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Sample records for litter consumption soil

  1. Climate and litter quality differently modulate the effects of soil fauna on litter decomposition across biomes.

    Science.gov (United States)

    García-Palacios, Pablo; Maestre, Fernando T; Kattge, Jens; Wall, Diana H

    2013-08-01

    Climate and litter quality have been identified as major drivers of litter decomposition at large spatial scales. However, the role played by soil fauna remains largely unknown, despite its importance for litter fragmentation and microbial activity. We synthesised litterbag studies to quantify the effect sizes of soil fauna on litter decomposition rates at the global and biome scales, and to assess how climate, litter quality and soil fauna interact to determine such rates. Soil fauna consistently enhanced litter decomposition at both global and biome scales (average increment ~ 37%). [corrected]. However, climate and litter quality differently modulated the effects of soil fauna on decomposition rates between biomes, from climate-driven biomes to those where climate effects were mediated by changes in litter quality. Our results advocate for the inclusion of biome-specific soil fauna effects on litter decomposition as a mean to reduce the unexplained variation in large-scale decomposition models. © 2013 John Wiley & Sons Ltd/CNRS.

  2. Tropical terrestrial model ecosystems for evaluation of soil fauna and leaf litter quality effects on litter consumption, soil microbial biomass and plant growth Efeitos de fauna de solo e qualidade de liteira sobre o consumo, biomassa microbiana e crescimento de plantas em modelo de ecossistemas terrestres tropicais

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    Bernhard Förster

    2009-08-01

    Full Text Available The aim of this work was to evaluate whether terrestrial model ecosystems (TMEs are a useful tool for the study of the effects of litter quality, soil invertebrates and mineral fertilizer on litter decomposition and plant growth under controlled conditions in the tropics. Forty-eight intact soil cores (17.5-cm diameter, 30-cm length were taken out from an abandoned rubber plantation on Ferralsol soil (Latossolo Amarelo in Central Amazonia, Brazil, and kept at 28ºC in the laboratory during four months. Leaf litter of either Hevea pauciflora (rubber tree, Flemingia macrophylla (a shrubby legume or Brachiaria decumbens (a pasture grass was put on top of each TME. Five specimens of either Pontoscolex corethrurus or Eisenia fetida (earthworms, Porcellionides pruinosus or Circoniscus ornatus (woodlice, and Trigoniulus corallinus (millipedes were then added to the TMEs. Leaf litter type significantly affected litter consumption, soil microbial biomass and nitrate concentration in the leachate of all TMEs, but had no measurable effect on the shoot biomass of rice seedlings planted in top soil taken from the TMEs. Feeding rates measured with bait lamina were significantly higher in TMEs with the earthworm P. corethrurus and the woodlouse C. ornatus. TMEs are an appropriate tool to assess trophic interactions in tropical soil ecossistems under controlled laboratory conditions.O objetivo deste trabalho foi avaliar o modelo de ecossistema terrestre (TME como ferramenta para o estudo dos efeitos da qualidade da liteira, de invertebrados do solo e da fertilização mineral na decomposição da liteira e no crescimento das plantas em condições controladas. Foram coletados quarenta e oito cilindros de solo intacto (Latossolo Amarelo de 17,5 cm de diâmetro e 30 cm de comprimento em um seringal abandonado na Amazônia Central brasileira e mantidos a 28ºC em laboratório, por quatro meses. Folhas da liteira de Hevea pauciflora (seringueira, ou de Flemingia

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

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

    2016-10-01

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

  4. Pulse frequency and soil-litter mixing alter the control of cumulative precipitation over litter decomposition.

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    Joly, François-Xavier; Kurupas, Kelsey L; Throop, Heather L

    2017-09-01

    Macroclimate has traditionally been considered the predominant driver of litter decomposition. However, in drylands, cumulative monthly or annual precipitation typically fails to predict decomposition. In these systems, the windows of opportunity for decomposer activity may rather depend on the precipitation frequency and local factors affecting litter desiccation, such as soil-litter mixing. We used a full-factorial microcosm experiment to disentangle the relative importance of cumulative precipitation, pulse frequency, and soil-litter mixing on litter decomposition. Decomposition, measured as litter carbon loss, saturated with increasing cumulative precipitation when pulses were large and infrequent, suggesting that litter moisture no longer increased and/or microbial activity was no longer limited by water availability above a certain pulse size. More frequent precipitation pulses led to increased decomposition at high levels of cumulative precipitation. Soil-litter mixing consistently increased decomposition, with greatest relative increase (+194%) under the driest conditions. Collectively, our results highlight the need to consider precipitation at finer temporal scale and incorporate soil-litter mixing as key driver of decomposition in drylands. © 2017 by the Ecological Society of America.

