues below the crowns of old spruce trees were significantly lower than those in the patches between the crowns. This was explained by the high C/N and lignin/N ratios in the residues of evergreens which contribute significantly to litterfall below the crowns and by lower soil temperature during winter and spring below the crowns. In addition, a lower amount of precipitation reaching the forest floor below the dense, long crowns of old Norway spruce trees may result in considerably lower washing out of the organic compounds from the residues. Lower mass-loss rates below the crowns of old spruce trees may be part of the evidence that the old-growth spruce forests can

  11. Elevation and forest clearing effects on foraging differ between surface--and subterranean--foraging army ants (Formicidae: Ecitoninae).

    Science.gov (United States)

    Kumar, Anjali; O'Donnell, Sean

    2009-01-01

    1. Forest fragmentation often results in a matrix of open areas mixed with patches of forest. Both biotic and abiotic factors can affect consumer species' ability to utilize the altered habitat, especially for species that range over large areas searching for prey. 2. Army ants (Formicidae: Ecitoninae) are highly mobile top predators in terrestrial Neotropical ecosystems. Army ant foraging behaviour is influenced by forest clearing at lowland sites, and clearing can reduce army ant population persistence. 3. Because high temperatures are implicated in hindering above-ground army ant foraging, we predicted that forest clearing effects on army ant foraging would be reduced at higher (cooler) elevations in montane forest. We also predicted that subterranean foraging, employed by some army ant species, would buffer them from the negative effects of forest clearing. 4. We quantified the foraging rates of above-ground and underground foraging army ants at eight sites along an elevational gradient from 1090 to 1540 m a.s.l. We asked whether these two foraging strategies cause a difference in the ability of army ants to forage in open matrix areas relative to elevationally matched forested habitats, and whether elevation predicts open area vs. forest foraging rate differences. 5. As predicted, army ants that forage above-ground had lower foraging rates in open areas, but the open area vs. forest difference declined with elevation. In contrast, underground foragers were not affected by habitat type, and underground foraging rates increased with elevation. Ground surface temperatures were higher in open areas than forested areas. Temperatures declined with elevation, and temperature differences between open and forested areas decreased with elevation. 6. We conclude that army ants that forage above-ground may be restricted to forested areas due to a thermal tolerance threshold, but that they are released from this limitation at higher elevations. We further suggest that

  12. Initial growth of six forest tree species in differents spacing conditions

    Directory of Open Access Journals (Sweden)

    Daniel Ferreira do Nascimento

    2012-03-01

    Full Text Available This work veriflied the influence of planting spacing on the initial growth of six forest species, at the age of 22 months, in plantations of forest recomposition in the Guandu River Basin. The experiment was installed in the SFE - thermoelectric power plants Barbosa Lima Sobrinho, located in the City of Seropédica-RJ. Forty eight tree species were planted, using the spacings, 1.0 x 1.0, 1.5 x 1.5, 2.0 and 2.0 x 3.0 x 2.0 m, which are the study treatments. At 22 months after planting, it was evaluated the growth in height, diameter at ground level (DNS and area of the canopy for the species, Anadenanthera macrocarpa Benth. Brenan (angico vermelho, Schinus terebinthifolius Raddi (aroeira pimenteira, Schizolobium parahyba Blake (guapuruvu Chorisia speciosa St. Hill (paineira, Cordia sp. (babosa branca and Inga marginata (ingá. It was found that the studied species behaved in a different way in the differents spacing of planting, and that the planting density significantly influenced on the initial growth of all the species. In general, in wider planting spacings, the plants had higher growth.

  13. Avian relationships with wildfire at two dry forest locations with different historical fire regimes

    Science.gov (United States)

    Quresh Latif; Jamie Sanderlin; Vicki Saab; William Block; Jonathan Dudley

    2016-01-01

    Wildfire is a key factor influencing bird community composition in western North American forests. We need to understand species and community responses to wildfire and how responses vary regionally to effectively manage dry conifer forests for maintaining biodiversity. We compared avian relationships with wildfire burn severity between two dry forest...

  14. Forest commons and local enforcement.

    Science.gov (United States)

    Chhatre, Ashwini; Agrawal, Arun

    2008-09-09

    This article examines the relationship between local enforcement and forests used as commons. It uses a unique multicountry dataset, created over the past 15 years by the International Forestry Resources and Institutions Research Program. Drawing on original enforcement and forest commons data from 9 countries, we find that higher levels of local enforcement have a strong and positive but complex relationship to the probability of forest regeneration. This relationship holds even when the influence of a number of other factors such as user group size, subsistence, and commercial importance of forests, size of forest, and collective action for forest improvement activities is taken into account. Although several of the above factors have a statistically significant relationship to changes in the condition of forest commons, differences in levels of local enforcement strongly moderate their link with forest commons outcomes. The research, using data from diverse political, social, and ecological contexts, shows both the importance of enforcement to forest commons and some of the limits of forest governance through commons arrangements.

  15. Integrating different knowledge sources and disciplines for practical applications in Forest and Agricultural Engineering

    Science.gov (United States)

    Guzmán, Gema; Castillo, Carlos; Taguas, Encarnación

    2013-04-01

    One of the aims of 'The Bologna Process' is to promote among the students the acquisition of practical, social and creative skills to face real-life situations and to solve the difficulties they might find during their professional life. It involves an important change in the educational system, from a traditional approach focused on teaching, towards a new one that encourages learning. Under this context, University teaching implies the design of activities addressed to the dissemination of "know-how" to solve different problems associated with two technical disciplines: Forest and Agricultural Engineering. This study presents a preliminary experience where a group of information and communication technologies (ICT) such as, audiovisual resources (videos, reports and photo gallery), virtual visits to blogs and interactive activities have been used to provide a comprehensive knowledge of the environmental and sociocultural components of the landscape in order to facilitate the decision-making process in the engineering project context . With these tools, the students must study and characterize all these aspects in order to justify the chosen solutions and the project design. This approach was followed in the analysis of the limiting factors of practical cases in projects about forestation, landscape restoration and hydrological planning. This communication shows how this methodology has been applied in Forest and Agricultural Engineering and the students' experience with these innovative tools. The use of ICTs involved a friendly framework that stimulated students' interest and made subjects more attractive, since it allowed to assess the complex relationships between landscape, history and economy. Furthermore, this type of activities promotes the interdisciplinary training and the acquisition of creative and autonomous skills which are not included in many cases into the main objectives of the subjects.

  16. Effect of pollution with cement dust on the edaphic gamasid mite fauna (Acari: Gamasina) in different forest ecosystems from Romania

    OpenAIRE

    Călugăr, A.

    2013-01-01

    International audience; The present study analyzes the effects of pollution with cement powder on the Gamasina mite communities from soil organic horizon of some forest ecosystems. The study was carried out in two main polluted areas - one situated in Southern Romania (Cement Plant from Campulung Muscel - Arges County) and the other one in the North-East (the Tasca-Bicaz Cement Plant - Neamt County). Forest ecosystems located at different distances from the pollution sources were studied and ...

  17. Persistent differences between coastal and offshore kelp forest communities in a warming Gulf of Maine.

    Directory of Open Access Journals (Sweden)

    Jon D Witman

    Full Text Available Kelp forests provide important ecosystem services, yet coastal kelp communities are increasingly altered by anthropogenic impacts. Kelp forests in remote, offshore locations may provide an informative contrast due to reduced impacts from local stressors. We tested the hypothesis that shallow kelp assemblages (12-15 m depth and associated fish and benthic communities in the coastal southwest Gulf of Maine (GOM differed significantly from sites on Cashes Ledge, 145 km offshore by sampling five coastal and three offshore sites at 43.0 +/- 0.07° N latitude. Offshore sites on Cashes Ledge supported the greatest density (47.8 plants m2 and standing crop biomass (5.5 kg m2 fresh weight of the foundation species Saccharina latissima kelp at this depth in the Western North Atlantic. Offshore densities of S. latissima were over 150 times greater than at coastal sites, with similar but lower magnitude trends for congeneric S. digitata. Despite these differences, S. latissima underwent a significant 36.2% decrease between 1987 and 2015 on Cashes Ledge, concurrent with a rapid warming of the GOM and invasion by the kelp-encrusting bryozoan Membranipora membranacea. In contrast to kelp, the invasive red alga Dasysiphonia japonica was significantly more abundant at coastal sites, suggesting light or dispersal limitation offshore. Spatial differences in fish abundance mirrored those of kelp, as the average biomass of all fish on Cashes Ledge was 305 times greater than at the coastal sites. Remote video censuses of cod (Gadus morhua, cunner (Tautaogolabrus adspersus, and pollock (Pollachius virens corroborated these findings. Understory benthic communities also differed between regions, with greater abundance of sessile invertebrates offshore. Populations of kelp-consuming sea urchins Stronglyocentrotus droebachiensis, were virtually absent from Cashes Ledge while small urchins were abundant onshore, suggesting recruitment limitation offshore. Despite

  18. Persistent differences between coastal and offshore kelp forest communities in a warming Gulf of Maine.

    Science.gov (United States)

    Witman, Jon D; Lamb, Robert W

    2018-01-01

    Kelp forests provide important ecosystem services, yet coastal kelp communities are increasingly altered by anthropogenic impacts. Kelp forests in remote, offshore locations may provide an informative contrast due to reduced impacts from local stressors. We tested the hypothesis that shallow kelp assemblages (12-15 m depth) and associated fish and benthic communities in the coastal southwest Gulf of Maine (GOM) differed significantly from sites on Cashes Ledge, 145 km offshore by sampling five coastal and three offshore sites at 43.0 +/- 0.07° N latitude. Offshore sites on Cashes Ledge supported the greatest density (47.8 plants m2) and standing crop biomass (5.5 kg m2 fresh weight) of the foundation species Saccharina latissima kelp at this depth in the Western North Atlantic. Offshore densities of S. latissima were over 150 times greater than at coastal sites, with similar but lower magnitude trends for congeneric S. digitata. Despite these differences, S. latissima underwent a significant 36.2% decrease between 1987 and 2015 on Cashes Ledge, concurrent with a rapid warming of the GOM and invasion by the kelp-encrusting bryozoan Membranipora membranacea. In contrast to kelp, the invasive red alga Dasysiphonia japonica was significantly more abundant at coastal sites, suggesting light or dispersal limitation offshore. Spatial differences in fish abundance mirrored those of kelp, as the average biomass of all fish on Cashes Ledge was 305 times greater than at the coastal sites. Remote video censuses of cod (Gadus morhua), cunner (Tautaogolabrus adspersus), and pollock (Pollachius virens) corroborated these findings. Understory benthic communities also differed between regions, with greater abundance of sessile invertebrates offshore. Populations of kelp-consuming sea urchins Stronglyocentrotus droebachiensis, were virtually absent from Cashes Ledge while small urchins were abundant onshore, suggesting recruitment limitation offshore. Despite widespread warming of

  19. Differences in the impacts of formal and informal recreational trails on urban forest loss and tree structure.

    Science.gov (United States)

    Ballantyne, Mark; Pickering, Catherine Marina

    2015-08-15

    Recreational trails are one of the most common types of infrastructure used for nature-based activities such as hiking and mountain biking worldwide. Depending on their design, location, construction, maintenance and use, these trails differ in their environmental impacts. There are few studies, however, comparing the impacts of different trail types including between formal management-created trails and informal visitor-created trails. Although both types of trails can be found in remote natural areas, dense networks of them often occur in forests close to cities where they experience intense visitor use. To assess the relative impacts of different recreational trails in urban forests, we compared the condition of the trail surface, loss of forest strata and changes in tree structure caused by seven types of trails (total network 46.1 km) traversing 17 remnants of an endangered urban forest in Australia. After mapping and classifying all trails, we assessed their impact on the forest condition at 125 sites (15 sites per trail type, plus 15 control sites within undisturbed forest). On the trail sites, the condition of the trail surface, distance from the trail edge to four forest strata (litter, understory, midstorey and tree cover) and structure of the tree-line were assessed. Informal trails generally had poorer surface conditions and were poorly-designed and located. Per site, formal and informal trails resulted in similar loss of forest strata, with wider trails resulting in greater loss of forest. Because there were more informal trails, however, they accounted for the greatest cumulative forest loss. Structural impacts varied, with the widest informal trails and all formal hardened trails resulting in similar reductions in canopy cover and tree density but an increase in saplings. These structural impacts are likely a function of the unregulated and intense use of large informal trails, and disturbance from the construction and maintenance of formal trails

  20. Relationship between radiocesium and stable cesium in plants and mushrooms collected from forest ecosystems with different contamination levels

    International Nuclear Information System (INIS)

    Yoshida, S.; Muramatsu, Y.; Steiner, M.

    2000-01-01

    Radiocesium contamination of forest products is still high in contrast to agricultural products, even more than 10 years after the Chernobyl accident. Since the removal of radiocesium from a contaminated forest is not feasible on a large scale, studies on the distribution and transfer of radiocesium in forest ecosystems are important from radiation protection viewpoint. However, the long-term fate of radiocesium in forest ecosystems is still difficult to predict because of the changes in vertical profiles and availability with time of radiocesium in soil, and particularly because of varying stand characteristics. As the chemical behavior of radiocesium is expected to be almost identical to that of stable Cs, analysis of stable Cs should be useful to understand the long-term behavior of radiocesium and its equilibrium distribution. In this study, the concentrations of stable Cs and related alkali and alkaline earth elements in mushrooms, plants and soils were determined by inductively coupled plasma-mass spectrometry (ICP-MS) or inductively coupled plasma-atomic emission spectrometry (ICP-AES). Samples were collected in forests with different contamination levels in Japan, Germany, Finland, Italy, Ireland and Belarus. Data of stable elements were summarized together with those of radiocesium. A good correlation between Cs-137 and stable Cs in mushrooms was observed for each site independently, suggesting that mushrooms take up Cs-137 together with stable Cs. The Cs-137/Cs ratios were almost constant for samples collected at the same site except a German forest. A detailed study on the transfer of Cs-134 from organic soil horizons to fungal fruit bodies in a German forest showed that the Cs-134/Cs ratio reflected the ratios of those soil layers, from which the corresponding mushroom species takes up Cs-134. Different Cs-137/Cs ratios at different sites might be attributable to different depositions of Cs-137 and different forest (soil and vegetation) types. Positive

  1. Stand structure, composition and illegal logging in selectively logged production forests of Myanmar: Comparison of two compartments subject to different cutting frequency

    Directory of Open Access Journals (Sweden)

    Tual Cin Khai

    2016-07-01

    Full Text Available Appropriate cutting cycles and annual allowable cuts are crucial to ensure sustainability of tropical selective logging, but there have been limited field data to verify long-term effects of different cutting cycles. This study reveals some evidence of forest degradation in selectively logged production forests of Myanmar, which are subject to inappropriate cutting frequency. We compared stand structure, commercial species composition, and incidence of illegal logging between two compartments with low (LCF; 1 time and high (HCF; 5 times cutting frequency over a recent 18 years. Prior to the latest cutting, LCF had 176 trees ha−1 with an inverted-J shape distribution of diameter at breast height (DBH, including a substantial amount of teak (Tectona grandis and other commercially important species in each DBH class. HCF prior to the latest cut had only 41 trees ha−1 without many commercially important species. At HCF, nearly half the standing trees of various species and size were illegally cut following legal operations; this was for charcoal making in nearby kilns. At LCF, two species, teak and Xylia xylocarpa, were cut illegally and sawn for timber on the spot. More extensive and systematic surveys are needed to generalize the findings of forest degradation and illegal logging. However, our study calls for urgent reconsideration of logging practices with high cutting frequency, which can greatly degrade forests with accompanying illegal logging, and for rehabilitating strongly degraded, bamboo-dominated forests. To reduce illegal logging, it would be important to pay more attention on a MSS regulation stating that logging roads should be destroyed after logging operations.

  2. Ectomycorrhizal fungus communities of Quercus liaotungensis Koidz of different ages in a northern China temperate forest.

    Science.gov (United States)

    Wang, Qin; He, Xin Hua; Guo, Liang-Dong

    2012-08-01

    Ectomycorrhizal (ECM) fungal communities of Quercus liaotungensis of different ages (seedlings, young trees and mature trees) in the growing seasons (June and September) between 2007 and 2009 were studied in a temperate forest of northern China. A total of 66 ECM fungal taxa were identified based on ECM morphotyping, PCR-RFLP, and DNA sequence data. Of these fungal taxa, 51 were Basidiomycetes (77.3%) and 15 were Ascomycetes (22.7%). Cenococcum geophilum was the dominant species. Thelephoraceae (16 taxa), Sebacinaceae (12 taxa) and Russulaceae (seven taxa) were the most species-rich and abundant ECM fungi, accounting for 19.5%, 17.6% and 8.3% of the total ECM root tips, respectively. Results of multiple response permutation procedure (MRPP) analysis indicated that there were marginally significant effects of tree ages (A = 0.01801, P = 0.054) and growing seasons (A = 0.01908, P = 0.064) on the ECM fungal species composition of Q. liaotungensis in a temperate forest.

  3. The effects of different fertilizers on the ciliate communities of forests

    International Nuclear Information System (INIS)

    Lehle, E.; Funke, W.

    1993-01-01

    The influence of lime, mineral fertilizers and different composts on the ciliate communities (Protozoa: Ciliophora) of very acidified spruce forests were tested. In succession culture experiments species range, total numbers, abundance and dominance structure of the ciliate communities showed continued changes over a 90 day period. This method offers the opportunity not only to diagnose, but also to quantify effects of soil treatments. Investigations at the ARINUS-site Schluchsee (Black Forest) showed the following results: Liming led to a greater change in the ciliate communities than fertilization with magnesium-sulphate and ammonia-sulphate. Liming and treatment with compost, made from household garbage, and compost, made from chopped wood on the Beimerstetten site (Swabian Alb) led also to remarkably changes in the ciliate communities. The total ciliate numbers of the household garbage area were very low. In contrast, the ciliate community of the chopped wood compost areas were characterized by a great species number and high abundances of spirotrichuous ciliates, especially Halteria grandinella. (orig./UWA) [de

  4. Nesting success of birds in different silvicultural treatments in southeastern U.S. Pine Forests

    Science.gov (United States)

    Barber, D.R.; Martin, T.E.; Melchiors, M.A.; Thill, R.E.; Wigley, T.B.

    2001-01-01

    We examined nesting success and levels of nest predation and cowbird parasitism among five different silvicultural treatments: regenerating (3-6 years old), mid-rotation (12-15 years old), and thinned (17-23 years old) pine plantations, single-tree selection, and late-rotation pine-hardwood stands in the Ouachita Mountains of Arkansas from 1993 to 1995. We monitored 1674 nests. Differences in daily mortality and daily predation rate among two or more treatments were found for 4 and 3 of 12 species, respectively. These differences were lost following Bonferroni adjustments, but thinned stands had higher levels of predation than single-tree selection stands when predation levels were averaged across species. Daily predation rates were positively correlated with the relative abundance of birds, suggesting that nest predators respond to prey availability (i.e., nests) in a density-dependent manner. The relative abundance of cowbirds differed among treatments, with the highest densities in regenerating, thinned, and single-tree selection stands. Field Sparrows (Spizella pusilla) and Yellow-breasted Chats (Icteria virens) experienced higher levels of parasitism in thinned than regenerating plantations, whereas White-eyed Vireos (Vireo griseus) experienced higher parasitism in regenerating plantations than in mid-rotation or thinned plantations. Several shrub-nesting and 1 ground-nesting species had lower nesting success in thinned and regenerating plantations than has been reported in previously published studies. Thus, some seral stages of even-aged management may provide low-quality nesting habitat for several early-successional bird species. In contrast, many species nesting in mid-rotation and single-tree selection stands had nesting success similar to or greater than that found in previous studies, suggesting that some silvicultural treatments, when embedded in a largely forested landscape, may provide suitable habitat for forest land birds without affecting their

  5. Diversity, Abundance and Morphological Variations of the Xanthopimpla (Ichneumonidae: Pimplinae) in Different Forest Habitats

    International Nuclear Information System (INIS)

    Ng, Y.F.; Idris, A.B.

    2015-01-01

    The diversity and abundance of Xanthopimpla (Ichneumonidae: Pimplinae) in the secondary and primary forest of Pasoh Forest Reserve (PFR) were studied. A total of 44 individuals of Xanthopimpla and 16 species were recorded. Fifteen species were recorded from the primary forest and only seven species were recorded from the secondary forest. The X. disjunta, X. guptai maculibasis and X. verrucula verrucula were new records for Malaysia. Meanwhile, X. pleurosticta was new record for Peninsular Malaysia. Shannon Diversity Index (H ' ) indicated that the Xanthopimpla diversity at the primary forest was significantly higher (p<0.001) than the secondary forest in PFR. This suggests that logging activity would cause depletion on insect diversity. In the secondary forest a total of 20 Xanthopimpla individuals were caught, whereas 24 individuals were caught from the primary forest. The individual of Xanthopimpla abundance in primary forest was not significantly (p>0.05) higher than secondary forest. The species domination in the secondary forest was more pronounced compared to the primary forest. In the secondary forests, X. elegans elegans (30.0 %) was the highest percentage of total species representation which was higher compared with X. melanacantha melanacantha (16.7 %) and X. honorata honorata (16.7 %) in the primary forest. This suggests that logging activity would cause disappearance of certain species of Xanthopimpla and at the same time might have provided an opportunity for some species to be dominant over the other species. The evolution of the Xanthopimpla in term of morphological characters changes were also discussed in this paper. (author)

  6. The effect of drought on the structure and diversity of bacterial communities in forest soils differently polluted with heavy metals

    Science.gov (United States)

    Chodak, Marcin; Gołębiewski, Marcin; Morawska-Płoskonka, Justyna; Kuduk, Katarzyna; Niklińska, Maria

    2013-04-01

    The chemical properties of soil such as nutrient contents, acidity or heavy metal pollution may affect the ability of soil microorganisms to withstand stressing factors. The objective of this study was to assess the effect of drought stress on the structure of bacterial communities in organic horizons of forest soils differing in acidity and heavy metal pollution. The samples were taken from coniferous forest soils at nine sites differently polluted with Cu, Zn and Pb and having different pH. The samples were placed at stressing conditions (temperature 20 - 30 °C, drought) for eight weeks. The structure of soil bacterial communities was determined prior to and directly after the drought period using pyrosequencing of 16S rRNA genes. The Chao1 index calculated based on the pyrosequencing data was used to assess diversity of the bacterial communities. The chemical analyses of samples included measurement of pH and the contents of Corg, Nt, St, Zn, Cu and Pb. After the drought period the share of Proteobacteria decreased whereas the shares of Actinobaceria and Acidobacteria increased. Decrease of Proteobacteria and increase of Acidobacteria after drought was stronger in soils with lower pH. The share of Bacteroidetes decreased strongly after drought in more acid soils but in the less acid ones remained almost constant. The increase of Actinobacteria share after drought did not depend on soil pH or heavy metal pollution. The heavy metal pollution affected the reaction of Betaproteobacteria, Verrucomicrobia, Cyanobacteria and Chloroflexi to the drought stress. For Betaproteobacteria stronger decrease was observed in the less polluted soils. Similarly, the share of Verrucomicrobia after drought stress increased in the heavy metal polluted soils but decreased in the clean ones. For Cyanobacteria and Chloroflexi the opposite was the case - the shares of these bacterial phyla decreased due to the drought stress in the polluted soils, but remained constant or increased in

  7. THE CONTENT OF ZINC, LEAD AND CADMIUM IN BAY BOLETE (XEROCOMUS BADIUS (FR. E. COLLECTED FROM A STRONGLY POLLUTED FOREST COMPLEX

    Directory of Open Access Journals (Sweden)

    Marek Pająk

    2016-09-01

    Full Text Available The research was carried out in the Świerklaniec Forest District, the Brynica sub-district, which is located in the immediate vicinity of a metallurgical plant, a zinc mine named Huta Cynku "Miasteczko Śląskie" (HCMŚ. In autumn 2008, in the area in question, 31 permanent trial plots were established, aligned within a regular net of squares, with dimensions of 1500×1500 m. The trial plots were located to the north-east and to the east of the emitter (the HCMŚ zinc mine, accordingly with the direction of prevailing winds. In September 2013, and September and October 2014, sporocarps of bay bolete (Xerocomus badius (Fr. E. were collected from the trial plots. The analyses performed for the material gathered covered a determination of heavy metal content in mushrooms (Zn, Pb and Cd, using a method of inductively coupled plasma atomic emission spectroscopy ICP-AES. This paper aimed to establish the accumulation levels of selected heavy metals (Zn, Pb and Cd in bay bolete growing in forests of the Brynica sub-district, in the Świerklaniec Forest District, and the correlation between their content in soil and in the mushrooms under scrutiny. The analyses revealed that the contamination degree in the investigated species was extremely high. The content of toxic elements in bay bolete significantly exceeded the acceptable standards referring to the maximum content of heavy metals in mushrooms, which was particularly true for cadmium.

  8. Carbon storage as affected by different site preparation techniques two years after mixed forest stand installation

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, F.; Figueiredo, T. de; Martins, A.

    2014-06-01

    Aim of study: This study aims at evaluating the impact of site preparation techniques prior to plantation on carbon storage and distribution in a young mixed stand of Pseudotsuga menziesii (PM) and Castanea sativa (CS). Area of study: The experimental field was established near Macedo de Cavaleiros, Northern Portugal, at 700 m elevation, mean annual temperature 12 degree centigrade and mean annual rainfall 678 mm. Material and methods: The experimental layout includes three replicates, where the different treatments corresponding to different tillage intensities were randomly distributed (high, moderate and slight intensity), in plots with an area of 375 m{sup 2} each. Twenty six months after forest stand installation, samples of herbaceous vegetation (0.49 m{sup 2} quadrat), forest species (8 PM and 8 CS) and mineral soil (at 0-5, 5-15, 15-30 and 30-60 cm depth) were collected in 15 randomly selected points in each treatment, processed in laboratory and analyzed for carbon by elemental carbon analyzer. Main results: The results obtained showed that: (i) more than 90% of the total carbon stored in the system is located in the soil, increasing in depth with tillage intensity; (ii) the contribution of herbaceous vegetation and related roots to the carbon storage is very low; (iii) the amount of carbon per tree is higher in CS than in PM; (iv) the global carbon storage was affected by soil tillage generally decreasing with the increase of tillage intensity. Accordingly, carbon storage capacity as affected by the application of different site preparation techniques should be a decision support tool in afforestation schemes. (Author)

  9. Diversity of Social Wasps on Semideciduous Seasonal Forest Fragments with Different Surrounding Matrix in Brazil

    Directory of Open Access Journals (Sweden)

    Getulio Minoru Tanaka Junior

    2011-01-01

    Full Text Available We surveyed social wasps (Polistinae present in forest fragments of northwest of São Paulo state with different surroundings composed of a matrix of citrus crops and sugarcane in the expectation that the former matrix would be more diverse than the latter. We collected specimens actively using attractive liquids. We obtained 20 species in Magda, 13 in Bebedouro, 13 in Matão, and 19 in Barretos. The most common genus was Agelaia in all of the areas. The greatest Shannon-Wiener index of diversity was obtained in Magda (H′=2.12. Species such as Brachygastra moebiana, Metapolybia docilis, Mischocyttarus ignotus, M. paulistanus and M. consimilis had not been recorded on recent surveys in the state. Furthermore M. consimilis is a new record for the state. We concluded that, with our data, a relation between the occurrence of social wasps and the surrounding matrix was not detected.

  10. Comparison of different methods for the in situ measurement of forest litter moisture content

    Science.gov (United States)

    Schunk, C.; Ruth, B.; Leuchner, M.; Wastl, C.; Menzel, A.

    2016-02-01

    Dead fine fuel (e.g., litter) moisture content is an important parameter for both forest fire and ecological applications as it is related to ignitability, fire behavior and soil respiration. Real-time availability of this value would thus be a great benefit to fire risk management and prevention. However, the comprehensive literature review in this paper shows that there is no easy-to-use method for automated measurements available. This study investigates the applicability of four different sensor types (permittivity and electrical resistance measuring principles) for this measurement. Comparisons were made to manual gravimetric reference measurements carried out almost daily for one fire season and overall agreement was good (highly significant correlations with 0.792 fuel moisture measurements are made anyway. Additionally, a number of potential methodological improvements are suggested.

  11. The strongly generalized double difference χ sequence spaces defined by a modulus - doi: 10.4025/actascitechnol.v35i4.16184

    Directory of Open Access Journals (Sweden)

    Subramanian Nagarajan

    2013-10-01

    Full Text Available In this paper we introduce the strongly generalized difference sequence spaces of modulus function and is a non-negative four dimensional matrix of complex numbers and (pi(mn is a sequence of positive real numbers. We also give natural relationship between strongly generalized difference summable sequences with respect of modulus. We examine some topological properties of the above spaces and investigate some inclusion relations between these spaces.  

  12. Mean age of carbon in fine roots from temperate forests and grasslands with different management

    Directory of Open Access Journals (Sweden)

    E. Solly

    2013-07-01

    Full Text Available Fine roots are the most dynamic portion of a plant's root system and a major source of soil organic matter. By altering plant species diversity and composition, soil conditions and nutrient availability, and consequently belowground allocation and dynamics of root carbon (C inputs, land-use and management changes may influence organic C storage in terrestrial ecosystems. In three German regions, we measured fine root radiocarbon (14C content to estimate the mean time since C in root tissues was fixed from the atmosphere in 54 grassland and forest plots with different management and soil conditions. Although root biomass was on average greater in grasslands 5.1 ± 0.8 g (mean ± SE, n = 27 than in forests 3.1 ± 0.5 g (n = 27 (p p r = 0.65 and with the number of perennial species (r = 0.77. Fine root mean C age in grasslands was also affected by study region with averages of 0.7 ± 0.1 yr (n = 9 on mostly organic soils in northern Germany and of 1.8 ± 0.3 yr (n = 9 and 2.6 ± 0.3 (n = 9 in central and southern Germany (p < 0.05. This was probably due to differences in soil nutrient contents and soil moisture conditions between study regions, which affected plant species diversity and the presence of perennial species. Our results indicate more long-lived roots or internal redistribution of C in perennial species and suggest linkages between fine root C age and management in grasslands. These findings improve our ability to predict and model belowground C fluxes across broader spatial scales.

  13. Structure of the tree stratum of three swamp forest communities in southern Brazil under different soil conditions

    Directory of Open Access Journals (Sweden)

    Luciana Carla Mancino

    2015-03-01

    Full Text Available Restinga forests are commonly known to be plant communities rather poor in tree species. This study aimed to describe and explain the association between the floristic-structural similarities and the environmental conditions in three Swamp Restinga Forest communities in southern Brazil. In 13 plots of 100 m2 each, we sampled all individual trees (circumference at breast height >12 cm and height ≥3 m. We collected soil samples in each plot for chemical and textural analyses. Phytosociological parameters were calculated and different structural variables were compared between areas. The density of individuals did not differ between areas; however, the maximum height and abundance of species differed between the site with Histosols and the other two sites with Gleysols. Further, a canonical correspondence analysis based on a matrix of vegetation and that of environmental characteristics explained 31.5% of the total variation. The high floristic and environmental heterogeneity indicate that swamp-forests can shelter many species with low frequency. Most species were generalists that were not exclusive to this type of forest. Overall, our study showed that swamp-forests within the same region can show considerable differences in composition and structure and can include species-rich communities, mostly due to the presence of species with a broader distribution in the Atlantic Rainforest domain on sites with less stressful environmental conditions and without waterlogged conditions.

  14. Species Turnover across Different Life Stages from Seedlings to Canopy Trees in Swamp Forests of Central Brazil

    Directory of Open Access Journals (Sweden)

    Clarissa G. Fontes

    2015-01-01

    Full Text Available Processes driving the assembly of swamp forest communities have been poorly explored. We analyzed natural regeneration and adult tree communities data of a swamp gallery forest in Central Brazil to discuss the role of ecological filters in shaping plant species turnover in a successional gradient. Species data of 120 plots were used to assess species turnover between natural regeneration and adult tree communities. Our analyses were based on 4995 individuals belonging to 72 species. Community patterns were discerned using ordination analyses. A clear floristic turnover among plant life stages was distinguished. Regeneration community of swamp forests was richer in species composition than the adult community. Tree species commonly found in nonflooded gallery forests were present in the regeneration plots but not in the adult community. Differences in the floristic composition of these two strata suggest that not all species in the seedling stage can stand permanent flooding conditions and only a few tolerant species survive to become adult trees. We propose that natural disturbances play an important role by altering limiting resources, allowing seeds of nonflooded forest species to germinate. This paper elucidates the turnover between plant life stages in swamp forests and suggests mechanisms that may shape these communities.

  15. [Temperature sensitivity of soil organic carbon mineralization and β-glucosidase enzymekinetics in the northern temperate forests at different altitudes, China].

    Science.gov (United States)

    Fan, Jin-juan; Li, Dan-dan; Zhang, Xin-yu; He, Nian-peng; Bu, Jin-feng; Wang, Qing; Sun, Xiao-min; Wen, Xue-fa

    2016-01-01

    Soil samples, which were collected from three typical forests, i.e., Betula ermanii forest, coniferous mixed broad-leaved forest, and Pinus koraiensis forest, at different altitudes along the southern slope of Laotuding Mountain of Changbai Mountain range in Liaoning Province of China, were incubated over a temperature gradient in laboratory. Soil organic carbon mineralization rates (Cmin), soil β-1,4-glucosidase (βG) kinetics and their temperature sensitivity (Q₁₀) were measured. The results showed that both altitude and temperature had significant effects on Cmin · Cmin increased with temperature and was highest in the B. ermanii forest. The temperature sensitivity of Cmin [Q₁₀(Cmin)] ranked in order of B. ermanii forest > P. koraiensis forest > coniferous mixed broad-leaved forest, but did not differ significantly among the three forests. Both the maximum activity (Vmax) and the Michaelis constant (Km) of the βG responded positively to temperature for all the forests. The temperature sensitivity of Vmax [Q₁₀(Vmax)] ranged from 1.78 to 1.90, and the temperature sensitivity of Km [Q₁₀(Km)] ranged from 1.79 to 2.00. The Q₁₀(Vmax)/Q10(Km) ratios were significantly greater in the B. ermanii soil than in the other two forest soils, suggesting that the βG kinetics-dependent impacts of the global warming or temperature increase on the decomposition of soil organic carbon were temperature sensitive for the forests at the higher altitudes.

  16. Different leaf cost-benefit strategies of ferns distributed in contrasting light habitats of sub-tropical forests.

    Science.gov (United States)

    Zhu, Shi-Dan; Li, Rong-Hua; Song, Juan; He, Peng-Cheng; Liu, Hui; Berninger, Frank; Ye, Qing

    2016-03-01

    Ferns are abundant in sub-tropical forests in southern China, with some species being restricted to shaded understorey of natural forests, while others are widespread in disturbed, open habitats. To explain this distribution pattern, we hypothesize that ferns that occur in disturbed forests (FDF) have a different leaf cost-benefit strategy compared with ferns that occur in natural forests (FNF), with a quicker return on carbon investment in disturbed habitats compared with old-growth forests. We chose 16 fern species from contrasting light habitats (eight FDF and eight FNF) and studied leaf functional traits, including leaf life span (LLS), specific leaf area (SLA), leaf nitrogen and phosphorus concentrations (N and P), maximum net photosynthetic rates (A), leaf construction cost (CC) and payback time (PBT), to conduct a leaf cost-benefit analysis for the two fern groups. The two groups, FDF and FNF, did not differ significantly in SLA, leaf N and P, and CC, but FDF had significantly higher A, greater photosynthetic nitrogen- and phosphorus-use efficiencies (PNUE and PPUE), and shorter PBT and LLS compared with FNF. Further, across the 16 fern species, LLS was significantly correlated with A, PNUE, PPUE and PBT, but not with SLA and CC. Our results demonstrate that leaf cost-benefit analysis contributes to understanding the distribution pattern of ferns in contrasting light habitats of sub-tropical forests: FDF employing a quick-return strategy can pre-empt resources and rapidly grow in the high-resource environment of open habitats; while a slow-return strategy in FNF allows their persistence in the shaded understorey of old-growth forests. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Using ALS and MODIS data to evaluate degradation in different forests types over the Xingu basin - Brazilian Amazon

    Science.gov (United States)

    Moura, Y.; Aragão, L. E.; Galvão, L. S.; Dalagnol, R.; Lyapustin, A.; Santos, E. G.; Espirito-Santo, F.

    2017-12-01

    Degradation of Amazon rainforests represents a vital threat to carbon storage, climate regulation and biodiversity; however its effect on tropical ecosystems is largely unknown. In this study we evaluate the effects of forest degradation on forest structure and functioning over the Xingu Basin in the Brazilian Amazon. The vegetation types in the area is dominated by Open Ombrophilous Forest (Asc), Semi-decidiuous Forest (Fse) and Dense Ombrophilous Forest (Dse). We used Airborne Laser Scanning (ALS) data together with time series of optical remote sensing images from the Moderate Resolution Imaging Spectroradiometer (MODIS) bi-directional corrected using the Multi-Angle Implementation for Atmospheric Correction (MAIAC). We derive time-series (2008 to 2016) of the Enhanced Vegetation Index (EVI) and Green-Red Normalized Difference (GRND) to analyze the dynamics of degraded areas with related changes in canopy structure and greenness values, respectively. Airborne ALS measurements showed the largest tree heights in the Dse class with values up to 40m tall. Asc and Fse vegetation types reached up to 30m and 25m in height, respectively. Differences in canopy structure were also evident from the analysis of canopy volume models (CVMs). Asc showed higher proportion of sunlit, as expected for open forest types. Fse showed gaps predominantly in lower height levels, and a higher overall proportion of shaded crown. Full canopy closure was reached at about15 m height for both Asc and Dse, and at about 20 m height for Fse. We also used a base map of degraded areas (available from Imazon - Instituto do Homen e Meio Ambiente da Amazônia) to follow these regions throughout time using EVI and GRND from MODIS. All three forest types displayed seasonal cycles. Notable differences in amplitude were detected during the periods when degradation occurred and both indexes showed a decrease in their response. However, there were marked differences in timing and amplitude depending on

  18. Evaluating regional differences in macroinvertebrate communities from forested depressional wetlands across eastern and central North America

    Science.gov (United States)

    Darold P. Batzer; Susan E. Dietz-Brantley; Barbara E. Taylor; Adrienne E. DeBiase

    2005-01-01

    Forested depressional wetlands are an important seasonal wetland type across eastern and central North America. Macroinvertebrates are crucial ecosystem components of most forested depressional wetlands, but community compositions can vary widely across the region. We evaluated variation in macroinvertebrate faunas across eastern and central North America using 5...

  19. Trends over time in tree and seedling phylogenetic diversity indicate regional differences in forest biodiversity change

    Science.gov (United States)

    Kevin M. Potter; Christopher W. Woodall

    2012-01-01

    Changing climate conditions may impact the short-term ability of forest tree species to regenerate in many locations. In the longer term, tree species may be unable to persist in some locations while they become established in new places. Over both time frames, forest tree biodiversity may change in unexpected ways. Using repeated inventory measurements five years...

  20. Functional groups show distinct differences in nitrogen cycling during early stand development: implications for forest management

    Science.gov (United States)

    Doug P. Aubrey; David R. Coyle; Mark D. Coleman

    2012-01-01

    Background and aims Nutrient acquisition of forest stands is controlled by soil resource availability and belowground production, but tree species are rarely compared in this regard. Here, we examine ecological and management implications of nitrogen (N) dynamics during early forest stand development in productive commercial tree species with narrow (Populus...

  1. Public Preferences Across Europe for Different Forest Stand Types as Sites for Recreation

    Directory of Open Access Journals (Sweden)

    David M. Edwards

    2012-03-01

    Full Text Available A Delphi survey involving experts in forest preference research was carried out to derive scores for the recreational value of 240 forest stand types across Europe. The survey was organized around four regional panels: Great Britain, Nordic Region, Central Europe, and Iberia. In each region, 60 forest stand types were defined according to five forest management alternatives (FMAs on a continuum of management intensity, four phases of development (establishment, young, medium, and adult, and three tree species types (conifer, broadleaved, and mixed stands of conifer and broadleaved. The resulting scores were examined using conjoint analysis to determine the relative importance of the three structural attributes (FMA, phase of development, and tree species type, and each level or component of the attributes. The findings quantify the extent to which forest visitors prefer a degree of management to unmanaged forest nature reserves across the four regions. Phase of development was shown to make the highest contribution to the recreational value of forests while the contribution of tree species type was shown to be relatively unimportant. While the results are indicative, they provide evidence to support long-term retention and low-impact silviculture in forests where recreation is a primary objective of management.

  2. [NDVI difference rate recognition model of deciduous broad-leaved forest based on HJ-CCD remote sensing data].

    Science.gov (United States)

    Wang, Yan; Tian, Qing-Jiu; Huang, Yan; Wei, Hong-Wei

    2013-04-01

    The present paper takes Chuzhou in Anhui Province as the research area, and deciduous broad-leaved forest as the research object. Then it constructs the recognition model about deciduous broad-leaved forest was constructed using NDVI difference rate between leaf expansion and flowering and fruit-bearing, and the model was applied to HJ-CCD remote sensing image on April 1, 2012 and May 4, 2012. At last, the spatial distribution map of deciduous broad-leaved forest was extracted effectively, and the results of extraction were verified and evaluated. The result shows the validity of NDVI difference rate extraction method proposed in this paper and also verifies the applicability of using HJ-CCD data for vegetation classification and recognition.

  3. Changes of forest stands vulnerability to future wind damage resulting from different management methods

    DEFF Research Database (Denmark)

    Panferov, O.; Sogachev, Andrey; Ahrends, B.

    2010-01-01

    The structure of forests stands changes continuously as a result of forest growth and both natural and anthropogenic disturbances like windthrow or management activities – planting/cutting of trees. These structure changes can stabilize or destabilize forest stands in terms of their resistance...... to wind damage. The driving force behind the damage is the climate, but the magnitude and sign of resulting effect depend on tree species, management method and soil conditions. The projected increasing frequency of weather extremes in the whole and severe storms in particular might produce wide area...... damage in European forest ecosystems during the 21st century. To assess the possible wind damage and stabilization/destabilization effects of forest management a number of numeric experiments are carried out for the region of Solling, Germany. The coupled small-scale process-based model combining Brook90...

  4. Differences in N loading affect DOM dynamics during typhoon events in a forested mountainous catchment.

    Science.gov (United States)

    Yeh, Tz-Ching; Liao, Chien-Sen; Chen, Ting-Chien; Shih, Yu-Ting; Huang, Jr-Chuan; Zehetner, Franz; Hein, Thomas

    2018-03-21

    The dissolved organic matter (DOM) and nutrient dynamics in small mountainous rivers (SMRs) strongly depend on hydrologic conditions, and especially on extreme events. Here, we investigated the quantity and quality of DOM and inorganic nutrients during base-flow and typhoon events, in a chronically N-saturated mainstream and low N-loaded tributaries of a forested small mountainous reservoir catchment in Taiwan. Our results suggest that divergent transport mechanisms were triggered in the mainstream vs. tributaries during typhoons. The mainstream DON increased from 3.4 to 34.7% of the TDN pool with a static DOC:NO 3 -N ratio and enhanced DOM freshness, signalling a N-enriched DOM transport. Conversely, DON decreased from 46 to 6% of the TDN pool in the tributaries and was coupled with a rapid increase of the DOC:NO 3 -N ratio and humified DOM signals, suggesting the DON and DOC were passively and simultaneously transported. This study confirmed hydrology and spatial dimensions being the main drivers shaping the composition and concentration of DOM and inorganic nutrients in small mountainous catchments subject to hydrologic extremes. We highlighted that the dominant flow paths largely controlled the N-saturation status and DOM composition within each sub-catchment, the effect of land-use could therefore be obscured. Furthermore, N-saturation status and DOM composition are not only a result of hydrologic dynamics, but potential agents modifying the transport mechanism of solutes export from fluvial systems. We emphasize the importance of viewing elemental dynamics from the perspective of a terrestrial-aquatic continuum; and of taking hydrologic phases and individual catchment characteristics into account in water quality management. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Quantifying and reducing the differences in forest CO2-fluxes estimated by eddy covariance, biometric and chamber methods: A global synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xingchang; Wang, Chuankuan; Bond-Lamberty, Benjamin

    2017-12-15

    Carbon dioxide (CO2) fluxes between terrestrial ecosystems and the atmosphere are primarily measured with eddy covariance (EC), biometric, and chamber methods. However, it is unclear why the estimates of CO2-fluxes, when measured using these different methods, converge at some sites but diverge at others. We synthesized a novel global dataset of forest CO2-fluxes to evaluate the consistency between EC and biometric or chamber methods for quantifying CO2 budget in forests. The EC approach, comparing with the other two methods, tended to produce 25% higher estimate of net ecosystem production (NEP, 0.52Mg C ha-1 yr-1), mainly resulting from lower EC-estimated Re; 10% lower ecosystem respiration (Re, 1.39Mg C ha-1 yr-1); and 3% lower gross primary production (0.48 Mg C ha-1 yr-1) The discrepancies between EC and the other methods were higher at sites with complex topography and dense canopies versus those with flat topography and open canopies. Forest age also influenced the discrepancy through the change of leaf area index. The open-path EC system induced >50% of the discrepancy in NEP, presumably due to its surface heating effect. These results provided strong evidence that EC produces biased estimates of NEP and Re in forest ecosystems. A global extrapolation suggested that the discrepancies in CO2 fluxes between methods were consistent with a global underestimation of Re, and overestimation of NEP, by the EC method. Accounting for these discrepancies would substantially improve the our estimates of the terrestrial carbon budget .