  5. Nitrogen Transformations in Broiler Litter-Amended Soils

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    Kokoasse Kpomblekou-A

    2012-01-01

    Full Text Available Nitrogen mineralization rates in ten surface soils amended with (200 μg N g−1 soil or without broiler litter were investigated. The soil-broiler litter mixture was incubated at 25±1∘C for 28 weeks. A nonlinear regression approach for N mineralization was used to estimate the readily mineralizable organic N pools (N0 and the first-order rate constant (k. The cumulative N mineralized in the nonamended soils did not exceed 80 mg N kg−1 soil. However, in Decatur soil amended with broiler litter 2, it exceeded 320 mg N kg−1 soil. The greatest calculated N0 of the native soils was observed in Sucarnoochee soil alone (123 mg NO3− kg−1 soil which when amended with broiler litter 1 reached 596 mg N kg−1 soil. The added broiler litter mineralized initially at a fast rate (k1 followed by a slow rate (k2 of the most resistant fraction. Half-life of organic N remaining in the soils alone varied from 33 to 75 weeks and from 43 to 15 weeks in the amended soils. When N0 was regressed against soil organic N (=0.782∗∗ and C (=0.884∗∗∗, positive linear relationships were obtained. The N0 pools increased with sand but decreased with silt and clay contents.

  6. Broiler diet modification and litter storage: impacts on phosphorus in litters, soils, and runoff.

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    McGrath, Joshua M; Sims, J Thomas; Maguire, Rory O; Saylor, William W; Angel, C Roselina; Turner, Benjamin L

    2005-01-01

    Modifying broiler diets to mitigate water quality concerns linked to excess phosphorus (P) in regions of intensive broiler production has recently increased. Our goals were to evaluate the effects of dietary modification, using phytase and reduced non-phytate phosphorus (NPP) supplementation, on P speciation in broiler litters, changes in litter P forms during long-term storage, and subsequent impacts of diets on P in runoff from litter-amended soils. Four diets containing two levels of NPP with and without phytase were fed to broilers in a three-flock floor pen study. After removal of the third flock, litters were stored for 440 d at their initial moisture content (MC; 24%) and at a MC of 40%. Litter P fractions and orthophosphate and phytate P concentrations were determined before and after storage. After storage, litters were incorporated with a sandy and silt loam and simulated rainfall was applied. Phytase and reduced dietary NPP significantly reduced litter total P. Reducing dietary NPP decreased water-extractable inorganic phosphorus (IP) and the addition of dietary phytase reduced NaOH- and HCl-extractable organic P in litter, which correlated well with orthophosphate and phytic acid measured by 31P nuclear magnetic resonance (NMR), respectively. Although dry storage caused little change in P speciation, wet storage increased concentrations of water-soluble IP, which increased reactive P in runoff from litter-amended soils. Therefore, diet modification with phytase and reduced NPP could be effective in reducing P additions on a watershed scale. Moreover, efforts to minimize litter MC during storage may reduce the potential for dissolved P losses in runoff.

  7. Revegetation of coal mine soil with forest litter

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-11-01

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

  8. DECOTAB: a multipurpose standard substrate to assess effects of litter quality on microbial decomposition and invertebrate consumption

    NARCIS (Netherlands)

    Kampfraath, A.A.; Hunting, E.R.; Mulder, C.; Breure, A.M.; Gessner, M.O.; Kraak, M.H.S.; Admiraal, W.

    2012-01-01

    Currently available tools for studying plant litter decomposition and invertebrate consumption in aquatic ecosystems have at least 2 major limitations: 1) the difficulty of manipulating litter chemical composition to provide mechanistic insights into attributes of litter quality controlling

  9. Energetic contaminants inhibit plant litter decomposition in soil.

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    Kuperman, Roman G; Checkai, Ronald T; Simini, Michael; Sunahara, Geoffrey I; Hawari, Jalal

    2018-05-30

    Individual effects of nitrogen-based energetic materials (EMs) 2,4-dinitrotoluene (2,4-DNT), 2-amino-4,6-dinitrotoluene (2-ADNT), 4-amino-2,6-dinitrotoluene (4-ADNT), nitroglycerin (NG), and 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20) on litter decomposition, an essential biologically-mediated soil process, were assessed using Orchard grass (Dactylis glomerata) straw in Sassafras sandy loam (SSL) soil, which has physicochemical characteristics that support "very high" qualitative relative bioavailability for organic chemicals. Batches of SSL soil were separately amended with individual EMs or acetone carrier control. To quantify the decomposition rates, one straw cluster was harvested from a set of randomly selected replicate containers from within each treatment, after 1, 2, 3, 4, 6, and 8 months of exposure. Results showed that soil amended with 2,4-DNT or NG inhibited litter decomposition rates based on the median effective concentration (EC50) values of 1122 mg/kg and 860 mg/kg, respectively. Exposure to 2-ADNT, 4-ADNT or CL-20 amended soil did not significantly affect litter decomposition in SSL soil at ≥ 10,000 mg/kg. These ecotoxicological data will be helpful in identifying concentrations of EMs in soil that present an acceptable ecological risk for biologically-mediated soil processes. Published by Elsevier Inc.

  10. Effects of fire frequency on litter decomposition as mediated by changes to litter chemistry and soil environmental conditions.

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    Cari D Ficken

    Full Text Available Litter quality and soil environmental conditions are well-studied drivers influencing decomposition rates, but the role played by disturbance legacy, such as fire history, in mediating these drivers is not well understood. Fire history may impact decomposition directly, through changes in soil conditions that impact microbial function, or indirectly, through shifts in plant community composition and litter chemistry. Here, we compared early-stage decomposition rates across longleaf pine forest blocks managed with varying fire frequencies (annual burns, triennial burns, fire-suppression. Using a reciprocal transplant design, we examined how litter chemistry and soil characteristics independently and jointly influenced litter decomposition. We found that both litter chemistry and soil environmental conditions influenced decomposition rates, but only the former was affected by historical fire frequency. Litter from annually burned sites had higher nitrogen content than litter from triennially burned and fire suppression sites, but this was correlated with only a modest increase in decomposition rates. Soil environmental conditions had a larger impact on decomposition than litter chemistry. Across the landscape, decomposition differed more along soil moisture gradients than across fire management regimes. These findings suggest that fire frequency has a limited effect on litter decomposition in this ecosystem, and encourage extending current decomposition frameworks into disturbed systems. However, litter from different species lost different masses due to fire, suggesting that fire may impact decomposition through the preferential combustion of some litter types. Overall, our findings also emphasize the important role of spatial variability in soil environmental conditions, which may be tied to fire frequency across large spatial scales, in driving decomposition rates in this system.

  11. Effects of fire frequency on litter decomposition as mediated by changes to litter chemistry and soil environmental conditions.

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    Ficken, Cari D; Wright, Justin P

    2017-01-01

    Litter quality and soil environmental conditions are well-studied drivers influencing decomposition rates, but the role played by disturbance legacy, such as fire history, in mediating these drivers is not well understood. Fire history may impact decomposition directly, through changes in soil conditions that impact microbial function, or indirectly, through shifts in plant community composition and litter chemistry. Here, we compared early-stage decomposition rates across longleaf pine forest blocks managed with varying fire frequencies (annual burns, triennial burns, fire-suppression). Using a reciprocal transplant design, we examined how litter chemistry and soil characteristics independently and jointly influenced litter decomposition. We found that both litter chemistry and soil environmental conditions influenced decomposition rates, but only the former was affected by historical fire frequency. Litter from annually burned sites had higher nitrogen content than litter from triennially burned and fire suppression sites, but this was correlated with only a modest increase in decomposition rates. Soil environmental conditions had a larger impact on decomposition than litter chemistry. Across the landscape, decomposition differed more along soil moisture gradients than across fire management regimes. These findings suggest that fire frequency has a limited effect on litter decomposition in this ecosystem, and encourage extending current decomposition frameworks into disturbed systems. However, litter from different species lost different masses due to fire, suggesting that fire may impact decomposition through the preferential combustion of some litter types. Overall, our findings also emphasize the important role of spatial variability in soil environmental conditions, which may be tied to fire frequency across large spatial scales, in driving decomposition rates in this system.

  12. Using dynamic energy budget modeling to predict the influence of temperature and food density on the effect of Cu on earthworm mediated litter consumption.

    NARCIS (Netherlands)

    Hobbelen, P.H.F.; van Gestel, C.A.M.