  6. Exploring different forest definitions and their impact on developing REDD+ reference emission levels: A case study for Indonesia

    NARCIS (Netherlands)

    Romijn, J.E.; Ainembabazi, J.H.; Wijaya, A.; Herold, M.; Angelsen, A.; Verchot, L.; Murdiyarso, D.

    2013-01-01

    Developing countries participating in the mitigation mechanism of reducing emissions from deforestation and forest degradation and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks (REDD+), need to determine a national forest reference emission level

  7. Dynamic response of the scenic beauty value of different forests to various thinning intensities in central eastern China.

    Science.gov (United States)

    Deng, Songqiu; Yin, Na; Guan, Qingwei; Katoh, Masato

    2014-11-01

    Forest management has a significant influence on the preferences of people for forest landscapes. This study sought to evaluate the dynamic effects of thinning intensities on the landscape value of forests over time. Five typical stands in Wuxiangsi National Forest Park in Nanjing, China, were subjected to a thinning experiment designed with four intensities: unthinned, light thinning, moderate thinning, and heavy thinning. People's preferences for landscape photographs taken in plots under various thinning intensities were assessed through scenic beauty estimation (SBE) at 2 and 5 years after thinning. The differences in scenic beauty value between different thinning intensities were then analyzed with a paired samples t test for the two periods. The results indicated that the landscape value of all of the thinned plots significantly exceeded that of the unthinned plots 2 years after thinning (p beautiful than the lightly thinned and moderately thinned plots, whereas there was no significant difference between moderate thinning and light thinning. At 5 years after thinning, however, the moderately thinned plots received the highest preference scores among the four intensities, displaying an average improvement of 11.32 % compared with the unthinned plots. A multiple linear regression (MLR) model indicated that landscape value improved with increases in the average diameter at breast height (DBH) and with the improvement of environmental cleanliness in the stand, whereas the value decreased with an increasing stem density, species diversity, litter coverage, and canopy density. In addition, we found that the performance of a neural network model based on a multilayer perception (MLP) algorithm for predicting scenic beauty was slightly better than that of the MLR model. The findings of our study suggest that moderate to heavy thinning should be recommended to manage forests for the improvement of forest landscape value.

  8. Comparing the epidermal growth factor interaction with four different cell lines: intriguing effects imply strong dependency of cellular context.

    Directory of Open Access Journals (Sweden)

    Hanna Björkelund

    Full Text Available The interaction of the epidermal growth factor (EGF with its receptor (EGFR is known to be complex, and the common over-expression of EGF receptor family members in a multitude of tumors makes it important to decipher this interaction and the following signaling pathways. We have investigated the affinity and kinetics of (125I-EGF binding to EGFR in four human tumor cell lines, each using four culturing conditions, in real time by use of LigandTracer®.Highly repeatable and precise measurements show that the overall apparent affinity of the (125I-EGF - EGFR interaction is greatly dependent on cell line at normal culturing conditions, ranging from K(D ≈ 200 pM on SKBR3 cells to K(D≈8 nM on A431 cells. The (125I-EGF - EGFR binding curves (irrespective of cell line have strong signs of multiple simultaneous interactions. Furthermore, for the cell lines A431 and SKOV3, gefitinib treatment increases the (125I-EGF - EGFR affinity, in particular when the cells are starved. The (125I-EGF - EGFR interaction on cell line U343 is sensitive to starvation while as on SKBR3 it is insensitive to gefitinib and starvation.The intriguing pattern of the binding characteristics proves that the cellular context is important when deciphering how EGF interacts with EGFR. From a general perspective, care is advisable when generalizing ligand-receptor interaction results across multiple cell-lines.

  9. Strongly seasonal Proterozoic glacial climate in low palaeolatitudes: Radically different climate system on the pre-Ediacaran Earth

    Directory of Open Access Journals (Sweden)

    George E. Williams

    2016-07-01

    Full Text Available Proterozoic (pre-Ediacaran glaciations occurred under strongly seasonal climates near sea level in low palaeolatitudes. Metre-scale primary sand wedges in Cryogenian periglacial deposits are identical to those actively forming, through the infilling of seasonal (winter thermal contraction-cracks in permafrost by windblown sand, in present-day polar regions with a mean monthly air temperature range of 40 °C and mean annual air temperatures of −20 °C or lower. Varve-like rhythmites with dropstones in Proterozoic glacial successions are consistent with an active seasonal freeze–thaw cycle. The seasonal (annual oscillation of sea level recorded by tidal rhythmites in Cryogenian glacial successions indicates a significant seasonal cycle and extensive open seas. Palaeomagnetic data determined directly for Proterozoic glacial deposits and closely associated rocks indicate low palaeolatitudes: Cryogenian deposits in South Australia accumulated at ≤10°, most other Cryogenian deposits at 54° during Proterozoic low-latitude glaciations, whereby the equator would be cooler than the poles, on average, and global seasonality would be greatly amplified.

  10. Litter production in different successional stages of a subtropical secondary rain forest, in Antonina, PR

    Directory of Open Access Journals (Sweden)

    Kauana Melissa Cunha Dickow

    2012-03-01

    Full Text Available This study was conducted in the Cachoeira River Natural Reserve, in Antonina, Paraná state, Brazil. The main goal was to assess the litter production of secondary tropical rain forests in different sucessional stages (initial, medium and advanced stages. The litter fall was collected every 3 weeks during four years (2004 to 2007, in circular litter traps of 0.25m2, distributed in 30 plots of 100m2 of area. A total of 60 litter traps were installed in an area of 3000m2. The litter fall collected at each retrieval date was dried, separated into fractions (leaves, twigs, reproductive organs and miscellaneous and weighed. Leaves of some tree species were selected from the total litter for a specific study of their contribution to the total litter. The average annual litter production for the three years was 5201, 5399 and 5323 kg.ha-1.year-1, and the percentage contribution of the leaf fraction was 77, 75 and 68%, in the initial, medium and advanced sucessional stages, respectively. The leaf litter fraction produced in the initial stage was dominated by the species Tibouchina pulchra (jacatirão (75%, but in the medium and advanced stages the dominance of only one tree species in leaf litter fraction did not occur. The production of twigs and reproductive organs did not differ statistically among the sucessional stages. The production of miscellaneous fraction was higher in the advanced stage and did not differ between the initial and medium stages. In general, the differences in litter production were little along the sucessional stage in the area of the study.

  11. Differences between Pygmy and Non-Pygmy Hunting in Congo Basin Forests.

    Directory of Open Access Journals (Sweden)

    John E Fa

    Full Text Available We use data on game harvest from 60 Pygmy and non-Pygmy settlements in the Congo Basin forests to examine whether hunting patterns and prey profiles differ between the two hunter groups. For each group, we calculate hunted animal numbers and biomass available per inhabitant, P, per year (harvest rates and killed per hunter, H, per year (extraction rates. We assess the impact of hunting of both hunter groups from estimates of numbers and biomass of prey species killed per square kilometre, and by examining the proportion of hunted taxa of low, medium and high population growth rates as a measure of their vulnerability to overhunting. We then map harvested biomass (kg-1P-1Yr-1 of bushmeat by Pygmies and non-Pygmies throughout the Congo Basin. Hunting patterns differ between Pygmies and non-Pygmies; Pygmies take larger and different prey and non-Pygmies sell more for profit. We show that non-Pygmies have a potentially more severe impact on prey populations than Pygmies. This is because non-Pygmies hunt a wider range of species, and twice as many animals are taken per square kilometre. Moreover, in non-Pygmy settlements there was a larger proportion of game taken of low population growth rate. Our harvest map shows that the non-Pygmy population may be responsible for 27 times more animals harvested than the Pygmy population. Such differences indicate that the intense competition that may arise from the more widespread commercial hunting by non-Pygmies is a far more important constraint and source of conflict than are protected areas.

  12. Pyrosequencing-based assessment of bacterial community structure along different management types in German forest and grassland soils.

    Directory of Open Access Journals (Sweden)

    Heiko Nacke

    Full Text Available BACKGROUND: Soil bacteria are important drivers for nearly all biogeochemical cycles in terrestrial ecosystems and participate in most nutrient transformations in soil. In contrast to the importance of soil bacteria for ecosystem functioning, we understand little how different management types affect the soil bacterial community composition. METHODOLOGY/PRINCIPAL FINDINGS: We used pyrosequencing-based analysis of the V2-V3 16S rRNA gene region to identify changes in bacterial diversity and community structure in nine forest and nine grassland soils from the Schwäbische Alb that covered six different management types. The dataset comprised 598,962 sequences that were affiliated to the domain Bacteria. The number of classified sequences per sample ranged from 23,515 to 39,259. Bacterial diversity was more phylum rich in grassland soils than in forest soils. The dominant taxonomic groups across all samples (>1% of all sequences were Acidobacteria, Alphaproteobacteria, Actinobacteria, Betaproteobacteria, Deltaproteobacteria, Gammaproteobacteria, and Firmicutes. Significant variations in relative abundances of bacterial phyla and proteobacterial classes, including Actinobacteria, Firmicutes, Verrucomicrobia, Cyanobacteria, Gemmatimonadetes and Alphaproteobacteria, between the land use types forest and grassland were observed. At the genus level, significant differences were also recorded for the dominant genera Phenylobacter, Bacillus, Kribbella, Streptomyces, Agromyces, and Defluviicoccus. In addition, soil bacterial community structure showed significant differences between beech and spruce forest soils. The relative abundances of bacterial groups at different taxonomic levels correlated with soil pH, but little or no relationships to management type and other soil properties were found. CONCLUSIONS/SIGNIFICANCE: Soil bacterial community composition and diversity of the six analyzed management types showed significant differences between the land

  13. The existence of Sumatran tiger (Panthera tigris sumatrae Pocock, 1929) and their prey in different forest habitat types in Kerinci Seblat National Park, Sumatra

    OpenAIRE

    YOAN DINATA; JITO SUGARDJITO

    2008-01-01

    A study on the relationships between prey animals and the occurence of sumatran tiger was conducted in Kerinci Seblat National Park, western Sumatra from May up to September 2001. The data have been collected from eight study sites based on the forest habitat types and its threats. The results showed that frequency of encounters with prey animals in different forest habitats were no difference. This might indicates that the prey animals were distributed fairly in all types of forest habitat. ...

  14. Random Forests Are Able to Identify Differences in Clotting Dynamics from Kinetic Models of Thrombin Generation.

    Directory of Open Access Journals (Sweden)

    Jayavel Arumugam

    Full Text Available Current methods for distinguishing acute coronary syndromes such as heart attack from stable coronary artery disease, based on the kinetics of thrombin formation, have been limited to evaluating sensitivity of well-established chemical species (e.g., thrombin using simple quantifiers of their concentration profiles (e.g., maximum level of thrombin concentration, area under the thrombin concentration versus time curve. In order to get an improved classifier, we use a 34-protein factor clotting cascade model and convert the simulation data into a high-dimensional representation (about 19000 features using a piecewise cubic polynomial fit. Then, we systematically find plausible assays to effectively gauge changes in acute coronary syndrome/coronary artery disease populations by introducing a statistical learning technique called Random Forests. We find that differences associated with acute coronary syndromes emerge in combinations of a handful of features. For instance, concentrations of 3 chemical species, namely, active alpha-thrombin, tissue factor-factor VIIa-factor Xa ternary complex, and intrinsic tenase complex with factor X, at specific time windows, could be used to classify acute coronary syndromes to an accuracy of about 87.2%. Such a combination could be used to efficiently assay the coagulation system.

  15. Hydrologic response to and recovery from differing silvicultural systems in a deciduous forest landscape with seasonal snow cover

    Science.gov (United States)

    Buttle, J. M.; Beall, F. D.; Webster, K. L.; Hazlett, P. W.; Creed, I. F.; Semkin, R. G.; Jeffries, D. S.

    2018-02-01

    Hydrological consequences of alternative harvesting strategies in deciduous forest landscapes with seasonal snow cover have received relatively little attention. Most forest harvesting experiments in landscapes with seasonal snow cover have focused on clearcutting in coniferous forests. Few have examined alternative strategies such as selection or shelterwood cutting in deciduous stands whose hydrologic responses to harvesting may differ from those of conifers. This study presents results from a 31-year examination of hydrological response to and recovery from alternative harvesting strategies in a deciduous forest landscape with seasonal snow cover in central Ontario, Canada. A quantitative means of assessing hydrologic recovery to harvesting is also developed. Clearcutting resulted in increased water year (WY) runoff. This was accompanied by increased runoff in all seasons, with greatest relative increases in Summer. Direct runoff and baseflow from treatment catchments generally increased following harvesting, although annual peak streamflow did not. Largest increases in WY runoff and seasonal runoff as well as direct runoff and baseflow generally occurred in the selection harvest catchment, likely as a result of interception of hillslope runoff by a forest access road and redirection to the stream channel. Hydrologic recovery appeared to begin towards the end of the experimental period for several streamflow metrics but was incomplete for all harvesting strategies 15 years after harvesting. Geochemical tracing indicated that harvesting enhanced the relative importance of surface and near-surface water pathways on catchment slopes for all treatments, with the clearcut catchment showing the most pronounced and prolonged response. Such insights into water partitioning between flow pathways may assist assessments of the ecological and biogeochemical consequences of forest disturbance.

  16. Ectomycorrhizal community structure of different genotypes of Scots pine under forest nursery conditions.

    Science.gov (United States)

    Leski, Tomasz; Aucina, Algis; Skridaila, Audrius; Pietras, Marcin; Riepsas, Edvardas; Rudawska, Maria

    2010-10-01

    In this paper, we report the effect of Scots pine genotypes on ectomycorrhizal (ECM) community and growth, survival, and foliar nutrient composition of 2-year-old seedlings grown in forest bare-root nursery conditions in Lithuania. The Scots pine seeds originated from five stands from Latvia (P1), Lithuania (P2 and P3), Belarus (P4), and Poland (P5). Based on molecular identification, seven ECM fungal taxa were identified: Suillus luteus and Suillus variegatus (within the Suilloid type), Wilcoxina mikolae, Tuber sp., Thelephora terrestris, Cenococcum geophilum, and Russuloid type. The fungal species richness varied between five and seven morphotypes, depending on seed origin. The average species richness and relative abundance of most ECM morphotypes differed significantly depending on pine origin. The most essential finding of our study is the shift in dominance from an ascomycetous fungus like W. mikolae in P2 and P4 seedlings to basidiomycetous Suilloid species like S. luteus and S. variegatus in P1 and P5 seedlings. Significant differences between Scots pine origin were also found in seedling height, root dry weight, survival, and concentration of C, K, Ca, and Mg in the needles. The Spearman rank correlation coefficient revealed that survival and nutritional status of pine seedlings were positively correlated with abundance of Suilloid mycorrhizas and negatively linked with W. mikolae abundance. However, stepwise multiple regression analysis showed that only survival and magnesium content in pine needles were significantly correlated with abundance of ECM fungi, and Suilloid mycorrhizas were a main significant predictor. Our results may have implications for understanding the physiological and genetic relationship between the host tree and fungi and should be considered in management decisions in forestry and ECM fungus inoculation programs.

  17. FLORISTIC-STRUCTURAL VARIATION OF NATURAL REGENERATION ALONG DIFFERENT TOPOGRAPHIC POSITIONS OF AN ECOTONAL FOREST IN SANTA CATARINA, BRAZIL

    Directory of Open Access Journals (Sweden)

    Chayane Cristina de Souza

    2017-08-01

    Full Text Available ABSTRACT Studies on the natural regeneration of tree species communities are important for providing information on forest development capacity. This research aimed to evaluate the floristic-structural variations of the tree regenerative component along a topographic gradient in an ecotonal area between a Mixed Ombrophilous Forest and a Deciduous Seasonal Forest of Santa Catarina, Brazil. 30 sampling units of which all regenerating tree species individuals have been identified were allocated in the forest fragment. The sampling units were then distributed along a topographic gradient into lower, intermediate and upper sectors. Abundance, richness, Shannon's diversity index (H' and Pielou's evenness index (J have been determined for both the whole community as for each sector. The community floristic-structural organization was verified by the means of the non-metric multidimensional scaling (NMDS, the indicator species analysis and the permutational multivariate analysis of variance (PERMANOVA. Abundance differences among sectors were analyzed through the Kruskal-Wallis test with post hoc multiple nonparametric test while richness differences were verified through rarefaction. Regenerating individuals density in the upper sector [129 (21.300 ind.ha-1] was lower than both in the lower [401 (63.800 ind.ha-1] and intermediary [241 (36.300 ind.ha-1] sectors. There was variation in the floristic-structural composition (p < 0.001 among topographic positions; the lower sector was the most distinct one and showed the highest number of indicator species.

  18. Solidago altissima differs with respect to ploidy frequency and clinal variation across the prairie-forest biome border in Minnesota.

    Science.gov (United States)

    Etterson, Julie R; Toczydlowski, Rachel H; Winkler, Katharine J; Kirschbaum, Jessica A; McAulay, Tim S

    2016-01-01

    Although our awareness of ploidy diversity has expanded with the application of flow cytometry, we still know little about the extent to which cytotypes within mixed-ploidy populations are genetically differentiated across environmental gradients. To address this issue, we reared 14 populations of Solidago altissima spanning the prairie-forest ecotone in Minnesota in a common garden with a watering treatment. We assessed ploidy frequencies and measured survival, flowering phenology, and plant architectural traits for 4 years. All populations harbored multiple cytotypes; prairie populations were dominated by tetraploids, forest populations by hexaploids. Diploids and polyploids differed significantly for 84% of the traits. Beyond average differences, the slope of trait values covaried with latitude and longitude, but this relationship was stronger for diploids than the other two polyploid cytotypes as indicated by numerous ploidy × latitude and ploidy × longitude interactions. For example, the timing of flowering of the cytotypes overlapped in populations sampled from the northeastern hemiboreal forest but differed significantly between cytotypes sampled from populations in the southwestern prairie. The watering treatments had weak effects, and there were no ploidy differences for phenotypic plasticity. Our data show that diploids have diverged genetically to a greater extent than polyploids along the environmental clines sampled in this study. Moreover, different environments favor phenotypic convergence over divergence among cytotypes for some traits. Differences in ploidy frequency and phenotypic divergence among cytotypes across gradients of temperature and precipitation are important considerations for restoration in an age of climate change. © 2016 Botanical Society of America.

  19. Pine forest and grassland differently influence the response of soil microbial communities to metal contamination.

    Science.gov (United States)

    Stefanowicz, Anna M; Niklińska, Maria; Kapusta, Paweł; Szarek-Łukaszewska, Grażyna

    2010-11-15

    Metal pollution can affect soil microbial communities, and vegetation potentially influences this relationship. It can, for example, modify the toxicity of metal to soil microbes by controlling its input to the ground or by altering soil physicochemical properties. This study examined metal effects on soil respiration, potentially active microbial biomass (SIR) and catabolic abilities of culturable heterotrophic bacterial communities (Biolog GN) in pine forest and grassland ecosystems developed on soils contaminated with Zn, Pb and Cd. In samples from non-forested areas we found that metal pollution reduced the microbial biomass and functional diversity of bacteria, while increasing the metabolic quotient. In samples from pine forests we found no relationship between metal pollution and microbial parameters. Metals induced changes in soil respiration neither in forest nor in grassland sites. Generally, microbial performance was determined predominantly by soil physicochemical properties (nutrient content, acidity, contamination level). Vegetation type seemed a minor but important factor influencing microbial communities. More work is needed to determine why even relatively high metal concentrations do not significantly affect microbial communities in forest soils. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. [Distribution characteristics of soil organic carbon under different forest restoration modes on opencast coal mine dump].

    Science.gov (United States)

    Wen, Yue-rong; Dang, Ting-hui; Tang, Jun; Li, Jun-chao

    2016-01-01

    The content and storage of soil organic carbon (SOC) were compared in six wood restoration modes and adjacent abandoned land on opencast coal mine dump, and the mechanisms behind the differences and their influencing factors were analyzed. Results showed that the contents of SOC in six wood lands were significantly higher (23.8%-53.2%) than that of abandoned land (1.92 g · kg⁻¹) at 0-10 cm soil depth, the index were significantly higher (5.8%-70.4%) at 10-20 cm soil depth than the abandoned land (1.39 g · kg⁻¹), and then the difference of the contents of SOC in the deep soil (20-100 cm) were not significant. The contents of SOC decreased with increase of soil depth, but the decreasing magnitude of the topsoil (0-20 cm) was higher than that of the deep soil (20-100 cm). Compared with the deep soil, the topsoil significant higer storage of SOC in different woods, the SOC storage decreased with the soil depth. Along the 0-100 cm soil layer, the storage of SOC in six wood lands higher (18.1%-42.4%) than that of the abandoned land (17.52 t · hm⁻²). The SOC storage of Amorpha fruticosa land (24.95 t · hm⁻²) was obviously higher than that in the other wood lands. The SOC storage in the shrub lands was 12.4% higher than that of the arbor woods. There were significantly positive correlations among forest litter, fine root biomass, soil water content and SOC on the dump. Consequently, different plantation restorations significantly improved the SOC level on the dump in 0-100 cm soil, especially the topsoil. But there was still a big gap about SOC level between the wood restoration lands and the original landform. To improve the SOC on opencast coal mine dump, A. fruticosa could be selected as the main wood vegetation.

  1. Water table depth fluctuations during ENSO phenomenon on different tropical peat swamp forest land covers in Katingan, Indonesia

    Science.gov (United States)

    Rossita, A.; Witono, A.; Darusman, T.; Lestari, D. P.; Risdiyanto, I.

    2018-03-01

    As it is the main role to maintain hydrological function, peatland has been a limelight since drainage construction for agriculture evolved. Drainage construction will decrease water table depth (WTD) and result in CO2 emission release to the atmosphere. Regardless of human intervention, WTD fluctuations can be affected by seasonal climate and climate variability, foremost El Niño Southern Oscillation (ENSO). This study aims to determine the correlation between rainfall in Katingan and ENSO index, analyze the pattern of WTD fluctuation of open area and forest area in 2015 (during very strong El Niño) and 2016 (during weak La Niña), calculate the WTD trendline slope during the dry season, and rainfall and WTD correlation. The result showed that open area has a sharper slope of decreasing or increasing WTD when entering the dry, compared to the forest area. Also, it is found that very strong El Niño in 2015 generated a pattern of more extreme decreasing WTD during the dry season than weak La Niña in 2016.

  2. Quantifying Forest Spatial Pattern Trends at Multiple Extents: An Approach to Detect Significant Changes at Different Scales

    Directory of Open Access Journals (Sweden)

    Ludovico Frate

    2014-09-01

    Full Text Available We propose a procedure to detect significant changes in forest spatial patterns and relevant scales. Our approach consists of four sequential steps. First, based on a series of multi-temporal forest maps, a set of geographic windows of increasing extents are extracted. Second, for each extent and date, specific stochastic simulations that replicate real-world spatial pattern characteristics are run. Third, by computing pattern metrics on both simulated and real maps, their empirical distributions and confidence intervals are derived. Finally, multi-temporal scalograms are built for each metric. Based on cover maps (1954, 2011 with a resolution of 10 m we analyze forest pattern changes in a central Apennines (Italy reserve at multiple spatial extents (128, 256 and 512 pixels. We identify three types of multi-temporal scalograms, depending on pattern metric behaviors, describing different dynamics of natural reforestation process. The statistical distribution and variability of pattern metrics at multiple extents offers a new and powerful tool to detect forest variations over time. Similar procedures can (i help to identify significant changes in spatial patterns and provide the bases to relate them to landscape processes; (ii minimize the bias when comparing pattern metrics at a single extent and (iii be extended to other landscapes and scales.

  3. Comparison of different real time VOC measurement techniques in a ponderosa pine forest

    Directory of Open Access Journals (Sweden)

    L. Kaser

    2013-03-01

    Full Text Available Volatile organic compound (VOC mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS, a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS, a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA, a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS and a Fiber Laser-Induced Fluorescence Instrument (FILIF. The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, the sum of the oxygenated hemiterpene 2-methyl-3-buten-2-ol (MBO and the hemiterpene isoprene, acetaldehyde, the sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK and butanal. Measurements of the above VOCs conducted by different instruments agree within 20%. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK + MAC using PTR-(TOF-MS at this site. A study-average relative contribution of 85% for MVK + MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOF-MS was generally 20–25% higher than the sum of speciated monoterpenes measured by TOGA, which included α-pinene, β-pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the study

  4. Final report of the project CARBOFOR. Carbon sequestration in the big forest ecosystems in France. Quantification, spatialization, vulnerability and impacts of different climatic and forestry scenario; Rapport final du projet CARBOFOR. Sequestration de carbone dans les grands ecosystemes forestiers en France. Quantification, spatialisation, vulnerabilite et impacts de differents scenarios climatiques et sylvicoles

    Energy Technology Data Exchange (ETDEWEB)

    Loustau, D

    2004-06-15

    The main outcomes of the project allowed to revise the carbon stock estimate of the national french forests, to clarify the interactions between climate and sylviculture according to the ecological profile of main species, to describe the changes in species area distribution for forest trees and pathogens. Different approaches for estimating the national carbon stock in forest biomass were investigated such as biomass equations and architectural models. Some conclusions in terms of adaptation scenario can be drawn. The global production potential of the french forest will be changed. This change is rapid and will occur a time interval shorter than average tree life duration. Species substitution and changing practices must be considered from now. The soil water holding capacity and the nutrient availability interact strongly with the climate effects and are therefore target factors for adapting forest stands to future changes. The dramatic change in the potential area distribution of most pathogens over France lead to recommend strong regulations for avoiding dissemination of fungal diseases and to anticipate the pathogen risks through species distribution. (A.L.B.)

  5. Remote sensing?based landscape indicators for the evaluation of threatened?bird habitats in a tropical forest

    OpenAIRE

    Singh, Minerva; Tokola, Timo; Hou, Zhengyang; Notarnicola, Claudia

    2017-01-01

    Abstract Avian species persistence in a forest patch is strongly related to the degree of isolation and size of a forest patch and the vegetation structure within a patch and its matrix are important predictors of bird habitat suitability. A combination of space?borne optical (Landsat), ALOS?PALSAR (radar), and airborne Light Detection and Ranging (LiDAR) data was used for assessing variation in forest structure across forest patches that had undergone different levels of forest degradation i...

  6. Forest start restoration in the agricultural landscape: The effect of different methods of planting establishment

    Czech Academy of Sciences Publication Activity Database

    Dostálek, J.; Weber, M.; Matula, S.; Frantík, Tomáš

    2007-01-01

    Roč. 29, č. 1 (2007), s. 77-86 ISSN 0925-8574 Grant - others:GA MŽP(CZ) SE/640/5/00 Institutional research plan: CEZ:AV0Z60050516 Keywords : Forest stand restoration * Planting technique * Mulching Subject RIV: EF - Botanics Impact factor: 2.175, year: 2007

  7. Differences in forest area classification based on tree tally from variable- and fixed-radius plots

    Science.gov (United States)

    David Azuma; Vicente J. Monleon

    2011-01-01

    In forest inventory, it is not enough to formulate a definition; it is also necessary to define the "measurement procedure." In the classification of forestland by dominant cover type, the measurement design (the plot) can affect the outcome of the classification. We present results of a simulation study comparing classification of the dominant cover type...

  8. Different harvest intensity and soil CO2 efflux in sessile oak coppice forests

    Czech Academy of Sciences Publication Activity Database

    Dařenová, Eva; Majtaz, C.; Pavelka, Marian

    2016-01-01

    Roč. 9, feb (2016), s. 546-552 ISSN 1971-7458 R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) EE2.3.20.0267 Institutional support: RVO:67179843 Keywords : Low Forest * Soil Moisture * Soil Respiration * Temperature Dependence Subject RIV: GK - Forestry Impact factor: 1.623, year: 2016

  9. Changes in the genetic diversity of eastern hemlock as a result of different forest management practices

    Science.gov (United States)

    Gary J. Hawley; Donald H. DeHayes; John C. Brissette

    2000-01-01

    Loss of populations and individuals within species to human-induced selective forces can result in loss of specific genes and overall genetic diversity upon which productivity, ecosystem stability, long-term survival, and evolution depend. This is particularly true for long-lived organisms, such as forest trees, because genetic diversity confers adaptability necessary...

  10. Specific gravity of woody tissue from lowland Neotropical plants: differences among forest types.

    Science.gov (United States)

    Casas, Luisa Fernanda; Aldana, Ana María; Henao-Diaz, Francisco; Villanueva, Boris; Stevenson, Pablo R

    2017-05-01

    Wood density, or more precisely, wood specific gravity, is an important parameter when estimating aboveground biomass, which has become a central tool for the management and conservation of forests around the world. When using biomass allometric equations for tropical forests, researchers are often required to assume phylogenetic trait conservatism, which allows us to assign genus- and family-level wood specific gravity mean values, to many woody species. The lack of information on this trait for many Neotropical plant species has led to an imprecise estimation of the biomass stored in Neotropical forests. The data presented here has information of woody tissue specific gravity from 2,602 individual stems for 386 species, including trees, lianas, and hemi-epiphytes of lowland tropical forests in Colombia. This data set was produced by us collecting wood cores from woody species in five localities in the Orinoco and Magdalena Basins in Colombia. We found lower mean specific gravity values in várzea than in terra firme and igapó. © 2017 The Authors. Ecology, published by Wiley Periodicals, Inc., on behalf of the Ecological Society of America.

  11. Leaf traits show different relationships with shade tolerance in moist versus dry tropical forests

    NARCIS (Netherlands)

    Poorter, L.

    2009-01-01

    ¿ Shade tolerance is the central paradigm for understanding forest succession and dynamics, but there is considerable debate as to what the salient features of shade tolerance are, whether adult leaves show similar shade adaptations to seedling leaves, and whether the same leaf adaptations are found

  12. Architecture of 53 rain forest tree species differing in adult stature and shade tolerance

    NARCIS (Netherlands)

    Poorter, L.; Bongers, F.J.J.M.; Sterck, F.J.; Wöll, H.

    2003-01-01

    Tree architecture determines a tree's light capture, stability, and efficiency of crown growth. The hypothesis that light demand and adult stature of tree species within a community, independently of each other, determine species' architectural traits was tested by comparing 53 Liberian rain forest

  13. Small mammal diversity in the Beskydy Mts forest ecosystems subject to different forms of management

    Czech Academy of Sciences Publication Activity Database

    Čepelka, L.; Suchomel, J.; Purchart, L.; Heroldová, Marta

    2011-01-01

    Roč. 4, č. 2 (2011), s. 101-108 ISSN 1803-2451 R&D Projects: GA MZe QH72075 Institutional research plan: CEZ:AV0Z60930519 Keywords : small mammals * Rodentia * Soricomorpha * diversity * forest ecosystems * management Subject RIV: EH - Ecology, Behaviour

  14. Vulnerability of forests of the Midwest and Northeast United States to climate change

    Science.gov (United States)

    Chris Swanston; Leslie A. Brandt; Maria K. Janowiak; Stephen D. Handler; Patricia Butler-Leopold; Louis Iverson; Frank R. Thompson; Todd A. Ontl; P. Danielle. Shannon

    2018-01-01

    Forests of the Midwest and Northeast significantly define the character, culture, and economy of this large region but face an uncertain future as the climate continues to change. Forests vary widely across the region, and vulnerabilities are strongly influenced by regional differences in climate impacts and adaptive capacity. Not all forests are vulnerable; longer...

  15. Higher climate warming sensitivity of Siberian larch in small than large forest islands in the fragmented Mongolian forest steppe.

    Science.gov (United States)

    Khansaritoreh, Elmira; Dulamsuren, Choimaa; Klinge, Michael; Ariunbaatar, Tumurbaatar; Bat-Enerel, Banzragch; Batsaikhan, Ganbaatar; Ganbaatar, Kherlenchimeg; Saindovdon, Davaadorj; Yeruult, Yolk; Tsogtbaatar, Jamsran; Tuya, Daramragchaa; Leuschner, Christoph; Hauck, Markus

    2017-09-01

    Forest fragmentation has been found to affect biodiversity and ecosystem functioning in multiple ways. We asked whether forest size and isolation in fragmented woodlands influences the climate warming sensitivity of tree growth in the southern boreal forest of the Mongolian Larix sibirica forest steppe, a naturally fragmented woodland embedded in grassland, which is highly affected by warming, drought, and increasing anthropogenic forest destruction in recent time. We examined the influence of stand size and stand isolation on the growth performance of larch in forests of four different size classes located in a woodland-dominated forest-steppe area and small forest patches in a grassland-dominated area. We found increasing climate sensitivity and decreasing first-order autocorrelation of annual stemwood increment with decreasing stand size. Stemwood increment increased with previous year's June and August precipitation in the three smallest forest size classes, but not in the largest forests. In the grassland-dominated area, the tree growth dependence on summer rainfall was highest. Missing ring frequency has strongly increased since the 1970s in small, but not in large forests. In the grassland-dominated area, the increase was much greater than in the forest-dominated landscape. Forest regeneration decreased with decreasing stand size and was scarce or absent in the smallest forests. Our results suggest that the larch trees in small and isolated forest patches are far more susceptible to climate warming than in large continuous forests pointing to a grim future for the forests in this strongly warming region of the boreal forest that is also under high land use pressure. © 2017 John Wiley & Sons Ltd.

  16. Different Effects of Regional Species Pool on Plant Diversity between Forest and Grassland Biomes in Arid Northwest China.

    Science.gov (United States)

    Li, Liping; Liu, Yining; Wang, Xiangping; Fang, Jingyun; Wang, Qingchun; Zhang, Bengang; Xiao, Peigen; Mohammat, Anwar; Terwei, André

    2015-01-01

    Species pool hypothesis is broadly known and frequently tested in various regions and vegetation types. However it has not been tested in the arid Xinjiang region of China due to lack of data. Here with systematic data from references and field survey, we comprehensively examined species pool hypothesis in this region. Took species richness in 0.1° × 0.1° grid cells as regional species richness (RSR) which were obtained from the distribution maps of vascular plant species, and took species diversity of 190 and 103 plots in forest and grassland biomes across Xinjiang as local species richness (LSR), together with the digitalized soil pH and climate data, we tested the species pool hypothesis in this region. We found that: (1) the average RSR was higher in mountains than that in basins and it was negatively correlated with soil pH in mountains while positively correlated with soil pH in basins in Xinjiang; (2) RSR showed a positive correlation with mean annual precipitation (MAP) while showed a hump-shaped pattern with mean annual temperature (MAT); and the changing patterns of LSR were different for forest and grassland along the geographical and climate gradients; (3) LSR of forest was more affected by RSR than by climate, while on the contrary, LSR of grassland was more affected by climate than by RSR. Our results validated the species pool hypothesis in revealing that RSR had a significant role in shaping LSR patterns in addition to climate. We concluded that the relative effects of climate vs. RSR on LSR differed markedly between the forest and grassland communities across Xinjiang. Our results also showed that RSR revealed a contrasting relationship with soil pH in mountains and in basins, which might reflect differences in evolutionary processes of various habitats. In summary, our research systematically analyzed the correlation of species richness in regional and local scales in Xinjiang which provides more insights into the understanding of species pool

  17. Differences in satellite-derived NOx emission factors between Eurasian and North American boreal forest fires

    Science.gov (United States)

    Schreier, S. F.; Richter, A.; Schepaschenko, D.; Shvidenko, A.; Hilboll, A.; Burrows, J. P.

    2015-11-01

    Current fire emission inventories apply universal emission factors (EFs) for the calculation of NOx emissions over large biomes such as boreal forest. However, recent satellite-based studies over tropical and subtropical regions have indicated spatio-temporal variations in EFs within specific biomes. In this study, satellite measurements of tropospheric NO2 vertical columns (TVC NO2) from the GOME-2 instrument and fire radiative power (FRP) from MODIS are used for the estimation of fire emission rates (FERs) of NOx over Eurasian and North American boreal forests. The retrieval of TVC NO2 is based on a stratospheric correction using simulated stratospheric NO2 instead of applying the reference sector method, which was used in a previous study. The model approach is more suitable for boreal latitudes. TVC NO2 and FRP are spatially aggregated to a 1° × 1° horizontal resolution and temporally averaged to monthly values. The conversion of the satellite-derived tropospheric NO2 columns into production rates of NOx from fire (Pf) is based on the NO2/NOx ratio as obtained from the MACC reanalysis data set and an assumed lifetime of NOx. A global land cover map is used to define boreal forests across these two regions in order to evaluate the FERs of NOx for this biome. The FERs of NOx, which are derived from the gradients of the linear relationship between Pf and FRP, are more than 30% lower for North American than for Eurasian boreal forest fires. We speculate that these discrepancies are mainly related to the variable nitrogen content in plant tissues, which is higher in deciduous forests dominating large parts in Eurasia. In order to compare the obtained values with EFs found in the literature, the FERs are converted into EFs. The satellite-based EFs of NOx are estimated at 0.83 and 0.61 g kg-1 for Eurasian and North American boreal forests, respectively, which is in good agreement with the value found in a recent emission factor compilation. However, recent fire

  18. Communities of epigeic beetles in tree line from montane spruce forest to secondary meadow in the different stage of the forest decline in the area of Modrava (Bohemian forest, Czech Republic

    Directory of Open Access Journals (Sweden)

    Boháč Jaroslav

    2016-12-01

    Full Text Available Communities of epigeic beetles were studied using pitfall trapping on 10 plots with the different stage of decline and clear-cut plots without coarse woody debris. Species richness (number of all species, S, total species diversity as the Shannon-Wiener’s index (H and equitability (e were calculated in the DBreleve. The Ward’s method of hierarchical agglomerative classification with Euclidean distance was used for the differentiation of the communities on the plots. Species data for this analyse were represented by logarithm-transformed activities [log(x+1]. The single-factor analysis of variance (ANOVA was used for statistical testing of differences in structural parameters (e.g. species richness and diversity amongst distinguished groups of the plots. The species diversity and activity differs on glades without trees and coarse woody debris. The highest number of species was found in clear-cut areas. The lowest number of species was found on the plots with the living forest particularly invaded by bark beetle. This fact is caused by the fact that the clear-cut plots are invaded by ubiquitous and anthropotolerant species with good migration possibilities. These species are adapted to habitats without trees and are able to leave even in the habitats with very sparse or without vegetation. Species living in the forest even under the bark beetle attack are often stenotopic and adapted to the forest microclimate (higher humidity and low average temperature. These species are very sensitive to great difference in the daily changes of microclimate. The study of beetle communities support the hypothesis that the keeping of dead tree stands on plots after bark beetle outbreak is better for biodiversity conservation than the cutting down of trees and the abolishment of stems.

  19. Splitting the Difference: A Proposal for Benefit Sharing in Reduced Emissions from Deforestation and Forest Degradation (REDD+

    Directory of Open Access Journals (Sweden)

    Arturo Balderas Torres

    2012-03-01

    Full Text Available The objective of REDD+ is to create incentives for the reduction of emissions from deforestation and forest degradation and for the increase of carbon stocks through the enhancement, conservation and sustainable management of forests in developing countries. As part of the international negotiations under the United Nations Framework Convention on Climate Change (UNFCCC, compensation would be estimated in relation to national performance but how these incentives will be channeled within countries has not been specified and there are concerns about how the benefits will be shared among different stakeholders. One central issue is that under the national approach good performance in one region can be offset by underperformance in other regions of the country thus preventing the generation of predictable local incentives. Other issues relate to the need to provide incentives to a wide range of stakeholders and to avoid perverse reactions. To address these and other issues we propose separating the accounting of reduced deforestation, reduced degradation and enhancement of forests. The local attribution of credits would be easier for carbon enhancement, and possibly reduced degradation, than for reduced deforestation, since carbon gains can, in principle, be measured locally in the first two cases, while estimating achievements in reduced deforestation requires a regional approach. This separation in attribution of rewards can help to create adequate incentives for the different stakeholders and overcome some of the problems associated with the design and implementation of national REDD+ programs.

  20. Different types of nitrogen deposition show variable effects on the soil carbon cycle process of temperate forests.

    Science.gov (United States)

    Du, Yuhan; Guo, Peng; Liu, Jianqiu; Wang, Chunyu; Yang, Ning; Jiao, Zhenxia

    2014-10-01

    Nitrogen (N) deposition significantly affects the soil carbon (C) cycle process of forests. However, the influence of different types of N on it still remained unclear. In this work, ammonium nitrate was selected as an inorganic N (IN) source, while urea and glycine were chosen as organic N (ON) sources. Different ratios of IN to ON (1 : 4, 2 : 3, 3 : 2, 4 : 1, and 5 : 0) were mixed with equal total amounts and then used to fertilize temperate forest soils for 2 years. Results showed that IN deposition inhibited soil C cycle processes, such as soil respiration, soil organic C decomposition, and enzymatic activities, and induced the accumulation of recalcitrant organic C. By contrast, ON deposition promoted these processes. Addition of ON also resulted in accelerated transformation of recalcitrant compounds into labile compounds and increased CO2 efflux. Meanwhile, greater ON deposition may convert C sequestration in forest soils into C source. These results indicated the importance of the IN to ON ratio in controlling the soil C cycle, which can consequently change the ecological effect of N deposition. © 2014 John Wiley & Sons Ltd.

  1. Multiple metrics of diversity have different effects on temperate forest functioning over succession.

    OpenAIRE

    Yuan, Zuoqiang; Wang, Shaopeng; Gazol, Antonio; Mellard, Jarad Pope; Lin, Fei; Ye, Ji; Hao, Zhanqing; Wang, Xugao; Loreau, Michel

    2016-01-01

    Biodiversity can be measured by taxonomic, phylogenetic, and functional diversity. How ecosystem functioning depends on these measures of diversity can vary from site to site and depends on successional stage. Here, we measured taxonomic, phylogenetic, and functional diversity, and examined their relationship with biomass in two successional stages of the broad-leaved Korean pine forest in northeastern China. Functional diversity was calculated from six plant traits, and aboveground biomass (...

  2. Functional groups show distinct differences in nitrogen cycling during early stand development: implications for forest management.

    Energy Technology Data Exchange (ETDEWEB)

    Aubrey, Doug, P.; Coyle, David, R. Coleman, Mark, D.

    2011-08-26

    Nutrient acquisition of forest stands is controlled by soil resource availability and belowground production, but tree species are rarely compared in this regard. Here, we examine ecological and management implications of nitrogen (N) dynamics during early forest stand development in productive commercial tree species with narrow (Populus deltoides Bartr. and Platanus occidentalis L.) and broad (Liquidambar styraciflua L. and Pinus taeda L.) site requirements while grown with a range of nutrient and water resources. We constructed N budgets by measuring N concentration ([N]) and N content (N{sub C}) of above- and belowground perennial and ephemeral tissues, determined N uptake (N{sub UP}), and calculated N use efficiency (NUE). Forest stands regulated [N] within species-specific operating ranges without clear temporal or treatment patterns, thus demonstrating equilibrium between tissue [N] and biomass accumulation. Forest stand N{sub C} and N{sub UP} increased with stand development and paralleled treatment patterns of biomass accumulation, suggesting productivity is tightly linked to N{sub UP}. Inclusion of above- and belowground ephemeral tissue turnover in N{sub UP} calculations demonstrated that maximum N demand for narrow-sites adapted species exceeded 200 kg N ha{sup -1} year{sup -1} while demand for broad-site adapted species was below this level. NUE was species dependent but not consistently influenced by N availability, suggesting relationships between NUE and resource availability were species dependent. Based on early stand development, species with broad site adaptability are favored for woody cropping systems because they maintain high above- and belowground productivity with minimal fertilization requirements due to higher NUE than narrow site adapted species.

  3. Active and total microbial communities in forest soil are largely different and highly stratified during decomposition

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr; Kolařík, Miroslav; Štursová, Martina; Kopecký, J.; Valášková, Vendula; Větrovský, Tomáš; Žifčáková, Lucia; Šnajdr, Jaroslav; Rídl, Jakub; Vlček, Čestmír; Voříšková, Jana

    2012-01-01

    Roč. 6, č. 2 (2012), s. 248-258 ISSN 1751-7362 R&D Projects: GA ČR GA526/08/0751; GA MŠk LC06066 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50520514 Keywords : cellulose decomposition * bacteria * forest soil Subject RIV: EE - Microbiology, Virology Impact factor: 8.951, year: 2012

  4. Bryophyte flora in upland forests at different successional stages and in the various strata of host trees in northeastern Pará, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Caldeira Tavares-Martins

    2014-03-01

    Full Text Available In the northeastern region of the Brazilian state of Pará, approximately 90% of the forested areas are secondary forests. Secondary forests are interesting areas for floristic studies aimed at determining the effects that clear-cutting has on bryophyte communities. The aim of this study was to compare upland forests at different successional stages and the various strata of host trees, in terms of the bryophyte species composition. Bryophyte specimens were collected between August 2005 and September 2006 from host trees in primary and secondary forests of different ages and of different heights, within the municipality of Capitão Poço, in the state of Pará. The vertical distribution of bryophytes was evaluated in 15 host trees within the primary forest. We identified a total of 99 bryophyte species: 33 mosses and 66 liverworts. The dominant family was Lejeuneaceae, with 56 species. Most of the species (n = 60 had a neotropical distribution, and 3 species were endemic to Brazil. Cololejeunea minutissima var. myriocarpa (Nees & Mont. R.M.Schust., Pycnolejeunea papillosa X.-L. He, Radula mammosa Spruce and Verdoornianthus marsupiifolius (Spruce Gradst. represent new records for the state of Pará. In the successional forests evaluated, we identified 78 species, most of which (n = 38 occurred in primary forest. On the host tree trunks evaluated in the primary forest, we observed 31 species occurring at heights ranging from 2 m to 20 m. Despite the fact that secondary forests account for such a large proportion of the forested areas in Capitão Poço, we found that the bryoflora was relatively rich, comprising 31% of the species recorded for the state. The fact that 40% of the species recorded occurred exclusively in the secondary forests and the fact that 45.5% of the species recorded in primary forest occurred within the 2-20 m height range show the importance of studies focusing on bryophytes in secondary forests and in the upper strata of

  5. National and global greenhouse gas dynamics of different forest management and wood use scenarios: a model-based assessment

    International Nuclear Information System (INIS)

    Werner, Frank; Taverna, Ruedi; Hofer, Peter; Thuerig, Esther; Kaufmann, Edgar

    2010-01-01

    An increased use of wood products and an adequate management of forests can help to mitigate climate change. However, planning horizons and response time to changes in forest management are usually long and the respective GHG effects related to the use of wood depend on the availability of harvested wood. Therefore, an integral long-term strategic approach is required to formulate the most effective forest and wood management strategies for mitigating climate change. The greenhouse gas (GHG) dynamics related to the production, use and disposal of wood products are manifold and show a complex time pattern. On the one hand, wood products can be considered as a carbon pool, as is the forest itself. On the other hand, an increased use of wood can lead to the substitution of usually more energy-intense materials and to the substitution of fossil fuels when the thermal energy of wood is recovered. Country-specific import/export flows of wood products and their alternative products as well as their processing stage have to be considered if substitution effects are assessed on a national basis. We present an integral model-based approach to evaluate the GHG impacts of various forest management and wood use scenarios. Our approach allows us to analyse the complex temporal and spatial patterns of GHG emissions and removals including trade-offs of different forest management and wood use strategies. This study shows that the contributions of the forestry and timber sector to mitigate climate change can be optimized with the following key recommendations: (1) the maximum possible, sustainable increment should be generated in the forest, taking into account biodiversity conservation as well as the long-term preservation of soil quality and growth performance; (2) this increment should be harvested continuously; (3) the harvested wood should be processed in accordance with the principle of cascade use, i.e. first be used as a material as long as possible, preferably in

  6. Sensitivity of understorey bird species in two different successional stages of the lowland Atlantic Forest, Brazil

    Directory of Open Access Journals (Sweden)

    Alan Loures-Ribeiro

    2011-09-01

    Full Text Available The Atlantic Forest has a high destruction rate and there is little information available on some aspects of the neotropical bird biology. Changes in environment are important factors that affect the resources available to birds. We compared the species sensitivity level of understorey birds in two areas in distinct successional stages (primary and secondary sections. Two 100 ha plots of lowland Atlantic Forest were analysed between August and December 2006. Among 25 bird species recorded, thirteen had lower abundance in secondary forest, two in primary forest, and ten had not clear tendency. According to the criteria used, the percentages for species with low, and medium and high sensitivity to habitat change were 44% and 56%, respectively. The number of species was not associated with the endemism level or foraging strata. Results show the importance of knowing bird species' sensitivity level with regard to habitat modification, and not only forest fragmentation.A Floresta Atlântica apresenta uma alta taxa de destruição e pouca informação disponível de alguns aspectos da biologia da avifauna neotropical. Alterações do ambiente são fatores importantes que influenciam nos recursos disponíveis para as aves. Nós comparamos o nível de sensibilidade das espécies de aves do sub-bosque de dois trechos em diferentes estágios sucessionais (trechos de floresta primária e secundária. Dois trechos de 100 ha cada de Floresta Atlântica de baixada foram analisados entre agosto e dezembro de 2006. Entre as 25 espécies de aves analisadas, treze tiveram menor abundância no trecho de floresta secundária, duas na floresta primária, e dez não mostraram qualquer tendência. De acordo com os critérios adotados, as porcentagens de espécies que apresentaram sensibilidades baixa, e média e alta às alterações de habitat foram de 44% e 56%, respectivamente. O número de espécies afetadas não esteve associado ao grau de endemismo ou estrato de

  7. Effects of different types of moderate severity disturbance on forest structural complexity and ecosystem functioning: A story of ice and fire

    Science.gov (United States)

    Fahey, R. T.; Atkins, J.; Gough, C. M.; Hardiman, B. S.; Haber, L.; Stuart-Haentjens, E.; David, O.; Campbell, J. L.; Rustad, L.; Duffy, M.

    2017-12-01

    Disturbances that alter the structure and function of forest ecosystems occur along a continuum of severity. In contrast to the extremes of the disturbance gradient (i.e., stand-replacing disturbance and small gap formation), moderate severity disturbances are poorly understood, even though they make up the majority of the gradient and their spatial extent (and likely overall importance to regional disturbance regimes) often exceeds that of more severe disturbances. Moderate severity disturbances originate from a variety of causes, such as fires, ice storms, or pest and pathogen outbreaks, and each of these could reshape structure and function in different ways. Observational data from a limited number of sites shows that moderate disturbance can increase ecosystem complexity, but the generality of this effect has not been tested across a broad range of disturbance types and severities. Here, we utilize data from a set of five case studies of experimental or natural moderate disturbance to assess the effects of different types and severities of disturbance on forest canopy structural complexity (CSC) and the relationship of canopy structure with ecosystem functioning. Using pre- and post-disturbance measures of CSC derived from aerial and terrestrial LiDAR, UAV imagery, and Landsat data we quantified changes in CSC following an experimental ice storm, a low-severity surface fire, Beech Bark Disease and Hemlock Wooly Adelgid outbreaks, and experimental accelerated succession. Our initial findings indicate that different disturbance types have highly variable effects on CSC, and also that progressive increases in disturbance severity alter CSC differently among disturbance types. Differential effects of variable disturbance types on CSC has implications for the carbon cycle, as forest structure is strongly linked with both growth-limiting resource (e.g., nutrients and light) acquisition and net primary productivity. Understanding how different types and severities of

  8. [Long-term effects of different management strategies on Larix gmelinii forests in Great Hing' an Mountains after the catastrophic fire in 1987].

    Science.gov (United States)

    Wang, Xu-gao; Li, Xiu-zhen; He, Hong-shi

    2008-04-01

    In this paper, LANDIS model was used to study the effects of different management strategies on the larch (Larix gmelinii) forests of Tuqiang Forest Bureau on the northern slopes of Great Hing' an Mountains after the catastrophic fire in 1987. Three management strategies, i. e., natural regeneration if the catastrophic fire in 1987 was not happened (M1), natural regeneration after the catastrophic fire in 1987 (M2), and current management strategy after the catastrophic fire in 1987 (M3), were compared over a 300-year period. The results showed that the abundance of larch forests over 300 simulation years under the three management strategies had significant difference. In the whole Bureau, the abundance of larch forests under M2 was obviously lower than that under M1 and M3 over 300 years, and the abundance under M3 was lower than that under M1 at the beginning. Due to the reforestation after the catastrophic fire in 1987, the abundance of larch under M3 increased rapidly, and caught up with that under M1 after about 100 years. In addition, different forest management strategies also had significant influence on the age structure of larch forests, especially for mature and over-matured larch forests. The abundance of mature and over-matured larch forests under M1 was higher than that under M2. This abundance under M3 had tremendous decrease because of forest harvesting for about 10 years, and then, increased with time and would exceed that under M1 and M2 for over 100 years. Furthermore, in unburned areas and burned areas, the abundance of mature and over-matured larch forests also had significant difference over 300 simulation years under the three management strategies.

  9. Worker morphology of the ant Gnamptogenys striatula Mayr (Formicidae, Ectatomminae in different landscapes from the Atlantic Forest domain

    Directory of Open Access Journals (Sweden)

    Roseli F. Oliveira

    2015-03-01

    Full Text Available Morphological traits, such as size and shape, may reflect a combination of ecological and evolutionary responses by organisms. Ants have been used to evaluate the relationship between the environment and species coexistence and morphology. In the present study, we analyzed the morphology of workers of Gnamptogenys striatula Mayr in different landscapes from the Atlantic Domain in southeastern Brazil, focusing on the variation in the morphological attributes of these populations compared to those from a dense ombrophilous forest. Eighteen morphological traits of functional importance for interactions between workers and the environment were measured to characterize the size and shape of the workers. In general, the results show that ants of urban areas possess some morphological attributes of smaller size, with highly overlapped morphological space between the populations in forested ecosystems. Further, some of the traits related to predation were relatively smaller in modified land areas than in the populations from preserved areas of dense ombrophilous forest. These results help broaden the knowledge regarding morphological diversity in G. striatula, suggesting that the characterization of the morphology may be important to quantify the effects of land use on morphological diversity, and presumably, to facilitate the use of ants as biological indicators.

  10. Characteristics of organic matter fractions separated by wet-sieving and differences in density from five soils of different pedogenesis under mature beech forest.

    Science.gov (United States)

    Vormstein, Svendja; Kaiser, Michael; Ludwig, Bernard

    2017-04-01

    Forest top- and subsoil account for approximately 70 % of the organic C (OC) globally stored in soil reasoning their large importance for terrestrial ecosystem services such as the mitigation of climate change. In contrast to forest topsoil, there is much less information about the decomposition and stabilization of organic matter (OM) in subsoil. Therefore, we sampled the pedogenetic horizons of five soils under mature beech forest developed on different parent material (i.e. Tertiary Sand, Loess, Basalt, Lime Stone, Red Sandstone) down to the bedrock. The bulk soil samples were characterized for texture, oxalate and dithionite soluble Fe and Al, pH, OC, microbial biomass C and basal respiration (cumulative CO2 emission after 7 and 14 days). Furthermore, we analyzed aggregate size fractions separated by wet-sieving (i.e. >1000 µm, 1000-250 µm, 250-53 µm, soil horizon specific samples. The OC of the topsoil (Ah horizon) on Lime Stone and Red Sandstone was predominately stored in the larger macro-aggregates (>1000 µm). In contrast, the major part of the topsoil OC on Basalt and Tertiary Sand was found in the smaller macro-aggregates (1000-250 µm). For the topsoil samples, we found that the basal respiration as well as the microbial biomass C were positively correlated (p ≤0.05) with the OC amounts associated with the free and occluded light fraction and with the macro-aggregates (1000-250 µm) and micro-aggregates (250-53 µm) suggesting these fractions to store the major part of the easily decomposable OM. The OC amount associated with the heavy fraction and the fraction organic compounds and Fe- and Al-oxides to be highly important for the OM stabilization in forest topsoil. In the subsoil (horizons below the Ah), the contribution of the OC associated with the aggregate size fractions 53 µm were positively correlated with basal respiration and the microbial biomass C. This suggests, in contrast to the topsoil, the easily decomposable OM to be distributed

  11. Comparing the impacts of hiking, skiing and horse riding on trail and vegetation in different types of forest.

    Science.gov (United States)

    Törn, A; Tolvanen, A; Norokorpi, Y; Tervo, R; Siikamäki, P

    2009-03-01

    Nature-based tourism in protected areas has increased and diversified dramatically during the last decades. Different recreational activities have a range of impacts on natural environments. This paper reports results from a comparison of the impacts of hiking, cross-country skiing and horse riding on trail characteristics and vegetation in northern Finland. Widths and depths of existing trails, and vegetation on trails and in the neighbouring forests were monitored in two research sites during 2001 and 2002. Trail characteristics and vegetation were clearly related to the recreational activity, research site and forest type. Horse trails were as deep as hiking trails, even though the annual number of users was 150-fold higher on the hiking trails. Simultaneously, cross-country skiing had the least effect on trails due to the protective snow cover during winter. Hiking trail plots had little or no vegetation cover, horse riding trail plots had lower vegetation cover than forest plots, while skiing had no impact on total vegetation cover. On the other hand, on horse riding trails there were more forbs and grasses, many of which did not grow naturally in the forest. These species that were limited to riding trails may change the structure of adjacent plant communities in the long run. Therefore, the type of activities undertaken and the sensitivity of habitats to these activities should be a major consideration in the planning and management of nature-based tourism. Establishment of artificial structures, such as stairs, duckboards and trail cover, or complete closure of the site, may be the only way to protect the most sensitive or deteriorated sites.

  12. Temperate and boreal old-growth forests: how do their growth dynamics and biodiversity differ from young stands and managed forests?

    NARCIS (Netherlands)

    Schulze, E.D.; Hessenmoeller, D; Knohl, A.; Luyssaert, S; Boerner, A; Grace, J.

    2009-01-01

    This chapter investigates biomass, net primary productivity (NPP), and net ecosystem productivity (NEP) of boreal and temperate forest ecosystems in relation to stand density and age. Forests may accumulate woody biomass at constant rate for centuries and there is little evidence of an age-related

  13. Mite diversity on plants of different families found in the Brazilian Atlantic Forest

    International Nuclear Information System (INIS)

    Castro, Tatiane M.M.G. de; Moraes, Gilberto J. de

    2007-01-01

    This work reports the occurrence of mites predominantly predatory, phytophagous and with varied feeding habits on plants of the Atlantic Forest vegetation type of the State of Sao Paulo. The objective was to estimate the possible role of the Atlantic Forest vegetation as reservoir of these groups of mites which are also found on plants of agricultural importance. Samples were taken from 187 plant species belonging to 73 families in three vegetation types of the Atlantic Forest from February of 2001 to October of 2002. A total of 2,887 mites belonging to 163 morpho-species of 16 families were collected. Mite diversity was high, especially of predatory mites; these corresponded to 1,562 specimens of 92 morpho-species. Within this group, Phytoseiidae comprised 71% of the specimens and 62% of the morpho-species. Phytophagous mites comprised 836 specimens of 36 morpho-species. Within this group, Tenuipalpidae comprised the larger proportion of specimens (61%) whereas Tetranychidae corresponded to the larger proportion of morpho-species (64%). Mites with varied feeding habits corresponded to 491 specimens of 36 morpho-species. In this group, the larger proportion of specimens (52%) consisted of Ascidae and the larger proportion of morpho-species (42%) consisted of Tydeinae (family Tydeidae). High abundance and high morpho-species richness of mites of predominantly predatory, phytophagous and variable feeding habits were observed on 17, five and nine plant species, respectively. The results obtained suggest the importance of plants of the studied vegetation as reservoirs of predatory mites. (author)

  14. Mite diversity on plants of different families found in the Brazilian Atlantic Forest.

    Science.gov (United States)

    de Castro, Tatiane M M G; de Moraes, Gilberto J

    2007-01-01

    This work reports the occurrence of mites predominantly predatory, phytophagous and with varied feeding habits on plants of the Atlantic Forest vegetation type of the State of São Paulo. The objective was to estimate the possible role of the Atlantic Forest vegetation as reservoir of these groups of mites which are also found on plants of agricultural importance. Samples were taken from 187 plant species belonging to 73 families in three vegetation types of the Atlantic Forest from February of 2001 to October of 2002. A total of 2,887 mites belonging to 163 morpho-species of 16 families were collected. Mite diversity was high, especially of predatory mites; these corresponded to 1,562 specimens of 92 morpho-species. Within this group, Phytoseiidae comprised 71% of the specimens and 62% of the morpho-species. Phytophagous mites comprised 836 specimens of 36 morpho-species. Within this group, Tenuipalpidae comprised the larger proportion of specimens (61%) whereas Tetranychidae corresponded to the larger proportion of morpho-species (64%). Mites with varied feeding habits corresponded to 491 specimens of 36 morpho-species. In this group, the larger proportion of specimens (52%) consisted of Ascidae and the larger proportion of morpho-species (42%) consisted of Tydeinae (family Tydeidae). High abundance and high morpho-species richness of mites of predominantly predatory, phytophagous and variable feeding habits were observed on 17, five and nine plant species, respectively. The results obtained suggest the importance of plants of the studied vegetation as reservoirs of predatory mites.

  15. Mite diversity on plants of different families found in the Brazilian Atlantic Forest

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Tatiane M.M.G. de [UNESP, Jaboticabal, SP (Brazil). Faculdade de Ciencias Agrarias e Veterinarias. Dept. de Fitossanidade]. E-mail: tatianemarie@yahoo.com.br; Moraes, Gilberto J. de [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. Entomologia, Fitopatologia e Zoologia Agricola]. E-mail: gjmoraes@esalq.usp.br

    2007-09-15

    This work reports the occurrence of mites predominantly predatory, phytophagous and with varied feeding habits on plants of the Atlantic Forest vegetation type of the State of Sao Paulo. The objective was to estimate the possible role of the Atlantic Forest vegetation as reservoir of these groups of mites which are also found on plants of agricultural importance. Samples were taken from 187 plant species belonging to 73 families in three vegetation types of the Atlantic Forest from February of 2001 to October of 2002. A total of 2,887 mites belonging to 163 morpho-species of 16 families were collected. Mite diversity was high, especially of predatory mites; these corresponded to 1,562 specimens of 92 morpho-species. Within this group, Phytoseiidae comprised 71% of the specimens and 62% of the morpho-species. Phytophagous mites comprised 836 specimens of 36 morpho-species. Within this group, Tenuipalpidae comprised the larger proportion of specimens (61%) whereas Tetranychidae corresponded to the larger proportion of morpho-species (64%). Mites with varied feeding habits corresponded to 491 specimens of 36 morpho-species. In this group, the larger proportion of specimens (52%) consisted of Ascidae and the larger proportion of morpho-species (42%) consisted of Tydeinae (family Tydeidae). High abundance and high morpho-species richness of mites of predominantly predatory, phytophagous and variable feeding habits were observed on 17, five and nine plant species, respectively. The results obtained suggest the importance of plants of the studied vegetation as reservoirs of predatory mites. (author)

  16. $K^{0} \\leftrightharpoons \\overline{K}^0$ transitions monitored by strong interactions a new determination of the $K_{L} - K_{S}$ mass difference

    CERN Document Server

    Angelopoulos, Angelos; Backenstoss, Gerhard; Bargassa, P; Behnke, O; Benelli, A; Bertin, V; Blanc, F; Bloch, P; Carlson, P J; Carroll, M; Cawley, E; Chertok, M B; Danielsson, M; Dejardin, M; Derré, J; Ealet, A; Eleftheriadis, C; Fetscher, W; Fidecaro, Maria; Filipcic, A; Francis, D; Fry, J; Gabathuler, Erwin; Gamet, R; Gerber, H J; Go, A; Haselden, A; Haymen, P J; Henry-Coüannier, F; Hollander, R W; Jon-And, K; Kettle, P R; Kokkas, P; Kreuger, R; Le Gac, R; Leimgruber, F; Mandic, I; Manthos, N; Marel, Gérard; Mikuz, M; Miller, J; Montanet, François; Müller, A; Nakada, Tatsuya; Pagels, B; Papadopoulos, I M; Pavlopoulos, P; Polivka, G; Rickenbach, R; Roberts, B L; Ruf, T; Sakelliou, L; Schäfer, M; Schaller, L A; Schietinger, T; Schopper, A; Tauscher, Ludwig; Thibault, C; Touchard, F; Touramanis, C; van Eijk, C W E; Vlachos, S; Weber, P; Wigger, O; Wolter, M; Zavrtanik, D; Zimmerman, D

    2001-01-01

    The CPLEAR set-up (modified) has been used to determine the K/sub L/- K/sub S/ mass difference by a method where neutral-kaon strangeness oscillations are monitored through kaon strong interactions, rather than semileptonic decays, thus requiring no assumptions on CPT invariance for the decay amplitudes. The result, Delta m= (0.5343+or-0.0063/sub stat/+or-0.0025/sub syst/)*10/sup 10/ h(cross) /s, provides a valuable input for CPT tests. (22 refs).

  17. Seasonality in the dung beetle community in a Brazilian tropical dry forest: Do small changes make a difference?

    Science.gov (United States)

    Medina, Anderson Matos; Lopes, Priscila Paixão

    2014-01-01

    Dung beetle (Coleoptera: Scarabaeoidea: Scarabaeinae) activity is influenced by rainfall seasonality. We hypothesized that rainfall might also play a major role in regulating the community structure of this group. In this study, we describe seasonal changes in the richness, composition, and structure of the Scarabaeinae community in a Brazilian tropical dry forest. A fragment of arboreal Caatinga was sampled using baited pitfall traps during the early dry season (EDS), late dry season (LDS), early wet season (EWS), and middle wet season (MWS). We compared the dung beetle community in each season in relationship to species richness, rank-dominance, curves, and composition. We collected 1352 Scarabaeinae individuals , belonging to 15 species. Dichotomius aff. laevicollis Felsche (Coleoptera: Scarabaeidae) was the dominant species, representing 73.89% of the individuals. There were no seasonal changes in the rank dominance curves; all had a single dominant species and a few species with low abundance, typical for arid areas. Estimated richness was highest in MWS, followed by EWS. Dry-season samples (EDS and LDS) had lower richness, with no significant difference between the dry seasons. Although species richness increased as the habitat became wetter, the difference between the wet and dry seasons was small, which differs completely from the findings of other studies in Neotropical dry forests, where almost all species cease activities in the dry season. Species composition changes were found in non-metric multidimensional scaling and sustained by analysis of similarity. All the seasons had pairwise differences in composition, with the exception of EDS and MWS, which indicates that the dung beetle community in this fragment requires more than three months of drought to trigger changes in species composition; this is probably due to small changes in the forest canopy. There was no difference in composition between EDS and MWS. As in other tropical dry forests, although

  18. Differences in the ability of vegetation models to predict small mammal abundance in different aged Douglas-fir forests

    Science.gov (United States)

    Cathy A. Taylor; C. John Ralph; Arlene T. Doyle

    1988-01-01

    Three trapping techniques for small mammals were used in 47 study stands in northern California and southern Oregon and resulted in different capture frequencies by the different techniques. In addition, the abundances of mammals derived from the different techniques produced vegetation association models which were often quite different. Only the California redbacked...

  19. Divergent responses of soil buffering capacity to long-term N deposition in three typical tropical forests with different land-use history.

    Science.gov (United States)

    Lu, Xiankai; Mao, Qinggong; Mo, Jiangming; Gilliam, Frank S; Zhou, Guoyi; Luo, Yiqi; Zhang, Wei; Huang, Juan

    2015-04-07

    Elevated anthropogenic nitrogen (N) deposition has become an important driver of soil acidification at both regional and global scales. It remains unclear, however, how long-term N deposition affects soil buffering capacity in tropical forest ecosystems and in ecosystems of contrasting land-use history. Here, we expand on a long-term N deposition experiment in three tropical forests that vary in land-use history (primary, secondary, and planted forests) in Southern China, with N addition as NH4NO3 of 0, 50, 100, and 150 kg N ha(-1) yr(-1), respectively. Results showed that all three forests were acid-sensitive ecosystems with poor soil buffering capacity, while the primary forest had higher base saturation and cation exchange capacity than others. However, long-term N addition significantly accelerated soil acidification and decreased soil buffering capacity in the primary forest, but not in the degraded secondary and planted forests. We suggest that ecosystem N status, influenced by different land-use history, is primarily responsible for these divergent responses. N-rich primary forests may be more sensitive to external N inputs than others with low N status, and should be given more attention under global changes in the future, because lack of nutrient cations is irreversible.

  20. Choice of forest map has implications for policy analysis

    DEFF Research Database (Denmark)

    Seebach, Lucia Maria; McCallum, Ian; Fritz, Steffen

    2012-01-01

    and harmonised approach at the European level. However, they possess different characteristics in terms of spatial detail or thematic accuracy. Little attention has been paid to the effect of these characteristics on simulation models and the resultant policy implications. In this study we tested whether...... the choice of a forest map has substantial influence on model output, i.e. if output differences can be related to the input differences. A sensitivity analysis of the spatially explicit Global Forest Model (G4M) was performed using four different forest maps: the pan-European high resolution forest...... utilization of forest biomass. The sensitivity analysis showed that the choice of the forest cover map has a major influence on the model outputs in particular at the country-level, while having less influence at the EU27 level. Differences between the input datasets are strongly reflected in the outputs...

  1. Structural aspects and floristic similarity among tropical dry forest fragments with different management histories in northern Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Meira Arruda

    2011-02-01

    Full Text Available In order to produce useful knowledge to the initiatives of protection and management of forest fragments, more specifically for tropical dry forests which suffer with frequent anthropic activities, and due to the lack of specific studies, this article aimed describe the structure and the floristic similarity among three areas of dry forest with different management histories. The study was developed in Capitão Enéas municipality, Northern Minas Gerais, Brazil, where three fragments were evaluated, being one in regeneration for 30 years, another submitted to occasional fire and the third with selective cut in small scale. The sampling was developed through the point quarter method considering all the alive phanerophyte individuals with circumference at breast height (CBH > 15 cm. In the three fragments, 512 individuals, distributed in 60 species, 47 genera, and 23 families were sampled. The most representative families were Fabaceae (26, Anacardiaceae (4, Bignoniaceae (3 and Combretaceae (3. However, fourteen families were represented by only one species. Only eight species were common to all fragments - Myracrodruon urundeuva standed out with 26.9% of all sampled individuals - while a great number of species were exclusive of each fragment. The floristic and structural differences between the fragments are possibly related to the history and intensity of management in each area besides the topography variations and the presence or absence of limestone outcrops. These results show the importance of each fragment, indicating that the loss of anyone would cause negative impacts on the regional flora and consequently to the associated biodiversity.

  2. Assessment of Nutrient Limitation in Floodplain Forests with Two Different Techniques

    Directory of Open Access Journals (Sweden)

    Matthew A. Neatrour

    2008-01-01

    Full Text Available We assessed nitrogen and phosphorus limitation in a floodplain forest in southern Georgia in USA using two commonly used methods: nitrogen to phosphorus (N:P ratios in litterfall and fertilized ingrowth cores. We measured nitrogen (N and phosphorus (P concentrations in litterfall to determine N:P mass ratios. We also installed ingrowth cores within each site containing native soil amended with nitrogen (N, phosphorus (P, or nitrogen and phosphorus (N + P fertilizers or without added fertilizer (C. Litter N:P ratios ranged from 16 to 22, suggesting P limitation. However, fertilized ingrowth cores indicated N limitation because fine-root length density was greater in cores fertilized with N or N + P than in those fertilized with P or without added fertilizer. We feel that these two methods of assessing nutrient limitation should be corroborated with fertilization trials prior to use on a wider basis.

  3. 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.

  4. How much different are conifer forests? Comparison of Lepidoptera community in silver fir and black pine stands in Calabria (southern Italy

    Directory of Open Access Journals (Sweden)

    Infusino M

    2017-02-01

    Full Text Available The main coniferous forests of Calabria (Italy are certainly the Calabrian black pine (Pinus nigra calabrica forests of the Sila massif and the silver fir (Abies alba forests of the Serre Vibonesi. Despite these woodlands are of great importance both economically and from a conservationist point of view, biodiversity of moth has been investigated in a non occasional way only for the Sila Calabrian black pine forests, while the silver fir woods of the Serre have been only recently the subject of studies. Apart from increasing the knowledge on the biodiversity of the nocturnal Lepidoptera hosted by Calabrian coniferous forests, the aim of this study was to compare the sampled communities to find out the main differences and their causes. The sampling was conducted in 9 sites for each forest type, distributed so as to cover the different development stages of ecological succession, from open areas to mature woodlands. A light trap was monthly placed at each site from May to November 2015, for a total of 126 nights/trap. The two communities showed low similarity indices (Classic Jaccard = 0.396; Sorensen Classic = 0.568, due both to the component trophically linked to the dominant forest species and to the component linked to the herbaceous layer. In fact, the dominant species in the Calabrian black pine wood and in the silver fir wood (Thera firmata and Macaria liturata, respectively are absent or only occasionally present in the other forest type, and the community linked to the herbaceous layer is much better represented in the Calabrian black pine forest (29.7% of the total than in the silver fir forest (14.9%. The arrangement of the Sila landscape, where Calabrian black pine forests alternate with pastures, shrubs and cultivated fields, seems to be the cause of the increased presence of species related to non-forest vegetation layer, while the micro-climatic conditions of the silver fir forest, more humid and temperate, favor the presence of a

  5. Sap flow based transpiration estimates in species-rich secondary forests of different ages in central Panama during a wet-season drought

    Science.gov (United States)

    Bretfeld, M.; Ewers, B. E.; Hall, J. S.; Ogden, F. L.

    2015-12-01

    Many landscapes that were previously covered by mature tropical forests in central Panama today comprise of a mosaic of mature forest fragments, pastures and agricultural land, and regrowing secondary forests. An increasing demand for water due to urbanization and the expansion of the Panama Canal, along with a predicted transition into a dryer climatic period necessitate a better understanding regarding the effects of land use and land use history on hydrological processes. Such knowledge, including water storage, residence times, and fluxes is essential to develop effective land management strategies and propose incentives to alter land use practices to enhance hydrological services. To quantify transpiration rates at different stages of secondary forest succession, we measured sap flow in forests growing for 8, ~25, and 80+ years since last known land use in the 15 km2 "Agua Salud" study area, located in central Panama. In each forest, we selected a subset of at least 15 individuals, representing the local tree size distribution, and recorded data from heat-ratio sap flow sensors every 30 minutes starting in February 2015. All instrumented trees were identified to species and compared to local species distributions. Basal area in the three forest types was 9.1, 10.8, and 50.2 m2 ha-1 for 8, ~25, and 80+ year old forests, respectively. Average daily transpiration was highly correlated to forest age, with highest rates in the oldest forest (3.0 to 18.2 mm ha-1 day-1), followed by intermediate (1.2 to 6.7 mm ha-1 day-1) and youngest forests (0.2 to 2.7 mm ha-1 day-1), suggesting roughly a doubling in transpiration from 8 to ~25 year old forests, despite similar basal area, and again from ~25 to 80+ year old forests. Flow rates in individual trees generally reflected the dry-to-wet season transition but behaved differently in response to the unprecedentedly dry conditions during the first half of 2015 in central Panama.

  6. [Microclimate dynamics of pit and mound complex within different sizes of forest gaps in Pinus koraiensis-dominated broadleaved mixed forest].

    Science.gov (United States)

    Wei, Quan-Shuai; Wang, Jing-Hua; Duan, Wen-Biao; Chen, Li-Xin; Wang, Ting; Han, Dong-Hui; Gu, Wei

    2014-03-01

    An investigation was conducted in a 2.25 hm2 plot of Pinus koraiensis-dominated broad-leaved mixed forest to study basic characteristics of 7 small gaps, 5 middle gaps, 3 large gaps and 7 closed stands within 38 pit and mound complexes caused by treefall in May 2012. From June to September 2012, the soil temperature, soil water content and relative humidity at five microsites (pit bottom, pit wall, mound top, mound face and undisturbed closed stands) were measured in six sunny days each month. The results showed that among the five microsites in every month, the mound top had the highest soil temperature and the lowest water content and relative humidity, and vice versa for the pit bottom. Mostly, the differences in the above indicators among the five microsites were significant. From June to September, the mean soil temperatures for all microsites at pit and mound complex in the various gaps and closed stands were in the order of large gap>middle gap >small gap>closed stand; but the soil water content ranked differently every month. In June, August and September, the mean relative humidities for all microsites in the various gaps and closed stands were in the order of closed stand>small gap>middle gap>large gap. Mostly, the differences in the above indicators between all microsites in the various gaps and closed stand were significant. The mean monthly soil temperature and relative humidity were highest in July, but lowest in September. The maximal mean monthly soil water content occurred in July and the minimal one in September for each microsite except the undisturbed closed stands, where the maximal mean monthly soil water content occurred in July. The variation of the microclimate at the pit and mound complex was mainly influenced by gap size, microsite, and time.

  7. Helminth communities of owls (strigiformes) indicate strong biological and ecological differences from birds of prey (accipitriformes and falconiformes) in southern Italy.

    Science.gov (United States)

    Santoro, Mario; Mattiucci, Simonetta; Nascetti, Giuseppe; Kinsella, John M; Di Prisco, Francesca; Troisi, Sabatino; D'Alessio, Nicola; Veneziano, Vincenzo; Aznar, Francisco J

    2012-01-01

    We compared the helminth communities of 5 owl species from Calabria (Italy) and evaluated the effect of phylogenetic and ecological factors on community structure. Two host taxonomic scales were considered, i.e., owl species, and owls vs. birds of prey. The latter scale was dealt with by comparing the data here obtained with that of birds of prey from the same locality and with those published previously on owls and birds of prey from Galicia (Spain). A total of 19 helminth taxa were found in owls from Calabria. Statistical comparison showed only marginal differences between scops owls (Otus scops) and little owls (Athene noctua) and tawny owls (Strix aluco). It would indicate that all owl species are exposed to a common pool of 'owl generalist' helminth taxa, with quantitative differences being determined by differences in diet within a range of prey relatively narrow. In contrast, birds of prey from the same region exhibited strong differences because they feed on different and wider spectra of prey. In Calabria, owls can be separated as a whole from birds of prey with regard to the structure of their helminth communities while in Galicia helminths of owls represent a subset of those of birds of prey. This difference is related to the occurrence in Calabria, but not Galicia, of a pool of 'owl specialist' species. The wide geographical occurrence of these taxa suggest that local conditions may determine fundamental differences in the composition of local communities. Finally, in both Calabria and Galicia, helminth communities from owls were species-poor compared to those from sympatric birds of prey. However, birds of prey appear to share a greater pool of specific helmith taxa derived from cospeciation processes, and a greater potential exchange of parasites between them than with owls because of phylogenetic closeness.

  8. Helminth communities of owls (strigiformes indicate strong biological and ecological differences from birds of prey (accipitriformes and falconiformes in southern Italy.

    Directory of Open Access Journals (Sweden)

    Mario Santoro

    Full Text Available We compared the helminth communities of 5 owl species from Calabria (Italy and evaluated the effect of phylogenetic and ecological factors on community structure. Two host taxonomic scales were considered, i.e., owl species, and owls vs. birds of prey. The latter scale was dealt with by comparing the data here obtained with that of birds of prey from the same locality and with those published previously on owls and birds of prey from Galicia (Spain. A total of 19 helminth taxa were found in owls from Calabria. Statistical comparison showed only marginal differences between scops owls (Otus scops and little owls (Athene noctua and tawny owls (Strix aluco. It would indicate that all owl species are exposed to a common pool of 'owl generalist' helminth taxa, with quantitative differences being determined by differences in diet within a range of prey relatively narrow. In contrast, birds of prey from the same region exhibited strong differences because they feed on different and wider spectra of prey. In Calabria, owls can be separated as a whole from birds of prey with regard to the structure of their helminth communities while in Galicia helminths of owls represent a subset of those of birds of prey. This difference is related to the occurrence in Calabria, but not Galicia, of a pool of 'owl specialist' species. The wide geographical occurrence of these taxa suggest that local conditions may determine fundamental differences in the composition of local communities. Finally, in both Calabria and Galicia, helminth communities from owls were species-poor compared to those from sympatric birds of prey. However, birds of prey appear to share a greater pool of specific helmith taxa derived from cospeciation processes, and a greater potential exchange of parasites between them than with owls because of phylogenetic closeness.

  9. Determining source areas of biodegradable dissolved organic matter in two peatland catchments with different upland forest types, Minnesota, USA

    Science.gov (United States)

    Sebestyen, S. D.; Funke, M.; Cotner, J.

    2016-12-01

    Long-term studies at the Marcell Experimental Forest in Minnesota have shown that peatland catchments have distinct landscape areas (peatlands or upland mineral soils), with unique hydrological and biogeochemical processes that affect flows of water and solutes. Nonetheless, little has been known about the relative importance of source areas or forest cover types on the biodegradability of dissolved organic matter (DOM) as waters water move from bogs or uplands to outlet streams. In this study, we measured biodegradable dissolved organic carbon (BDOC) from multiple sources (upland surface and subsurface runoff, upland-peatland interfaces in laggs, and stream outlets) in two catchments having different upland forest types, deciduous or coniferous. We measured: total organic carbon (TOC), total nitrogen (TN), and dissolved organic nitrogen (DON) to calculate DOC:TN and DOC:DON; short-term (48-hour) bacterial respiration (BR); long-term (one-year), bottle incubation assays of BDOC; streamflow; and volumes of upland runoff along surface and subsurface flowpaths. We also experimented by mixing various waters to assess priming effects on BDOC concentrations and BR. The BDOC concentrations and BR were greater in upland surface runoff than in subsurface flow, laggs, or outlets, indicating that DOC in the upland surface runoff was most biodegradable. We did not observe priming effects with the mixing of any waters. In terms of catchment hydrology, most streamflow (43 to 87%) was derived from bogs, not uplands. Consequently, bogs were more important sources of biodegradable DOC. Nonetheless, there was some effect of upland cover type: BDOC concentrations and BR were greater in the outlet of the coniferous catchment than the deciduous catchment, which could be due to greater TN relative to carbon in the coniferous than in the deciduous upland catchment (C:N < 100 versus 130-150; respectively). The results show that source areas and compositional differences among catchments

  10. Different pollinator assemblages ensure reproductive success of Cleisostoma linearilobatum (Orchidaceae) in fragmented holy hill forest and traditional tea garden.

    Science.gov (United States)

    Zhou, Xiang; Liu, Qiang; Han, Jessie Yc; Gao, JiangYun

    2016-02-24

    Orchids are generally recognized to have specialist pollination systems and low fruit set is often thought to be characteristic of the family. In this study, we investigated the reproductive ecology of Cleisostoma linearilobatum, an epiphytic tropical orchid, in a holy hill forest fragment and a traditional tea garden in SW China using comparable methods. C. linearilobatum is self-compatible and dependent on insects for pollination. Fruit production in natural conditions was both pollinator- and resource-limited. However, the natural fruit set remained stable over multiple years at both sites. Pollination observations showed that C. linearilobatum has a generalized pollination system and seven insect species were observed as legitimate pollinators. Although the visit frequencies of different pollinators were different in the two sites, the pollinator assemblages ensured reproductive success of C. linearilobatum in both study sites over multiple years. The results partly explain why C. linearilobatum is so successful in the area, and also suggest that holy hill forest fragments and traditional tea gardens in Xishuangbanna are important in preserving orchids, especially those with generalist pollination.

  11. Soil properties in different types of Eucalypt Plantations in a small forested watershed, north-central Portugal

    Science.gov (United States)

    Santos, J. M.; van Beersum, S.; van Hall, I.; Bernard-Jannin, L.; Rial-Rivas, M. E.; Nunes, J. P.; Keizer, J. J.

    2012-04-01

    The main aim of the HIDRIA project is to improve the knowledge and understanding of factors and processes that determine the hydrological behaviour of forested foothills in the Caramulo mountain range, North-Central Portugal. The changes from natural forest cover to Eucalyptus plantations in the last decades in Portugal is present in Serra de Cima catchment, one of the four experimental catchments monitored within the framework of the project. The objectives of the present study are to determine the effects of these changes on soil properties, and to improve the parameterization of the SWAT model to simulate the impact of land-use changes associated with forestry practices on hydrological processes. The study catchment (Serra de Cima) is located in the Águeda Basin, draining the foothills of the Caramulo mountains east of Águeda (40°36'N, -8°20'E). The climate is wet Mediterranean with a mean annual precipitation of about 1600 mm at 445 m a.s.l. Soils are generally Umbric Leptosols (Molarity of Ethanol Droplet test); and near-saturated hydraulic conductivity (mini-disk experiments). There were clear differences in almost every parameter between eucalypt and pine plots, but also for eucalypt stands of different ages, indicating an impact of eucalypt growth on the properties of the underlying soil. The repetition of some measurements is foreseen to evaluate their seasonal variability.

  12. Seasonal differences in leaf-level physiology give lianas a competitive advantage over trees in a tropical seasonal forest

    NARCIS (Netherlands)

    Cai, Z.Q.; Schnitzer, S.A.; Bongers, F.

    2009-01-01

    Lianas are an important component of most tropical forests, where they vary in abundance from high in seasonal forests to low in aseasonal forests. We tested the hypothesis that the physiological ability of lianas to fix carbon (and thus grow) during seasonal drought may confer a distinct advantage

  13. Structural, physiognomic and above-ground biomass variation in savanna–forest transition zones on three continents – how different are co-occurring savanna and forest formations?

    Directory of Open Access Journals (Sweden)

    E. M. Veenendaal

    2015-05-01

    Full Text Available Through interpretations of remote-sensing data and/or theoretical propositions, the idea that forest and savanna represent "alternative stable states" is gaining increasing acceptance. Filling an observational gap, we present detailed stratified floristic and structural analyses for forest and savanna stands located mostly within zones of transition (where both vegetation types occur in close proximity in Africa, South America and Australia. Woody plant leaf area index variation was related to tree canopy cover in a similar way for both savanna and forest with substantial overlap between the two vegetation types. As total woody plant canopy cover increased, so did the relative contribution of middle and lower strata of woody vegetation. Herbaceous layer cover declined as woody cover increased. This pattern of understorey grasses and herbs progressively replaced by shrubs as the canopy closes over was found for both savanna and forests and on all continents. Thus, once subordinate woody canopy layers are taken into account, a less marked transition in woody plant cover across the savanna–forest-species discontinuum is observed compared to that inferred when trees of a basal diameter > 0.1 m are considered in isolation. This is especially the case for shrub-dominated savannas and in taller savannas approaching canopy closure. An increased contribution of forest species to the total subordinate cover is also observed as savanna stand canopy closure occurs. Despite similarities in canopy-cover characteristics, woody vegetation in Africa and Australia attained greater heights and stored a greater amount of above-ground biomass than in South America. Up to three times as much above-ground biomass is stored in forests compared to savannas under equivalent climatic conditions. Savanna–forest transition zones were also found to typically occur at higher precipitation regimes for South America than for Africa. Nevertheless, consistent across all three

  14. Comparison between AOT40 and ozone uptake in forest trees of different species, age and site conditions

    Science.gov (United States)

    Matyssek, R.; Wieser, G.; Nunn, A. J.; Kozovits, A. R.; Reiter, I. M.; Heerdt, C.; Winkler, J. B.; Baumgarten, M.; Häberle, K.-H.; Grams, T. E. E.; Werner, H.; Fabian, P.; Havranek, W. M.

    The current AOT40 concept for inferring risks in forest trees by ozone (O 3) injury is based on an accumulated external O 3 exposure rather than an internal O 3 dose or uptake rate. AOT40 assumes O 3 concentrations below 40 nl l -1 and night-time exposure to be negligible. Hence, this concept is rather inconsistent with observed forest conditions. In contrast, the flux concept of cumulative O 3 uptake (CU) into the leaves has the potential of reflecting a physiologically meaningful internal O 3 dose experienced by trees. In this paper, we relate AOT40 to cumulative O 3 uptake into European beech ( Fagus sylvatica), Norway spruce ( Picea abies), European larch ( Larix decidua) and cembran pine ( Pinus cembra) trees differing in size, age and site conditions. We demonstrate that the flux concept can be extended to the tree and the stand level, making use of sap flow measurements through tree trunks. Although in both seedlings and adult trees AOT40 may show some linearity in correlations with average CU, the latter varies, at given AOT40, by 25±11% within and between species. This is because O 3 flux is primarily influenced by stomatal aperture, the latter being affected by climate, canopy position, leaf and tree age while varying between species. In particular, if weighed by detoxification capacity, we suggest, therefore, O 3 uptake related air quality indices to be promoted towards ecologically meaningful standards in forest protection, overcoming the shortcomings of exposure concepts. As O 3 injury results from the balance between O 3 uptake and detoxification in the leaf mesophyll, we conclude the flux concept in combination with measures of biochemical defence to have the capacity for predicting tree response to O 3 stress.

  15. Entity-Based Landscape Modelling to Assess the Impacts of Different Incentives Mechanisms on Argan Forest Dynamics

    Directory of Open Access Journals (Sweden)

    Farid El Wahidi

    2015-11-01

    Full Text Available Illegal occupation of argan forest parcels by local households is a new phenomenon in South West Morocco. This is primarily due to the weakening of traditional common control systems and to the boom of the argan oil price. The scope of this work is to develop a decision support system based on dynamic spatial modelling, allowing to anticipate the land tenure dynamics and their impact on forest stand degradation under different policy scenarios. The model simulates the change of land possession by locals and the forest stand degradation levels. The methodological approach combines a Markov chain analysis (MCA with stakeholders’ preferences for land tenure. First, parcels’ transition probabilities are computed using the MCA. Second, the acquiring suitability map is derived from multi-criteria evaluation procedure (AHP using biophysical and socio-economic data. Finally, uncertainty is introduced in the simulation based on probabilistic analysis for supporting socio-economic diversity and non-mechanistic human behavior. The modelling approach was successfully used to compare three scenarios: business as usual (continuation of illegal acquiring, total disengagement of the population and private/public partnership with incentives for restoring argan parcel. The model yields geographic information about (i the magnitude of the on-going process; (ii the potential occurrence of land use conflicts induced by new policies; and (iii the location of land conservation or degradation hot-spots. The outcomes of the “business as usual” and of the “total disengagement” models were similar over a 30-year simulation period: in both cases, the proportion of “highly degraded” parcels was doubled and the number of “quite degraded” parcels was increased by 50%. On the other hand, should the private/public partnership effectively work, about 40% of the parcels could be restored to a sustainable level.