    2007-01-01

    The aim of this study was to predict the dependence on temperature and food density of effects of Cu on the litter consumption by the earthworm Lumbricus rubellus, using a dynamic energy budget model (DEB-model). As a measure of the effects of Cu on food consumption, EC50s (soil concentrations

  13. SOA Formation Potential of Emissions from Soil and Leaf Litter

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    Faiola, C. L.; Vanderschelden, G. S.; Wen, M.; Cobos, D. R.; Jobson, B. T.; VanReken, T. M.

    2013-12-01

    In the United States, emissions of volatile organic compounds (VOCs) from natural sources exceed all anthropogenic sources combined. VOCs participate in oxidative chemistry in the atmosphere and impact the concentrations of ozone and particulate material. The formation of secondary organic aerosol (SOA) is particularly complex and is frequently underestimated using state-of-the-art modeling techniques. We present findings that suggest emissions of important SOA precursors from soil and leaf litter are higher than current inventories would suggest, particularly under conditions typical of Fall and Spring. Soil and leaf litter samples were collected at Big Meadow Creek from the University of Idaho Experimental Forest. The dominant tree species in this area of the forest are ponderosa pine, Douglas-fir, and western larch. Samples were transported to the laboratory and housed within a 0.9 cubic meter Teflon dynamic chamber where VOC emissions were continuously monitored with a GC-FID-MS and PTR-MS. Aerosol was generated from soil and leaf litter emissions by pumping the emissions into a 7 cubic meter Teflon aerosol growth chamber where they were oxidized with ozone in the absence of light. The evolution of particle microphysical and chemical characteristics was monitored over the following eight hours. Particle size distribution and chemical composition were measured with a SMPS and HR-ToF-AMS respectively. Monoterpenes dominated the emission profile with emission rates up to 283 micrograms carbon per meter squared per hour. The dominant monoterpenes emitted were beta-pinene, alpha-pinene, and delta-3-carene in descending order. The composition of the SOA produced was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and alpha-pinene. Measured soil/litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest that during fall and spring when tree emissions are lower, monoterpene emissions within forests may be

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

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    Bing Mao

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

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

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

    2017-01-01

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

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

    OpenAIRE

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

    2017-01-01

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

  17. Biological Oxygen Demand in Soils and Litters

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    Smagin, A. V.; Smagina, M. V.; Sadovnikova, N. B.

    2018-03-01

    Biological oxygen demand (BOD) in mineral and organic horizons of soddy-podzolic soils in the forest-park belt of Moscow as an indicator of their microbial respiration and potential biodestruction function has been studied. The BOD of soil samples has been estimated with a portable electrochemical analyzer after incubation in closed flasks under optimum hydrothermal conditions. A universal gradation scale of this parameter from very low (140 g O2/(m3 h)) has been proposed for mineral and organic horizons of soil. A physically substantiated model has been developed for the vertical distribution of BOD in the soil, which combines the diffusion transport of oxygen from the atmosphere and its biogenic uptake in the soil by the first-order reaction. An analytical solution of the model in the stationary state has been obtained; from it, the soil oxygen diffusivity and the kinetic constants of O2 uptake have been estimated, and the profile-integrated total BOD value has been calculated (0.4-1.8 g O2/(m2 h)), which is theoretically identical to the potential oxygen flux from the soil surface due to soil respiration. All model parameters reflect the recreation load on the soil cover by the decrease in their values against the control.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

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

    OpenAIRE

    Zhizhong Yuan; Yang Cui; Shaokui Yan

    2013-01-01

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

  20. Litter quality impacts short- but not long-term soil carbon dynamics in soil aggregate fractions.

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    Gentile, Roberta; Vanlauwe, Bernard; Six, Johan

    2011-04-01

    Complex molecules are presumed to be preferentially stabilized as soil organic carbon (SOC) based on the generally accepted concept that the chemical composition of litter is a major factor in its rate of decomposition. Hence, a direct link between litter quality and SOC quantity has been assumed, accepted, and ultimately incorporated in SOC models. Here, however, we present data from an incubation and field experiment that refutes the influence of litter quality on the quantity of stabilized SOC. Three different qualities of litter (Tithonia diversifolia, Calliandra calothyrsus, and Zea mays stover; 4 Mg C x ha(-1) yr(-1)) with and without the addition of mineral N fertilizer (0 or 120 kg N x ha(-1)season(-1) were added to a red clay Humic Nitisol in a 3-yr field trial and a 1.5-yr incubation experiment. The litters differed in their concentrations of N, lignin, and polyphenols with the ratio of (lignin + polyphenols): N ranging from 3.5 to 9.8 for the field trial and from 2.3 to 4.0 for the incubation experiment in the order of T. diversifolia stabilized after three annual additions in the field trial. Even within the most sensitive soil aggregate fractions, SOC contents and C:N ratios did not differ with litter quality, indicating that litter quality did not influence the mechanisms by which SOC was stabilized. While increasing litter quality displayed faster decomposition and incorporation of C into soil aggregates after 0.25 yr in the incubation study, all litters resulted in equivalent amounts of C stabilized in the soil after 1.5 yr, further corroborating the results of the field trial. The addition of N fertilizer did not affect SOC stabilization in either the field or the incubation trial. Thus, we conclude that, while litter quality controls shorter-term dynamics of C decomposition and accumulation in the soil, longer-term SOC patterns cannot be predicted based on initial litter quality effects. Hence, the formation and stabilization of SOC is more