  16. Relative importance of various regeneration mechanisms in different restoration stages of Quercus variabilis forest after selective logging

    Directory of Open Access Journals (Sweden)

    Yaoqin Xue

    2014-08-01

    Full Text Available Aim of study: Quercus variabilis (Chinese cork oak reproduces asexually and sexually. This study aimed to determine the status and growth of asexual and sexual recruits of Q. variabilis in different forest recovery stages.Area of study: Three selective logged stands and one unlogged stand in Q. variabilis forest, Shaanxi Province, China.Material and Methods: Origin, number, basal diameter, height and size structure of Q. variabilis shoots (height ≤200 cm were investigated in the plots of 5, 10, and 20-years post-logging stands and unlogged stand. Effects of recovery stage on the density and growth of the three original recruits (stump sprouts, stem base sprouts and true seedlings were analysis by One-way ANOVA.Main results: Sprouts dominated logged stands, whereas true seedlings dominated unlogged stand, stem base sprouts only existed in 20-years post-logging and unlogged stands. Stump sprout density and sprout number per stump both declined with extended post-logging time. True seedlings density increased from 7 to 20 shoots/100 m2 as the postlogging time extended, and peaked in unlogged stand (94 shoots/100 m2. An ongoing size structure was observed in true seedlings in all stands. Stump sprouts were taller and greater than true seedlings.Research highlights: Stump sprouts contributed more to Q. variabilis forest recovery in the early stage after disturbance. The contribution of true seedlings was limited in the same stage, but they were beneficial for population long-term development. Stem base sprouts were most likely to be a survival strategy rather than a reproductive strategy.Key words: asexual reproduction; true seedling; post-logging time; Chinese cork oak.

  17. Comparison of the composition of forest soil litter derived from three different sites at various decompositional stages using FTIR spectroscopy

    International Nuclear Information System (INIS)

    Haberhauer, G.; Rafferty, B.; Strebl, F.; Gerzabek, M. H.

    1998-06-01

    Transmission Fourier transformed infrared spectroscopy was used to compare organic soil layers originating from three different sites in two climatic regions. A variety of bands characteristic of molecular structures and functional groups have been identified for these samples from a humic podsol, a dystric cambisol and a spodo dystric cambisol. Similar results were obtained for all three soils. From L to H soil horizons, an increase of the band at 1630 cm -1 and decrease of bands in the region from 1510 cm -1 to 1230 cm -1 were observed. The band at 1630 cm -1 can be assigned to carboxylic and aromatic groups. The decline of the peak intensity at 1510 cm -1 is significantly correlated to the total carbon content and C/N ratio. The mineral material of the Ah horizons leads to an increase of the band at 1050 cm -1 due to IR-absorbance of the Si-O bond and to an appearance of bands in the region from 900 to 400 cm -1 , which are characteristic for clay and quartz minerals. Analysis of the FTIR absorbance showed that intensities of distinct peaks (e.g., at 1510 cm -1 ) can be a measure of decomposition of forest litter. Therefore, the proposed simple FTIR method has potential for identification and differentiation of organic soil horizons originating from known tree litter. The similarity of the characteristics of the spectra of the three soil profiles investigated suggests a broad applicability of this method to distinguish organic forest soil horizons. On the basis of the data presented in this study, it may be concluded that FTIR spectroscopy offers a simple, powerful, non-destructive tool for the investigation of decomposition of L to H horizons in forest soils. (author)

  18. Forest Histories & Forest Futures

    OpenAIRE

    Whitlock, Cathy

    2009-01-01

    The climate changes projected for the future will have significant consequences for forest ecosystems and our ability to manage them. It is reasonable to ask: Are there historical precedents that help us understand what might happen in the future or are historical perspectives becoming irrelevant? What synergisms and feedbacks might be expected between rapidly changing climate and land–use in different settings, especially at the wildland–urban interface? What lessons from the past might help...

  19. Tropical dry forest trees and lianas differ in leaf economic spectrum traits but have overlapping water-use strategies.

    Science.gov (United States)

    Werden, Leland K; Waring, Bonnie G; Smith-Martin, Christina M; Powers, Jennifer S

    2017-10-26

    Tree species in tropical dry forests employ a wide range of strategies to cope with seasonal drought, including regulation of hydraulic function. However, it is uncertain if co-occurring lianas also possess a diversity of strategies. For a taxonomically diverse group of 14 tree and 7 liana species, we measured morphological and hydraulic functional traits during an unusual drought and under non-drought conditions to determine (i) if trees have different water-use strategies than lianas and (ii) if relationships among these traits can be used to better understand how tree and liana species regulate diurnal leaf water potential (Ψdiurnal). In this Costa Rican tropical dry forest, lianas and trees had overlapping water-use strategies, but differed in many leaf economic spectrum traits. Specifically, we found that both lianas and trees employed a diversity of Ψdiurnal regulation strategies, which did not differ statistically. However, lianas and trees did significantly differ in terms of certain traits including leaf area, specific leaf area, petiole length, wood vessel diameter and xylem vessel density. All liana and tree species we measured fell along a continuum of isohydric (partial) to anisohydric (strict or extreme) Ψdiurnal regulation strategies, and leaf area, petiole length, stomatal conductance and wood vessel diameter correlated with these strategies. These findings contribute to a trait-based understanding of how plants regulate Ψdiurnal under both drought stress and sufficient water availability, and underscore that lianas and trees employ a similarly wide range of Ψdiurnal regulation strategies, despite having vastly different growth forms. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Meta-analysis of associations between human brain volume and intelligence differences: How strong are they and what do they mean?

    Science.gov (United States)

    Pietschnig, Jakob; Penke, Lars; Wicherts, Jelte M; Zeiler, Michael; Voracek, Martin

    2015-10-01

    Positive associations between human intelligence and brain size have been suspected for more than 150 years. Nowadays, modern non-invasive measures of in vivo brain volume (Magnetic Resonance Imaging) make it possible to reliably assess associations with IQ. By means of a systematic review of published studies and unpublished results obtained by personal communications with researchers, we identified 88 studies examining effect sizes of 148 healthy and clinical mixed-sex samples (>8000 individuals). Our results showed significant positive associations of brain volume and IQ (r=.24, R(2)=.06) that generalize over age (children vs. adults), IQ domain (full-scale, performance, and verbal IQ), and sex. Application of a number of methods for detection of publication bias indicates that strong and positive correlation coefficients have been reported frequently in the literature whilst small and non-significant associations appear to have been often omitted from reports. We show that the strength of the positive association of brain volume and IQ has been overestimated in the literature, but remains robust even when accounting for different types of dissemination bias, although reported effects have been declining over time. While it is tempting to interpret this association in the context of human cognitive evolution and species differences in brain size and cognitive ability, we show that it is not warranted to interpret brain size as an isomorphic proxy of human intelligence differences. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Forest owner representation of forest management and perception of resource efficiency: a structural equation modeling study

    Directory of Open Access Journals (Sweden)

    Andrej Ficko

    2015-03-01

    Full Text Available Underuse of nonindustrial private forests in developed countries has been interpreted mostly as a consequence of the prevailing noncommodity objectives of their owners. Recent empirical studies have indicated a correlation between the harvesting behavior of forest owners and the specific conceptualization of appropriate forest management described as "nonintervention" or "hands-off" management. We aimed to fill the huge gap in knowledge of social representations of forest management in Europe and are the first to be so rigorous in eliciting forest owner representations in Europe. We conducted 3099 telephone interviews with randomly selected forest owners in Slovenia, asking them whether they thought they managed their forest efficiently, what the possible reasons for underuse were, and what they understood by forest management. Building on social representations theory and applying a series of structural equation models, we tested the existence of three latent constructs of forest management and estimated whether and how much these constructs correlated to the perception of resource efficiency. Forest owners conceptualized forest management as a mixture of maintenance and ecosystem-centered and economics-centered management. None of the representations had a strong association with the perception of resource efficiency, nor could it be considered a factor preventing forest owners from cutting more. The underuse of wood resources was mostly because of biophysical constraints in the environment and not a deep-seated philosophical objection to harvesting. The difference between our findings and other empirical studies is primarily explained by historical differences in forestland ownership in different parts of Europe and the United States, the rising number of nonresidential owners, alternative lifestyle, and environmental protectionism, but also as a consequence of our high methodological rigor in testing the relationships between the constructs

  2. Different regional climatic drivers of Holocene large wildfires in boreal forests of northeastern America

    Science.gov (United States)

    Remy, Cécile C.; Hély, Christelle; Blarquez, Olivier; Magnan, Gabriel; Bergeron, Yves; Lavoie, Martin; Ali, Adam A.

    2017-03-01

    Global warming could increase climatic instability and large wildfire activity in circumboreal regions, potentially impairing both ecosystem functioning and human health. However, links between large wildfire events and climatic and/or meteorological conditions are still poorly understood, partly because few studies have covered a wide range of past climate-fire interactions. We compared palaeofire and simulated climatic data over the last 7000 years to assess causes of large wildfire events in three coniferous boreal forest regions in north-eastern Canada. These regions span an east-west cline, from a hilly region influenced by the Atlantic Ocean currently dominated by Picea mariana and Abies balsamea to a flatter continental region dominated by Picea mariana and Pinus banksiana. The largest wildfires occurred across the entire study zone between 3000 and 1000 cal. BP. In western and central continental regions these events were triggered by increases in both the fire-season length and summer/spring temperatures, while in the eastern region close to the ocean they were likely responses to hydrological (precipitation/evapotranspiration) variability. The impact of climatic drivers on fire size varied spatially across the study zone, confirming that regional climate dynamics could modulate effects of global climate change on wildfire regimes.

  3. Bat Response to Differing Fire Severity in Mixed-Conifer Forest California, USA

    Science.gov (United States)

    Heady, Paul A.; Hayes, John P.; Frick, Winifred F.

    2013-01-01

    Wildlife response to natural disturbances such as fire is of conservation concern to managers, policy makers, and scientists, yet information is scant beyond a few well-studied groups (e.g., birds, small mammals). We examined the effects of wildfire severity on bats, a taxon of high conservation concern, at both the stand (Bat activity in burned areas was either equivalent or higher than in unburned stands for all six phonic groups measured, with four groups having significantly greater activity in at least one burn severity level. Evidence of differentiation between fire severities was observed with some Myotis species having higher levels of activity in stands of high-severity burn. Larger-bodied bats, typically adapted to more open habitat, showed no response to fire. We found differential use of riparian and upland habitats among the phonic groups, yet no interaction of habitat type by fire severity was found. Extent of high-severity fire damage in the landscape had no effect on activity of bats in unburned sites suggesting no landscape effect of fire on foraging site selection and emphasizing stand-scale conditions driving bat activity. Results from this fire in mixed-conifer forests of California suggest that bats are resilient to landscape-scale fire and that some species are preferentially selecting burned areas for foraging, perhaps facilitated by reduced clutter and increased post-fire availability of prey and roosts. PMID:23483936

  4. Performance of forest bryophytes with different geographical distributions transplanted across a topographically heterogeneous landscape.

    Science.gov (United States)

    Dahlberg, C Johan; Ehrlén, Johan; Hylander, Kristoffer

    2014-01-01

    Most species distribution models assume a close link between climatic conditions and species distributions. Yet, we know little about the link between species' geographical distributions and the sensitivity of performance to local environmental factors. We studied the performance of three bryophyte species transplanted at south- and north-facing slopes in a boreal forest landscape in Sweden. At the same sites, we measured both air and ground temperature. We hypothesized that the two southerly distributed species Eurhynchium angustirete and Herzogiella seligeri perform better on south-facing slopes and in warm conditions, and that the northerly distributed species Barbilophozia lycopodioides perform better on north-facing slopes and in relatively cool conditions. The northern, but not the two southern species, showed the predicted relationship with slope aspect. However, the performance of one of the two southern species was still enhanced by warm temperatures. An important reason for the inconsistent results can be that microclimatic gradients across landscapes are complex and influenced by many climate-forcing factors. Therefore, comparing only north- and south-facing slopes might not capture the complexity of microclimatic gradients. Population growth rates and potential distributions are the integrated results of all vital rates. Still, the study of selected vital rates constitutes an important first step to understand the relationship between population growth rates and geographical distributions and is essential to better predict how climate change influences species distributions.

  5. The existence of Sumatran tiger (Panthera tigris sumatrae Pocock, 1929 and their prey in different forest habitat types in Kerinci Seblat National Park, Sumatra

    Directory of Open Access Journals (Sweden)

    YOAN DINATA

    2008-07-01

    Full Text Available A study on the relationships between prey animals and the occurence of sumatran tiger was conducted in Kerinci Seblat National Park, western Sumatra from May up to September 2001. The data have been collected from eight study sites based on the forest habitat types and its threats. The results showed that frequency of encounters with prey animals in different forest habitats were no difference. This might indicates that the prey animals were distributed fairly in all types of forest habitat. The frequency encounters of the sumatran tiger signs, however, have shown differently between locations. The encounters of tiger signs were more frequent in the forest habitats that close to the streams; in forest habitats with few animal huntings; and in forest habitats with no logging activities. This findings support the hypotheses that the existence of sumatran tiger as a predator is determined by the dense vegetations surrounding streams as hiding place used in an ambush; availability of prey animals as food, and habitat disturbances as shown by logging.

  6. Comparative Analysis of Different Types of Bacterial Colonies from the Soils of Yusmarg Forest, Kashmir valley India

    Directory of Open Access Journals (Sweden)

    Gowhar Hamid Dar

    2013-06-01

    Full Text Available The present work was carried out in the soils of Yusmarg forest to study about the bacterial load (density and diversity, to identify and isolate the bacteria from the soils. During the study a total of thirty six isolates were obtained, among thirty-six different isolates obtained at the four sites B7 and B8 were present at all the four sites, B6 and B9 were present only at site I in November, B16 and B17 were present only at site II in November, B19, B22, B23 and B24 were present only at site III in November, B32, B33 and B34 were present only at site III in December and B35 was present only at site IV in December. Comparative analysis of different types of colonies found at the four sites during the study indicates that the bacterial load was dominant in the month of November.

  7. Strong biotic influences on regional patterns of climate regulation services

    Science.gov (United States)

    Serna-Chavez, H. M.; Swenson, N. G.; Weiser, M. D.; van Loon, E. E.; Bouten, W.; Davidson, M. D.; van Bodegom, P. M.

    2017-05-01

    Climate regulation services from forests are an important leverage in global-change mitigation treaties. Like most ecosystem services, climate regulation is the product of various ecological phenomena with unique spatial features. Elucidating which abiotic and biotic factors relate to spatial patterns of climate regulation services advances our understanding of what underlies climate-mitigation potential and its variation within and across ecosystems. Here we quantify and contrast the statistical relations between climate regulation services (albedo and evapotranspiration, primary productivity, and soil carbon) and abiotic and biotic factors. We focus on 16,955 forest plots in a regional extent across the eastern United States. We find the statistical effects of forest litter and understory carbon on climate regulation services to be as strong as those of temperature-precipitation interactions. These biotic factors likely influence climate regulation through changes in vegetation and canopy density, radiance scattering, and decomposition rates. We also find a moderate relation between leaf nitrogen traits and primary productivity at this regional scale. The statistical relation between climate regulation and temperature-precipitation ranges, seasonality, and climatic thresholds highlights a strong feedback with global climate change. Our assessment suggests the expression of strong biotic influences on climate regulation services at a regional, temperate extent. Biotic homogenization and management practices manipulating forest structure and succession will likely strongly impact climate-mitigation potential. The identity, strength, and direction of primary influences differed for each process involved in climate regulation. Hence, different abiotic and biotic factors are needed to monitor and quantify the full climate-mitigation potential of temperate forest ecosystems.

  8. The Effects of Forest Therapy on Coping with Chronic Widespread Pain: Physiological and Psychological Differences between Participants in a Forest Therapy Program and a Control Group

    Directory of Open Access Journals (Sweden)

    Jin-Woo Han

    2016-02-01

    Full Text Available This study aimed to investigate the effects of a two-day forest therapy program on individuals with chronic widespread pain. Sixty one employees of a public organization providing building and facilities management services within the Seoul Metropolitan area participated in the study. Participants were assigned to an experimental group (n = 33 who participated in a forest therapy program or a control group (n = 28 on a non-random basis. Pre- and post-measures of heart rate variability (HRV, Natural Killer cell (NK cell activity, self-reported pain using the visual analog scale (VAS, depression level using the Beck Depression Inventory (BDI, and health-related quality of life measures using the EuroQol Visual Analog Scale (EQ-VAS were collected in both groups. The results showed that participants in the forest therapy group, as compared to the control group, showed physiological improvement as indicated by a significant increase in some measures of HRV and an increase in immune competence as indicated by NK cell activity. Participants in the forest therapy group also reported significant decreases in pain and depression, and a significant improvement in health-related quality of life. These results support the hypothesis that forest therapy is an effective intervention to relieve pain and associated psychological and physiological symptoms in individuals with chronic widespread pain.

  9. Relationship between Normalized Difference Vegetation Index by Ground Observations and Evapotranspiration at Forested Areas on the Lake Biwa Project.

    Science.gov (United States)

    Ebisu, N.; Nishikawa, A.; Kondho, A.; Nakakita, E.; Tanaka, K.

    2001-12-01

    Knowledge of relationship between normalized difference vegetation index (NDVI) and evapotranspiration is essential in order to estimate distribution of evapotranspiration at wide forest areas using satellite remote sensing. The relationship between NDVI and evapotranspiration was examined by the ground observation method of NDVI on the Lake Biwa Project. The Lake Biwa Project has been developed and proceeded by a Japanese group for investigating the hydrological cycle near land surface in and over the Lake Biwa Basin, which is composed of tens of members from about twenty universities, institutions and consulting companies. This NDVI values on the ground observation is calculated by reflected solar radiation and photosynthetic photon flux using a pyranometer and a quantum sensor. From the result of the observation at a forest experimental site, it was found that the seasonal variations of NDVI by ground observations corresponded to NDVI calculated from Landsat TM data. The research examines the relationship among NDVI and seasonal changes of evapotranspiration, leaf area index (LAI), and canopy resistance of Penman-Monteith method. The results indicate that the correlation coefficient between NDVI and LAI was high (r=0.71) and NDVI was not correlated to evapotranspiration and moving average of canopy resistance. However, high correlation was found between NDVI and the maximum values of evapotranspiration (r=0.82) for each 14-day periods and canopy resistance (r=0.79) was also correlated to NDVI at that time.

  10. Thermal Acclimation of Photosynthesis and Respiration Differ Across Mature Conifer Species in a Boreal Forest Peatland

    Science.gov (United States)

    Dusenge, M. E.; Stinziano, J. R.; Warren, J.; Ward, E. J.; Wullschleger, S.; Hanson, P. J.; Way, D.

    2017-12-01

    Boreal forests are often assumed to be temperature-limited, and warming is therefore expected to stimulate their carbon uptake. However, much of our information on the ability of boreal conifers to acclimate photosynthesis and respiration to rising temperatures comes from seedlings. We measured net CO2 assimilation rates (A) and dark respiration (R) at 25 °C (A25 and R25) and at prevailing growth temperatures (Ag and Rg) in mature Picea mariana (spruce) and Larix laricina (tamarack) exposed to ambient, +2.25, +4.5, +6.75 and +9 °C warming treatments in open top chambers in the field at the SPRUCE experiment (MN, USA). In spruce, A25 and Ag were similar across plots in May and June. In August, spruce in warmer treatments had higher A25, an effect that was offset by warmer leaf temperatures in the Ag data. In tamarack, A25 was stimulated by warming in both June and August, an effect that was mainly offset by higher leaf temperatures when Ag was assessed in June, while in August, Ag was still slightly higher in the warmest treatments (+6.75 and +9) compared to the ambient plots. In spruce, R25 was enhanced in warm-grown trees in May, but was similar across treatments in June and August, indicating little acclimation of R. Rg slightly increased with warming treatments across the season in spruce. In contrast, R in tamarack thermally acclimated, as R25 decreased with warming. But while this acclimation generated homeostatic Rg in June, Rg in August was still highest in the warmest treatments. Our work suggests that the capacity for thermal acclimation in both photosynthesis and respiration varies among boreal tree species, which may lead to shifts in the performance of these species as the climate warms.

  11. The influence of pine forests of different ages on the biological activity of layland soils in the middle Angara River basin

    Science.gov (United States)

    Sorokina, O. A.; Sorokin, N. D.

    2007-05-01

    The influence of pine forests of different ages (from 25 to 85 years) restoring on old plow land soils is reflected in the biological processes proceeding in them. The drastic decrease in the absolute and relative number of actinomycetes, along with an increase of the fungal population in the microbial complexes of the soils (within the whole profiles), indicates that the microbocenoses acquire “forest” properties. In the soils under the younger pine forests, the processes of microbiological mineralization and specific respiration activity are more active than in the soils under the older pine forests. With the age of the pine forests, the soil profiles become more differentiated according to the eluvial-illuvial type.

  12. Influence of the larval phase on connectivity: strong differences in the genetic structure of brooders and broadcasters in the Ophioderma longicauda species complex.

    Science.gov (United States)

    Weber, A A-T; Mérigot, B; Valière, S; Chenuil, A

    2015-12-01

    Closely related species with divergent life history traits are excellent models to infer the role of such traits in genetic diversity and connectivity. Ophioderma longicauda is a brittle star species complex composed of different genetic clusters, including brooders and broadcasters. These species diverged very recently and some of them are sympatric and ecologically syntopic, making them particularly suitable to study the consequences of their trait differences. At the scale of the geographic distribution of the broadcasters (Mediterranean Sea and northeastern Atlantic), we sequenced the mitochondrial marker COI and genotyped an intron (i51) for 788 individuals. In addition, we sequenced 10 nuclear loci newly developed from transcriptome sequences, for six sympatric populations of brooders and broadcasters from Greece. At the large scale, we found a high genetic structure within the brooders (COI: 0.07 lecithotrophic larval stage allows on average a 50-fold increase in migration rates, a 280-fold increase in effective size and a threefold to fourfold increase in genetic diversity. Our work, investigating complementary genetic markers on sympatric and syntopic taxa, highlights the strong impact of the larval phase on connectivity and genetic diversity. © 2015 John Wiley & Sons Ltd.

  13. The Geographic Distribution of Saccharomyces cerevisiae Isolates within three Italian Neighboring Winemaking Regions Reveals Strong Differences in Yeast Abundance, Genetic Diversity and Industrial Strain Dissemination

    Directory of Open Access Journals (Sweden)

    Alessia Viel

    2017-08-01

    Full Text Available In recent years the interest for natural fermentations has been re-evaluated in terms of increasing the wine terroir and managing more sustainable winemaking practices. Therefore, the level of yeast genetic variability and the abundance of Saccharomyces cerevisiae native populations in vineyard are becoming more and more crucial at both ecological and technological level. Among the factors that can influence the strain diversity, the commercial starter release that accidentally occur in the environment around the winery, has to be considered. In this study we led a wide scale investigation of S. cerevisiae genetic diversity and population structure in the vineyards of three neighboring winemaking regions of Protected Appellation of Origin, in North-East of Italy. Combining mtDNA RFLP and microsatellite markers analyses we evaluated 634 grape samples collected over 3 years. We could detect major differences in the presence of S. cerevisiae yeasts, according to the winemaking region. The population structures revealed specificities of yeast microbiota at vineyard scale, with a relative Appellation of Origin area homogeneity, and transition zones suggesting a geographic differentiation. Surprisingly, we found a widespread industrial yeast dissemination that was very high in the areas where the native yeast abundance was low. Although geographical distance is a key element involved in strain distribution, the high presence of industrial strains in vineyard reduced the differences between populations. This finding indicates that industrial yeast diffusion it is a real emergency and their presence strongly interferes with the natural yeast microbiota.

  14. Blood gas analysis, anion gap, and strong ion difference in horses treated with polyethylene glycol balanced solution (PEG 3350 or enteral and parenteral electrolyte solutions

    Directory of Open Access Journals (Sweden)

    Cláudio Luís Nina Gomes

    2014-06-01

    Full Text Available Large volumes of different electrolytes solutions are commonly used for ingesta hydration in horses with large colon impaction, but little is known about their consequences to blood acid-base balance. To evaluate the effects of PEG 3350 or enteral and parenteral electrolyte solutions on the blood gas analysis, anion gap and strong ion difference, five adult female horses were used in a 5x5 latin square design. The animals were divided in five groups and distributed to each of the following treatments: NaCl (0.9% sodium chloride solution; EES (enteral electrolyte solution, EES+LR (EES plus lactated Ringer's solution; PEG (balanced solution with PEG 3350 and PEG+LR (PEG plus lactated Ringer's solution. Treatments PEG or PEG + LR did not change or promoted minimal changes, while the EES caused a slight decrease in pH, but its association with lactated Ringer's solution induced increase in AG and SID values, as well as caused hypernatremia. In turn, the treatment NaCl generated metabolic acidosis. PEG 3350 did not alter the acid-base balance. Despite it's slight acidifying effect, the enteral electrolyte solution (EES did not cause clinically relevant changes.

  15. Alteration of anion gap and strong ion difference caused by hydroxyethyl starch 6% (130/0.42) and gelatin 4% in children.

    Science.gov (United States)

    Witt, Lars; Osthaus, Wilhelm Alexander; Jüttner, Björn; Heimbucher, Christian; Sümpelmann, Robert

    2008-10-01

    Synthetic colloid administration is a common practice for preventing perioperative hypovolemia and consecutive circulatory failure in children. This prospective, randomized study was conducted to investigate the effects of two different unbalanced synthetic colloid solutions on acid-base equilibrium in children. Fifty pediatric patients (aged 0-12 years) scheduled for major pediatric surgery were randomized to receive either 10 ml x kg(-1) of 6% hydroxyethyl starch solution 130/0.42 (HES) or 4% modified fluid gelatin (GEL) to maintain adequate systemic hemodynamics. Before and after colloid administration, a blood sample was collected to analyze hemoglobin, hematocrit, electrolytes, and acid-base parameters. The anion gap and the strong ion difference (SID) were calculated using standard formulas. Both HES and GEL administration caused a significant increase in plasma chloride concentration (P anion gap decreased significantly (P anion gap remained stable in the GEL group. In both groups, initial actual base excess and pH did not change significantly after colloid administration. Moderate intraoperative plasma replacement with unbalanced synthetic colloids HES and GEL leads to a decrease in SID and, in the case of HES, to a significant decrease in the anion gap in children. These alterations may result in a possible misinterpretation when the anion gap and SID are used for differential diagnosis of metabolic disturbances during major pediatric surgery.

  16. Effects of harvest of nontimber forest products and ecological differences between sites on the demography of African mahogany.

    Science.gov (United States)

    Gaoue, Orou G; Ticktin, Tamara

    2010-04-01

    The demographic impacts of harvesting nontimber forest products (NTFP) have been increasingly studied because of reports of potentially unsustainable harvest. Nevertheless, our understanding of how plant demographic response to harvest is altered by variation in ecological conditions, which is critical for developing realistic sustainable-use plans, is limited. We built matrix population models to test whether and how variation in ecological conditions affects population responses to harvest. In particular, we examined the effect of bark and foliage harvest on the demography of populations of African mahogany (Khaya senegalensis) in two contrasting ecological regions of Benin, West Africa. K. senegalensis bark and foliage harvest significantly reduced its stochastic population growth rates, but ecological differences between regions had a greater effect on population growth rates than did harvest. The effect of harvest on population growth rates (Deltalambda) was slightly stronger in the moist than in the drier region. Life-table response experiments revealed that the mechanism by which harvesting reduced lambda differed between ecological regions. Lowered stasis (persistence) of larger life stages lead to a reduction in lambda in the drier region, whereas lowered growth of all life stages lowered lambda in moist region. Potential strategies to increase population growth rates should include decreasing the proportion of individuals harvested, promoting harvester-owned plantations of African mahogany, and increasing survival and growth by promoting no-fire zones in gallery forests. Our results show how population responses to harvest of NTFP may be altered by ecological differences across sites and emphasize the importance of monitoring populations over the climatic range in which they occur to develop more realistic recommendations for conservation.

  17. Molecular analysis of fungal communities and laccase genes in decomposing litter reveals differences among forest types but no impact of nitrogen deposition

    Science.gov (United States)

    Blackwood, C.B.; Waldrop, M.P.; Zak, D.R.; Sinsabaugh, R. L.

    2007-01-01

    The fungal community of the forest floor was examined as the cause of previously reported increases in soil organic matter due to experimental N deposition in ecosystems producing predominantly high-lignin litter, and the opposite response in ecosystems producing low-lignin litter. The mechanism proposed to explain this phenomenon was that white-rot basidiomycetes are more important in the degradation of high-lignin litter than of low-lignin litter, and that their activity is suppressed by N deposition. We found that forest floor mass in the low-lignin sugar-maple dominated system decreased in October due to experimental N deposition, whereas forest floor mass of high-lignin oak-dominated ecosystems was unaffected by N deposition. Increased relative abundance of basidiomycetes in high-lignin forest floor was confirmed by denaturing gradient gel electrophoresis (DGGE) and sequencing. Abundance of basidiomycete laccase genes, encoding an enzyme used by white-rot basidiomycetes in the degradation of lignin, was 5-10 times greater in high-lignin forest floor than in low-lignin forest floor. While the differences between the fungal communities in different ecosystems were consistent with the proposed mechanism, no significant effects of N deposition were detected on DGGE profiles, laccase gene abundance, laccase length heterogeneity profiles, or phenol oxidase activity. Our observations indicate that the previously detected accumulation of soil organic matter in the high-lignin system may be driven by effects of N deposition on organisms in the mineral soil, rather than on organisms residing in the forest floor. However, studies of in situ gene expression and temporal and spatial variability within forest floor communities will be necessary to further relate the ecosystem dynamics of organic carbon to microbial communities and atmospheric N deposition. ?? 2007 The Authors; Journal compilation ?? 2007 Society for Applied Microbiology and Blackwell Publishing Ltd.

  18. Comparison of different modelling strategies for simulating gas exchange of Douglas-fir forest

    NARCIS (Netherlands)

    Wijk, van M.T.; Bouten, W.; Verstraten, J.M.

    2002-01-01

    Carbon and latent heat fluxes can be simulated with different model strategies to fulfil different research purposes. In this study we compared four different model concepts: artificial neural networks (ANN), fuzzy logic (FL), an index model (IM, using light use efficiency and water use efficiency)

  19. Trade-offs among forest value components in community forests of southwestern Amazonia

    Directory of Open Access Journals (Sweden)

    Christopher Baraloto

    2014-12-01

    Full Text Available Contemporary conservation interventions must balance potential trade-offs between multiple ecosystem services. In tropical forests, much attention has focused on the extent to which carbon-based conservation provided by REDD+ policies can also mitigate biodiversity conservation. In the nearly one-third of tropical forests that are community owned or managed, conservation strategies must also balance the multiple uses of forest products that support local livelihoods. Although much discussion has focused on policy options, little empirical evidence exists to evaluate the potential for trade-offs among different tropical forest value components. We assessed multiple components of forest value, including tree diversity, carbon stocks, and both timber and nontimber forest product resources, in forest communities across the trinational frontier of Brazil, Peru, and Bolivia. We installed 69 0.5-ha vegetation plots in local communities, and we characterized 15 components of forest value for each plot. Principal components analyses revealed two major axes of forest value, the first of which defined a trade-off between diversity of woody plant communities (taxonomic and functional versus aboveground biomass and standing timber volume. The second axis described abundance of commercial species, with strong positive loadings for density of timber and nontimber forest products, including Brazil nut (Bertholletia excelsa and copaiba oil (Copaifera spp.. The observed trade-off between different components of forest value suggests a potential for management conflicts prioritizing biodiversity conservation versus carbon stocks in the region. We discuss the potential for integrative indices of forest value for tropical forest conservation.

  20. Variation in carbon stocks on different slope aspects in seven major forest types of temperate region of Garhwal Himalaya, India.

    Science.gov (United States)

    Sharma, C M; Gairola, Sumeet; Baduni, N P; Ghildiyal, S K; Suyal, Sarvesh

    2011-09-01

    The present study was undertaken in seven major forest types of temperate zone (1500 m a.s.l. to 3100 m a.s.l.) of Garhwal Himalaya to understand the effect of slope aspects on carbon (C) density and make recommendations for forest management based on priorities for C conservation/sequestration. We assessed soil organic carbon (SOC) density, tree density, biomass and soil organic carbon (SOC) on four aspects, viz. north/east (NE), north/west (NW), south-east (SE) and south-west (SW), in forest stands dominated by Abies pindrow, Cedrus deodara, Pinus roxburghii, Cupressus torulosa, Quercus floribunda, Quercus semecarpifolia and Quercus leucotrichophora. TCD ranged between 77.3 CMg ha⁻¹ on SE aspect (Quercus leucotrichophora forest) and 291.6 CMg ha⁻¹ on NE aspect (moist Cedrus deodara forest). SOC varied between 40.3 CMg ha⁻¹ on SW aspect (Himalayan Pinus roxburghii forest) and 177.5 CMg ha⁻¹ on NE aspect (moist Cedrus deodara forest). Total C density (SOC+TCD) ranged between 118.1 CMg ha⁻¹ on SW aspect (Himalayan Pinus roxburghii forest) and 469.1 CMg ha⁻¹ on NE aspect (moist Cedrus deodara forest). SOC and TCD were significantly higher on northern aspects as compared with southern aspects. It is recommended that for C sequestration, the plantation silviculture be exercised on northern aspects, and for C conservation purposes, mature forest stands growing on northern aspects be given priority.

  1. Conservation in a crowded place : forest and people on Mount Elgon Uganda

    NARCIS (Netherlands)

    Sassen, M.

    2014-01-01

    <strong>Key words: tropical forest, conservation management, local livelihoods, forest cover change, disturbance, fuelwood, forest structure, species richness, biomass, Mount Elgonstrong>   A growing world population has important consequences for forests. In this study I investigate how

  2. Regional Variability of Cd, Hg, Pb and C Concentrations in Different Horizons of Swedish Forest Soils

    International Nuclear Information System (INIS)

    Alriksson, A.

    2001-01-01

    Contents of cadmium (Cd), mercury (Hg), lead (Pb) and carbon(C) in the O, B and C horizons of podzolized forest soils in Sweden were surveyed. Concentrations and storage of Cd, Hg and Pb in the O and B horizons were high in southern Sweden and gradually decreased towards the north, though with considerable local variability. This pattern reflects the influence of anthropogenic emissions of these metals, as well as the effects of soil-forming processes. Parent till material, as represented by the C horizon concentration of the respective metal, accounted for little of the variation in metal concentration in the O horizon. For Cd and Pb, the correlations were not significant or slightly negative (R 2 = 0.12 and 0.09 respectively) depending on region, while for Hg the correlation was not significant or slightly positive (R 2 = 0.03 and 0.08). Furthermore, parent till material accounted for more of the variation in metal concentrations in the B horizons in the northern part of Sweden than in the middle and southernmost parts, where the concentration of total carbon had more influence. The correlation between the metal concentrations in the B and C horizon was strongest for Pb (R 2 = 0.63 and 0.36 in the two northernmost regions), lower for Cd (R 2 = 0.19 and 0.16) and not significant for Hg. For all soil horizons, total C concentration accounted for much of the variation in Hg concentration in particular (O-horizon R 2 = 0.15-0.69, B horizon R 2 = 0.36-0.50, C horizon R 2 = 0.23-0.50 and ns in one region). Ratios of metal concentrations between the B and C horizons were highest for Hg(maximum value of 30), indicating a relatively larger addition or retention of Hg compared to Cd and Pb (maximum value of 10)in the B horizon. This study indicate that factors other than parent material account for the large scale variation in O horizon concentrations of metals but patterns correspond well with those of atmospheric deposition of heavy metals and acidifying substances

  3. Response of protozoan and microbial communities in various coniferous forest soils after transfer to forests with different levels of atmospheric pollution.

    NARCIS (Netherlands)

    Couteaux, M.-M.; Raubuch, M.; Berg, M.P.

    1998-01-01

    During recent decades, forest ecosystems have been exposed to high levels of atmospheric pollution, and it has been argued that this affects the composition and activity of decomposer communities and, subsequently, ecosystem functioning. To investigate the effects of atmospheric pollution on

  4. OCCURRENCE OF MACROSCOPIC FUNGI IN DIFFERENT FOREST TYPES IN THE FORESTRY RESEARCH CENTRE (FEPAGRO, SANTA MARIA, RS, BRAZIL

    Directory of Open Access Journals (Sweden)

    C. G. Maciel

    2015-06-01

    Full Text Available The macroscopic fungi performance a important role in the maintenance of forest environments, and studies related with the identification of species are fundamental to the research progress. This study aimed to realize a survey the species diversity of wood decomposing fungi in populations of Pinus elliottii Engelm, Eucalyptus globulus Labill, Acacia mearnsii de Wild and natural forest, in State Foundation for Agricultural Research - FEPAGRO, Forestry Research Center, located in Santa Maria, RS. Were collected 53 samples of macroscopic fungi in four areas, being 16 samples in forest of P. Elliottii; 12 samples in forest of E. globulus, 12 samples in forest of A. mearnsii and 13 samples in of native forest. In the laboratory, five genera were identified to the species level: Fuligo septica (L. F.H. Wigg, Gloeoporus dichrous (Fr. Bress., Lycogala epidendrum (L. Fr. e Trametes villosa (Sw. Kreisel.

  5. Tree species richness, diversity, and regeneration status in different oak (Quercus spp. dominated forests of Garhwal Himalaya, India

    Directory of Open Access Journals (Sweden)

    Sushma Singh

    2016-09-01

    Full Text Available Himalayan forests are dominated by different species of oaks (Quercus spp. at different altitudes. These oaks are intimately linked with hill agriculture as they protect soil fertility, watershed, and local biodiversity. They also play an important role in maintaining ecosystem stability. This work was carried out to study the diversity and regeneration status of some oak forests in Garhwal Himalaya, India. A total of 18 tree species belonging to 16 genera and 12 families were reported from the study area. Species richness varied for trees (4–7, saplings (3–10, and seedlings (2–6. Seedling and sapling densities (Ind/ha varied between 1,376 Ind/ha and 9,600 Ind/ha and 167 Ind/ha and 1,296 Ind/ha, respectively. Species diversity varied from 1.27 to 1.86 (trees, from 0.93 to 3.18 (saplings, and from 0.68 to 2.26 (seedlings. Total basal area (m2/ha of trees and saplings was 2.2–87.07 m2/ha and 0.20–2.24 m2/ha, respectively, whereas that of seedlings varied from 299 cm2/ha to 8,177 cm2/ha. Maximum tree species (20–80% had “good” regeneration. Quercus floribunda, the dominant tree species in the study area, showed “poor” regeneration, which is a matter of concern, and therefore, proper management and conservation strategies need to be developed for maintenance and sustainability of this oak species along with other tree species that show poor or no regeneration.

  6. Vascular Epiphyte Diversity Differs with Host Crown Zone and Diameter, but Not Orientation in a Tropical Cloud Forest.

    Directory of Open Access Journals (Sweden)

    Xixi Wang

    Full Text Available Vascular epiphytes are important components of biological diversity in tropical forests. We measured the species richness and abundance of vascular epiphytes along four vertical crown zones and five horizontal orientations on 376 trees, as well as the diameter at breast height (DBH of host trees in tropical cloud forests in Bawangling, Hainan, China. The relationship between vascular epiphyte species richness and host tree DBH was assessed using a generalized linear model. There were 1,453 vascular individual epiphytes attributed to 9 families, 24 genera and 35 species, with orchids and pteridophytes dominating. Both the species richness and abundance of epiphytes significantly differed among the four crown zones for all collections and each host tree, suggesting that vertical microhabitats contribute to the distribution of epiphytes on host trees. Neither epiphyte abundance nor species richness differed among the eastern, southern, western, and northern orientations for all host trees; however, both richness and abundance were significantly higher for epiphytes that encircled host tree trunks. This suggests that morphological and physiological characteristics of the tree, but not microclimates probably contribute to the distribution of epiphytes on host trees. Epiphyte species richness was positively correlated with tree DBH across the six host tree species studied, with increases in DBH among smaller trees resulting in larger increases in richness, while increases in DBH among larger host trees resulting in more modest increases in ephiphyte richness. Our findings contribute support for a positive relationship between epiphyte species richness and host tree DBH and provide important guidance for future surveys of epiphyte community development.

  7. Taboos and forest governance: informal protection of hot spot dry forest in southern Madagascar.

    Science.gov (United States)

    Tengö, Maria; Johansson, Kristin; Rakotondrasoa, Fanambinantsoa; Lundberg, Jakob; Andriamaherilala, Jean-Aimé; Rakotoarisoa, Jean-Aimé; Elmqvist, Thomas

    2007-12-01

    In the dry forest of southern Madagascar, a region of global conservation priority, formally protected areas are nearly totally absent. We illustrate how the continued existence of unique forest habitats in the Androy region is directly dependent on informal institutions, taboos, regulating human behavior. Qualitative interviews to map and analyze the social mechanisms underlying forest protection have been combined with vegetation analyses of species diversity and composition. Of 188 forest patches, 93% were classified as protected, and in Southern Androy all remaining forest patches larger than 5 ha were protected. Eight different types of forests, with a gradient of social fencing from open access to almost complete entry prohibitions, were identified. Transgressions were well enforced with strong sanctions of significant economic as well as religious importance. Analyses of species diversity between protected and unprotected forests were complicated because of size differences and access restrictions. However, since, for example, in southern Androy >90% of the total remaining forest cover is protected through taboos, these informal institutions represent an important, and presently the only, mechanism for conservation of the highly endemic forest species. We conclude that social aspects, such as local beliefs and legitimate sanctioning systems, need to be analyzed and incorporated along with biodiversity studies for successful conservation.

  8. Individual Differences in the Speed of Facial Emotion Recognition Show Little Specificity but Are Strongly Related with General Mental Speed: Psychometric, Neural and Genetic Evidence

    Science.gov (United States)

    Liu, Xinyang; Hildebrandt, Andrea; Recio, Guillermo; Sommer, Werner; Cai, Xinxia; Wilhelm, Oliver

    2017-01-01

    Facial identity and facial expression processing are crucial socio-emotional abilities but seem to show only limited psychometric uniqueness when the processing speed is considered in easy tasks. We applied a comprehensive measurement of processing speed and contrasted performance specificity in socio-emotional, social and non-social stimuli from an individual differences perspective. Performance in a multivariate task battery could be best modeled by a general speed factor and a first-order factor capturing some specific variance due to processing emotional facial expressions. We further tested equivalence of the relationships between speed factors and polymorphisms of dopamine and serotonin transporter genes. Results show that the speed factors are not only psychometrically equivalent but invariant in their relation with the Catechol-O-Methyl-Transferase (COMT) Val158Met polymorphism. However, the 5-HTTLPR/rs25531 serotonin polymorphism was related with the first-order factor of emotion perception speed, suggesting a specific genetic correlate of processing emotions. We further investigated the relationship between several components of event-related brain potentials with psychometric abilities, and tested emotion specific individual differences at the neurophysiological level. Results revealed swifter emotion perception abilities to go along with larger amplitudes of the P100 and the Early Posterior Negativity (EPN), when emotion processing was modeled on its own. However, after partialling out the shared variance of emotion perception speed with general processing speed-related abilities, brain-behavior relationships did not remain specific for emotion. Together, the present results suggest that speed abilities are strongly interrelated but show some specificity for emotion processing speed at the psychometric level. At both genetic and neurophysiological levels, emotion specificity depended on whether general cognition is taken into account or not. These

  9. Individual Differences in the Speed of Facial Emotion Recognition Show Little Specificity but Are Strongly Related with General Mental Speed: Psychometric, Neural and Genetic Evidence

    Directory of Open Access Journals (Sweden)

    Xinyang Liu

    2017-08-01

    Full Text Available Facial identity and facial expression processing are crucial socio-emotional abilities but seem to show only limited psychometric uniqueness when the processing speed is considered in easy tasks. We applied a comprehensive measurement of processing speed and contrasted performance specificity in socio-emotional, social and non-social stimuli from an individual differences perspective. Performance in a multivariate task battery could be best modeled by a general speed factor and a first-order factor capturing some specific variance due to processing emotional facial expressions. We further tested equivalence of the relationships between speed factors and polymorphisms of dopamine and serotonin transporter genes. Results show that the speed factors are not only psychometrically equivalent but invariant in their relation with the Catechol-O-Methyl-Transferase (COMT Val158Met polymorphism. However, the 5-HTTLPR/rs25531 serotonin polymorphism was related with the first-order factor of emotion perception speed, suggesting a specific genetic correlate of processing emotions. We further investigated the relationship between several components of event-related brain potentials with psychometric abilities, and tested emotion specific individual differences at the neurophysiological level. Results revealed swifter emotion perception abilities to go along with larger amplitudes of the P100 and the Early Posterior Negativity (EPN, when emotion processing was modeled on its own. However, after partialling out the shared variance of emotion perception speed with general processing speed-related abilities, brain-behavior relationships did not remain specific for emotion. Together, the present results suggest that speed abilities are strongly interrelated but show some specificity for emotion processing speed at the psychometric level. At both genetic and neurophysiological levels, emotion specificity depended on whether general cognition is taken into account

  10. Conversion from forests to pastures in the Colombian Amazon leads to differences in dead wood dynamics depending on land management practices.

    Science.gov (United States)

    Navarrete, Diego; Sitch, Stephen; Aragão, Luiz E O C; Pedroni, Lucio; Duque, Alvaro

    2016-04-15

    Dead wood, composed of coarse standing and fallen woody debris (CWD), is an important carbon (C) pool in tropical forests and its accounting is needed to reduce uncertainties within the strategies to mitigate climate change by reducing deforestation and forest degradation (REDD+). To date, information on CWD stocks in tropical forests is scarce and effects of land-cover conversion and land management practices on CWD dynamics remain largely unexplored. Here we present estimates on CWD stocks in primary forests in the Colombian Amazon and their dynamics along 20 years of forest-to-pasture conversion in two sub-regions with different management practices during pasture establishment: high-grazing intensity (HG) and low-grazing intensity (LG) sub-regions. Two 20-year-old chronosequences describing the forest-to-pasture conversion were identified in both sub-regions. The line-intersect and the plot-based methods were used to estimate fallen and standing CWD stocks, respectively. Total necromass in primary forests was similar between both sub-regions (35.6 ± 5.8 Mg ha(-1) in HG and 37.0 ± 7.4 Mg ha(-1) in LG). An increase of ∼124% in CWD stocks followed by a reduction to values close to those at the intact forests were registered after slash-and-burn practice was implemented in both sub-regions during the first two years of forest-to-pasture conversion. Implementation of machinery after using fire in HG pastures led to a reduction of 82% in CWD stocks during the second and fifth years of pasture establishment, compared to a decrease of 41% during the same period in LG where mechanization is not implemented. Finally, average necromass 20 years after forest-to-pasture conversion decreased to 3.5 ± 1.4 Mg ha(-1) in HG and 9.3 ± 3.5 Mg ha(-1) in LG, representing a total reduction of between 90% and 75% in each sub-region, respectively. These results highlight the importance of low-grazing intensity management practices during ranching activities in the Colombian

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

    Science.gov (United States)

    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.

  12. Effects of different land use changes on SOC stocks: From Mediterranean forest to agricultural land and vice versa

    Science.gov (United States)

    Lozano-García, Beatriz; Francaviglia, Rosa; Renzi, Gianluca; Doro, Luca; Parras-Alcántara, Luis; Ledda, Luigi; Concepción Benítez, M.

    2017-04-01

    During the past century there has been a general trend to alter ecosystems based on both the conversion from forest to agricultural land and the intensification of agriculture. The land use change (LUC) from forest to agricultural land is the origin of serious and direct soil problems, such as soil losses and degradation but there are other indirect problems as the decrease of soil carbon storage worldwide. Therefore, the deforestation involves an important loss of soil carbon, its emission to the atmosphere and a high contribution to the global warming. In addition, it is important to point out that due to the low yields and the high cost of modern tillage equipments, frequently the agricultural lands are abandoned, suffering a secondly LUC. This abandonment can exacerbate soil degradation, but in some cases gives the soil the opportunity to restore by revegetation (naturally in some cases, and induced in others). Thus, by reforestation/revegetation these soils can increase their capacity of storage soil organic carbon. To determine the effects both of deforestation and revegetation on SOC stock is highly important to consider the quantification of SOC stock in the hole profile, taking into account the surface layer and the subsurface horizons, since many research have shown the importance of the amount of C stored in depth and its significance in the role of soil as C sink. The main goal of this research was to assess the effect of a double LUC in the SOC stocks along the soil entire profile. After LUC from the agroforestry system to agricultural lands there were different situations. The first one in which the SOC stock did not suffer changes (when the land use was hay crop and pasture). There was no change in SOC stock both in the surface layer and in the subsurface. However, when the LUC was toward vineyards, both tilled and no tilled vineyards, the SOC stock decreased considerably in the topsoil. In the second land use change considered, derived from the

  13. Different slopes of a mountain can determine the structure of ferns and lycophytes communities in a tropical forest of Brazil

    Directory of Open Access Journals (Sweden)

    FELIPE C. NETTESHEIM

    2014-03-01

    Full Text Available A community of Ferns and Lycophytes was investigated by comparing the occurrence of species on different slopes of a paleoisland in Southeastern Brazil. Our goal was to evaluate the hypothesis that slopes with different geographic orientations determine a differentiation of Atlantic Forest ferns and lycophytes community. We recorded these plants at slopes turned towards the continent and at slopes turned towards the open sea. Analysis consisted of a preliminary assessment on fern beta diversity, a Non Metric Multidimensional Scaling (NMDS and a Student t-test to confirm if sites sampling units ordination was different at each axis. We further used the Pearson coefficient to relate fern species to the differentiation pattern and again Student's t-test to determine if richness, plant cover and abundance varied between the two sites. There was a relatively low number of shared species between the two sites and ferns and lycophytes community variation was confirmed. Some species were detected as indicators of the community variation but we were unable to detect richness, plant cover or abundance differences. Despite the evidence of this variation between the slopes, further works are needed to evaluate which processes are contributing to determine this pattern.

  14. Ecosystem services and climate change: Understanding the differences and identifying opportunities for forest carbon

    Science.gov (United States)

    Robert L. Deal; Crystal Raymond; David L. Peterson; Cindy. Glick

    2010-01-01

    There are a number of misunderstandings about “ecosystem services” and “climate change” and these terms are often used incorrectly to describe different concepts. These concepts address different issues and objectives but have some important integrating themes relating to carbon and carbon sequestration. In this paper, we provide definitions and distinctions between...

  15. Measurement of incoming radiation below forest canopies: A comparison of different radiometer configurations

    OpenAIRE

    Webster, Clare; Rutter, Nick; Zahner, Franziska; Jonas, Tobias

    2016-01-01

    Ground-based, sub-canopy measurements of incoming shortwave and longwave radiation are frequently used to drive and validate energy balance and snowmelt models. These sub-canopy measurements are frequently obtained using different configurations (linear or distributed; stationary or moving) of radiometer arrays that are installed to capture the spatial and temporal variability of longwave and shortwave radiation. Three different radiometer configurations (stationary distributed, stationary li...

  16. Carbonizing forest governance: analyzing the consequences of REDD+ for multilevel forest governance

    NARCIS (Netherlands)

    Vijge, M.J.

    2016-01-01

    <strong>Carbonizing forest governance: strong>

    <strong>Analyzing the consequences of REDD+ for multilevel forest governancestrong>

    Marjanneke J. Vijge

    Despite the fifty years of global action to combat deforestation and forest degradation, the world is still

  17. Nitrogen fluxes in the forests of the Congo Basin

    Science.gov (United States)

    Bauters, Marijn; Verbeeck, Hans; Cizungu, Landry; Makelele, Isaac; Boeckx, Pascal

    2017-04-01

    The tropical forest of the Congo basin remains very poorly investigated and understood; mainly because of logistic, political and research capacity constraints. Nevertheless, characterization and monitoring of fundamental processes in this biome is vital to understand future responses and to correctly parameterize Earth system models. Nutrient fluxes are key in these processes for the functioning of tropical forests, since CO2 uptake by terrestrial ecosystems strongly depends on site fertility, i.e. nutrient availability. Accurate projections of future net forest growth and terrestrial CO2 uptake thus necessitate an improved understanding on nutrient cycles and how these are coupled to the carbon (C) cycle in forests. Research in the Congo Basin region should combine assessments of both carbon fluxes and the underlying nutrient cycles which directly impact the forest productivity. We set up a monitoring network for nitrogen fluxes in four different forest types in the Congo Basin, resulting in a unique and integrate dataset. The questions to be answered: How do the N-budgets of four different forest types in the Congo Basin compare? How do these fluxes compare to fluxes in the Amazon forest? What is the influence from the strong slash-and-burn regimes on the N-cycle in the natural forests? We answer these questions with our empirical dataset of one hydrological year, combined with satellite and modeling data.

  18. Maintaining the confidentiality of plot locations by exploiting the low sensitivity of forest structure models to different spectral extraction kernels

    Science.gov (United States)

    Sean P. Healey; Elizabeth Lapoint; Gretchen G. Moisen; Scott L. Powell

    2011-01-01

    The United States Forest Service Forest Inventory and Analysis (FIA) unit maintains a large national network of inventory plots.While the consistency and extent of this network make FIA data attractive for ecological modelling, the FIA is charged by statute not to publicly reveal inventory plot locations. However, use of FIA plot data by the remote sensing community...

  19. Seasonal abundance and development of the Asian longhorned beetle and natural enemy prevalence in different forest types in China

    Science.gov (United States)

    Houping Liu; Leah S. Bauer; Tonghai Zhao; Ruitong Gao; Therese M. Poland

    2016-01-01

    Seasonal abundance and population development of the Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), and prevalence of its natural enemies were studied on Hankow willow (Salix matsudana Koidz.) at an urban forest site (Anci) and a rural forest site (Tangerli) in Hebei province...

  20. Does biodiversity make a difference? Relationships between species richness, evolutionary diversity, and aboveground live tree biomass across US forests

    Science.gov (United States)

    Kevin M. Potter; Christopher W. Woodall

    2014-01-01

    Biodiversity conveys numerous functional benefits to forested ecosystems, including community stability and resilience. In the context of managing forests for climate change mitigation/adaptation, maximizing and/or maintaining aboveground biomass will require understanding the interactions between tree biodiversity, site productivity, and the stocking of live trees....

  1. Splitting the difference: a proposal for benefit sharing in reducing emissions from deforestation and forest degradation (REDD+)

    NARCIS (Netherlands)

    Balderas Torres, Arturo; Skutsch, Margaret

    2012-01-01

    The objective of REDD+ is to create incentives for the reduction of emissions from deforestation and forest degradation and for the increase of carbon stocks through the enhancement, conservation and sustainable management of forests in developing countries. As part of the international negotiations

  2. Fires of differing intensities rapidly select distinct soil fungal communities in a Northwest US ponderosa pine forest ecosystem

    Science.gov (United States)

    C. Reazin; S. Morris; Jane Smith; A.D. Cowan; A. Jumpponen

    2016-01-01

    Environmental change and long-term fire management in the western United States have created conditions that facilitate high-intensity burn areas in forested systems. Such burns may have dramatic effects on the soil microbial communities. In this study, we utilized experimental infrastructure in the Pringle Falls Experimental Forest in Oregon, where ten pairs of sites...

  3. Correlations between Motor Symptoms across Different Motor Tasks, Quantified via Random Forest Feature Classification in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Andreas Kuhner

    2017-11-01

    Full Text Available BackgroundObjective assessments of Parkinson’s disease (PD patients’ motor state using motion capture techniques are still rarely used in clinical practice, even though they may improve clinical management. One major obstacle relates to the large dimensionality of motor abnormalities in PD. We aimed to extract global motor performance measures covering different everyday motor tasks, as a function of a clinical intervention, i.e., deep brain stimulation (DBS of the subthalamic nucleus.MethodsWe followed a data-driven, machine-learning approach and propose performance measures that employ Random Forests with probability distributions. We applied this method to 14 PD patients with DBS switched-off or -on, and 26 healthy control subjects performing the Timed Up and Go Test (TUG, the Functional Reach Test (FRT, a hand coordination task, walking 10-m straight, and a 90° curve.ResultsFor each motor task, a Random Forest identified a specific set of metrics that optimally separated PD off DBS from healthy subjects. We noted the highest accuracy (94.6% for standing up. This corresponded to a sensitivity of 91.5% to detect a PD patient off DBS, and a specificity of 97.2% representing the rate of correctly identified healthy subjects. We then calculated performance measures based on these sets of metrics and applied those results to characterize symptom severity in different motor tasks. Task-specific symptom severity measures correlated significantly with each other and with the Unified Parkinson’s Disease Rating Scale (UPDRS, part III, correlation of r2 = 0.79. Agreement rates between different measures ranged from 79.8 to 89.3%.ConclusionThe close correlation of PD patients’ various motor abnormalities quantified by different, task-specific severity measures suggests that these abnormalities are only facets of the underlying one-dimensional severity of motor deficits. The identification and characterization of this underlying motor deficit

  4. Effects of different tree species on soil organic matter composition, decomposition rates and temperature sensitivities in boreal forest

    Science.gov (United States)

    Segura, Javier; Nilsson, Mats B.; Erhagen, Björn; Sparrman, Tobias; Ilstedt, Ulrik; Schleucher, Jürgen; Öquist, Mats

    2017-04-01

    important implications for both the understanding of forest ecosystem carbon balances in high latitude ecosystems and also the selection of different tree species in forest management schemes.

  5. The Challenge of Forest Diagnostics

    Directory of Open Access Journals (Sweden)

    Harini Nagendra

    2011-06-01

    Full Text Available Ecologists and practitioners have conventionally used forest plots or transects for monitoring changes in attributes of forest condition over time. However, given the difficulty in collecting such data, conservation practitioners frequently rely on the judgment of foresters and forest users for evaluating changes. These methods are rarely compared. We use a dataset of 53 forests in five countries to compare assessments of forest change from forest plots, and forester and user evaluations of changes in forest density. We find that user assessments of changes in tree density are strongly and significantly related to assessments of change derived from statistical analyses of randomly distributed forest plots. User assessments of change in density at the shrub/sapling level also relate to assessments derived from statistical evaluations of vegetation plots, but this relationship is not as strong and only weakly significant. Evaluations of change by professional foresters are much more difficult to acquire, and less reliable, as foresters are often not familiar with changes in specific local areas. Forester evaluations can instead better provide valid single-time comparisons of a forest with other areas in a similar ecological zone. Thus, in forests where local forest users are present, their evaluations can be used to provide reliable assessments of changes in tree density in the areas they access. However, assessments of spatially heterogeneous patterns of human disturbance and regeneration at the shrub/sapling level are likely to require supplemental vegetation analysis.

  6. Comparing the sustainability of different action policy possibilities: application to the issue of both household survival and forest preservation in the corridor of Fianarantsoa.

    Science.gov (United States)

    Bernard, C; Martin, S

    2013-10-01

    A sustainability issue for the rain forest in the corridor of Fianarantsoa (Madagascar) is to preserve the forest while ensuring the development of the local population. The aim of this paper is to determine whether the current situation is sustainable or not according to different action policy possibilities. We propose a general procedure based on viability analysis: Translation of sustainability issues into constraints on the system state; elaboration of a mathematical model of system evolution rules in the form of controlled dynamical system; computations of the viability kernels according to different action policy possibilities. Among control variables, we focus on monetary transfer. Without monetary transfer, we show that the current situation of the rain forest corridor is not sustainable in our mathematical modeling framework. We then estimate the minimal maximal amount per year necessary to make the current situation sustainable. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Characteristics of initial deposition and behavior of radiocesium in forest ecosystems of different locations and species affected by the Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    Komatsu, Masabumi; Kaneko, Shinji; Ohashi, Shinta; Kuroda, Katsushi; Sano, Tetsuya; Ikeda, Shigeto; Saito, Satoshi; Kiyono, Yoshiyuki; Tonosaki, Mario; Miura, Satoru; Akama, Akio; Kajimoto, Takuya; Takahashi, Masamichi

    2016-01-01

    After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, information about stand-level spatial patterns of radiocesium initially deposited in the surrounding forests was essential for predicting the future dynamics of radiocesium and suggesting a management plan for contaminated forests. In the first summer (approximately 6 months after the accident), we separately estimated the amounts of radiocesium ( 134 Cs and 137 Cs; Bq m −2 ) in the major components (trees, organic layers, and soils) in forests of three sites with different contamination levels. For a Japanese cedar (Cryptomeria japonica) forest studied at each of the three sites, the radiocesium concentration greatly differed among the components, with the needle and organic layer having the highest concentrations. For these cedar forests, the proportion of the 137 Cs stock in the aboveground tree biomass varied from 22% to 44% of the total 137 Cs stock; it was 44% in highly contaminated sites (7.0 × 10 5 Bq m −2 ) but reduced to 22% in less contaminated sites (1.1 × 10 4 Bq m −2 ). In the intermediate contaminated site (5.0–5.8 × 10 4 Bq m −2 ), 34% of radiocesium was observed in the aboveground tree biomass of the Japanese cedar stand. However, this proportion was considerably smaller (18–19%) in the nearby mixed forests of the Japanese red pine (Pinus densiflora) and deciduous broad-leaved trees. Non-negligible amounts of 134 Cs and 137 Cs were detected in both the sapwood and heartwood of all the studied tree species. This finding suggested that the uptake or translocation of radiocesium had already started within 6 months after the accident. The belowground compartments were mostly present in the organic layer and the uppermost (0–5 cm deep) mineral soil layer at all the study sites. We discussed the initial transfer process of radiocesium deposited in the forest and inferred that the type of initial deposition (i.e., dry versus wet radiocesium deposition), the amount of

  8. Effects of different thinning systems on the economic value of ecosystem services: A case-study in a black pine peri-urban forest in Central Italy

    Directory of Open Access Journals (Sweden)

    Alessandro Paletto

    2017-12-01

    Full Text Available Sustainable Forest Management (SFM should be able to produce an optimal level of bundle of Ecosystem Services (ES, thus ensuring more resilient forest ecosystems also creating benefits for local population and human well-being. Yet, choosing between alternative forest management practices is not straightforward as it necessarily involves ES trade-offs. Forest management decisions have to reconcile the socio-economic and ecological contributions of forest ecosystems by fostering a synergistic relation between multiple ES while lowering ES trade-offs. The aim of the study is to analyze different forest management practices (selective and traditional thinning in black pine peri-urban forest in Central Italy, by investigating their contribution in terms of provisioning (wood production, cultural (recreational benefits, regulating (climate change mitigation ES. For each management option was performed: (1 the biophysical assessment of selected ES by using primary data and calculating indicators for wood production with special regard to biomass for energy use (living trees and deadwood volume harvested, recreational benefits (tourists’ preferences for each forest management practice, climate change mitigation (carbon sequestration in above-ground and below-ground biomass, and (2 the economic valuation of wood production, recreational benefits and climate change mitigation ES using direct and indirect methods (environmental evaluation techniques. The results show that the effects of the selective thinning on ES is higher that the effects of the traditional thinning. The economic value of the three ES provided by traditional and selective thinning are respectively: bioenergy production 154.2 € ha-1 yr-1 and 223.3 € ha-1 yr-1; recreational benefits 193.2 € ha-1 yr-1 and 231.9 € ha-1 yr-1; carbon sequestration 29.0 € ha-1 yr-1and 36.2 € ha-1 yr-1. The integrated (biophysical and economic assessment of ES in addition to the trade

  9. Relationships between soil water repellency and microbial community composition under different plant species in a Mediterranean semiarid forest

    Science.gov (United States)

    Lozano, Elena; García-Orenes, Fuensanta; Bárcenas-Moreno, Gema; Jiménez-Pinilla, Patricia; Mataix-Solera, Jorge; Arcenegui, Victoria; Morugán-Coronado, Alicia; Mataix-Beneyto, Jorge

    2014-05-01

    It is generally well accepted that soil water repellency (SWR) can greatly influence the hydrology and the ecology of the forest soils (Doerr et al., 2000). However, little is known whether SWR may influence the soil microbial community. Its appearance is mainly influence by many soil physic- chemical parameters like: SOM content and its quality, pH, moisture, texture etc. However, it might also be influence by the presence or activity of microorganisms. Early studies suggest that SWR might be caused by substances produced by the activity of certain fungi species (Savage et al., 1969). Soil WR is normally characterized by a high spatial variability in persistence, with wettable and water repellent patches (Lozano et al., 2013). Changes at the microsite scale (such as the presence of soil water repellent patches) might be reflected in the microbial community structure). In the current study we have analysed how SWR influence the microbial community in soil samples with a range of water repellency persistence under different plant species (P. halepensis, Q. rotundifolia, C. albidus and R officinalis) in a Mediterranean forest. The microbial community was determined through phospholipids fatty acids (PLFA). The relationships between microbiological community structure and other different soil properties like pH, Glomalin Related Soil Protein and Soil Organic Matter content were also studied. Different statistical analyses were used: Principal Component Analysis (PCA), ANOVA, Redundancy Analysis (RA) and Pearson correlations. The highest concentrations of PLFA were found in water repellent samples. PCA showed that microorganism composition was more dependent of the severity of SWR than the type of plant species. In the RA, SWR was the only significant factor (pGeoderma, 207-208, 212-220. Roper, M.M., 2004. The isolation and characterization of bacteria with the potential to degrade waxes that cause water repellency in sandy soils. Aust. J. Soil Res., 42, 427

  10. Soil Organic Carbon (SOC) distribution in two differents soil types (Podzol and Andosol) under natural forest cover.

    Science.gov (United States)

    Álvarez-Romero, Marta; Papa, Stefania; Verstraeten, Arne; Cools, Nathalie; Lozano-García, Beatriz; Parras-Alcántara, Luis; Coppola, Elio

    2017-04-01

    Andosols are young soils that shall know a successive evolution towards pedological types where the dominant pedogenetic processes are more evident. Vegetation and climate influence Andosols evolution to other order of soils. In cold and wet climates or on acid vulcanite under heavy leaching young Andosols could change into Podzols (Van Breemn and Buurman, 1998). Were investigated a Podzol soil (World References Base, 2014) at Zoniën (Belgium), were and an Andosol soil (World References Base, 2014) at Lago Laceno (Avellino, Italy). This study shows the data on the SOC (Soil Organic Carbon) fractionation in two profiles from two natural pine forest soils. Together with the conventional activities of sampling and analysis of soil profile were examined surveys meant to fractionation and characterization of SOC, in particular: Total Organic Carbon (TOC) and Total Extractable Carbon (TEC) soil contents were determined by Italian official method of soil analysis (Mi.P.A.F. (2000)). Different soil C fractions were also determined: Humic Acid Carbon (HAC), Fulvic Acid Carbon (FAC), Not Humic Carbon (NHC) and Humin Carbon (Huc) fractions were obtained by difference. In the whole profile, therefore, were also assayed cellulose and lignin contents. The aim of this work was to compare the distribution of different soil organic components in a podzol and a soil with andic properties. The data show great similarity, among the selected profiles, in the organic components distribution estudied. References: - Mi.P.A.F. - Ministero per le Politiche Agricole e Forestali - Osservatorio Nazionale Pedologico e per la Qualità del Suolo (2000): Metodi Ufficiali di Analisi Chimica del Suolo. In: Franco Angeli (Editor), Collana di metodi analitici per l'agricoltura diretta da Paolo Sequi, n. 1124.2, Milano, Italy. - Van Breemn N. and Buurman P. (1998) Chapter 12 Formation of Andisols. In: Soil formation. Kluwer Ed., Wageningen, The Netherlands, 271-289. -Ussiri D.A.N., Johnson C

  11. The public view of Pacific Northwest forests

    International Nuclear Information System (INIS)

    West, P.R.

    1991-01-01

    There are diverse communities that make up the public in the Pacific Northwest, all with differing views on the forest. To the media, the public are those indirect stakeholders, or average citizens, who have become keenly aware of the importance of environmental issues, including the implications for global change. Linkages between the forests, deforestation, global climate change, and overall environmental sustainability have been widely publicized, though less frequently analyzed in depth. Consequently, the state of Northwest forests has become a vital public interest. The need for an overall margin of global environmental security, and a concern over unsuspected consequences of all economic activity (including forestry) have created a community of interest among the urban population. In part, this is a spillover effect from promoting individual environmental responsibility and the conserver ethic into issues beyond the city boundary. In the Northwest, this often translates as a deep concern over forest management issues and strong conviction that changes are needed. At the same time, and largely as a direct response, the socioeconomic interests of rural forest communities have become a high-profile issue, raising debate over local empowerment and local forest stewardship models. The consequences of this complex and rapidly evolving public view of the forests are critical to forest managers and policymakers. 12 refs

  12. Nematode consumption by mite communities varies in different forest microhabitats as indicated by molecular gut content analysis.

    Science.gov (United States)

    Heidemann, Kerstin; Ruess, Liliane; Scheu, Stefan; Maraun, Mark

    2014-01-01

    Soil animals live in complex and heterogeneous habitats including litter of various types but also microhabitats such as mosses, fungal mats and grass patches. Soil food webs have been separated into a slow fungal and a fast bacterial energy channel. Bacterial-feeding nematodes are an important component of the bacterial energy channel by consuming bacteria and forming prey for higher trophic levels such as soil microarthropods. Investigating the role of nematodes as prey for higher trophic level consumers has been hampered by methodological problems related to their small body size and lack in skeletal structures which can be traced in the gut of consumers. Recent studies using molecular gut content analyses suggest that nematodes form major prey of soil microarthropods including those previously assumed to live as detritivores. Using molecular markers we traced nematode prey in fourteen abundant soil microarthropod taxa of Mesostigmata and Oribatida (both Acari) from three different microhabitats (litter, grass and moss). Consumption of nematodes varied between mite species indicating that trophic niche variation contributes to the high diversity of microarthropods in deciduous forests. Further, consumption of nematodes by Mesostigmata (but not Oribatida) differed between microhabitats indicating that trophic niches vary with habitat characteristics. Overall, the results suggest that free-living bacterial-feeding nematodes form important prey for soil microarthropods including those previously assumed to live as detritivores.

  13. Boreal forests

    Energy Technology Data Exchange (ETDEWEB)

    Essen, P.A.; Ericson, L. [Univ. of Umeaa, Dept. of Ecological Botany, Umeaa (Sweden); Ehnstroem, B. [Swedish Univ., of Agricultural Sciences, Swedish Threatened Species Unit, Uppsala (Sweden); Sjoeberg, K. [Swedish Univ. of Agricultural Sciences, Dept. of Animal Ecology, Umeaa (Sweden)

    1997-10-01

    We review patterns and processes important for biodiversity in the Fennoscandian boreal forest, describe man`s past and present impact and outline a strategy for conservation. Natural disturbances, particularly forest fire and gap formation, create much of the structural and functional diversity in forest ecosystems. Several boreal plants and animals are adapted to fire regimes. In contrast, many organisms (epiphytic lichens, fungi, invertebrates) require stable conditions with long continuity in canopy cover. The highly mechanized and efficient Fennoscandian forest industry has developed during the last century. The result is that most natural forest has been lost and that several hundreds of species, mainly cryptograms and invertebrates, are threatened. The forestry is now in a transition from exploitation to sustainable production and has recently incorporated some measures to protect the environment. Programmes for maintaining biodiversity in the boreal forest should include at least three parts. First, the system of forest reserves must be significantly improved through protection of large representative ecosystems and key biotopes that host threatened species. Second, we must restore ecosystem properties that have been lost or altered. Natural disturbance regimes must be allowed to operate or be imitated, for example by artificial fire management. Stand-level management should particularly increase the amount of coarse woody debris, the number of old deciduous trees and large, old conifers, by using partial cutting. Third, natural variation should also be mimicked at the landscape level, for example, by reducing fragmentation and increasing links between landscape elements. Long-term experiments are required to evaluate the success of different management methods in maintaining biodiversity in the boreal forest. (au) 260 refs.

  14. Boreal forests

    International Nuclear Information System (INIS)

    Essen, P.A.; Ericson, L.; Ehnstroem, B.; Sjoeberg, K.

    1997-01-01

    We review patterns and processes important for biodiversity in the Fennoscandian boreal forest, describe man's past and present impact and outline a strategy for conservation. Natural disturbances, particularly forest fire and gap formation, create much of the structural and functional diversity in forest ecosystems. Several boreal plants and animals are adapted to fire regimes. In contrast, many organisms (epiphytic lichens, fungi, invertebrates) require stable conditions with long continuity in canopy cover. The highly mechanized and efficient Fennoscandian forest industry has developed during the last century. The result is that most natural forest has been lost and that several hundreds of species, mainly cryptograms and invertebrates, are threatened. The forestry is now in a transition from exploitation to sustainable production and has recently incorporated some measures to protect the environment. Programmes for maintaining biodiversity in the boreal forest should include at least three parts. First, the system of forest reserves must be significantly improved through protection of large representative ecosystems and key biotopes that host threatened species. Second, we must restore ecosystem properties that have been lost or altered. Natural disturbance regimes must be allowed to operate or be imitated, for example by artificial fire management. Stand-level management should particularly increase the amount of coarse woody debris, the number of old deciduous trees and large, old conifers, by using partial cutting. Third, natural variation should also be mimicked at the landscape level, for example, by reducing fragmentation and increasing links between landscape elements. Long-term experiments are required to evaluate the success of different management methods in maintaining biodiversity in the boreal forest. (au) 260 refs

  15. Biomass and morphology of fine roots in temperate broad-leaved forests differing in tree species diversity: is there evidence of below-ground overyielding?

    Science.gov (United States)

    Meinen, Catharina; Hertel, Dietrich; Leuschner, Christoph

    2009-08-01

    Biodiversity effects on ecosystem functioning in forests have only recently attracted increasing attention. The vast majority of studies in forests have focused on above-ground responses to differences in tree species diversity, while systematic analyses of the effects of biodiversity on root systems are virtually non-existent. By investigating the fine root systems in 12 temperate deciduous forest stands in Central Europe, we tested the hypotheses that (1) stand fine root biomass increases with tree diversity, and (2) 'below-ground overyielding' of species-rich stands in terms of fine root biomass is the consequence of spatial niche segregation of the roots of different species. The selected stands represent a gradient in tree species diversity on similar bedrock from almost pure beech forests to medium-diverse forests built by beech, ash, and lime, and highly-diverse stands dominated by beech, ash, lime, maple, and hornbeam. We investigated fine root biomass and necromass at 24 profiles per stand and analyzed species differences in fine root morphology by microscopic analysis. Fine root biomass ranged from 440 to 480 g m(-2) in the species-poor to species-rich stands, with 63-77% being concentrated in the upper 20 cm of the soil. In contradiction to our two hypotheses, the differences in tree species diversity affected neither stand fine root biomass nor vertical root distribution patterns. Fine root morphology showed marked distinctions between species, but these root morphological differences did not lead to significant differences in fine root surface area or root tip number on a stand area basis. Moreover, differences in species composition of the stands did not alter fine root morphology of the species. We conclude that 'below-ground overyielding' in terms of fine root biomass does not occur in the species-rich stands, which is most likely caused by the absence of significant spatial segregation of the root systems of these late-successional species.

  16. Why do forest products become less available?A pan-tropical comparison of drivers of forest-resource degradation

    Science.gov (United States)

    Hermans-Neumann, Kathleen; Gerstner, Katharina; Geijzendorffer, Ilse R.; Herold, Martin; Seppelt, Ralf; Wunder, Sven

    2016-12-01

    Forest products provide an important source of income and wellbeing for rural smallholder communities across the tropics. Although tropical forest products frequently become over-exploited, only few studies explicitly address the dynamics of degradation in response to socio-economic drivers. Our study addresses this gap by analyzing the factors driving changes in tropical forest products in the perception of rural smallholder communities. Using the poverty and environment network global dataset, we studied recently perceived trends of forest product availability considering firewood, charcoal, timber, food, medicine, forage and other forest products. We looked at a pan-tropical sample of 233 villages with forest access. Our results show that 90% of the villages experienced declining availability of forest resources over the last five years according to the informants. Timber and fuelwood together with forest foods were featured as the most strongly affected, though with marked differences across continents. In contrast, availability of at least one main forest product was perceived to increase in only 39% of the villages. Furthermore, the growing local use of forest resources is seen as the main culprit for the decline. In villages with both growing forest resource use and immigration—vividly illustrating demographic pressures—the strongest forest resources degradation was observed. Conversely, villages with little or no population growth and a decreased use of forest resources were most likely to see significant forest-resource increases. Further, villages are less likely to perceive resource declines when local communities own a significant share of forest area. Our results thus suggest that perceived resource declines have only exceptionally triggered adaptations in local resource-use and management patterns that would effectively deal with scarcity. Hence, at the margin this supports neo-Malthusian over neo-Boserupian explanations of local resource

  17. Forest fruit production is higher on Sumatra than on Borneo.

    Directory of Open Access Journals (Sweden)

    Serge A Wich

    Full Text Available Various studies have shown that the population densities of a number of forest vertebrates, such as orangutans, are higher on Sumatra than Borneo, and that several species exhibit smaller body sizes on Borneo than Sumatra and mainland Southeast Asia. It has been suggested that differences in forest fruit productivity between the islands can explain these patterns. Here we present a large-scale comparison of forest fruit production between the islands to test this hypothesis.Data on fruit production were collated from Sumatran and Bornean sites. At six sites we assessed fruit production in three forest types: riverine, peat swamp and dryland forests. We compared fruit production using time-series models during different periods of overall fruit production and in different tree size classes. We examined overall island differences and differences specifically for fruiting period and tree size class. The results of these analyses indicate that overall the Sumatran forests are more productive than those on Borneo. This difference remains when each of the three forest types (dryland, riverine, and peat are examined separately. The difference also holds over most tree sizes and fruiting periods.Our results provide strong support for the hypothesis that forest fruit productivity is higher on Sumatra than Borneo. This difference is most likely the result of the overall younger and more volcanic soils on Sumatra than Borneo. These results contribute to our understanding of the determinants of faunal density and the evolution of body size on both islands.

  18. African Savanna-Forest Boundary Dynamics: A 20-Year Study.

    Science.gov (United States)

    Cuni-Sanchez, Aida; White, Lee J T; Calders, Kim; Jeffery, Kathryn J; Abernethy, Katharine; Burt, Andrew; Disney, Mathias; Gilpin, Martin; Gomez-Dans, Jose L; Lewis, Simon L

    2016-01-01

    Recent studies show widespread encroachment of forest into savannas with important consequences for the global carbon cycle and land-atmosphere interactions. However, little research has focused on in situ measurements of the successional sequence of savanna to forest in Africa. Using long-term inventory plots we quantify changes in vegetation structure, above-ground biomass (AGB) and biodiversity of trees ≥10 cm diameter over 20 years for five vegetation types: savanna; colonising forest (F1), monodominant Okoume forest (F2); young Marantaceae forest (F3); and mixed Marantaceae forest (F4) in Lopé National Park, central Gabon, plus novel 3D terrestrial laser scanning (TLS) measurements to assess forest structure differences. Over 20 years no plot changed to a new stage in the putative succession, but F1 forests strongly moved towards the structure, AGB and diversity of F2 forests. Overall, savanna plots showed no detectable change in structure, AGB or diversity using this method, with zero trees ≥10 cm diameter in 1993 and 2013. F1 and F2 forests increased in AGB, mainly as a result of adding recruited stems (F1) and increased Basal Area (F2), whereas F3 and F4 forests did not change substantially in structure, AGB or diversity. Critically, the stability of the F3 stage implies that this stage may be maintained for long periods. Soil carbon was low, and did not show a successional gradient as for AGB and diversity. TLS vertical plant profiles showed distinctive differences amongst the vegetation types, indicating that this technique can improve ecological understanding. We highlight two points: (i) as forest colonises, changes in biodiversity are much slower than changes in forest structure or AGB; and (ii) all forest types store substantial quantities of carbon. Multi-decadal monitoring is likely to be required to assess the speed of transition between vegetation types.

  19. <strong>OPTIMIZATION OF IMMOBILIZED METAL strong>>ION AFFINITYstrong>> strong>>CHROMATOGRAPHY strong>>FOR strong>>PHOSPHOPEPTIDE ENRICHMENT  PRIOR TO strong>>MASS SPECTROMETRYstrong>

    DEFF Research Database (Denmark)

    Ye, Juanying; Zhang, Xumin; Young, Clifford

    simple procedures.     Methods Tryptic digests of standard phosphoproteins (bovine α,β- casein) and 3 non-phosphoproteins (bovine serum albumin, bovine β-lactoglobulin, and bovine carbonic anhydrase) with different ratios (1:50, 1:200, 1:500, 1:1000) were used for Fe(III)-IMAC (Qiagen Ni-NTA) enrichment.......   Results Fe(III)-IMAC using NTA-silica from Qiagen  showed a better performance than two other commercially available resins under the testing conditions. Increase of the acetonitrile content to 60% in loading and washing buffer significantly improved the specificity of IMAC enrichment. It was demonstrated...

  20. Soil Acidobacterial 16S rRNA Gene Sequences Reveal Subgroup Level Differences between Savanna-Like Cerrado and Atlantic Forest Brazilian Biomes

    Directory of Open Access Journals (Sweden)

    Elisa C. P. Catão

    2014-01-01

    Full Text Available 16S rRNA sequences from the phylum Acidobacteria have been commonly reported from soil microbial communities, including those from the Brazilian Savanna (Cerrado and the Atlantic Forest biomes, two biomes that present contrasting characteristics of soil and vegetation. Using 16S rRNA sequences, the present work aimed to study acidobacterial diversity and distribution in soils of Cerrado savanna and two Atlantic forest sites. PCA and phylogenetic reconstruction showed that the acidobacterial communities found in “Mata de galeria” forest soil samples from the Cerrado biome have a tendency to separate from the other Cerrado vegetation microbial communities in the direction of those found in the Atlantic Forest, which is correlated with a high abundance of Acidobacteria subgroup 2 (GP2. Environmental conditions seem to promote a negative correlation between GP2 and subgroup 1 (GP1 abundance. Also GP2 is negatively correlated to pH, but positively correlated to high Al3+ concentrations. The Cerrado soil showed the lowest Acidobacteria richness and diversity indexes of OTUs at the species and subgroups levels when compared to Atlantic Forest soils. These results suggest specificity of acidobacterial subgroups to soils of different biomes and are a starting point to understand their ecological roles, a topic that needs to be further explored.

  1. Soil Acidobacterial 16S rRNA Gene Sequences Reveal Subgroup Level Differences between Savanna-Like Cerrado and Atlantic Forest Brazilian Biomes.

    Science.gov (United States)

    Catão, Elisa C P; Lopes, Fabyano A C; Araújo, Janaína F; de Castro, Alinne P; Barreto, Cristine C; Bustamante, Mercedes M C; Quirino, Betania F; Krüger, Ricardo H

    2014-01-01

    16S rRNA sequences from the phylum Acidobacteria have been commonly reported from soil microbial communities, including those from the Brazilian Savanna (Cerrado) and the Atlantic Forest biomes, two biomes that present contrasting characteristics of soil and vegetation. Using 16S rRNA sequences, the present work aimed to study acidobacterial diversity and distribution in soils of Cerrado savanna and two Atlantic forest sites. PCA and phylogenetic reconstruction showed that the acidobacterial communities found in "Mata de galeria" forest soil samples from the Cerrado biome have a tendency to separate from the other Cerrado vegetation microbial communities in the direction of those found in the Atlantic Forest, which is correlated with a high abundance of Acidobacteria subgroup 2 (GP2). Environmental conditions seem to promote a negative correlation between GP2 and subgroup 1 (GP1) abundance. Also GP2 is negatively correlated to pH, but positively correlated to high Al(3+) concentrations. The Cerrado soil showed the lowest Acidobacteria richness and diversity indexes of OTUs at the species and subgroups levels when compared to Atlantic Forest soils. These results suggest specificity of acidobacterial subgroups to soils of different biomes and are a starting point to understand their ecological roles, a topic that needs to be further explored.

  2. Spatial patterns of variation in the composition and structure of nematode communities in relation to different microhabitats: a case study of Quercus dalechampii Ten. forest

    NARCIS (Netherlands)

    Lazerova, S.S.; Goede, de R.G.M.; Peneva, V.K.; Bongers, A.M.T.

    2004-01-01

    Variability in the spatial distribution of nematode communities in relation to the structural heterogeneity of the environment was studied in nine different microhabitats within a relatively small area of a natural oak forest in Bulgaria. Maturity and diversity indices, trophic structure and the

  3. Soil surface CO2 efflux measurements in Norway spruce forests. Comparison between four different sites across Europe — from boreal to alpine forest

    Czech Academy of Sciences Publication Activity Database

    Acosta, Manuel; Pavelka, Marian; Montagnani, L.; Kutsch, W.; Lindroth, A.; Juszczak, R.; Janouš, Dalibor

    2013-01-01

    Roč. 192, JAN (2013), s. 295-303 ISSN 0016-7061 R&D Projects: GA MŠk OC08021; GA MŽP(CZ) SP/2D1/93/07; GA MŽP(CZ) SP/2D1/70/08; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : Soil CO2 efflux * Forest * Chamber method * Q10 * Soil temperature * Spatial variability Subject RIV: EH - Ecology, Behaviour Impact factor: 2.509, year: 2013

  4. Perceiving sustainable forest spaces: governance aspects of private and company owned forests in North-Karelia, Finland

    Directory of Open Access Journals (Sweden)

    Moritz Albrecht

    2012-01-01

    Full Text Available The integration of improved environmental or sustainable aspects in forest management is often affiliated with the rise of market-driven governance systems, such as forest certification. In terms of forest resource peripheries, like North-Karelia, Finland, these are often attributed to environmental business and consumer demands from the green Central European markets. While acknowledging these aspects related to the supply chains of wood-based products, this study evaluates the actual perceptions about environmental forest governance and its spaces in the resource peripheries themselves. It displays the perceived changes and practices in forestry by comparing private and corporate ownership and their governance networks. This is accomplished by a qualitative, interview based case study of North Karelian and Finnish forestry actors. Transnational forest governance is hereby treated as a relational space, with forest certification systems as possible technologies used to achieve improved, sustainable forest management. Utilizing the North-Karelian forestry sector, the varying positionalities of actors and institutions within such a relational space shape the knowledge networks, perceptions and decision-making. The study evaluates how these local-global positionalities of actors and individuals shapes their understanding, and guide the direction of sustainable forest management in Finland while it (re-produces opposing regimes of practice. With the discourse on forest certification being twofold, a more complex picture emerges if aspects of even- versus uneven-aged forest management in Finland are integrated. Shaped by the actor’s positionalities and related knowledge networks, perceptions regarding the quality of forest management practices and technologies used to achieve sustainability differ and thereby shape governance processes. The green markets are not perceived as the main driving force and a strong governmental influence, particularly

  5. Species richness and relative species abundance of Nymphalidae (Lepidoptera) in three forests with different perturbations in the North-Central Caribbean of Costa Rica.

    Science.gov (United States)

    Stephen, Carolyn; Sánchez, Ragde

    2014-09-01

    Measurements of species richness and species abundance can have important implications for regulations and conservation. This study investigated species richness and abundance of butterflies in the family Nymphalidae at undisturbed, and disturbed habitats in Tirimbina Biological Reserve and Nogal Private Reserve, Sarapiquí, Costa Rica. Traps baited with rotten banana were placed in the canopy and the understory of three habitats: within mature forest, at a river/forest border, and at a banana plantation/forest border. In total, 71 species and 487 individuals were caught and identified during May and June 2011 and May 2013. Species richness and species abundance were found to increase significantly at perturbed habitats (p < 0.0001, p < 0.0001, respectively). The edge effect, in which species richness and abundance increase due to greater complementary resources from different habitats, could be one possible explanation for increased species richness and abundance.

  6. 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)

    Xiao, Wenfa; Ge, Xiaogai; 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.

  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.

    Directory of Open Access Journals (Sweden)

    Wenfa Xiao

    Full Text Available 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.

  8. 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

  9. Diversity and dynamics of mycorrhizal associations in tropical rain forests with different disturbance regimes in South Cameroon

    OpenAIRE

    Onguene, N.A.

    2000-01-01

    The present study documents the occurrence of mycorrhizal associations in the rain forests of south Cameroon. All species investigated are mycorrhizal. Most timber species form arbuscular mycorrhiza, but some timber species, which usually occur in clumps, form ectomycorrhiza. Species diversity of ectomycorrhizal fungi in the undisturbed rain forest is substantial, with more than 125 species having been recorded. Inoculum potential of arbuscular mycorrhizal and ectomycorrhizal fungi i...

  10. Multiyear fate of a15N tracer in a mixed deciduous forest: retention, redistribution, and differences by mycorrhizal association.

    Science.gov (United States)

    Goodale, Christine L

    2017-02-01

    The impact of atmospheric nitrogen deposition on forest ecosystems depends in large part on its fate. Past tracer studies show that litter and soils dominate the short-term fate of added 15 N, yet few have examined its longer term dynamics or differences among forest types. This study examined the fate of a 15 N-NO3- tracer over 5-6 years in a mixed deciduous stand that was evenly composed of trees with ectomycorrhizal and arbuscular mycorrhizal associations. The tracer was expected to slowly mineralize from its main initial fate in litter and surface soil, with some 15 N moving to trees, some to deeper soil, and some net losses. Recovery of added 15 N in trees and litterfall totaled 11.3% both 1 and 5-6 years after the tracer addition, as 15 N redistributed from fine and especially coarse roots into cumulative litterfall and small accumulations in woody tissues. Estimates of potential carbon sequestration from tree 15 N recovery amounted to 12-14 kg C per kg of N deposition. Tree 15 N acquisition occurred within the first year after the tracer addition, with no subsequent additional net transfer of 15 N from detrital to plant pools. In both years, ectomycorrhizal trees gained 50% more of the tracer than did trees with arbuscular mycorrhizae. Much of the 15 N recovered in wood occurred in tree rings formed prior to the 15 N addition, demonstrating the mobility of N in wood. Tracer recovery rapidly decreased over time in surface litter material and accumulated in both shallow and deep soil, perhaps through mixing by earthworms. Overall, results showed redistribution of tracer 15 N through trees and surface soils without any losses, as whole-ecosystem recovery remained constant between 1 and 5-6 years at 70% of the 15 N addition. These results demonstrate the persistent ecosystem retention of N deposition even as it redistributes, without additional plant uptake over this timescale. © 2016 John Wiley & Sons Ltd.

  11. Differences in Human versus Lightning Fires between Urban and Rural Areas of the Boreal Forest in Interior Alaska

    Directory of Open Access Journals (Sweden)

    Monika P. Calef

    2017-11-01

    Full Text Available In western North America, the carbon-rich boreal forest is experiencing warmer temperatures, drier conditions and larger and more frequent wildfires. However, the fire regime is also affected by direct human activities through suppression, ignition, and land use changes. Models are important predictive tools for understanding future conditions but they are based on regional generalizations of wildfire behavior and weather that do not adequately account for the complexity of human–fire interactions. To achieve a better understanding of the intensity of human influence on fires in this sparsely populated area and to quantify differences between human and lightning fires, we analyzed fires by both ignition types in regard to human proximity in urban (the Fairbanks subregion and rural areas of interior Alaska using spatial (Geographic Information Systems and quantitative analysis methods. We found substantial differences in drivers of wildfire: while increases in fire ignitions and area burned were caused by lightning in rural interior Alaska, in the Fairbanks subregion these increases were due to human fires, especially in the wildland urban interface. Lightning fires are starting earlier and fires are burning longer, which is much more pronounced in the Fairbanks subregion than in rural areas. Human fires differed from lightning fires in several ways: they started closer to settlements and highways, burned for a shorter duration, were concentrated in the Fairbanks subregion, and often occurred outside the brief seasonal window for lightning fires. This study provides important insights that improve our understanding of the direct human influence on recently observed changes in wildfire regime with implications for both fire modeling and fire management.

  12. Start of reproduction and allozyme heterozygosity in Pinus sibirica under different techniques of artificial forest stand establishment

    Directory of Open Access Journals (Sweden)

    S.N. Velisevich

    2013-12-01

    Full Text Available Siberian stone pine (Pinus sibirica Du Tour is one of the main forest-forming tree species in boreal forests of Eurasia. Large edibleseeds of this species have an important resource value because of their high nutritious properties. Development of approaches toestablishment of early cone producing Siberian stone pine stands including utilization of corresponding genetic background is one of the priorities of forest resource management. The goal of our study was to evaluate the effect of stand density on the differentiation of trees bythe age of first reproduction and the relationship of allozyme heterozygosity and morphological traits variability in Siberian stone pine.Morphological and allozyme variability in artificial Pinus sibirica stands with high and low density was investigated. In the high-densitystand the distance between trees was 0.7 and 3 meters (4080 trees per ha while in the lowdensity stand it was 8 and 8 meters (144 treesper ha. Age of formation of first male and female cones was evaluated by retrospective method based on analysis of tracks of cones ona shoot bark. Tree height, diameter and number of male, female and vegetative shoots in a crown of model trees were measured.Genotypes of the trees were determined by 29 isozyme loci coding for 16 enzymes (ADH, FDH, FEST, GDH, GOT, IDH, LAP, MDH, MNR, PEPCA, 6-PGD, PGI, PGM, SDH, SKDH, SOD. In the low-density stand, the portion of generative trees was higher and differentiation of trees by age of reproduction starting was lower in spite of the smaller age of trees as compared to the high-density stand. Inboth samples, the age of formation of first generative organs was related negatively with stem height, stem diameter and number offemale shoots. In the high-density stand, positive relation of age of first reproduction with total number of shoots and number ofmale shoots was found. In both samples nonreproductive trees were less heterozygous at

  13. Evaluation of different approaches to quantify strong organic acidity and acid-base buffering of organic-rich surface waters in Sweden.

    Science.gov (United States)

    Köhler, Stephan; Hruska, Jakub; Jönsson, Jörgen; Lövgren, Lars; Lofts, Stephen

    2002-11-01

    The role of organic acids in buffering pH in surface waters has been studied using a small brownwater stream (26mg L(-1) TOC) draining a forested catchment in Northern Sweden. Under the conditions of elevated pressure of CO2 stream field pH was changed between 3.5 and 6.1 during the acidification and alkalinization experiment. Acid-base characteristics of the natural organic matter were also determined using a high precision potentiometric method for a concentrated sample from the same stream. We compared the predictions from the Windermere Humic Aqueous Model (WHAM Model V), a model derived from the potentiometric titration (diprotic/monoprotic acid model) and a previously derived triprotic acid model which only uses alkalinity and TOC as input variables. The predicted buffering characteristics of all three models are very similar in the pH range 4.5-7 which suggests that during routine analysis alkalinity and TOC are sufficient to give a good estimate of organic acid anion charge contribution in a large range of surface waters. A slightly adjusted version of WHAM V successfully describes the organic charge contribution in a large number of sampled surface water lakes, which were previously used to calibrate the triprotic model.

  14. Plasmons in strong superconductors

    International Nuclear Information System (INIS)

    Baldo, M.; Ducoin, C.

    2011-01-01

    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  15. Implementing Forest Landscape Restorationin Ethiopia

    Directory of Open Access Journals (Sweden)

    Till Pistorius

    2017-02-01

    Full Text Available Driven by various initiatives and international policy processes, the concept of Forest Landscape Restoration, is globally receiving renewed attention. It is seen internationally and in national contexts as a means for improving resilience of land and communities in the face of increasing environmental degradation through different forest activities. Ethiopia has made a strong voluntary commitment in the context of the Bonn Challenge—it seeks to implement Forest Landscape Restoration (FLR on 15 million ha. In the context of rural Ethiopia, forest establishment and restoration provide a promising approach to reverse the widespread land degradation, which is exacerbated by climate change and food insecurity. This paper presents an empirical case study of FLR opportunities in the Amhara National Regional State, Ethiopia’s largest spans of degraded and barren lands. Following the Restoration Opportunity Assessment Methodology, the study categorizes the main types of landscapes requiring restoration, identifies and prioritizes respective FLR options, and details the costs and benefits associated with each of the five most significant opportunities: medium to large‐scale afforestation and reforestation activities on deforested or degraded marginal land not suitable for agriculture, the introduction of participatory forest management, sustainable woodland management combined with value chain investments, restoration of afro‐alpine and sub‐afro‐alpine areas and the establishment of woodlots.

  16. Phylobetadiversity among forest types in the Brazilian Atlantic Forest complex.

    Science.gov (United States)

    Duarte, Leandro Da Silva; Bergamin, Rodrigo Scarton; Marcilio-Silva, Vinícius; Seger, Guilherme Dubal Dos Santos; Marques, Márcia Cristina Mendes

    2014-01-01

    Phylobetadiversity is defined as the phylogenetic resemblance between communities or biomes. Analyzing phylobetadiversity patterns among different vegetation physiognomies within a single biome is crucial to understand the historical affinities between them. Based on the widely accepted idea that different forest physiognomies within the Southern Brazilian Atlantic Forest constitute different facies of a single biome, we hypothesize that more recent phylogenetic nodes should drive phylobetadiversity gradients between the different forest types within the Atlantic Forest, as the phylogenetic divergence among those forest types is biogeographically recent. We compiled information from 206 checklists describing the occurrence of shrub/tree species across three different forest physiognomies within the Southern Brazilian Atlantic Forest (Dense, Mixed and Seasonal forests). We analyzed intra-site phylogenetic structure (phylogenetic diversity, net relatedness index and nearest taxon index) and phylobetadiversity between plots located at different forest types, using five different methods differing in sensitivity to either basal or terminal nodes (phylogenetic fuzzy weighting, COMDIST, COMDISTNT, UniFrac and Rao's H). Mixed forests showed higher phylogenetic diversity and overdispersion than the other forest types. Furthermore, all forest types differed from each other in relation phylobetadiversity patterns, particularly when phylobetadiversity methods more sensitive to terminal nodes were employed. Mixed forests tended to show higher phylogenetic differentiation to Dense and Seasonal forests than these latter from each other. The higher phylogenetic diversity and phylobetadiversity levels found in Mixed forests when compared to the others likely result from the biogeographical origin of several taxa occurring in these forests. On one hand, Mixed forests shelter several temperate taxa, like the conifers Araucaria and Podocarpus. On the other hand, tropical groups, like

  17. Phylobetadiversity among forest types in the Brazilian Atlantic Forest complex.

    Directory of Open Access Journals (Sweden)

    Leandro Da Silva Duarte

    Full Text Available Phylobetadiversity is defined as the phylogenetic resemblance between communities or biomes. Analyzing phylobetadiversity patterns among different vegetation physiognomies within a single biome is crucial to understand the historical affinities between them. Based on the widely accepted idea that different forest physiognomies within the Southern Brazilian Atlantic Forest constitute different facies of a single biome, we hypothesize that more recent phylogenetic nodes should drive phylobetadiversity gradients between the different forest types within the Atlantic Forest, as the phylogenetic divergence among those forest types is biogeographically recent. We compiled information from 206 checklists describing the occurrence of shrub/tree species across three different forest physiognomies within the Southern Brazilian Atlantic Forest (Dense, Mixed and Seasonal forests. We analyzed intra-site phylogenetic structure (phylogenetic diversity, net relatedness index and nearest taxon index and phylobetadiversity between plots located at different forest types, using five different methods differing in sensitivity to either basal or terminal nodes (phylogenetic fuzzy weighting, COMDIST, COMDISTNT, UniFrac and Rao's H. Mixed forests showed higher phylogenetic diversity and overdispersion than the other forest types. Furthermore, all forest types differed from each other in relation phylobetadiversity patterns, particularly when phylobetadiversity methods more sensitive to terminal nodes were employed. Mixed forests tended to show higher phylogenetic differentiation to Dense and Seasonal forests than these latter from each other. The higher phylogenetic diversity and phylobetadiversity levels found in Mixed forests when compared to the others likely result from the biogeographical origin of several taxa occurring in these forests. On one hand, Mixed forests shelter several temperate taxa, like the conifers Araucaria and Podocarpus. On the other hand

  18. Effects of harvesting on spatial and temporal diversity of carbon stocks in a boreal forest landscape.

    Science.gov (United States)

    Ter-Mikaelian, Michael T; Colombo, Stephen J; Chen, Jiaxin

    2013-10-01

    Carbon stocks in managed forests of Ontario, Canada, and in harvested wood products originated from these forests were estimated for 2010-2100. Simulations included four future forest harvesting scenarios based on historical harvesting levels (low, average, high, and maximum available) and a no-harvest scenario. In four harvesting scenarios, forest carbon stocks in Ontario's managed forest were estimated to range from 6202 to 6227 Mt C (millions of tons of carbon) in 2010, and from 6121 to 6428 Mt C by 2100. Inclusion of carbon stored in harvested wood products in use and in landfills changed the projected range in 2100 to 6710-6742 Mt C. For the no-harvest scenario, forest carbon stocks were projected to change from 6246 Mt C in 2010 to 6680 Mt C in 2100. Spatial variation in projected forest carbon stocks was strongly related to changes in forest age (r = 0.603), but had weak correlation with harvesting rates. For all managed forests in Ontario combined, projected carbon stocks in combined forest and harvested wood products converged to within 2% difference by 2100. The results suggest that harvesting in the boreal forest, if applied within limits of sustainable forest management, will eventually have a relatively small effect on long-term combined forest and wood products carbon stocks. However, there was a large time lag to approach carbon equality, with more than 90 years with a net reduction in stored carbon in harvested forests plus wood products compared to nonharvested boreal forest which also has low rates of natural disturbance. The eventual near equivalency of carbon stocks in nonharvested forest and forest that is harvested and protected from natural disturbance reflects both the accumulation of carbon in harvested wood products and the relatively young age at which boreal forest stands undergo natural succession in the absence of disturbance.

  19. Photoprotection related to xanthophyll cycle pigments in epiphytic orchids acclimated at different light microenvironments in two tropical dry forests of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    de la Rosa-Manzano, Edilia; Andrade, José Luis; García-Mendoza, Ernesto; Zotz, Gerhard; Reyes-García, Casandra

    2015-12-01

    Epiphytic orchids from dry forests of Yucatán show considerable photoprotective plasticity during the dry season, which depends on leaf morphology and host tree deciduousness. Nocturnal retention of antheraxanthin and zeaxanthin was detected for the first time in epiphytic orchids. In tropical dry forests, epiphytes experience dramatic changes in light intensity: photosynthetic photon flux density may be up to an order of magnitude higher in the dry season compared to the wet season. To address the seasonal changes of xanthophyll cycle (XC) pigments and photosynthesis that occur throughout the year, leaves of five epiphytic orchid species were studied during the early dry, dry and wet seasons in a deciduous and a semi-deciduous tropical forests at two vertical strata on the host trees (3.5 and 1.5 m height). Differences in XC pigment concentrations and photosynthesis (maximum quantum efficiency of photosystem II; F v/F m) were larger among seasons than between vertical strata in both forests. Antheraxanthin and zeaxanthin retention reflected the stressful conditions of the epiphytic microhabitat, and it is described here in epiphytes for the first time. During the dry season, both XC pigment concentrations and photosystem II heat dissipation of absorbed energy increased in orchids in the deciduous forest, while F v/F m and nocturnal acidification (ΔH(+)) decreased, clearly as a response to excessive light and drought. Concentrations of XC pigments were higher than those in orchids with similar leaf shape in semi-deciduous forest. There, only Encyclia nematocaulon and Lophiaris oerstedii showed somewhat reduced F v/F m. No changes in ΔH(+) and F v/F m were detected in Cohniella ascendens throughout the year. This species, which commonly grows in forests with less open canopies, showed leaf tilting that diminished light interception. Light conditions in the uppermost parts of the canopy probably limit the distribution of epiphytic orchids and the retention of

  20. Soil biogeochemistry properties vary between two boreal forest ecosystems in Quebec: significant differences in soil carbon, available nutrients and iron and aluminium crystallinity

    Science.gov (United States)

    Bastianelli, Carole; Ali, Adam A.; Beguin, Julien; Bergeron, Yves; Grondin, Pierre; Hély, Christelle; Paré, David

    2017-04-01

    At the northernmost extent of the managed forest in Quebec, the boreal forest is currently undergoing an ecological transition from closed-canopy black spruce-moss forests towards open-canopy lichen woodlands, which spread southward. Our study aim was to determine whether this shift could impact soil properties on top of its repercussions on forest productivity or carbon storage. We studied the soil biogeochemical composition of three pedological layers in moss forests (MF) and lichen woodlands (LW) north of the Manicouagan crater in Quebec. The humus layer (FH horizons) was significantly thicker and held more carbon, nitrogen and exchangeable Ca and Mg in MF plots than in LW plots. When considering mineral horizons, we found that the deep C horizon had a very close composition in both ecosystem plots, suggesting that the parent material was of similar geochemical nature. This was expected as all selected sites developed from glacial deposit. Multivariate analysis of surficial mineral B horizon showed however that LW B horizon displayed higher concentrations of Al and Fe oxides than MF B horizon, particularly for inorganic amorphous forms. Conversely, main exchangeable base cations (Ca, Mg) were higher in B horizon of MF than that of LW. Ecosystem types explained much of the variations in the B horizon geochemical composition. We thus suggest that the differences observed in the geochemical composition of the B horizon have a biological origin rather than a mineralogical origin. We also showed that total net stocks of carbon stored in MF soils were three times higher than in LW soils (FH + B horizons, roots apart). Altogether, we suggest that variations in soil properties between MF and LW are linked to a cascade of events involving the impacts of natural disturbances such as wildfires on forest regeneration that determines the of vegetation structure (stand density) and composition (ground cover type) and their subsequent consequences on soil environmental

  1. Laboratory measurements of nitric oxide release from forest soil with a thick organic layer under different understory types

    Directory of Open Access Journals (Sweden)

    A. Bargsten

    2010-05-01

    Full Text Available Nitric oxide (NO plays an important role in the photochemistry of the troposphere. NO from soil contributes up to 40% to the global budget of atmospheric NO. Soil NO emissions are primarily caused by biological activity (nitrification and denitrification, that occurs in the uppermost centimeter of the soil, a soil region often characterized by high contents of organic material. Most studies of NO emission potentials to date have investigated mineral soil layers. In our study we sampled soil organic matter under different understories (moss, grass, spruce and blueberries in a humid mountainous Norway spruce forest plantation in the Fichtelgebirge (Germany. We performed laboratory incubation and flushing experiments using a customized chamber technique to determine the response of net potential NO flux to physical and chemical soil conditions (water content and temperature, bulk density, particle density, pH, C/N ratio, organic C, soil ammonium, soil nitrate. Net potential NO fluxes (in terms of mass of N from soil samples taken under different understories ranged from 1.7–9.8 ng m−2 s−1 (soil sampled under grass and moss cover, 55.4–59.3 ng m−2 s−1 (soil sampled under spruce cover, and 43.7–114.6 ng m−2 s−1 (soil sampled under blueberry cover at optimum water content and a soil temperature of 10 °C. The water content for optimum net potential NO flux ranged between 0.76 and 0.8 gravimetric soil moisture for moss covered soils, between 1.0 and 1.1 for grass covered soils, 1.1 and 1.2 for spruce covered soils, and 1.3 and 1.9 for blueberry covered soils. Effects of soil physical and chemical characteristics on net potential NO flux were statistically significant (0.01 probability level only for NH4+. Therefore, as an alternative explanation for the differences in soil biogenic NO emission we consider more biological factors like understory

  2. Interactive effects of climate and nutrient enrichment on patterns of herbivory by different feeding guilds in mangrove forests

    KAUST Repository

    Feller, Ilka C.

    2017-09-28

    Aim Global warming and eutrophication are major threats to coastal environments worldwide. As a result of differences between temperate and tropical ecosystems in nutrient availability, nitrogen (N):phosphorus (P) coupling and carbon retention, primary productivity and biotic interactions in the tropics are predicted to have stronger responses to increased nutrients than in temperate ecosystems. Habitats that occur across broad climatic ranges, such as mangrove forests, provide an opportunity to test this hypothesis by investigating the responses of herbivores to nutrient enrichment in temperate versus tropical latitudes on the same species. Location Australia and New Zealand. Time period Fertilization experiments were established at Port Douglas and Cape Cleveland in October 2000; Batemans Bay and Waikopua in August 2001; Whangapoua in January 2003; Tinchi Tamba in September 2005; and Garalia in October 2007. Herbivory was measured in 2009. Major taxa studied Insect leaf miners; insect and fungal leaf gallers. Methods We used seven fertilization experiments in Australia and New Zealand across 20° of latitude to determine how increased nutrients affected herbivory and diversity of leaf miners and gallers of the mangrove Avicennia marina. Individual trees were fertilized annually with one of three treatments (Control, +N, +P); herbivory was measured in 2009. Results Fertilization did not significantly affect herbivory or herbivore diversity. Leaf N:P, latitude and rainfall contributed significantly to herbivory, accounting for > 56% of the variation. Latitude, temperature, %P and salinity differentiated herbivory by feeding guild in the tropical versus subtropical and temperate latitudes. The effect of N fertilization on folivory differed across climatic regions; relative to Control trees, N-fertilized trees in temperate areas had greater folivory than in tropical and subtropical latitudes. Species richness for leaf miners and gallers was correlated with latitude

  3. Seasonal differences in leaf-level physiology give lianas a competitive advantage over trees in a tropical seasonal forest.

    Science.gov (United States)

    Cai, Zhi-Quan; Schnitzer, Stefan A; Bongers, Frans

    2009-08-01

    Lianas are an important component of most tropical forests, where they vary in abundance from high in seasonal forests to low in seasonal forests. We tested the hypothesis that the physiological ability of lianas to fix carbon (and thus grow) during seasonal drought may confer a distinct advantage in seasonal tropical forests, which may explain pan-tropical liana distributions. We compared a range of leaf-level physiological attributes of 18 co-occurring liana and 16 tree species during the wet and dry seasons in a tropical seasonal forest in Xishuangbanna, China. We found that, during the wet season, lianas had significantly higher CO(2) assimilation per unit mass (A(mass)), nitrogen concentration (N(mass)), and delta(13)C values, and lower leaf mass per unit area (LMA) than trees, indicating that lianas have higher assimilation rates per unit leaf mass and higher integrated water-use efficiency (WUE), but lower leaf structural investments. Seasonal variation in CO(2) assimilation per unit area (A(area)), phosphorus concentration per unit mass (P(mass)), and photosynthetic N-use efficiency (PNUE), however, was significantly lower in lianas than in trees. For instance, mean tree A(area) decreased by 30.1% from wet to dry season, compared with only 12.8% for lianas. In contrast, from the wet to dry season mean liana delta(13)C increased four times more than tree delta(13)C, with no reduction in PNUE, whereas trees had a significant reduction in PNUE. Lianas had higher A(mass) than trees throughout the year, regardless of season. Collectively, our findings indicate that lianas fix more carbon and use water and nitrogen more efficiently than trees, particularly during seasonal drought, which may confer a competitive advantage to lianas during the dry season, and thus may explain their high relative abundance in seasonal tropical forests.

  4. Estimation and quantification of mangrove forest extent by using different spatial resolution satellite data for the sandspit area of Karachi coast

    International Nuclear Information System (INIS)

    Saeed, U.; Daud, A.; Ashraf, S.; Mahmood, A.

    2006-01-01

    Mangrove forest is an integral part of inter-tidal zone of the coastal environment extending throughout the tropics and subtropics of the world. In Pakistan, for the last thirty years, remote-sensing data has significantly been used for area estimation of mangrove forests. In the previous studies medium resolution satellite data have been used for the area estimation of mangrove forests that revealed some of the discrepancies in terms of recognition of the subtle variations of landcover features in the satellite imagery. Current study aims at the classification techniques employed for the area estimation using high and medium resolution satellite imageries. To study the effects of spatial resolution on classification results, three different satellite data were used, including Quickbird, TERRA and Landsat satellites. Thematic map derived from Quickbird data was comprised of maximum number of land cover classes with a definite zone of mangroves that extends from regeneration to mature canopies. Total estimated mangroves extent was 370 ha with 57.45, 125.9, 180.89, and 5.35 ha of tall, medium, small, and new recruitment mangrove plants respectively. While mangrove area estimations from thematic maps derived using TERRA and Landsat satellite data, showed a gradual increase in the mangrove extent from 390.95 ha to 417.92 ha. This increase in area is an indicative of the fact that some of the landcover classes may have been miss-classified and hence added to the area under mangrove forests. This study also showed that high-resolution satellite data could be used for identifying different height zones of mangrove forests, along with an accurate delineation of classes like salt bushes and algae, which could not be classified otherwise. (author)

  5. The seasonal variation of arthropods living on forest soil at different altitudes in fir (Abies nordmanniana subsp. bornmulleriana ecosystem in Bolu-Aladağ

    Directory of Open Access Journals (Sweden)

    Ahmet Duyar

    2016-07-01

    Full Text Available In the forest ecosystems, soil arthropods (Arthropoda, as primary and secondary consumers, have a significant role in litter decay and decomposition processes. The abundance, diversity and community structure of arthropods in soil ecosystem; give rapid response to change of site characteristics. The current study was aimed to determine of seasonal variation of soil arthropods on forest floor at different altitudes in Uludağ Fir (Abies nordmanniana subsp. bornmulleriana Mattf. ecosystem which is an important forest tree species in Turkey. The study was conducted in pure fir stands at 1200-1600 m altitudes (4 elevation gradients in Aladağ, Bolu. The sampling was carried out for each winter, spring, summer and autumn seasons. The samples were collected from forest floor by pitfall traps. Variations of abundance and diversity of arthropods were evaluated according to seasons and altitudes. The distributions in trophic levels and biological diversity of arthropods were also determined. During the study, the maximum abundance of arthropods was 7576 individuals/m² in summer among seasons, and was 7854 individuals/m² at 1200 m altitude. Shannon-Wiener Index (H′ and Species Richness (S′ values were detected in the pitfall traps (H′= 2.22; S′= 22.

  6. Seed dispersal of a useful palm (Astrocaryum chambira Burret) in three amazonian forests with different human intervention used in ecological restoration

    International Nuclear Information System (INIS)

    Ramirez Beatriz H; Parrado Rosselli Angela; Stevenson Pablo

    2009-01-01

    The young leaves of Astrocaryum chambira are used by the indigenous people in the Amazon as raw material for handicrafts. However, few studies have been made on the natural history of this palm and on the indirect impact caused by the decrease of its dispersal agents. Considering that the loss of animal dispersal vectors due to hunting and landscape modification can affect seed dispersal processes of tropical forest plants, the goal of this study was to compare seed dispersal of A. chambira in three terra firme forests of the Colombian Amazon, with different degrees of human intervention. We censused densities of dispersal agents of A. chambira, and characterized the seed shadow. We also marked seeds to estimate dispersal distances, and established density and distance-dependent experimental stations to assess their relevance on seed dispersal. The results showed that seed removal was proportional to dispersal agent densities and forest intervention levels. Insects were the main seed predators in all sites but their effect was less pronounced in the low intervened forest site. Seed density did not show any effect on removal, while a higher probability of survival at intermediate distances from the parent palm (10 m) was found. Future studies should focus on seedling establishment, recruitment rates and the effects of human intervention on subsequent life stages of the palm.

  7. Forest Fuels Management in Europe

    Science.gov (United States)

    Gavriil Xanthopoulos; David Caballero; Miguel Galante; Daniel Alexandrian; Eric Rigolot; Raffaella Marzano

    2006-01-01

    Current fuel management practices vary considerably between European countries. Topography, forest and forest fuel characteristics, size and compartmentalization of forests, forest management practices, land uses, land ownership, size of properties, legislation, and, of course, tradition, are reasons for these differences.Firebreak construction,...

  8. 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.

  9. Statistical analysis of high order moments is a turbulent boundary layer with strong density differences; Analyse statistique des moments d'ordre eleve dans une couche limite turbulente en presence de differences de densite importantes

    Energy Technology Data Exchange (ETDEWEB)

    Soudani, A. [Batna Univ., Dept. de Physique, Faculte des Sciences (Algeria); Bessaih, R. [Mentouri-Constantine Univ., Dept. de Genie Mecanique, Faculte des Sciences de l' Ingenieur (Algeria)

    2004-12-01

    The study of turbulent boundary layer with strong differences of density is important for the understanding of practical situations occurring for example in the cooling of turbine blades through the tangential injection of a different gas or in combustion. In order to study the fine structure of wall turbulence in the presence of significant variations of density, a statistical analysis of the experimental data, obtained in a wind tunnel, is carried out. The results show that the relaxation of the skewness factor of u'(S{sub u'}) is carried out more quickly in the external layer than close to the wall, as well for the air injection as for the helium injection. S{sub u'} grows close to the injection slot in an appreciable way and this increase is accentuated for the air injection than for the helium injection. This growth of the skewness factor close to the injection slot can be explained by the increase in the longitudinal convective flux of turbulent energy in this zone. The results show for the distribution of the flatness factor F{sub u'} that there is no significant effect of the density gradient on the intermittent structure of the instantaneous longitudinal velocity in the developed zone, x/{delta} {>=} 5. The statistical analysis carried out in this study shows that the helium injection in the boundary layer generates more violent ejections than in the case of air injection. This result is confirmed by the significant contribution of the ejections to turbulent mass flux.

  10. Effects of tropical montane forest disturbance on epiphytic macrolichens

    Energy Technology Data Exchange (ETDEWEB)

    Benitez, Angel [Instituto de Ecologia, Herbario HUTPL, Universidad Tecnica Particular de Loja, San Cayetano s/n, Loja (Ecuador); Prieto, Maria, E-mail: maria.prieto@urjc.es [Area de Biodiversidad y Conservacion, ESCET, Universidad Rey Juan Carlos, Mostoles, E-28933, Madrid (Spain); Gonzalez, Yadira [Instituto de Ecologia, Herbario HUTPL, Universidad Tecnica Particular de Loja, San Cayetano s/n, Loja (Ecuador); Aragon, Gregorio [Area de Biodiversidad y Conservacion, ESCET, Universidad Rey Juan Carlos, Mostoles, E-28933, Madrid (Spain)

    2012-12-15

    The high diversity of epiphytes typical of undisturbed montane tropical forests has been negatively affected by continuous deforestation and forest conversion to secondary vegetation. Macrolichens are an important component of these epiphytes. Because their physiology is strongly coupled to humidity and solar radiation, we hypothesized that microclimatic changes derived from forest clearing and logging can affect the diversity of these poikilohydric organisms. In southern Ecuador, we examined three types of forests according to a disturbance gradient (primary forests, secondary forests, and monospecific forests of Alnus acuminata) for the presence/absence and coverage of epiphytic macrolichens that we identified on 240 trees. We found that total richness tended to decrease when the range of the disturbance increased. The impoverishment was particularly drastic for 'shade-adapted lichens', while the richness of 'heliophytic lichens' increased in the drier conditions of secondary growth. Epiphytic composition also differed significantly among the three types of forests, and the similarity decreased when the range of the disturbance was greater. We concluded that a span of 40 years of recovery by secondary vegetation was not enough to regenerate the diversity of epiphytic macrolichens that was lost due to forest disturbances. -- Highlights: Black-Right-Pointing-Pointer Tropical montane forest disturbance drastically reduced macrolichen diversity. Black-Right-Pointing-Pointer Species loss was most severe for the 'shade-adapted lichens' because high radiation is harmful to them. Black-Right-Pointing-Pointer In secondary forests lichen diversity of native forests was not regenerated. Black-Right-Pointing-Pointer The protection of remnants of primary tropical forest might help to preserve a diverse community of epiphytic macrolichens.

  11. Diversity and dynamics of mycorrhizal associations in tropical rain forests with different disturbance regimes in South Cameroon

    NARCIS (Netherlands)

    Onguene, N.A.

    2000-01-01

    The present study documents the occurrence of mycorrhizal associations in the rain forests of south Cameroon. All species investigated are mycorrhizal. Most timber species form arbuscular mycorrhiza, but some timber species, which usually occur in clumps, form ectomycorrhiza. Species

  12. Estimating leaf area and above-ground biomass of forest regeneration areas using a corrected normalized difference vegetation index

    Science.gov (United States)

    Tommy L. Coleman; James H. Miller; Bruce R. Zutter

    1992-01-01

    The objective of this study was to investigate the regression relations between vegetation indices derived from remotely-sensed data of single and mixed forest regeneration plots. Loblolly pine (Pinus taeda L.) seedlings, sweelgum (Liquidambar styraciflua L.) seedlings and broomsedge (Andropogon virginicus L.)...

  13. Differences in top-soil features between beech-mixture and Norway spruce forests of the Šumava Mts

    Czech Academy of Sciences Publication Activity Database

    Matějka, K.; Starý, Josef

    2009-01-01

    Roč. 55, č. 12 (2009), s. 540-555 ISSN 1212-4834 R&D Projects: GA ČR GA206/07/1200 Institutional research plan: CEZ:AV0Z60660521 Keywords : ash content * Bohemia Forest * element content (P, Ca, Mg, Fe, Al) Subject RIV: EH - Ecology, Behaviour

  14. Avian Assemblages Differ between Old-Growth and Mature White Pine Forests of Ontario, Canada: A Role for Supercanopy Trees?

    Directory of Open Access Journals (Sweden)

    David Anthony. Kirk

    2012-06-01

    Full Text Available We predicted that bird diversity and abundance of some bird species would be higher in old-growth stands than in mature pine stands because of the greater structural diversity in old growth. We also predicted that patch size of stands should be influential. To test these predictions, we modeled counts of 79 bird species from 52 stands in 5 regions in the province of Ontario, Canada in relation to habitat at the local and landscape extents. Neither total species richness nor abundance differed between stand types. No significant difference was found in bird assemblages between stand types using ordination analysis. However, more Neotropical migrants were found in old-growth stands than in mature stands, while the reverse was true for short-distance migrants. Twenty-five species had higher counts in old-growth stands - three significantly so: Brown Creeper Certhia americana, Northern Parula Setophaga americana, and Scarlet Tanager Piranga olivacea. Supercanopy pine (> 60 cm dbh was a significant (P 40 cm/dbh was a significant positive predictor for Brown Creeper, Pine Warbler Setophaga pinus, and total species richness. The density of supercanopy and medium/large pine explained a small but significant amount of variation in bird assemblages (1%, after considering age, other tree variables (9%, and landscape metrics. Patch size was significant for Evening Grosbeak Coccothraustes vespertinus and total abundance. According to receiver operating characteristic (ROC thresholds, Brown Creeper required a minimum of 62 stems/ha of medium/large pine. Pileated Woodpecker Dryocopus pileatus and Black-throated Green Warbler required a minimum of 14 and 23 stems/ha of supercanopy pine, respectively. Blackburnian Warbler Setophaga fusca required a minimum stand age of 66 years. Current targets in shelterwood seed cuts for pine appear to be just within range for Brown Creeper - at least for the first cut, but not for subsequent cuts. We recommend that forest

  15. Serum aspirin esterase is strongly associated with glucose and lipids in healthy subjects: different association patterns in subjects with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Kotani Kazuhiko

    2010-07-01

    Full Text Available Abstract Background Aspirin esterase (AE activity can account for part of aspirin pharmacokinetics in the circulation, possibly being associated with the impairment of aspirin effectiveness as an inhibitor of platelet aggregation. Aims The study was aimed at investigating the correlations of serum AE activity with cholinesterase (ChE and metabolic variables in healthy subjects in comparison to subjects with type 2 diabetes mellitus (T2DM. Methods In cardiovascular disease-free T2DM subjects and healthy controls, the AE activity levels and/or the correlation patterns between AE and the other variables were analyzed. Results Neither AE nor ChE activities were higher in the subjects with T2DM. Serum AE activity strongly correlated with ChE as well as glucose/lipids variables such as total cholesterol and triglyceride in healthy subjects, while the correlations between AE and glucose/lipids variables were not present in T2DM subjects. Conclusions These data may reflect the pathophysiological changes between healthy and T2DM subjects. Our data may thus provide the basis for future studies to unravel the mechanisms.

  16. Ozone risk assessment for an Alpine larch forest in two vegetative seasons with different approaches: comparison of POD1and AOT40.

    Science.gov (United States)

    Finco, Angelo; Marzuoli, Riccardo; Chiesa, Maria; Gerosa, Giacomo

    2017-12-01

    The upper vegetation belts like larch forests are supposed to be under great pressure because of climate change in the next decades. For this reason, the evaluation of the risks due to abiotic stressors like ozone is a key step. Two different approaches were used here: mapping AOT40 index by means of passive samplers and direct measurements of ozone deposition.Measurements of ozone fluxes using the eddy-correlation technique were carried out for the first time over a larch forest in Paspardo (I) at 1750 m a.s.l. Two field campaigns were run: the first one in 2010 from July to October and the second one in the following year from June to September. Vertical exchange of ozone, energy, and momentum were measured on a tower platform at 26 m above ground level to study fluxes dynamics over this ecosystem. Since the tower was located on a gentle slope, an "ad hoc" methodology was developed to minimize the effects of the terrain inclination. The larch forest uptake was estimated by means of a two-layer model to separate the understorey uptake from the larch one. Even if the total ozone fluxes were generally high, up to 30-40 nmol O 3  m -2  s -1 in both years, the stomatal uptake by the larch forest was relatively low (around 15% of the total deposition).Ozone risk was assessed considering the POD 1 received by the larch forest and the exposure index AOT40 estimated with both local data and data from the map obtained by the passive samplers monitoring.

  17. Temporal Variation in Water Quality Parameters under Different Vegetative Communities in Two Flooded Forests of the Northern Pantanal, Mato Grosso, Brazil

    Science.gov (United States)

    Couto, E. G.; Dalmagro, H. J.; Lathuilliere, M. J.; Pinto Junior, O. B.; Johnson, M. S.

    2013-12-01

    The Pantanal is one of the largest flood plains in the world, and is characterized by large variability in vegetative communities and flooding dynamics. Some woody plant species have been observed to colonize large areas forming monospecific stands. We measured chemical parameters of flood waters including dissolved organic carbon (DOC), nitrate (NO3), dissolved oxygen (DO), and carbon dioxide (CO2) as well as physical parameters such as photosynthetically active radiation (PAR), temperature (Tw), turbidity (Turb) and water levels (WL). These chemical and physical measurements were conducted with the intent to characterize spatial and temporal differences of monospecific stands in order to understand if these different formations alter the biogeochemistry of the Pantanal waters. Water sample campaigns were conducted during the inundation period of January to May 2013 in two areas located in the Private Reserve of the Brazilian Social Service of Commerce (RPPN-SESC) near Poconé, Mato Grosso. Research sites included: (1) a flooded tall-stature forest (known as Cambarazal) dominated by the Vochysia divergens species; and (2) in a flooded scrub forest (known as Baia das Pedras) dominated by the Combretum lanceolatum species. Results showed three principal factors which explained 80% of variance in aquatic physical and chemical parameters. The first factor (PCA-1) explained 38% of variance (DO, PAR and WL), PCA-2 explained 23% (NO3, Tw, DOC), while PCA-3 explained only 19% of variance (CO2 and Turb). During the entire study period, the major concentration of variables were observed in the flooded forest. Physical variables presented small alterations, with the exception of water levels, that were greater in the flooded forest. With respect to temporal variables, all chemical parameters were greater at the beginning of the inundation and gradually dropped with the water level. With this work, we observed that the different monospecific formations influenced water

  18. Promotion of a strong nuclear safety culture: discussion about strengthens and weaknesses of the different regulatory strategies used by nuclear regulators

    International Nuclear Information System (INIS)

    Perez, Silvia S.

    2004-01-01

    Certain regulatory strategies have been in use since many years ago, but not in a systematic way. Argentinean regulators have used PSA since at least 2 decades ago. But it took more time (beginning in 1990) to licensees to start working on it. Simultaneously, other groups started research and development of different 'tools' like root cause analysis, evaluation of the influence of human behavior in the occurrence of events and some others, which now are part of that so-called 'outcome-based' strategies. However all this approaches were isolated projects. Different groups acted as separated units. Argentinean Nuclear Regulations have changed during the last years because of the need to act dynamically responding to variations in the context, within the regulatory authority policy of continuous improvement. (author)

  19. Individual Differences in the Speed of Facial Emotion Recognition Show Little Specificity but Are Strongly Related with General Mental Speed: Psychometric, Neural and Genetic Evidence

    OpenAIRE

    Liu, Xinyang; Hildebrandt, Andrea; Recio, Guillermo; Sommer, Werner; Cai, Xinxia; Wilhelm, Oliver

    2017-01-01

    Facial identity and facial expression processing are crucial socio-emotional abilities but seem to show only limited psychometric uniqueness when the processing speed is considered in easy tasks. We applied a comprehensive measurement of processing speed and contrasted performance specificity in socio-emotional, social and non-social stimuli from an individual differences perspective. Performance in a multivariate task battery could be best modeled by a general speed factor and a first-order ...

  20. What determines the differences found in forest edge flow between physical models and atmospheric measurements? – An LES study

    Directory of Open Access Journals (Sweden)

    Farah Kanani

    2014-06-01

    Full Text Available A recent study has shown that Doppler lidar is a state-of-the-art method to obtain spatially and temporally resolved flow fields in forest edge flow regimes. In that study, the general flow features observed by lidar were found to be similar to those detected above a physical tree model in a wind tunnel. But in pivotal details, for example regarding the absolute height and the inner structure of the internal boundary layer (IBL, significant differences were detected. The main objectives of this Large-Eddy Simulation (LES study are to analyze these differences and to associate them to the meteorological and physical differences between the set-ups of the wind tunnel and the atmospheric measurement. This enables on the one hand a model evaluation for the LES and the physical model respectively, and on the other hand a better understanding of the results from the lidar measurements. Results from an LES with neutral stratification and without Coriolis force show a similar IBL structure as in the wind tunnel and represent well-known characteristics of forest edge flow. A variation of the forest density only marginally affects the IBL structure. The presence of a finite forest clearing as observed at the lidar site increases the turbulence level of the IBL, compared to a set-up with a quasi-infinite clearing like in the wind tunnel. Including Coriolis force further enhances the turbulence levels to values observed by lidar. An increasing thermal instability results in even higher turbulence levels. Hence, differences between wind tunnel and atmospheric measurements are mainly traced back to differences in the flow forcing and in the onflow conditions upstream of the forest edge. Furthermore, a statistical analysis reveals that insufficient averaging of the lidar data also contributes to the observed deviations from the wind tunnel results. Based on this analysis, we suggest that at least two and a half hours of measurements during equivalent

  1. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  2. Effect of water stress on seedling growth in two species with different abundances: the importance of Stress Resistance Syndrome in seasonally dry tropical forest

    Directory of Open Access Journals (Sweden)

    Wanessa Nepomuceno Ferreira

    2015-09-01

    Full Text Available ABSTRACTIn seasonally dry tropical forests, species carrying attributes of Stress Resistance Syndrome (SRS may have ecological advantages over species demanding high quantities of resources. In such forests, Poincianella bracteosa is abundant, while Libidibia ferrea has low abundance; therefore, we hypothesized that P. bracteosa has characteristics of low-resource species, while L. ferrea has characteristics of high-resource species. To test this hypothesis, we assessed morphological and physiological traits of seedlings of these species under different water regimes (100%, 70%, 40%, and 10% field capacity over 85 days. For most of the studied variables we observed significant decreases with increasing water stress, and these reductions were greater in L. ferrea. As expected, L. ferreamaximized their growth with increased water supply, while P. bracteosa maintained slower growth and had minor adjustments in biomass allocation, characteristics representative of low-resource species that are less sensitive to stress. We observed that specific leaf area, biomass allocation to roots, and root/shoot ratio were higher in L. ferrea, while biomass allocation to leaves and photosynthesis were higher in P. bracteosa. Results suggest that the attributes of SRS can facilitate high abundance of P. bracteosa in dry forest.

  3. Species richness and relative species abundance of Nymphalidae (Lepidoptera in three forests with different perturbations in the North-Central Caribbean of Costa Rica

    Directory of Open Access Journals (Sweden)

    Carolyn Stephen

    2014-09-01

    Full Text Available Measurements of species richness and species abundance can have important implications for regulations and conservation. This study investigated species richness and abundance of butterflies in the family Nymphalidae at undisturbed, and disturbed habitats in Tirimbina Biological Reserve and Nogal Private Reserve, Sarapiquí, Costa Rica. Traps baited with rotten banana were placed in the canopy and the understory of three habitats: within mature forest, at a river/forest border, and at a banana plantation/forest border. In total, 71 species and 487 individuals were caught and identified during May and June 2011 and May 2013. Species richness and species abundance were found to increase significantly at perturbed habitats (p<0.0001, p<0.0001, respectively. The edge effect, in which species richness and abundance increase due to greater complementary resources from different habitats, could be one possible explanation for increased species richness and abundance. Rev. Biol. Trop. 62 (3: 919-928. Epub 2014 September 01.

  4. Estimation of different source contributions to sediment organic matter in an agricultural-forested watershed using end member mixing analyses based on stable isotope ratios and fluorescence spectroscopy.

    Science.gov (United States)

    Derrien, Morgane; Kim, Min-Seob; Ock, Giyoung; Hong, Seongjin; Cho, Jinwoo; Shin, Kyung-Hoon; Hur, Jin

    2018-03-15

    The two popular source tracing tools of stable isotope ratios (δ 13 C and δ 15 N) and fluorescence spectroscopy were used to estimate the relative source contributions to sediment organic matter (SeOM) at five different river sites in an agricultural-forested watershed (Soyang Lake watershed), and their capabilities for the source assignment were compared. Bulk sediments were used for the stable isotopes, while alkaline extractable organic matter (AEOM) from sediments was used to obtain fluorescent indices for SeOM. Several source discrimination indices were fully compiled for a range of the SeOM sources distributed in the catchments of the watershed, which included soils, forest leaves, crop (C3 and C4) and riparian plants, periphyton, and organic fertilizers. The relative source contributions to the river sediment samples were estimated via end member mixing analysis (EMMA) based on several selected discrimination indices. The EMMA based on the isotopes demonstrated that all sediments were characterized by a medium to a high contribution of periphyton ranging from ~30% to 70% except for one site heavily affected by forest and agricultural fields with relatively high contributions of terrestrial materials. The EMMA based on fluorescence parameters, however, did not show similar results with low contributions from forest leaf and periphyton. The characteristics of the studied watershed were more consistent with the source contributions determined by the isotope ratios. The discrepancy in the EMMA capability for source assignments between the two analytical tools can be explained by the limited analytical window of fluorescence spectroscopy for non-fluorescent dissolved organic matter (FDOM) and the inability of AEOM to represent original bulk particulate organic matter (POM). Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Genetic consequences of forest fragmentation for a highly specialized arboreal mammal--the edible dormouse.

    Directory of Open Access Journals (Sweden)

    Joanna Fietz

    Full Text Available Habitat loss and fragmentation represent the most serious extinction threats for many species and have been demonstrated to be especially detrimental for mammals. Particularly, highly specialized species with low dispersal abilities will encounter a high risk of extinction in fragmented landscapes. Here we studied the edible dormouse (Glis glis, a small arboreal mammal that is distributed throughout Central Europe, where forests are mostly fragmented at different spatial scales. The aim of this study was to investigate the effect of habitat fragmentation on genetic population structures using the example of edible dormouse populations inhabiting forest fragments in south western Germany. We genotyped 380 adult individuals captured between 2001 and 2009 in four different forest fragments and one large continuous forest using 14 species-specific microsatellites. We hypothesised, that populations in small forest patches have a lower genetic diversity and are more isolated compared to populations living in continuous forests. In accordance with our expectations we found that dormice inhabiting forest fragments were isolated from each other. Furthermore, their genetic population structure was more unstable over the study period than in the large continuous forest. Even though we could not detect lower genetic variability within individuals inhabiting forest fragments, strong genetic isolation and an overall high risk to mate with close relatives might be precursors to a reduced genetic variability and the onset of inbreeding depression. Results of this study highlight that connectivity among habitat fragments can already be strongly hampered before genetic erosion within small and isolated populations becomes evident.

  6. United States Forest Disturbance Trends Observed Using Landsat Time Series

    Science.gov (United States)

    Masek, Jeffrey G.; Goward, Samuel N.; Kennedy, Robert E.; Cohen, Warren B.; Moisen, Gretchen G.; Schleeweis, Karen; Huang, Chengquan

    2013-01-01

    Disturbance events strongly affect the composition, structure, and function of forest ecosystems; however, existing U.S. land management inventories were not designed to monitor disturbance. To begin addressing this gap, the North American Forest Dynamics (NAFD) project has examined a geographic sample of 50 Landsat satellite image time series to assess trends in forest disturbance across the conterminous United States for 1985-2005. The geographic sample design used a probability-based scheme to encompass major forest types and maximize geographic dispersion. For each sample location disturbance was identified in the Landsat series using the Vegetation Change Tracker (VCT) algorithm. The NAFD analysis indicates that, on average, 2.77 Mha/yr of forests were disturbed annually, representing 1.09%/yr of US forestland. These satellite-based national disturbance rates estimates tend to be lower than those derived from land management inventories, reflecting both methodological and definitional differences. In particular the VCT approach used with a biennial time step has limited sensitivity to low-intensity disturbances. Unlike prior satellite studies, our biennial forest disturbance rates vary by nearly a factor of two between high and low years. High western US disturbance rates were associated with active fire years and insect activity, while variability in the east is more strongly related to harvest rates in managed forests. We note that generating a geographic sample based on representing forest type and variability may be problematic since the spatial pattern of disturbance does not necessarily correlate with forest type. We also find that the prevalence of diffuse, non-stand clearing disturbance in US forests makes the application of a biennial geographic sample problematic. Future satellite-based studies of disturbance at regional and national scales should focus on wall-to-wall analyses with annual time step for improved accuracy.

  7. Managing Southeastern US Forests for Increased Water Yield

    Science.gov (United States)

    Acharya, S.; Kaplan, D. A.; Mclaughlin, D. L.; Cohen, M. J.

    2017-12-01

    Forested lands influence watershed hydrology by affecting water quantity and quality in surface and groundwater systems, making them potentially effective tools for regional water resource planning. In this study, we quantified water use and water yield by pine forests under varying silvicultural management (e.g., high density plantation, thinning, and prescribed burning). Daily forest water use (evapotranspiration, ET) was estimated using continuously monitored soil-moisture in the root-zone at six sites across Florida (USA), each with six plots ranging in forest leaf-area index (LAI). Plots included stands with different rotational ages (from clear-cut to mature pine plantations) and those restored to more historical conditions. Estimated ET relative to potential ET (PET) was strongly associated with LAI, root-zone soil-moisture status, and site hydroclimate; these factors explained 85% of the variation in the ET:PET ratio. Annual water yield (Yw) calculated from these ET estimates and a simple water balance differed significantly among sites and plots (ranging from -0.12 cm/yr to > 100 cm/yr), demonstrating substantive influence of management regimes. LAI strongly influenced Yw in all sites, and a general linear model with forest attributes (LAI and groundcover), hydroclimate, and site characteristics explained >90% of variation in observed Yw. These results can be used to predict water yield changes under different management and climate scenarios and may be useful in the development of payment for ecosystem services approaches that identify water as an important product of forest best management practices.

  8. Kentucky's forests, 2004

    Science.gov (United States)

    Jeffery A. Turner; Christopher M. Oswalt; James L. Chamberlain; Roger C. Conner; Tony G. Johnson; Sonja N. Oswalt; KaDonna C. Randolph

    2008-01-01

    Forest land area in the Commonwealth of Kentucky amounted to 11.97 million acres, including 11.6 million acres of timberland. Over 110 different species, mostly hardwoods, account for an estimated 21.2 billion cubic feet of all live tree volume. Hardwood forest types occupy 85 percent of Kentucky’s timberland, and oak-hickory is the dominant forest-type group...

  9. Comparison of different discriminant functions for mangrove species analysis in Matang Mangrove Forest Reserve (MMFR), Perak based on statistical approach

    Science.gov (United States)

    Beh, Boon Chun; Tan, Kok Chooi; Mat Jafri, Mohd. Zubir; Lim, Hwee San

    2017-10-01

    Mangroves are known as salt-tolerant evergreen forests, whereas its create land-ocean interface ecosystems. Besides, mangroves bring direct and indirect benefits to human activities and play a major role as significant habitat for sustaining biodiversity. However, mangrove ecosystem study based on the mangrove species are very crucial to get a better understanding of their characteristics and ways to separate among them. In this paper, discriminant functions obtained using statistical approach were used to generate the score range for six mangrove species (Rhizophora apiculata, Acrostichum aurem, Acrostichum speciosum, Acanthus ilicifolius, Ceriops tagal and Sonneratia ovata) in Matang Mangrove Forest Reserve (MMFR), Perak. With the computation of score range for each species, the fraction of the species can be determined using the proposed algorithm. The results indicate that by using 11 discriminant functions out of 16 are more effective to separate the mangrove species as the higher accuracy was obtained. Overall, the determination of leaf sample's species is chosen base on the highest fraction measured among the six mangrove species. The obtained accuracy for mangrove species using statistical approach is low since it is impossible to successfully separate all the mangrove species in leaf level using their inherent reflectance properties. However, the obtained accuracy results are satisfactory and able to discriminate the examined mangrove species at species scale.

  10. Novel and Lost Forests in the Upper Midwestern United States, from New Estimates of Settlement-Era Composition, Stem Density, and Biomass

    Science.gov (United States)

    Mladenoff, David J.; Cogbill, Charles V.; Record, Sydne; Paciorek, Christopher J.; Jackson, Stephen T.; Dietze, Michael C.; Dawson, Andria; Matthes, Jaclyn Hatala; McLachlan, Jason S.; Williams, John W.

    2016-01-01

    Background EuroAmerican land-use and its legacies have transformed forest structure and composition across the United States (US). More accurate reconstructions of historical states are critical to understanding the processes governing past, current, and future forest dynamics. Here we present new gridded (8x8km) reconstructions of pre-settlement (1800s) forest composition and structure from the upper Midwestern US (Minnesota, Wisconsin, and most of Michigan), using 19th Century Public Land Survey System (PLSS), with estimates of relative composition, above-ground biomass, stem density, and basal area for 28 tree types. This mapping is more robust than past efforts, using spatially varying correction factors to accommodate sampling design, azimuthal censoring, and biases in tree selection. Changes in Forest Structure We compare pre-settlement to modern forests using US Forest Service Forest Inventory and Analysis (FIA) data to show the prevalence of lost forests (pre-settlement forests with no current analog), and novel forests (modern forests with no past analogs). Differences between pre-settlement and modern forests are spatially structured owing to differences in land-use impacts and accompanying ecological responses. Modern forests are more homogeneous, and ecotonal gradients are more diffuse today than in the past. Novel forest assemblages represent 28% of all FIA cells, and 28% of pre-settlement forests no longer exist in a modern context. Lost forests include tamarack forests in northeastern Minnesota, hemlock and cedar dominated forests in north-central Wisconsin and along the Upper Peninsula of Michigan, and elm, oak, basswood and ironwood forests along the forest-prairie boundary in south central Minnesota and eastern Wisconsin. Novel FIA forest assemblages are distributed evenly across the region, but novelty shows a strong relationship to spatial distance from remnant forests in the upper Midwest, with novelty predicted at between 20 to 60km from

  11. Aridification determines changes in forest growth in Pinus halepensis forests under semiarid Mediterranean climate conditions

    OpenAIRE

    Vicente-Serrano, Sergio M.; Lasanta, Teodoro; Gracia, Carlos

    2010-01-01

    Using a set of 16 Landsat TM and Landsat ETM+ images from 1984 to 2006, we tested whether climate trends in the last three decades differentially controlled the vegetal activity of eight Pinus halepensis forests located across a marked bioclimatic gradient. Our results show spatial differences in trends in the normalized difference vegetation index (NDVI) between 1984 and 2006, which were highly related to the spatial distribution of aridity. There was a strong correlation between the change ...

  12. Forest hydrology

    Science.gov (United States)

    Ge Sun; Devendra Amatya; Steve McNulty

    2016-01-01

    Forest hydrology studies the distribution, storage, movement, and quality of water and the hydrological processes in forest-dominated ecosystems. Forest hydrological science is regarded as the foundation of modern integrated water¬shed management. This chapter provides an overview of the history of forest hydrology and basic principles of this unique branch of...

  13. Forest soils

    Science.gov (United States)

    Charles H. (Hobie) Perry; Michael C. Amacher

    2009-01-01

    Productive soils are the foundation of sustainable forests throughout the United States. Forest soils are generally subjected to fewer disturbances than agricultural soils, particularly those that are tilled, so forest soils tend to have better preserved A-horizons than agricultural soils. Another major contrast between forest and agricultural soils is the addition of...

  14. Forest commons and local enforcement

    OpenAIRE

    Chhatre, Ashwini; Agrawal, Arun

    2008-01-01

    This article examines the relationship between local enforcement and forests used as commons. It uses a unique multicountry dataset, created over the past 15 years by the International Forestry Resources and Institutions Research Program. Drawing on original enforcement and forest commons data from 9 countries, we find that higher levels of local enforcement have a strong and positive but complex relationship to the probability of forest regeneration. This relationship holds even when the inf...

  15. The response of soil carbon cycling in managed loblolly pine forests to fertilization and the planting of families with differing growth rates

    Science.gov (United States)

    Vogel, J. G.; Schuur, E. A.; Gill, C.; Bracho, R.; Jokela, E.

    2010-12-01

    Forest management practices in the southern United States have made the pine forests of the region some of the most productive in the world. This remarkable productivity makes the region attractive for offsetting anthropogenic emissions of CO2 through increased biomass capture, or through the biomass-to-fuel approach. In other agricultural systems, however, increased plant productivity from management has often corresponded to a decrease in soil carbon. Over half of a forest ecosystem’s carbon is found in the soil; therefore a decrease in soil carbon could counteract a considerable amount of the reduction in atmospheric CO2 that results from enhanced tree growth. We have examined two forestry practices, fertilization with nitrogen and phosphorus and the genetic control of planted seedlings, in terms of how these practices affect key controls on soil carbon cycling. Root biomass dynamics, soil CO2 efflux, and microbial respiration were contrasted for a “fast” and a “slow” growing family of loblolly pine receiving two different levels of fertilization at two sites in north central Florida. Our overarching hypothesis was that greater aboveground growth would correspond to increased inputs of carbon to the soil as root biomass, and a greater efflux of CO2 from roots and soil microbes. At both sites, the faster growing families supported significantly (pfamilies. However under higher levels of fertilization, the fast and the slow growing families had similar levels of fine root biomass and soil CO2 efflux. Results from this study suggest that greater aboveground growth due to genetic selection only related to greater inputs of carbon to the soil when fertilization levels were low. Radiocarbon measurements of microbial respiration indicated no differences in soil organic matter turnover among families or fertilization treatments. These results suggest that the response to management of soil carbon will be more sensitive to how fertilization or genetic selection

  16. Restoration of biogeochemical function in mangrove forests

    Science.gov (United States)

    McKee, K.L.; Faulkner, P.L.

    2000-01-01

    Forest structure of mangrove restoration sites (6 and 14 years old) at two locations (Henderson Creek [HC] and Windstar [WS]) in southwest Florida differed from that of mixed-basin forests (>50 years old) with which they were once contiguous. However, the younger site (HC) was typical of natural, developing forests, whereas the older site (WS) was less well developed with low structural complexity. More stressful physicochemical conditions resulting from incomplete tidal flushing (elevated salinity) and variable topography (waterlogging) apparently affected plant survival and growth at the WS restoration site. Lower leaf fall and root production rates at the WS restoration site, compared with that at HC were partly attributable to differences in hydroedaphic conditions and structural development. However, leaf and root inputs at each restoration site were not significantly different from that in reference forests within the same physiographic setting. Macrofaunal consumption of tethered leaves also did not differ with site history, but was dramatically higher at HC compared with WS, reflecting local variation in leaf litter processing rates, primarily by snails (Melampus coffeus). Degradation of leaves and roots in mesh bags was slow overall at restoration sites, however, particularly at WS where aerobic decomposition may have been more limited. These findings indicate that local or regional factors such as salinity regime act together with site history to control primary production and turnover rates of organic matter in restoration sites. Species differences in senescent leaf nitrogen content and degradation rates further suggest that restoration sites dominated by Laguncularia racemosa and Rhizophora mangle should exhibit slower recycling of nutrients compared with natural basin forests where Avicennia germinans is more abundant. Structural development and biogeochemical functioning of restored mangrove forests thus depend on a number of factors, but site

  17. SOIL COVER AND CHEMICAL AND PHYSICAL ATTRIBUTES IN OXISOL IN THE ATLANTIC FOREST BIOME

    OpenAIRE

    Ana Paula Almeida Bertossi; Paulo Roberto da Rocha Júnior; Paulo Henrique Ribeiro; João Paulo Cunha de Menezes; Roberto Avelino Cecílio; Felipe Vaz Andrade

    2016-01-01

    ABSTRACT The objective of this study was to evaluate the chemical and physical attributes of different soil cover in a Oxisol with a strong wavy relief in the Atlantic Forest Biome, in which were selected three watersheds, employed with grazing (watershed P), forest (watershed M) and coffee (watershed C). Deformed and not deformed samples were collected in three depths for physical and chemical characterization. The chemical characteristics of soil in different watershed studies presented low...

  18. Forest degradation and livelihood: a case study of government forest ...

    African Journals Online (AJOL)

    ... working and earning income, number of children in the household, earning income from tree crops and earning income from hunting were statistically significant factors influencing forest degradation within the study area. Therefore, the study recommends that strong and participatory forest management practices should ...

  19. Degraded forests are more susceptible to forest fires: Some possible ...

    African Journals Online (AJOL)

    There is a strong belief that degraded forests are more susceptible to forest fires than non-degraded ones, but this is more intuitive than scientifically proven. The present study was conducted to investigate how fuel loading and moisture content of combustible materials; two variables that influence ignition and fire impact ...

  20. Is splash erosion potential species specific? Measuring of splash erosion potential under forest in different succession stages along a biodiversity gradient in the humid subtropics

    Science.gov (United States)

    Geißler, C.; Kühn, P.; Scholten, T.

    2009-04-01

    It is widely accepted that (forest) vegetation is a key control for the type and intensity of soil erosion. The current paradigm is that natural or quasi-natural vegetation protects the soil from erosion and that agricultural vegetation or land use generally enhances erosion. The latter was in focus of most research during the last decades and less interest was paid on natural systems, which are more difficult to study. Nevertheless, afforestation is widely used as a measure of soil protection against soil erosion. Rainfall can be highly erosive particularly in the humid subtropics. Regarding climate change, also precipitation regime may change in direction to even more severe storms and higher rainfall intensities; it is a research field of growing importance. Key mechanisms of a vegetation cover in reducing or enhancing erosion are modifications of drop-size distribution, retention of raindrop impact on the soil and changes in amount and spatial distribution of rainfall at the ground surface. Controlling determinants are rainfall intensity, drop size distribution, drop fall velocity, height of the canopy as well as density of the canopy, crown and leaf traits, LAI and coverage by a litter layer. Large drops are supposed to be significant sources of splash detachment in forests (Brandt 1989; Vis 1986). However, the mechanisms of reducing (or enhancing?) splash detachment under forest in relation to species richness and species composition are not well understood. Some studies indicate that raindrop impact is species specific (Calder 2001; Nanko et al. 2006) and some neglect the effects of species specific impacts (Foot & Morgan 2005). Our research uses different methods of rainfall characterization (splash cups, tipping-bucket rain gauge, laser distrometer) to reveal the described mechanisms from the canopy through different vegetation layers to the ground. First results of splash cup measurements (revised after Ellison 1947) show that sand loss under vegetation

  1. Forest rights

    DEFF Research Database (Denmark)

    Balooni, Kulbhushan; Lund, Jens Friis

    2014-01-01

    One of the proposed strategies for implementation of reducing emissions from deforestation and forest degradation plus (REDD+) is to incentivize conservation of forests managed by communities under decentralized forest management. Yet, we argue that this is a challenging road to REDD+ because......+ transactions costs. Third, beyond the “conservation islands” represented by forests under decentralized management, processes of deforestation and forest degradation continue. Given these challenges, we argue that REDD+ efforts through decentralized forestry should be redirected from incentivizing further...

  2. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

    2009-01-01

    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  3. Novel and Lost Forests in the Upper Midwestern United States, from New Estimates of Settlement-Era Composition, Stem Density, and Biomass.

    Directory of Open Access Journals (Sweden)

    Simon J Goring

    Full Text Available EuroAmerican land-use and its legacies have transformed forest structure and composition across the United States (US. More accurate reconstructions of historical states are critical to understanding the processes governing past, current, and future forest dynamics. Here we present new gridded (8x8km reconstructions of pre-settlement (1800s forest composition and structure from the upper Midwestern US (Minnesota, Wisconsin, and most of Michigan, using 19th Century Public Land Survey System (PLSS, with estimates of relative composition, above-ground biomass, stem density, and basal area for 28 tree types. This mapping is more robust than past efforts, using spatially varying correction factors to accommodate sampling design, azimuthal censoring, and biases in tree selection.We compare pre-settlement to modern forests using US Forest Service Forest Inventory and Analysis (FIA data to show the prevalence of lost forests (pre-settlement forests with no current analog, and novel forests (modern forests with no past analogs. Differences between pre-settlement and modern forests are spatially structured owing to differences in land-use impacts and accompanying ecological responses. Modern forests are more homogeneous, and ecotonal gradients are more diffuse today than in the past. Novel forest assemblages represent 28% of all FIA cells, and 28% of pre-settlement forests no longer exist in a modern context. Lost forests include tamarack forests in northeastern Minnesota, hemlock and cedar dominated forests in north-central Wisconsin and along the Upper Peninsula of Michigan, and elm, oak, basswood and ironwood forests along the forest-prairie boundary in south central Minnesota and eastern Wisconsin. Novel FIA forest assemblages are distributed evenly across the region, but novelty shows a strong relationship to spatial distance from remnant forests in the upper Midwest, with novelty predicted at between 20 to 60km from remnants, depending on historical

  4. Novel and Lost Forests in the Upper Midwestern United States, from New Estimates of Settlement-Era Composition, Stem Density, and Biomass.

    Science.gov (United States)

    Goring, Simon J; Mladenoff, David J; Cogbill, Charles V; Record, Sydne; Paciorek, Christopher J; Jackson, Stephen T; Dietze, Michael C; Dawson, Andria; Matthes, Jaclyn Hatala; McLachlan, Jason S; Williams, John W

    2016-01-01

    EuroAmerican land-use and its legacies have transformed forest structure and composition across the United States (US). More accurate reconstructions of historical states are critical to understanding the processes governing past, current, and future forest dynamics. Here we present new gridded (8x8km) reconstructions of pre-settlement (1800s) forest composition and structure from the upper Midwestern US (Minnesota, Wisconsin, and most of Michigan), using 19th Century Public Land Survey System (PLSS), with estimates of relative composition, above-ground biomass, stem density, and basal area for 28 tree types. This mapping is more robust than past efforts, using spatially varying correction factors to accommodate sampling design, azimuthal censoring, and biases in tree selection. We compare pre-settlement to modern forests using US Forest Service Forest Inventory and Analysis (FIA) data to show the prevalence of lost forests (pre-settlement forests with no current analog), and novel forests (modern forests with no past analogs). Differences between pre-settlement and modern forests are spatially structured owing to differences in land-use impacts and accompanying ecological responses. Modern forests are more homogeneous, and ecotonal gradients are more diffuse today than in the past. Novel forest assemblages represent 28% of all FIA cells, and 28% of pre-settlement forests no longer exist in a modern context. Lost forests include tamarack forests in northeastern Minnesota, hemlock and cedar dominated forests in north-central Wisconsin and along the Upper Peninsula of Michigan, and elm, oak, basswood and ironwood forests along the forest-prairie boundary in south central Minnesota and eastern Wisconsin. Novel FIA forest assemblages are distributed evenly across the region, but novelty shows a strong relationship to spatial distance from remnant forests in the upper Midwest, with novelty predicted at between 20 to 60km from remnants, depending on historical forest

  5. Forests and water

    Science.gov (United States)

    Graeme Lockaby; Chelsea Nagy; James M. Vose; Chelcy R. Ford; Ge Sun; Steve McNulty; Pete Caldwell; Erika Cohen; Jennifer Moore Myers

    2013-01-01

    Key FindingsForest conversion to agriculture or urban use consistently causes increased discharge, peak flow, and velocity of streams. Subregional differences in hydrologic responses to urbanization are substantial.Sediment, water chemistry indices, pathogens, and other substances often become more concentrated after forest...

  6. Nitrogen enrichment regulates calcium sources in forests.

    Science.gov (United States)

    Hynicka, Justin D; Pett-Ridge, Julie C; Perakis, Steven S

    2016-12-01

    Nitrogen (N) is a key nutrient that shapes cycles of other essential elements in forests, including calcium (Ca). When N availability exceeds ecosystem demands, excess N can stimulate Ca leaching and deplete Ca from soils. Over the long term, these processes may alter the proportion of available Ca that is derived from atmospheric deposition vs. bedrock weathering, which has fundamental consequences for ecosystem properties and nutrient supply. We evaluated how landscape variation in soil N, reflecting long-term legacies of biological N fixation, influenced plant and soil Ca availability and ecosystem Ca sources across 22 temperate forests in Oregon. We also examined interactions between soil N and bedrock Ca using soil N gradients on contrasting basaltic vs. sedimentary bedrock that differed 17-fold in underlying Ca content. We found that low-N forests on Ca-rich basaltic bedrock relied strongly on Ca from weathering, but that soil N enrichment depleted readily weatherable mineral Ca and shifted forest reliance toward atmospheric Ca. Forests on Ca-poor sedimentary bedrock relied more consistently on atmospheric Ca across all levels of soil N enrichment. The broad importance of atmospheric Ca was unexpected given active regional uplift and erosion that are thought to rejuvenate weathering supply of soil minerals. Despite different Ca sources to forests on basaltic vs. sedimentary bedrock, we observed consistent declines in plant and soil Ca availability with increasing N, regardless of the Ca content of underlying bedrock. Thus, traditional measures of Ca availability in foliage and soil exchangeable pools may poorly reflect long-term Ca sources that sustain soil fertility. We conclude that long-term soil N enrichment can deplete available Ca and cause forests to rely increasingly on Ca from atmospheric deposition, which may limit ecosystem Ca supply in an increasingly N-rich world. © 2016 John Wiley & Sons Ltd.

  7. Nitrogen enrichment regulates calcium sources in forests

    Science.gov (United States)

    Hynicka, Justin D.; Pett-Ridge, Julie C.; Perakis, Steven

    2016-01-01

    Nitrogen (N) is a key nutrient that shapes cycles of other essential elements in forests, including calcium (Ca). When N availability exceeds ecosystem demands, excess N can stimulate Ca leaching and deplete Ca from soils. Over the long term, these processes may alter the proportion of available Ca that is derived from atmospheric deposition vs. bedrock weathering, which has fundamental consequences for ecosystem properties and nutrient supply. We evaluated how landscape variation in soil N, reflecting long-term legacies of biological N fixation, influenced plant and soil Ca availability and ecosystem Ca sources across 22 temperate forests in Oregon. We also examined interactions between soil N and bedrock Ca using soil N gradients on contrasting basaltic vs. sedimentary bedrock that differed 17-fold in underlying Ca content. We found that low-N forests on Ca-rich basaltic bedrock relied strongly on Ca from weathering, but that soil N enrichment depleted readily weatherable mineral Ca and shifted forest reliance toward atmospheric Ca. Forests on Ca-poor sedimentary bedrock relied more consistently on atmospheric Ca across all levels of soil N enrichment. The broad importance of atmospheric Ca was unexpected given active regional uplift and erosion that are thought to rejuvenate weathering supply of soil minerals. Despite different Ca sources to forests on basaltic vs. sedimentary bedrock, we observed consistent declines in plant and soil Ca availability with increasing N, regardless of the Ca content of underlying bedrock. Thus, traditional measures of Ca availability in foliage and soil exchangeable pools may poorly reflect long-term Ca sources that sustain soil fertility. We conclude that long-term soil N enrichment can deplete available Ca and cause forests to rely increasingly on Ca from atmospheric deposition, which may limit ecosystem Ca supply in an increasingly N-rich world.

  8. Impact of decentralised forest management on forest cover changes ...

    African Journals Online (AJOL)

    In the semi-arid, the forest under JFM experienced substantial increase in forest cover (+3.5%.y-1) as compared to exclusive state management and CBFM. More tree basal area were harvested under exclusive state management in the montane study forests as compared to JFM and CBFM and the differences were ...

  9. Forests, woods, forest plantations

    Directory of Open Access Journals (Sweden)

    Giannini R

    2006-01-01

    Full Text Available In protected areas the forest ecosystem management is directed to define the best approaches with high protection levels from ecological, historical, anthropological and landscape point of view. The conservation purposes have to be taken in consideration to not disturb the natural and functional processes, and therefore any forest human activity has to be done. Through a detailed analysis of the relations among functionality, stability, productivity and genetic diversity, the statement of the reasons for application of close-to-nature silviculture is described and discussed. Some specific silvicultural systems are illustrated on the basis of very large quantity of data and information originated from researches carried out for long time. A major challenge facing modern silviculture is to reconcile the traditional objectives of timber production with the demand for multifunctional forest ecosystems which arises from the society. The preservation of the functionality is strictly related to the forest genetic pool which is the basis of biodiversity, as it represents the basis for adaptation and survival of species and individual.

  10. Forest Plant and Bird Communities in the Lau Group, Fiji

    Science.gov (United States)

    Franklin, Janet; Steadman, David W.

    2010-01-01

    Background We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km2), Nayau (18.4 km2), and Aiwa Levu (1.2 km2), islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa) has been subjected to prehistoric human-caused extinctions but little was previously known about this topic in the Lau Group. We expected that the degree of human disturbance would be a strong determinant of tree species composition and habitat quality for surviving landbirds, while island area would be unrelated to bird diversity. Methodology/Principal Findings All trees >5 cm diameter were measured and identified in 23 forest plots of 500 m2 each. We recognized four forest species assemblages differentiated by composition and structure: coastal forest, dominated by widely distributed species, and three forest types with differences related more to disturbance history (stages of secondary succession following clearing or selective logging) than to environmental gradients (elevation, slope, rockiness). Our point counts (73 locations in 1 or 2 seasons) recorded 18 of the 24 species of landbirds that exist on the three islands. The relative abundance and species richness of birds were greatest in the forested habitats least disturbed by people. These differences were due mostly to increased numbers of columbid frugivores and passerine insectivores in forests on Lakeba and Aiwa Levu. Considering only forested habitats, the relative abundance and species richness of birds were greater on the small but completely forested (and uninhabited) island of Aiwa Levu than on the much larger island of Lakeba. Conclusions/Significance Forest disturbance history is more important than island area in structuring both tree and landbird communities on remote Pacific islands. Even very small islands may be suitable for conservation reserves if they are protected from human

  11. Impacts of climate change on the global forest sector

    Science.gov (United States)

    Perez-Garcia, J.; Joyce, L.A.; McGuire, A.D.; Xiao, X.

    2002-01-01

    The path and magnitude of future anthropogenic emissions of carbon dioxide will likely influence changes in climate that may impact the global forest sector. These responses in the global forest sector may have implications for international efforts to stabilize the atmospheric concentration of carbon dioxide. This study takes a step toward including the role of global forest sector in integrated assessments of the global carbon cycle by linking global models of climate dynamics, ecosystem processes and forest economics to assess the potential responses of the global forest sector to different levels of greenhouse gas emissions. We utilize three climate scenarios and two economic scenarios to represent a range of greenhouse gas emissions and economic behavior. At the end of the analysis period (2040), the potential responses in regional forest growing stock simulated by the global ecosystem model range from decreases and increases for the low emissions climate scenario to increases in all regions for the high emissions climate scenario. The changes in vegetation are used to adjust timber supply in the softwood and hardwood sectors of the economic model. In general, the global changes in welfare are positive, but small across all scenarios. At the regional level, the changes in welfare can be large and either negative or positive. Markets and trade in forest products play important roles in whether a region realizes any gains associated with climate change. In general, regions with the lowest wood fiber production cost are able to expand harvests. Trade in forest products leads to lower prices elsewhere. The low-cost regions expand market shares and force higher-cost regions to decrease their harvests. Trade produces different economic gains and losses across the globe even though, globally, economic welfare increases. The results of this study indicate that assumptions within alternative climate scenarios and about trade in forest products are important factors

  12. Forest plant and bird communities in the Lau Group, Fiji.

    Directory of Open Access Journals (Sweden)

    Janet Franklin

    2010-12-01

    Full Text Available We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km², Nayau (18.4 km², and Aiwa Levu (1.2 km², islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa has been subjected to prehistoric human-caused extinctions but little was previously known about this topic in the Lau Group. We expected that the degree of human disturbance would be a strong determinant of tree species composition and habitat quality for surviving landbirds, while island area would be unrelated to bird diversity.All trees > 5 cm diameter were measured and identified in 23 forest plots of 500 m² each. We recognized four forest species assemblages differentiated by composition and structure: coastal forest, dominated by widely distributed species, and three forest types with differences related more to disturbance history (stages of secondary succession following clearing or selective logging than to environmental gradients (elevation, slope, rockiness. Our point counts (73 locations in 1 or 2 seasons recorded 18 of the 24 species of landbirds that exist on the three islands. The relative abundance and species richness of birds were greatest in the forested habitats least disturbed by people. These differences were due mostly to increased numbers of columbid frugivores and passerine insectivores in forests on Lakeba and Aiwa Levu. Considering only forested habitats, the relative abundance and species richness of birds were greater on the small but completely forested (and uninhabited island of Aiwa Levu than on the much larger island of Lakeba.Forest disturbance history is more important than island area in structuring both tree and landbird communities on remote Pacific islands. Even very small islands may be suitable for conservation reserves if they are protected from human disturbance.

  13. Landscape-scale forest disturbance regimes in southern Peruvian Amazonia.

    Science.gov (United States)

    Boyd, Doreen S; Hill, Ross A; Hopkinson, Chris; Baker, Timothy R

    2013-10-01

    Landscape-scale gap-size frequency distributions in tropical forests are a poorly studied but key ecological variable. Currently, a scale gap currently exists between local-scale field-based studies and those employing regional-scale medium-resolution satellite data. Data at landscape scales but of fine resolution would, however, facilitate investigation into a range of ecological questions relating to gap dynamics. These include whether canopy disturbances captured in permanent sample plots (PSPs) are representative of those in their surrounding landscape, and whether disturbance regimes vary with forest type. Here, therefore, we employ airborne LiDAR data captured over 142.5 km2 of mature, swamp, and regenerating forests in southeast Peru to assess the landscape-scale disturbance at a sampling resolution of up to 2 m. We find that this landscape is characterized by large numbers of small gaps; large disturbance events are insignificant and infrequent. Of the total number of gaps that are 2 m2 or larger in area, just 0.45% were larger than 100 m2, with a power-law exponent (alpha) value of the gap-size frequency distribution of 2.22. However, differences in disturbance regimes are seen among different forest types, with a significant difference in the alpha value of the gap-size frequency distribution observed for the swamp/regenerating forests compared with the mature forests at higher elevations. Although a relatively small area of the total forest of this region was investigated here, this study presents an unprecedented assessment of this landscape with respect to its gap dynamics. This is particularly pertinent given the range of forest types present in the landscape and the differences observed. The coupling of detailed insights into forest properties and growth provided by PSPs with the broader statistics of disturbance events using remote sensing is recommended as a strong basis for scaling-up estimates of landscape and regional-scale carbon balance.

  14. What is forest landscape restoration?

    Science.gov (United States)

    David Lamb; John Stanturf; Palle Madsen

    2012-01-01

    The extent and distribution of global forests is a matter of considerable concern. The overall rate of deforestation remains high although recent reports suggest it is fi nally beginning to decline (FAO 2011 ) . But this hides regional differences. In temperate regions net forest cover is increasing because of afforestation and natural expansion of forests. By contrast...

  15. Neogene and Quaternary development of the neotropical rain forest: the forest refugia hypothesis, and a literature overview

    Science.gov (United States)

    Hooghiemstra, Henry; van der Hammen, Thomas

    1998-09-01

    The upheaval of the northern Andes in Miocene and Pliocene time changed the drainage system in northern South America significantly and caused the present-day rain forest areas of Chocó and the Lower Magdalena Valley became separated from Amazonas. Plant diversity may have reached the highest level in the Miocene or Pliocene, and excessive present-day phytodiversity may be regarded as a legacy of the Tertiary, rather than an evolutionary product of the Quaternary. In the Quaternary strong temperature oscillations, related to the series of ice-ages, were superposed on the Late Tertiary forest dynamics, which included river displacement and latitudinal migrations of the equatorial rain belt (caloric equator) with the rhythm of the precession cycle of orbital climate forcing. The hypothesis that claims a permanent rain forest cover all over the Amazon basin during the last glacial is in contrast with the `forest refugia hypothesis', which accepts replacement of rain forest by savanna, or savanna forest, during dry climatic intervals. Both scenarios have been evidenced by pollen records. In this paper, it is suggested that both hypotheses are not necessarily conflicting and apparently did occur in different parts of the Amazon basin, and in different periods, depending on the climatological constraints. A compilation of the most important literature concerning the vegetational, climatic, and environmental history of the rain forest areas of Amazonas and Chocó, and surrounding dry ecosystems has been included.

  16. Land-use history affects understorey plant species distributions in a large temperate-forest complex, Denmark

    DEFF Research Database (Denmark)

    Svenning, J.-C.; Baktoft, Karen H.; Balslev, Henrik

    2009-01-01

    spatial, and 5 historical variables, and principal components analysis (PCA), redundancy analysis (RDA) as well as indicator species analysis. The historical variables were status as ancient (1805 AD) high forest, reclaimed bogs, ≤100 m from Bronze Age burial mounds, or former conifer plantation...... dispersal and a strong literature record as ancient-forest species, were still concentrated in areas that were high forest in 1805. Among the younger forests, there were clear floristic differences between those on reclaimed bogs and those not. Apparently remnant populations of wet-soil plants were still...

  17. Temporal shifts in floristic and avian diversity in Mediterranean pine forest ecosystems under different fire pressure: The island of Zakynthos as a case study

    Directory of Open Access Journals (Sweden)

    Konstantinos Poirazidis

    2014-01-01

    Full Text Available We evaluated how fire impacts the ecological coherence of Aleppo pine forests and their biodiversity over a 40-year period. The study area forms part of an insular ecosystem of Zakynthos Island (Zante in western Greece, which forms part of the Ionian Islands. Post-fire effects were studied for both plant and bird diversity at 20 sampling plots, using stratified random sampling, during the summer of 2012. The plots were selected based on the frequency of burning since the 1970s. Sites were categorized as: 1 no burning for >40 years, 2 burnt once in the 1970s, 3 burnt twice, first in the 1970s and again in 2000–2010, 4 burnt three times, first in the 1970s, and twice more in 2000–2010, and 5 burnt four times, first in the1970s, twice more in 2000–2010, and again in 2011. A total of 79 plant species and 26 bird species were recorded at the studied sites. One-way ANOVA analysis showed that fire intensity has a significant impact on alpha floristic diversity. Average plant species richness at sites that burned in 2011 was significantly higher than in those that burned in the 1970s. Detected differences in bird species richness were not significant; however, more species were documented in the forested habitats (unburnt for >40 years, and burnt in the 1970s. The highest Jaccard similarity index was observed between the sites that had not burned for more than 40 years and the sites that burned in the 1970s. The lowest floristic similarity to non-burnt sites was observed between the recently burnt sites in 2011 and the sites that burned in the 1970s. The lowest bird similarity was detected between recently burnt sites in 2011 and sites that had not burned for more than 40 years. DCA ordination showed the presence of a clear fire gradient, from intensively burnt open sites to non-burnt forest sites. We suggest that fire is essential to maintain biodiversity in Aleppo pine forests, but only at intermediate frequency.

  18. Strongly Correlated Topological Insulators

    Science.gov (United States)

    2016-02-03

    Strongly Correlated Topological Insulators In the past year, the grant was used for work in the field of topological phases, with emphasis on finding...surface of topological insulators. In the past 3 years, we have started a new direction, that of fractional topological insulators. These are materials...in which a topologically nontrivial quasi-flat band is fractionally filled and then subject to strong interactions. The views, opinions and/or

  19. Strong Cosmic Censorship

    Science.gov (United States)

    Isenberg, James

    2017-01-01

    The Hawking-Penrose theorems tell us that solutions of Einstein's equations are generally singular, in the sense of the incompleteness of causal geodesics (the paths of physical observers). These singularities might be marked by the blowup of curvature and therefore crushing tidal forces, or by the breakdown of physical determinism. Penrose has conjectured (in his `Strong Cosmic Censorship Conjecture`) that it is generically unbounded curvature that causes singularities, rather than causal breakdown. The verification that ``AVTD behavior'' (marked by the domination of time derivatives over space derivatives) is generically present in a family of solutions has proven to be a useful tool for studying model versions of Strong Cosmic Censorship in that family. I discuss some of the history of Strong Cosmic Censorship, and then discuss what is known about AVTD behavior and Strong Cosmic Censorship in families of solutions defined by varying degrees of isometry, and discuss recent results which we believe will extend this knowledge and provide new support for Strong Cosmic Censorship. I also comment on some of the recent work on ``Weak Null Singularities'', and how this relates to Strong Cosmic Censorship.

  20. Forest Classification Based on Forest texture in Northwest Yunnan Province

    Science.gov (United States)

    Wang, Jinliang; Gao, Yan; Wang, Xiaohua; Fu, Lei

    2014-03-01

    Forest texture is an intrinsic characteristic and an important visual feature of a forest ecological system. Full utilization of forest texture will be a great help in increasing the accuracy of forest classification based on remote sensed data. Taking Shangri-La as a study area, forest classification has been based on the texture. The results show that: (1) From the texture abundance, texture boundary, entropy as well as visual interpretation, the combination of Grayscale-gradient co-occurrence matrix and wavelet transformation is much better than either one of both ways of forest texture information extraction; (2) During the forest texture information extraction, the size of the texture-suitable window determined by the semi-variogram method depends on the forest type (evergreen broadleaf forest is 3×3, deciduous broadleaf forest is 5×5, etc.). (3)While classifying forest based on forest texture information, the texture factor assembly differs among forests: Variance Heterogeneity and Correlation should be selected when the window is between 3×3 and 5×5 Mean, Correlation, and Entropy should be used when the window in the range of 7×7 to 19×19 and Correlation, Second Moment, and Variance should be used when the range is larger than 21×21.

  1. Forest Classification Based on Forest texture in Northwest Yunnan Province

    International Nuclear Information System (INIS)

    Wang, Jinliang; Gao, Yan; Fu, Lei; Wang, Xiaohua

    2014-01-01

    Forest texture is an intrinsic characteristic and an important visual feature of a forest ecological system. Full utilization of forest texture will be a great help in increasing the accuracy of forest classification based on remote sensed data. Taking Shangri-La as a study area, forest classification has been based on the texture. The results show that: (1) From the texture abundance, texture boundary, entropy as well as visual interpretation, the combination of Grayscale-gradient co-occurrence matrix and wavelet transformation is much better than either one of both ways of forest texture information extraction; (2) During the forest texture information extraction, the size of the texture-suitable window determined by the semi-variogram method depends on the forest type (evergreen broadleaf forest is 3×3, deciduous broadleaf forest is 5×5, etc.). (3)While classifying forest based on forest texture information, the texture factor assembly differs among forests: Variance Heterogeneity and Correlation should be selected when the window is between 3×3 and 5×5; Mean, Correlation, and Entropy should be used when the window in the range of 7×7 to 19×19; and Correlation, Second Moment, and Variance should be used when the range is larger than 21×21

  2. The forests are waiting for a stocktaking

    International Nuclear Information System (INIS)

    Beer, G.; Sobinkovic, B.

    2004-01-01

    In spite of that the stock of wood is gradually rising from 313.3 mn m 3 in 1970 to 428 million m 3 in 2003, a part of foresters are asserting, that nobody exactly knows how much and what wood is in Slovak forests in the present time. State forests of the Slovak Republic plans to realize a stocktaking of a content of wood staff in the forests. Wood output in Slovak forests was fluctuating sharply since 1980. It dropped from 5.8 million cubic meters in 1980 under a level of 4.4 million m 3 at the beginning of the nineties. In 2003 more than 6,6 million m 3 was cut down. The problem is beginning the enforced wood-cuttings, which are caused by different calamities. Therefore a coniferous wood was cut down more than in 29 percent as was determined by the forest economic plans. However the official forecasts of possibility of cutting down of wood till 2010 determine, that only slightly over 6 million m 3 of wood can be cut down annually. In spite of the rising output a demand on individual kinds of wood was strongly changed during the last two years. While an over-spill of leafy wood was on the market recently, in the present time there is a lack of it. It is suggested to solve a fight for a leafy fibre also by a planting of poplars at free surroundings. The wood can be cut down after twenty or twenty-five years in the areas forested by the poplars. It is calculated, that much money can be gained from one hectare after twenty years, in contrast of if a corn would be sew out annually at the same area for two decades

  3. Forest fuel and carbon balances

    International Nuclear Information System (INIS)

    Lundborg, A.

    1994-10-01

    Forest fuel, i.e., branches and tops that remain after felling, are not considered to give a net surplus of carbon dioxide to the atmosphere. In order to, if possible, verify this theory a survey was made of the literature concerning different carbon flows related to forest fuel. Branches and needles that are not utilised as fuel nonetheless eventually become decomposed to carbon dioxide. Branches and stem wood are broken down in occasional cases to 60-80% already within 5-6 years but the decomposition rate varies strongly. A small amount of existing data suggest that branches and stems are broken down almost completely within 60-70 years, and earlier in some cases. Lignin is the component in needles and wood that is the most resistant to decomposition. Decomposition is favoured by optimal temperature and moisture, ground contact and ground animals. Material that is mulched during soil preparation is decomposed considerably faster than material that lies on the soil surface. Felling residues that are left on the soil are a large momentary addition to the soil's reserves of organic material but after a number of years the difference in soil organic material is small between places where fuel has been removed and places where felling residues have been left. High nitrogen deposition, fire control and effective forestry are factors that contribute to the increases in the reserves of soil organic material. It appears to be a good approximation to consider the forest fuel as being a neutral fuel as regards carbon dioxide in a longer perspective. In comparison with other biofuels and fossil fuels, forest fuel appears, together with Salix, to be the fuel that results in very little extra discharge of carbon dioxide or other greenhouse gases during its production, transport and processing. 70 refs, 5 figs, tabs

  4. Forest Resources

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Forest biomass is an abundant biomass feedstock that complements the conventional forest use of wood for paper and wood materials. It may be utilized for bioenergy production, such as heat and electricity, as well as for biofuels and a variety of bioproducts, such as industrial chemicals, textiles, and other renewable materials. The resources within the 2016 Billion-Ton Report include primary forest resources, which are taken directly from timberland-only forests, removed from the land, and taken to the roadside.

  5. Land crabs as key drivers in tropical coastal forest recruitment

    Science.gov (United States)

    Lindquist, E.S.; Krauss, K.W.; Green, P.T.; O'Dowd, D. J.; Sherman, P.M.; Smith, T. J.

    2009-01-01

    Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influence seed dispersal and viability, and seedling establishment and growth at the microsite. Rarely does one animal guild exert as significant an influence on different plant assemblages as land crabs. We review three tropical coastal ecosystems-mangroves, island maritime forests, and mainland coastal terrestrial forests-where land crabs directly influence forest composition by limiting tree establishment and recruitment. Land crabs differentially prey on seeds, propagules and seedlings along nutrient, chemical and physical environmental gradients. In all of these ecosystems, but especially mangroves, abiotic gradients are well studied, strong and influence plant species distributions. However, we suggest that crab predation has primacy over many of these environmental factors by acting as the first limiting factor of tropical tree recruitment to drive the potential structural and compositional organisation of coastal forests. We show that the influence of crabs varies relative to tidal gradient, shoreline distance, canopy position, time, season, tree species and fruiting periodicity. Crabs also facilitate forest growth and development through such activities as excavation of burrows, creation of soil mounds, aeration of soils, removal of leaf litter into burrows and creation of carbon-rich soil microhabitats. For all three systems, land crabs influence the distribution, density and size-class structure of tree populations. Indeed, crabs are among the major drivers of tree recruitment in tropical coastal forest ecosystems, and their conservation should be included in management plans of these forests. ?? 2009 Cambridge Philosophical Society.

  6. Assessing the bibliometric productivity of forest scientists in Italy

    Directory of Open Access Journals (Sweden)

    Francesca Giannetti

    2016-07-01

    Full Text Available Since 2010, the Italian Ministry of University and Research issued new evaluation protocols to select candidates for University professorships and assess the bibliometric productivity of Universities and Research Institutes based on bibliometric indicators, i.e. scientific paper and citation numbers and the h-index. Under this framework, the objective of this study was to quantify the bibliometric productivity of the Italian forest research community during the 2002-2012 period. We examined the following productivity parameters: (i the bibliometric productivity under the Forestry subject category at the global level; (ii compared the aggregated bibliometric productivity of Italian forest scientists with scientists from other countries; (iii analyzed publication and citation temporal trends of Italian forest scientists and their international collaborations; and (iv characterized productivity distribution among Italian forest scientists at different career levels. Results indicated the following: (i the UK is the most efficient country based on the ratio between Gross Domestic Spending (GDS on Research and Development (R&D and bibliometric productivity under the Forestry subject category, followed by Italy; (ii Italian forest scientist productivity exhibited a significant positive time trend, but was characterized by high inequality across authors; (iii one-half of the Italian forest scientist publications were written in collaboration with foreign scientists; (iv a strong relationship exists between bibliometric indicators calculated by WOS and SCOPUS, suggesting these two databases have the same potential to evaluate the forestry research community; and (v self-citations did not significantly affect the rank of Italian forest scientists.

  7. Land crabs as key drivers in tropical coastal forest recruitment.

    Science.gov (United States)

    Lindquist, Erin Stewart; Krauss, Ken W; Green, Peter T; O'Dowd, Dennis J; Sherman, Peter M; Smith, Thomas J

    2009-05-01

    Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influence seed dispersal and viability, and seedling establishment and growth at the microsite. Rarely does one animal guild exert as significant an influence on different plant assemblages as land crabs. We review three tropical coastal ecosystems-mangroves, island maritime forests, and mainland coastal terrestrial forests-where land crabs directly influence forest composition by limiting tree establishment and recruitment. Land crabs differentially prey on seeds, propagules and seedlings along nutrient, chemical and physical environmental gradients. In all of these ecosystems, but especially mangroves, abiotic gradients are well studied, strong and influence plant species distributions. However, we suggest that crab predation has primacy over many of these environmental factors by acting as the first limiting factor of tropical tree recruitment to drive the potential structural and compositional organisation of coastal forests. We show that the influence of crabs varies relative to tidal gradient, shoreline distance, canopy position, time, season, tree species and fruiting periodicity. Crabs also facilitate forest growth and development through such activities as excavation of burrows, creation of soil mounds, aeration of soils, removal of leaf litter into burrows and creation of carbon-rich soil microhabitats. For all three systems, land crabs influence the distribution, density and size-class structure of tree populations. Indeed, crabs are among the major drivers of tree recruitment in tropical coastal forest ecosystems, and their conservation should be included in management plans of these forests.

  8. Strong Arcwise Connectedness

    OpenAIRE

    Espinoza, Benjamin; Gartside, Paul; Kovan-Bakan, Merve; Mamatelashvili, Ana

    2012-01-01

    A space is `n-strong arc connected' (n-sac) if for any n points in the space there is an arc in the space visiting them in order. A space is omega-strong arc connected (omega-sac) if it is n-sac for all n. We study these properties in finite graphs, regular continua, and rational continua. There are no 4-sac graphs, but there are 3-sac graphs and graphs which are 2-sac but not 3-sac. For every n there is an n-sac regular continuum, but no regular continuum is omega-sac. There is an omega-sac ...

  9. Abortion: Strong's counterexamples fail

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2009-01-01

    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally......'s scenarios have some valuable future or admitted that killing them is not seriously morally wrong. Finally, if "valuable future" is interpreted as referring to objective standards, one ends up with implausible and unpalatable moral claims....

  10. Environmental variables and tree population structures in deciduous forests of central Brazil with different levels of logging

    Directory of Open Access Journals (Sweden)

    Daniel Luis Mascia Vieira

    2008-04-01

    Full Text Available Population structures of six tree species in three fragments of intact seasonal deciduous forest and three fragments disturbed by logging were studied in the northeastern Goiás. Forty random 400 m² plots were allocated in each fragment to survey plant population structures, number of stumps, cattle feces, burnt logs, and canopy openness. Soil cover by life forms was estimated in 1m² sub-plots. Lianas were abundant in intermediately logged fragments and invasive herbs in the most disturbed fragment. Cattle avoided dense herbaceous strata, such as liana tangles. Cavanillesia arborea, Eugenia dysenterica and Swartzia multijuga trees occurred at very low densities in all the fragments and their seedlings were practically absent, which might endanger their future populations in these fragments. Myracrodruon urundeuva, Tabebuia impetiginosa and Astronium fraxinifolium, the most logged species, had high density of seedlings in all the fragments. However, the highest density of saplings and juvenile individuals occurred in the most disturbed fragment.As estruturas populacionais de seis espécies de árvores foram estudadas em três fragmentos de floresta estacional decidual intactos e três fragmentos impactados pela exploração seletiva de madeira no nordeste goiano. Quarenta parcelas de 400m² foram estabelecidas em cada fragmento para a amostragem de populações, número de tocos, fezes de gado, troncos queimados e abertura de dossel. A cobertura do solo por formas de vida foi estimada em sub-parcelas de 1m². Lianas foram mais abundantes em fragmentos com perturbação intermediária, enquanto herbáceas invasoras no fragmento mais perturbado. Cavanillesia arborea, Eugenia dysenterica e Swartzia multijuga ocorreram em densidades muito baixas em todos os fragmentos e plântulas foram praticamente ausentes, o que pode ameaçar o futuro de suas populações. Myracrodruon urundeuva, Tabebuia impetiginosa e Astronium fraxinifolium, as espécies mais

  11. Assessing environmental impacts on stream water quality: the use of cumulative flux and cumulative flux difference approaches to deforestation of the Hafren Forest, mid-Wales

    Directory of Open Access Journals (Sweden)

    C. Neal

    2002-01-01

    Full Text Available A method for examining the impacts of disturbance on stream water quality based on paired catchment “controlâ€? and “responseâ€? water quality time series is described in relation to diagrams of cumulative flux and cumulative flux difference. The paper describes the equations used and illustrates the patterns expected for idealised flux changes followed by an application to stream water quality data for a spruce forested catchment, the Hore, subjected to clear fell. The water quality determinands examined are sodium, chloride, nitrate, calcium and acid neutralisation capacity. The anticipated effects of felling are shown in relation to reduction in mist capture and nitrate release with felling as well as to the influence of weathering and cation exchange mechanisms, but in a much clearer way than observed previously using other approaches. Keywords: Plynlimon, stream, Hore, acid neutralisation capacity, calcium, chloride, nitrate, sodium, cumulative flux, flux

  12. Modeling erosion from forest roads with WEPP

    Science.gov (United States)

    J. McFero Grace

    2007-01-01

    Forest roads can be major sources of soil erosion from forest watersheds. Sediments from forest roads are a concern due to their potential delivery to stream systems resulting in degradation of water quality. The Water Erosion Prediction Project (WEPP) was used to predict erosion from forest road components under different management practices. WEPP estimates are...

  13. A strong comeback

    International Nuclear Information System (INIS)

    Marier, D.

    1992-01-01

    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders

  14. Temporal changes in soil water repellency after a forest fire in a Mediterranean calcareous soil: Influence of ash and different vegetation type.

    Science.gov (United States)

    Jiménez-Pinilla, P; Lozano, E; Mataix-Solera, J; Arcenegui, V; Jordán, A; Zavala, L M

    2016-12-01

    Forest fires usually modify soil water repellency (SWR), and its persistence and intensity show a high variability both in space and time. This research studies the evolution of SWR in a Mediterranean calcareous soil affected by a forest fire, which occurred in Gorga (SE Spain) in July 2011, comparing the effect of the main vegetation cover between pine (Pinus halepensis) and shrubs species (Quercus coccifera, Rosmarinus officinalis, Cistus albidus, Erica arborea and Brachypodium retusum) and the relationship with soil moisture content (SMC). Also the study analyzed the effect of ash on SWR dynamics under field conditions. Six plots were established on the fire-affected area and the unburned-control-adjacent area to monitoring SWR with the water drop penetration time (WDPT) test, SMC through moist sensors (5cm depth) and three different ash treatments: ash presence, ash absence and incorporation of ash into the soil. An immediate increase of SWR was observed in the fire-affected area, mainly in pine plots. SWR changes in control (unburned) plots were quite similar between different types of vegetation influence, despite higher SWR values being observed on pine plots during the study period. A noticeable decrease of SWR was observed during the first months after fire in the affected areas, especially after the first rainy period, both in pine and shrubs plots. SWR increase was registered in all plots, and the highest levels were in March 2012 in burned pine plots. SWR decrease was higher in plots where ash was removed. Fire-affected soils became wettable 1year and a half after the fire. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Long and short term changes in the forests of the Cumberland Plateau and Mountains using large scale forest inventory data

    Science.gov (United States)

    Christopher M. Oswalt; Andrew J. Hartsell

    2012-01-01

    The Cumberland Plateau and Mountains (CPM) are a significant component of the eastern deciduous forest with biological and cultural resources strongly connected to and dependent upon the forest resources of the region. As a result, continuous inventory and monitoring is critical. The USDA Forest Service Forest Inventory and Analysis (FIA) program has been collecting...

  16. The effect of altitude, patch size and disturbance on species richness and density of lianas in montane forest patches

    Science.gov (United States)

    Mohandass, Dharmalingam; Campbell, Mason J.; Hughes, Alice C.; Mammides, Christos; Davidar, Priya

    2017-08-01

    The species richness and density of lianas (woody vines) in tropical forests is determined by various abiotic and biotic factors. Factors such as altitude, forest patch size and the degree of forest disturbance are known to exert strong influences on liana species richness and density. We investigated how liana species richness and density were concurrently influenced by altitude (1700-2360 m), forest patch size, forest patch location (edge or interior) and disturbance intensity in the tropical montane evergreen forests, of the Nilgiri and Palni hills, Western Ghats, southern India. All woody lianas (≥1 cm dbh) were enumerated in plots of 30 × 30 m in small, medium and large forest patches, which were located along an altitudinal gradient ranging from 1700 to 2360 m. A total of 1980 individual lianas were recorded, belonging to 45 species, 32 genera and 21 families, from a total sampling area of 13.86 ha (across 154 plots). Liana species richness and density decreased significantly with increasing altitude and increased with increasing forest patch size. Within forest patches, the proportion of forest edge or interior habitat influenced liana distribution and succession especially when compared across the patch size categories. Liana species richness and density also varied along the altitudinal gradient when examined using eco-physiological guilds (i.e. shade tolerance, dispersal mode and climbing mechanism). The species richness and density of lianas within these ecological guilds responded negatively to increasing altitude and positively to increasing patch size and additionally displayed differing sensitivities to forest disturbance. Importantly, the degree of forest disturbance significantly altered the relationship between liana species richness and density to increasing altitude and patches size, and as such is likely the primary influence on liana response to montane forest succession. Our findings suggest that managing forest disturbance in the examined

  17. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  18. Effects of white-tailed deer and invasive plants on the herb layer of suburban forests.

    Science.gov (United States)

    Morrison, Janet A

    2017-11-01

    Lack of hunting and predators and proximity to human communities make suburban forests prone to high deer abundance and non-native plant invasions. I investigated these likely drivers of community structure in the herb layers of six suburban forests in one region of New Jersey, USA. In 223 plots I assessed the herb layer response to 2.5 years with or without deer fencing and the early stage of invasion from seed additions of Microstegium vimineum , an invasive, annual grass. Non-native plants and herbaceous native plants were affected very little by fencing or M. vimineum invasion. In contrast, across all forests the combination of deer access and M. vimineum addition had a strongly negative effect on woody native percent cover. Forests differed in overall fencing effects on woody natives; their cover was greater in fenced plots in just three forests, suggesting greater deer pressure in those forests during the experiment. The early invasion by M. vimineum was greatest in two of these same forests, but was not influenced by fencing. Multi-group structural equation modelling compared two groups of forests that differed in vegetation abundance and other characteristics. It paralleled the results above and also showed no negative influence of non-native cover on native cover, even in the forests where non-native cover was greater. It identified a positive effect of light level on herb layer plants in the forests with less vegetation, and also revealed a positive effect of soil water potential (SWP) on non-native plants in the forests with more vegetation, which had higher SWP. These suburban forests within a common region varied widely in native and non-native herb layer abundance, the early success of M. vimineum invasion and the herb layer's response to early invasion and protection from deer.

  19. On the difference in the net ecosystem exchange of CO2 between deciduous and evergreen forests in the southeastern United States

    Science.gov (United States)

    Kimberly A. Novick; A. Christopher Oishi; Eric J. Ward; Mario B.S. Siqueira; Jehn-Yih Juang; Paul C. Stoy

    2015-01-01

    The southeastern United States is experiencing a rapid regional increase in the ratio of pine to deciduous forest ecosystems at the same time it is experiencing changes in climate. This study is focused on exploring how these shifts will affect the carbon sink capacity of southeastern US forests, which we show here are among the strongest carbon sinks in the...

  20. Population dynamics of aerial and terrestrial populations Phytophthora ramorum in a California forest under different climatic conditions

    Science.gov (United States)

    C.A. Eyre; M. Kozanitas; M. Garbelotto

    2013-01-01

    Limited information is available on how soil and leaf populations of the sudden oak death pathogen, Phytophthora ramorum, may differ in their response to changing weather conditions, and their corresponding role in initiating the next disease cycle after unfavorable weather conditions. We sampled and cultured from 425 trees in six sites, three...

  1. {sup 137}Cs and {sup 40}K in fruiting bodies of different fungal species collected in a single forest in southern Poland

    Energy Technology Data Exchange (ETDEWEB)

    Mietelski, Jerzy W., E-mail: Jerzy.mietelski@ifj.edu.p [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Krakow (Poland); Dubchak, Sergiy [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Blazej, Sylwia [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Krakow (Poland); Anielska, Teresa; Turnau, Katarzyna [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland)

    2010-09-15

    Fruiting bodies of fungi belonging to more than 70 species were collected within a few thousand square meter area of one forest during 2006 and 2007. The soil profile was collected to check the cumulative deposition of {sup 137}Cs, which was relatively high, equal to 64 {+-} 2 kBq/m{sup 2} (calculated for October 2006). The majority of this activity was in the first 6 cm. Fruitbodies were analyzed for radiocesium and {sup 40}K by means of gamma-spectrometry. The highest {sup 137}Cs activity was 54.1 {+-} 0.7 kBq/kg (dry weight) for a sample of Lactarius helvus collected in 2006. The results for 2006 were higher than those for 2007. In a few cases the traces of short-lived (T{sub 1/2} = 2.06 a) {sup 134}Cs were still found in samples. The importance of mycorrhizal fungi for radiocesium accumulation is confirmed. The differences in activity among the species are discussed in relation to observations and predictions from previous studies, where the change in relative accumulation between fruiting bodies of different species was at least partially explained by the differences in the depth of the mycelium localization in a litter/soil system. It is concluded that in some cases, such as Boletus edulis and Xerocomus badius, this prediction is fulfilled and therefore this explanation confirmed.

  2. Exploring the role nurses play at different stages of the birthing process. Developing strong and long-term relationships with women by examining relationship-building stages prior to delivery, during delivery, and after delivery.

    Science.gov (United States)

    Peltier, J W; Schibrowski, J A; Westfall, J

    2000-01-01

    The health care community is becoming increasingly aware of the need to develop strong and long-term relationships with the women who make up the majority of the health care market. The perceived quality of obstetric care positively impacts future revenue streams by creating "family" loyalty for an umbrella of other health services offered by the provider organization. This article examines the differential impact that various service performance dimensions have on women's perceptions of quality for different stages of the birthing process, and how relationship-marketing principles can be utilized to develop loyal partnerships. The three distinct relationship-building stages are examined--birthing experiences prior to delivery, during delivery, and after delivery--along with their implications for perceptions of quality analyzed.

  3. Role of Forest Resources to Local Livelihoods: The Case of East Mau Forest Ecosystem, Kenya

    Directory of Open Access Journals (Sweden)

    D. K. Langat

    2016-01-01

    Full Text Available Forests in Kenya are threatened by unsustainable uses and conversion to alternative land uses. In spite of the consequences of forest degradation and biodiversity loss and reliance of communities on forests livelihoods, there is little empirical data on the role of forest resources in livelihoods of the local communities. Socioeconomic, demographic, and forest use data were obtained by interviewing 367 households. Forest product market survey was undertaken to determine prices of various forest products for valuation of forest use. Forest income was significant to households contributing 33% of total household income. Fuel wood contributed 50%, food (27%, construction material (18%, and fodder, and thatching material 5% to household forest income. Absolute forest income and relative forest income (% were not significantly different across study locations and between ethnic groups. However, absolute forest income and relative forest income (% were significantly different among wealth classes. Poor households were more dependent on forests resources. However, in absolute terms, the rich households derived higher forest income. These results provide valuable information on the role of forest resources to livelihoods and could be applied in developing forest conservation policies for enhanced ecosystem services and livelihoods.

  4. Climate indices strongly influence old-growth forest carbon exchange

    Science.gov (United States)

    Sonia Wharton; Matthias Falk

    2016-01-01

    We present a decade and a half (1998–2013) of carbon dioxide fluxes from an old-growth stand in the American Pacific Northwest to identify ecosystem-level responses to Pacific teleconnection patterns, including the El Niño/Southern Oscillation (ENSO). This study provides the longest, continuous record of old-growth eddy flux data to date from one of the longest running...

  5. Strong-coupling approximations

    International Nuclear Information System (INIS)

    Abbott, R.B.

    1984-03-01

    Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi 4 field theory in 1 + 1 dimensions. 9 references, 6 figures

  6. Strong interaction and QFD

    International Nuclear Information System (INIS)

    Ebata, T.

    1981-01-01

    With an assumed weak multiplet structure for bosonic hadrons, which is consistent with the ΔI = 1/2 rule, it is shown that the strong interaction effective hamiltonian is compatible with the weak SU(2) x U(1) gauge transformation. Especially the rho-meson transforms as a triplet under SU(2)sub(w), and this is the origin of the rho-photon analogy. It is also shown that the existence of the non-vanishing Cabibbo angle is a necessary condition for the absence of the exotic hadrons. (orig.)

  7. Study of the inorganic constituents in different species of Casearia medicinal plant collected in distinct regions of the Atlantic Forest, SP State, Brazil

    International Nuclear Information System (INIS)

    Yamashita, Celina Izumi

    2006-01-01

    The use of medicinal plants in the treatment of diseases has increased significantly in the last years, as has research concerning chemical characterization of these plants. In this study, inorganic constituents were determined in leaves and in extracts from three medicinal plant species of the Casearia genus (C. sylvestris, C. decandra and C. obliqua) collected in distinct regions of the Atlantic Forest, SP. The elemental compositions of the soils in which these plants were grown were also determined. Traditionally, these plants are used due to their antiinflammatory, antiacid, antiseptic and cicatrizing properties. The antiulcer and the antitumor activities of the Casearia genus and its capacity to neutralize snake and bee venoms, have also been scientifically confirmed. The analytical methodology used was neutron activation analysis. Long and short irradiation periods of the samples and the standards were carried out at IPEN's IEA-R1 nuclear research reactor. In the leaf K was found at the percentage levels, Ca, Cl, Mg and Na at mg g -1 levels and the elements Br, Fe, Mn, Rb and Zn at the μg g -1 levels. As, Co, Cr, Cs, La, Sb, Sc and Se at the ng g -1 levels. Results obtained in the extracts indicated that the same elements present in the leaves are also found in their extracts. The comparison between the inorganic composition of Casearia sylvestris leaves collected from three different regions of the Atlantic Forest showed that the elemental concentrations in the plants leaves varied depending on the place where they were grown. Different Casearia species cultivated in a same region presented similar elemental compositions. Based on these findings it can be concluded that the studies about the pharmacological effect of Casearia genus plants grown in different types of soil are of great importance. The quality of the obtained results was assured by the analyses of the certified reference materials NIST 1573a Tomato Leaves, NIST 1515 Apple Leaves, INCT-TL-1 Tea

  8. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia

    2009-01-01

    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  9. Spatial variation in the storages and age-related dynamics of forest carbon sequestration in different climate zones-evidence from black locust plantations on the Loess Plateau of China.

    Science.gov (United States)

    Li, Taijun; Ren, Bowen; Wang, Dahui; Liu, Guobin

    2015-01-01

    Knowledge about the long-term influences of climate change on the amount of potential carbon (C) sequestration in forest ecosystems, including age-related dynamics, remains unclear. This study used two similar age-sequences of black locust forests (Robinia pseudoacacia L.) in the semi-arid and semi-humid zones of China's Loess Plateau to assess the variation in C stocks and age-related dynamics. Our results demonstrated that black locust forests of the semi-humid zone stored significantly more C than did forests in the semi-arid zone, across the chronosequence (p zone, while the semi-arid zone had a capacity of only 79.4 Mg C ha-1. Soil organic C (SOC) increased continuously with stand age in the semi-arid zone (R2 = 0.84, p = 0.010). However, in the semi-humid zone, SOC declined sharply by 47.8% after the initial stage (5 to 10 y). The C stock in trees increased continuously with stand age in the semi-humid zone (R2 = 0.83, p = 0.011), yet in the semi-arid zone, it decreased dramatically from 43.0 Mg C ha-1 to 28.4 Mg C ha-1 during the old forest stage (38 to 56 y). The shift from being a net C sink to a net C source occurred at the initial stage in the semi-humid zone versus at the old forest stage in the semi-arid zone after reforestation. Surprisingly, with the exception of the initial and later stages (55 y), the patterns of C allocation among trees, soils, understory and litter were not statistically different between the two climate zones. Our results suggest that climate factors can alter the potential amount and age-related dynamics of forest C sequestration.

  10. Spatial Variation in the Storages and Age-Related Dynamics of Forest Carbon Sequestration in Different Climate Zones—Evidence from Black Locust Plantations on the Loess Plateau of China

    Science.gov (United States)

    Li, Taijun; Ren, Bowen; Wang, Dahui; Liu, Guobin

    2015-01-01

    Knowledge about the long-term influences of climate change on the amount of potential carbon (C) sequestration in forest ecosystems, including age-related dynamics, remains unclear. This study used two similar age-sequences of black locust forests (Robinia pseudoacacia L.) in the semi-arid and semi-humid zones of China’s Loess Plateau to assess the variation in C stocks and age-related dynamics. Our results demonstrated that black locust forests of the semi-humid zone stored significantly more C than did forests in the semi-arid zone, across the chronosequence (p zone, while the semi-arid zone had a capacity of only 79.4 Mg C ha−1. Soil organic C (SOC) increased continuously with stand age in the semi-arid zone (R2 = 0.84, p = 0.010). However, in the semi-humid zone, SOC declined sharply by 47.8% after the initial stage (5 to 10 y). The C stock in trees increased continuously with stand age in the semi-humid zone (R2 = 0.83, p = 0.011), yet in the semi-arid zone, it decreased dramatically from 43.0 Mg C ha−1 to 28.4 Mg C ha−1 during the old forest stage (38 to 56 y). The shift from being a net C sink to a net C source occurred at the initial stage in the semi-humid zone versus at the old forest stage in the semi-arid zone after reforestation. Surprisingly, with the exception of the initial and later stages (55 y), the patterns of C allocation among trees, soils, understory and litter were not statistically different between the two climate zones. Our results suggest that climate factors can alter the potential amount and age-related dynamics of forest C sequestration. PMID:25799100

  11. Conservation in a crowded place : forest and people on Mount Elgon Uganda

    NARCIS (Netherlands)

    Sassen, M.

    2014-01-01

    <strong>Key words: tropical forest, conservation management, local livelihoods, forest cover change, disturbance, fuelwood, forest structure, species richness, biomass, Mount Elgonstrong>

    A growing world population has important consequences for forests. In this study I

  12. Helminth parasite communities of two Physalaemus cuvieri Fitzinger, 1826 (Anura: Leiuperidae populations under different conditions of habitat integrity in the Atlantic Rain Forest of Brazil

    Directory of Open Access Journals (Sweden)

    A. Aguiar

    Full Text Available Abstract Adults of Physalaemus cuvieri were collected and necropsied between November 2009 and January 2010. This was carried out in order to report and compare the helminth fauna associated with two populations of this anuran species from the Brazilian Atlantic rain forest under different conditions of habitat integrity. The hosts from the disturbed area were parasitized with five helminth taxa: Cosmocerca parva, Aplectana sp., Physaloptera sp., Rhabdias sp., Oswaldocruzia subauricularis (Nematoda and Polystoma cuvieri (Monogenea while those from the preserved area had four helminth taxa: C. parva, Aplectana sp., Physaloptera sp., Rhabdias sp., and Acanthocephalus saopaulensis (Acanthocephala. Prevalence, mean intensity of infection, mean abundance, mean richness, importance index and dominance frequency of helminth component communities were similar in both areas. The helminth community associated with anurans from the disturbed area had higher diversity than that from the preserved area. This study is the first to report on the acanthocephalan parasites of Ph. cuvieri, and the similarity between helminth fauna composition of two host populations under different selective pressures.

  13. Helminth parasite communities of two Physalaemus cuvieri Fitzinger, 1826 (Anura: Leiuperidae) populations under different conditions of habitat integrity in the Atlantic Rain Forest of Brazil.

    Science.gov (United States)

    Aguiar, A; Toledo, G M; Anjos, L A; Silva, R J

    2015-11-01

    Adults of Physalaemus cuvieri were collected and necropsied between November 2009 and January 2010. This was carried out in order to report and compare the helminth fauna associated with two populations of this anuran species from the Brazilian Atlantic rain forest under different conditions of habitat integrity. The hosts from the disturbed area were parasitized with five helminth taxa: Cosmocerca parva, Aplectana sp., Physaloptera sp., Rhabdias sp., Oswaldocruzia subauricularis (Nematoda) and Polystoma cuvieri (Monogenea) while those from the preserved area had four helminth taxa: C. parva, Aplectana sp., Physaloptera sp., Rhabdias sp., and Acanthocephalus saopaulensis (Acanthocephala). Prevalence, mean intensity of infection, mean abundance, mean richness, importance index and dominance frequency of helminth component communities were similar in both areas. The helminth community associated with anurans from the disturbed area had higher diversity than that from the preserved area. This study is the first to report on the acanthocephalan parasites of Ph. cuvieri, and the similarity between helminth fauna composition of two host populations under different selective pressures.

  14. Discriminative Analysis of Different Grades of Gaharu (Aquilaria malaccensis Lamk. via 1H-NMR-Based Metabolomics Using PLS-DA and Random Forests Classification Models

    Directory of Open Access Journals (Sweden)

    Siti Nazirah Ismail

    2017-09-01

    Full Text Available Gaharu (agarwood, Aquilaria malaccensis Lamk. is a valuable tropical rainforest product traded internationally for its distinctive fragrance. It is not only popular as incense and in perfumery, but also favored in traditional medicine due to its sedative, carminative, cardioprotective and analgesic effects. The current study addresses the chemical differences and similarities between gaharu samples of different grades, obtained commercially, using 1H-NMR-based metabolomics. Two classification models: partial least squares-discriminant analysis (PLS-DA and Random Forests were developed to classify the gaharu samples on the basis of their chemical constituents. The gaharu samples could be reclassified into a ‘high grade’ group (samples A, B and D, characterized by high contents of kusunol, jinkohol, and 10-epi-γ-eudesmol; an ‘intermediate grade’ group (samples C, F and G, dominated by fatty acid and vanillic acid; and a ‘low grade’ group (sample E and H, which had higher contents of aquilarone derivatives and phenylethyl chromones. The results showed that 1H- NMR-based metabolomics can be a potential method to grade the quality of gaharu samples on the basis of their chemical constituents.

  15. Leaf Trait Variation with Environmental Factors at Different Spatial Scales: A Multilevel Analysis Across a Forest-Steppe Transition

    Directory of Open Access Journals (Sweden)

    Haijing Shi

    2018-03-01

    Full Text Available In mountain areas, the distribution of plant communities is affected by both regional and microhabitat conditions. The degree to which these different spatial factors contribute to plant communities is not well understood, because few studies have used a uniform sampling methodology to measure trait variation across the range of ecological scales. In this study, a stratified sampling method was used to study community weighted leaf traits and environment factors at different spatial (transect and plot scales. We measured 6 leaf traits (specific leaf area, leaf tissue density, leaf thickness, leaf carbon, nitrogen and phosphorus content in 258 communities from 57 sites in 9 transects nested within 3 vegetation zones. These communities are located in the loess hilly and gully area of the Yanhe river watershed. We coupled climatic factors at the transect scale with topographic and edaphic factors at the plot scale using multilevel regression modeling to analyze the trait variation associated with spatial scales. At the transect scale, the mean annual rainfall showed a highly significant positive effect on the leaf nitrogen concentration (LNC (p < 0.01, while it had a highly significant negative effect on leaf thickness (LT and leaf tissue density (LTD (p < 0.001 and a significant negative effect on leaf carbon concentration (LCC (p < 0.05, explaining 10.91%, 36.08%, 57.25% and 66.01% of LTD, LT, LCC and LNC variation at transect scale respectively. At a plot scale, the slope aspect showed a highly significant positive effect on specific leaf area (SLA and LNC but a highly significant negative effect on LT and LTD. The soil water content had a significant negative effect on LT (p < 0.05 and LTD (p < 0.001 while soil organic matter showed a positive effect on SLA (p < 0.001 and LNC (p < 0.01. Totally, plot scale variables explained 7.28%, 43.60%, 46.43%, 75.39% and 81.17% of LCC, LT, LNC, LTD and SLA variation. The elevation showed positive effect

  16. Similar below-ground carbon cycling dynamics but contrasting modes of nitrogen cycling between arbuscular mycorrhizal and ectomycorrhizal forests.

    Science.gov (United States)

    Lin, Guigang; McCormack, M Luke; Ma, Chengen; Guo, Dali

    2017-02-01

    Compared with ectomycorrhizal (ECM) forests, arbuscular mycorrhizal (AM) forests are hypothesized to have higher carbon (C) cycling rates and a more open nitrogen (N) cycle. To test this hypothesis, we synthesized 645 observations, including 22 variables related to below-ground C and N dynamics from 100 sites, where AM and ECM forests co-occurred at the same site. Leaf litter quality was lower in ECM than in AM trees, leading to greater forest floor C stocks in ECM forests. By contrast, AM forests had significantly higher mineral soil C concentrations, and this result was strongly mediated by plant traits and climate. No significant differences were found between AM and ECM forests in C fluxes and labile C concentrations. Furthermore, inorganic N concentrations, net N mineralization and nitrification rates were all higher in AM than in ECM forests, indicating 'mineral' N economy in AM but 'organic' N economy in ECM trees. AM and ECM forests show systematic differences in mineral vs organic N cycling, and thus mycorrhizal type may be useful in predicting how different tree species respond to multiple environmental change factors. By contrast, mycorrhizal type alone cannot reliably predict below-ground C dynamics without considering plant traits and climate. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  17. Robustness of plant-insect herbivore interaction networks to climate change in a fragmented temperate forest landscape.

    Science.gov (United States)

    Bähner, K W; Zweig, K A; Leal, I R; Wirth, R

    2017-10-01

    Forest fragmentation and climate change are among the most severe and pervasive forms of human impact. Yet, their combined effects on plant-insect herbivore interaction networks, essential components of forest ecosystems with respect to biodiversity and functioning, are still poorly investigated, particularly in temperate forests. We addressed this issue by analysing plant-insect herbivore networks (PIHNs) from understories of three managed beech forest habitats: small forest fragments (2.2-145 ha), forest edges and forest interior areas within three continuous control forests (1050-5600 ha) in an old hyper-fragmented forest landscape in SW Germany. We assessed the impact of forest fragmentation, particularly edge effects, on PIHNs and the resulting differences in robustness against climate change by habitat-wise comparison of network topology and biologically realistic extinction cascades of networks following scores of vulnerability to climate change for the food plant species involved. Both the topological network metrics (complexity, nestedness, trophic niche redundancy) and robustness to climate change strongly increased in forest edges and fragments as opposed to the managed forest interior. The nature of the changes indicates that human impacts modify network structure mainly via host plant availability to insect herbivores. Improved robustness of PIHNs in forest edges/small fragments to climate-driven extinction cascades was attributable to an overall higher thermotolerance across plant communities, along with positive effects of network structure. The impoverishment of PIHNs in managed forest interiors and the suggested loss of insect diversity from climate-induced co-extinction highlight the need for further research efforts focusing on adequate silvicultural and conservation approaches.

  18. Heterogeneous movement of insectivorous Amazonian birds through primary and secondary forest: A case study using multistate models with radiotelemetry data

    Science.gov (United States)

    Hines, James; Powell, Luke L.; Wolfe, Jared D.; Johnson, Erik l.; Nichols, James D.; Stouffer, Phillip C.

    2015-01-01

    Given rates of deforestation, disturbance, and secondary forest accumulation in tropical rainforests, there is a great need to quantify habitat use and movement among different habitats. This need is particularly pronounced for animals most sensitive to disturbance, such as insectivorous understory birds. Here we use multistate capture–recapture models with radiotelemetry data to determine the successional stage at which within-day movement probabilities of Amazonian birds in secondary forest are similar to those in primary forest. We radio-tracked three common understory insectivore species in primary and secondary forest at the Biological Dynamics of Forest Fragments project near Manaus, Brazil: two woodcreepers, Glyphorynchus spirurus (n = 19) andXiphorhynchus pardalotus (n = 18), and the terrestrial antthrush Formicarius colma(n = 19). Forest age was a strong predictor of fidelity to a given habitat. All three species showed greater fidelity to primary forest than to 8–14-year-old secondary forest, indicating the latter’s relatively poor quality. The two woodcreeper species used 12–18-year-old secondary forest in a manner comparable to continuous forest, but F. colmaavoided moving even to 27–31-year-old secondary forest—the oldest at our site. Our results suggest that managers concerned with less sensitive species can assume that forest reserves connected by 12–18-year-old secondary forest corridors are effectively connected. On the other hand, >30 years are required after land abandonment before secondary forest serves as a primary forest-like conduit for movement by F. colma; more sensitive terrestrial insectivores may take longer still.

  19. Differences in Fine-Root Biomass of Trees and Understory Vegetation among Stand Types in Subtropical Forests.

    Directory of Open Access Journals (Sweden)

    Xiaoli Fu

    Full Text Available Variation of total fine-root biomass among types of tree stands has previously been attributed to the characteristics of the stand layers. The effects of the understory vegetation on total fine-root biomass are less well studied. We examined the variation of total fine-root biomass in subtropical tree stands at two sites of Datian and Huitong in China. The two sites have similar humid monsoon climate but different soil organic carbon. One examination compared two categories of basal areas (high vs. low basal area in stands of single species. A second examination compared single-species and mixed stands with comparable basal areas. Low basal area did not correlate with low total fine-root biomass in the single-species stands. The increase in seedling density but decrease in stem density for the low basal area stands at Datian and the quite similar stand structures for the basal-area contrast at Huitong helped in the lack of association between basal area and total fine-root biomass at the two sites, respectively. The mixed stands also did not yield higher total fine-root biomasses. In addition to the lack of niche complementarity between tree species, the differences in stem and seedling densities and the belowground competition between the tree and non-tree species also contributed to the similarity of the total fine-root biomasses in the mixed and single-species stands. Across stand types, the more fertile site Datian yielded higher tree, non-tree and total fine-root biomasses than Huitong. However, the contribution of non-tree fine-root biomass to the total fine-root biomass was higher at Huitong (29.4% than that at Datian (16.7%. This study suggests that the variation of total fine-root biomass across stand types not only was associated with the characteristics of trees, but also may be highly dependent on the understory layer.

  20. Differences in Fine-Root Biomass of Trees and Understory Vegetation among Stand Types in Subtropical Forests.

    Science.gov (United States)

    Fu, Xiaoli; Wang, Jianlei; Di, Yuebao; Wang, Huimin

    2015-01-01

    Variation of total fine-root biomass among types of tree stands has previously been attributed to the characteristics of the stand layers. The effects of the understory vegetation on total fine-root biomass are less well studied. We examined the variation of total fine-root biomass in subtropical tree stands at two sites of Datian and Huitong in China. The two sites have similar humid monsoon climate but different soil organic carbon. One examination compared two categories of basal areas (high vs. low basal area) in stands of single species. A second examination compared single-species and mixed stands with comparable basal areas. Low basal area did not correlate with low total fine-root biomass in the single-species stands. The increase in seedling density but decrease in stem density for the low basal area stands at Datian and the quite similar stand structures for the basal-area contrast at Huitong helped in the lack of association between basal area and total fine-root biomass at the two sites, respectively. The mixed stands also did not yield higher total fine-root biomasses. In addition to the lack of niche complementarity between tree species, the differences in stem and seedling densities and the belowground competition between the tree and non-tree species also contributed to the similarity of the total fine-root biomasses in the mixed and single-species stands. Across stand types, the more fertile site Datian yielded higher tree, non-tree and total fine-root biomasses than Huitong. However, the contribution of non-tree fine-root biomass to the total fine-root biomass was higher at Huitong (29.4%) than that at Datian (16.7%). This study suggests that the variation of total fine-root biomass across stand types not only was associated with the characteristics of trees, but also may be highly dependent on the understory layer.

  1. LIGO: The strong belief

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    Twenty years of designing, building and testing a number of innovative technologies, with the strong belief that the endeavour would lead to a historic breakthrough. The Bulletin publishes an abstract of the Courier’s interview with Barry Barish, one of the founding fathers of LIGO.   The plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. (Image: Caltech/MIT/LIGO Lab) On 11 February, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations published a historic paper in which they showed a gravitational signal emitted by the merger of two black holes. These results come after 20 years of hard work by a large collaboration of scientists operating the two LIGO observatories in the US. Barry Barish, Linde Professor of Physics, Emeritus at the California Institute of Technology and former Director of the Global Design Effort for the Internat...

  2. Forest rights : the micro-politics of decentralisation and forest tenure reform in tribal India

    NARCIS (Netherlands)

    Bose, P.

    2012-01-01

    <strong>Forest rights strong>are of utmost importance for the future of forest initiatives, be it for resource use, management, and conservation, or for climate change adaptation and mitigation. The growing trend towards acknowledging the relevance of the sustainable use and conservation of

  3. Forest rights : the micro-politics of decentralisation and forest tenure reform in tribal India

    NARCIS (Netherlands)

    Bose, P.

    2012-01-01

    <strong>Forest rights strong>are of utmost importance for the future of forest initiatives, be it for resource use, management, and conservation, or for climate change adaptation and mitigation. The growing trend towards acknowledging the relevance of the sustainable use and conservation of

  4. Aerial arthropod communities of native and invaded forests, Robinson Crusoe Island, Chile.

    Science.gov (United States)

    Hagen, Erin N; Bakker, Jonathan D; Gara, Robert I

    2010-08-01

    Invasive species significantly contribute to biological change and threaten biodiversity, with a growing body of evidence that plant invasions affect higher trophic levels. We explored the relative importance of plant invasion and forest structure on aerial arthropod abundance, diversity, and composition on Robinson Crusoe Island, Chile. We used flight intercept traps to sample aerial arthropods within distinct canopy strata of native and invaded forests over 3-mo periods in 2006 and 2007. Arthropod abundance and diversity were higher in native than invaded forest, and arthropod communities were distinct between forest types. In both forest types, arthropod abundance was highest in the lower canopy, and canopy strata exhibited some differences in arthropod community composition. Several morphospecies were distinctly associated with each forest type. The strong differences in aerial arthropod communities associated with the invasion of native forest by non-native plants may affect other trophic levels, such as insectivorous birds. Steps to stop invasive plant spread and to restore native forest composition and structure are needed to safeguard the integrity of native communities, from plants to higher-level consumers.

  5. Forest structure and composition in the lower montane rain forest of the Luquillo Mountains, Puerto Rico

    Science.gov (United States)

    Peter L. Weaver

    2010-01-01

    Six groups of three plots stratified by aspect and topography and varying in elevation were used to sample forest structure and tree species composition within the lower montane rain forest (tabonuco forest) of the Luquillo Experimental Forest (LEF) in Puerto Rico. Stem density, tree height, and total above ground biomass varied by site. Significant differences in...

  6. Preference for different prey allows the coexistence of several land planarians in areas of the Atlantic Forest.

    Science.gov (United States)

    Boll, Piter Kehoma; Leal-Zanchet, Ana Maria

    2016-06-01

    Land planarians are recognized as important predators, yet studies on their feeding habits are usually restricted to invasive species. Thus, it is difficult to determine the real ecological role of this group in ecosystems and how their communities are structured. In the present study, we analyzed the diet of six co-occurring Neotropical land planarians and their success in capturing prey, based on experiments in the laboratory, in order to determine how they share resources in the same environment. We also calculated indices of food niche breadth and food niche overlap for land planarians for the first time. The diet of Luteostriata abundans comprises only woodlice and the diets of Obama ficki and Obama ladislavii are composed only of gastropods, while Paraba multicolor and Obama anthropophila feed on both gastropods and other land planarians. An invasive species recently found in Western Europe, Obama nungara, showed the highest food niche breadth, feeding on gastropods, earthworms and planarians. We found the highest niche overlap between O. anthropophila and P. multicolor. The results suggest that land planarians are frequent predators of woodlice and land gastropods in the Neotropical ecozone and thus are important for the maintenance of native ecosystems and for the control of invasive species. The coexistence of several species in the same habitat is possible due to the use of different species as main prey, which reduces interspecific competition. Copyright © 2016 Elsevier GmbH. All rights reserved.

  7. From Paper to Forest: Local Motives for Participation in Different Conservation Initiatives. Case Studies in Southeastern Mexico.

    Science.gov (United States)

    Méndez-López, María Elena; García-Frapolli, Eduardo; Ruiz-Mallén, Isabel; Porter-Bolland, Luciana; Reyes-Garcia, Victoria

    2015-09-01

    Under the assumption that local participation can contribute toward conservation, various policies have sought to increase the participation of local communities in conservation, but not always with success. Despite this failure, the drivers that explain local participation remain unclear and few studies have attempted to understand the motivations behind involvement (or lack of it) in different conservation initiatives and adopting the perspective of the local stakeholder. In this study, we analyze the motives behind the participation (or lack thereof) of local populations in three conservation schemes: Protected Areas, Areas Voluntary Devoted to Conservation, and areas under Payment for Environmental Services. The study, conducted in 6 communities of southeastern Mexico, comprises an ethnographic stage and the application of a survey exploring the motives for participation. Our results show similarities among the motives for participation in these three initiatives, predominantly the obligation to comply with acquired commitments and a desire to "care for the land". Results also show that 77 % of the people interviewed did not participate in any conservation initiatives, often due to the lack of mechanisms by which to participate. We conclude by questioning the feasibility of achieving local participation in conservation as currently proposed and for the aims that are outlined.

  8. Influence of Different Slope Aspects on Some Soil Properties and Forest Soils Evolution (Case Study: Rostam Abad Region, Guilan Province

    Directory of Open Access Journals (Sweden)

    M. Zarinibahador

    2016-02-01

    Full Text Available Introduction: Spatial variation of soil properties is significantly influenced by numerous environmental factors such as landscape features, including position, topography, slope gradient and aspect, parent material, climate and vegetation. Soil properties vary spatially in south- and north-facing hill slopes. This factor (different slope aspects can affect the distribution of soil organic matter, the presence or absence of a layer, pH, nutrient levels, soil mineralogical and micromorphological properties. Topographic factors such as the orientation of the hill slope and the steepness of the slope affect microclimate, vegetation establishment, water movement and erosion. Aspect and slope control the movement of water and materials in a hill slope and contribute to differences in soil properties. Temperature, precipitation and climate vary with elevation and influence pedogenic processes. Accelerated rates of weathering and soil development were found to occur in soils on south-facing slopes. Slopes with a south aspect are dominated by stone and bare soil patches, while slopes with a north aspect are dominated by biotic components. Northern slopes have higher productivity and species diversity compared to Southern slopes. Slope aspect has a significant effect on the composition, species richness, structure and density of plant communities, differed significantly between North- and South- facing slopes. Materials and Methods: In the present study, the effects of two slope aspects on some soil properties and soil evolution was investigated in Northern Rostam Abad region in the Guilan Province. Five profiles in Southern hill slope(South-facing hill slopes and five profiles in Northern hill slopes(North-facing hill slopes with 40% slope and same parent material (basaltic andesite and same plant cover were dug. The elevation of two slope aspects was 240 meters from the sea level. Average annual temperatures and precipitation are16 degrees centigrade

  9. Long term carbon dioxide exchange above a mixed forest in the Belgian Ardennes: evaluation of different approaches to deduce total ecosystem respiration from Eddy covariance measurements

    Science.gov (United States)

    Jérôme, Elisabeth; Aubinet, Marc; Heinesch, Bernard

    2010-05-01

    The general aim of this research is to analyze inter annual variability of carbon dioxide (CO2) fluxes exchanged by a mixed forest located at the Vielsalm experimental site in Belgium. At this site, CO2 flux measurements started in 1996 and are still going on. Thirteen complete years of measurements are thus available. Net Ecosystem Exchange (NEE) inter annual variability may be driven by gross primary productivity (GPP) or Total Ecosystem Respiration (TER), which should thus be both quantified. Using flux partitioning methods, TER is deduced from NEE measurements. GPP is then obtained by subtracting TER from NEE. Initially, a robust estimation of TER is required. This work seeks to compare two independent approaches to assess TER in order to quantify the implications on inter-annual variability. The comparison was performed on twelve complete years. TER estimates can be deduced by extrapolating to the whole day NEE measurements taken during selected night or day periods. In both case, the extrapolation is performed by using a respiration response to temperature. The first approach, referred as the night-time approach, consisted in calculating TER using a temperature response function derived from night-time data sets (Reichstein et al., 2005). The second approach, referred as the daytime approach, consisted in assessing TER from the intercept of the NEE/Photosynthetically Photon Flux Density (PPFD) response (Wohlfahrt et al., 2005). For each approach, different modalities were compared: the use of long term (annual) or short term (15 days) data sets for the night-time approach and the use of different types of regression for the daytime approach. In addition, the impact of the temperature choice was studied for each of the approaches. For the night-time approach, main results showed that air temperature sensitivity of ecosystem respiration derived from annual data did not reflect the short-term air temperature sensitivity. Vielsalm is a summer active ecosystem

  10. Roles of Fog and Topography in Redwood Forest Hydrology

    Science.gov (United States)

    Francis, E. J.; Asner, G. P.

    2017-12-01

    Spatial variability of water in forests is a function of both climatic gradients that control water inputs and topo-edaphic variation that determines the flows of water belowground, as well as interactions of climate with topography. Coastal redwood forests are hydrologically unique because they are influenced by coastal low clouds, or fog, that is advected onto land by a strong coastal-to-inland temperature difference. Where fog intersects the land surface, annual water inputs from summer fog drip can be greater than that of winter rainfall. In this study, we take advantage of mapped spatial gradients in forest canopy water storage, topography, and fog cover in California to better understand the roles and interactions of fog and topography in the hydrology of redwood forests. We test a conceptual model of redwood forest hydrology with measurements of canopy water content derived from high-resolution airborne imaging spectroscopy, topographic variables derived from high-resolution LiDAR data, and fog cover maps derived from NASA MODIS data. Landscape-level results provide insight into hydrological processes within redwood forests, and cross-site analyses shed light on their generality.

  11. Carbon sequestration in managed temperate coniferous forests under climate change

    Science.gov (United States)

    Dymond, Caren C.; Beukema, Sarah; Nitschke, Craig R.; Coates, K. David; Scheller, Robert M.

    2016-03-01

    Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management, and climate change