  1. Crop rotations and poultry litter impact dynamic soil chemical properties and soil biota long-term

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    Dynamic soil physiochemical interactions with conservation agricultural practices and soil biota are largely unknown. Therefore, this study aims to quantify long-term (12-yr) impacts of cover crops, poultry litter, crop rotations, and conservation tillage and their interactions on soil physiochemica...

  2. Litter decay controlled by temperature, not soil properties, affecting future soil carbon.

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    Gregorich, Edward G; Janzen, Henry; Ellert, Benjamin H; Helgason, Bobbi L; Qian, Budong; Zebarth, Bernie J; Angers, Denis A; Beyaert, Ronald P; Drury, Craig F; Duguid, Scott D; May, William E; McConkey, Brian G; Dyck, Miles F

    2017-04-01

    Widespread global changes, including rising atmospheric CO 2 concentrations, climate warming and loss of biodiversity, are predicted for this century; all of these will affect terrestrial ecosystem processes like plant litter decomposition. Conversely, increased plant litter decomposition can have potential carbon-cycle feedbacks on atmospheric CO 2 levels, climate warming and biodiversity. But predicting litter decomposition is difficult because of many interacting factors related to the chemical, physical and biological properties of soil, as well as to climate and agricultural management practices. We applied 13 C-labelled plant litter to soil at ten sites spanning a 3500-km transect across the agricultural regions of Canada and measured its decomposition over five years. Despite large differences in soil type and climatic conditions, we found that the kinetics of litter decomposition were similar once the effect of temperature had been removed, indicating no measurable effect of soil properties. A two-pool exponential decay model expressing undecomposed carbon simply as a function of thermal time accurately described kinetics of decomposition. (R 2  = 0.94; RMSE = 0.0508). Soil properties such as texture, cation exchange capacity, pH and moisture, although very different among sites, had minimal discernible influence on decomposition kinetics. Using this kinetic model under different climate change scenarios, we projected that the time required to decompose 50% of the litter (i.e. the labile fractions) would be reduced by 1-4 months, whereas time required to decompose 90% of the litter (including recalcitrant fractions) would be reduced by 1 year in cooler sites to as much as 2 years in warmer sites. These findings confirm quantitatively the sensitivity of litter decomposition to temperature increases and demonstrate how climate change may constrain future soil carbon storage, an effect apparently not influenced by soil properties. © 2016 Her Majesty

  3. Do soil organisms affect aboveground litter decomposition in the semiarid Patagonian steppe, Argentina?

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    Araujo, Patricia I; Yahdjian, Laura; Austin, Amy T

    2012-01-01

    Surface litter decomposition in arid and semiarid ecosystems is often faster than predicted by climatic parameters such as annual precipitation or evapotranspiration, or based on standard indices of litter quality such as lignin or nitrogen concentrations. Abiotic photodegradation has been demonstrated to be an important factor controlling aboveground litter decomposition in aridland ecosystems, but soil fauna, particularly macrofauna such as termites and ants, have also been identified as key players affecting litter mass loss in warm deserts. Our objective was to quantify the importance of soil organisms on surface litter decomposition in the Patagonian steppe in the absence of photodegradative effects, to establish the relative importance of soil organisms on rates of mass loss and nitrogen release. We estimated the relative contribution of soil fauna and microbes to litter decomposition of a dominant grass using litterboxes with variable mesh sizes that excluded groups of soil fauna based on size class (10, 2, and 0.01 mm), which were placed beneath shrub canopies. We also employed chemical repellents (naphthalene and fungicide). The exclusion of macro- and mesofauna had no effect on litter mass loss over 3 years (P = 0.36), as litter decomposition was similar in all soil fauna exclusions and naphthalene-treated litter. In contrast, reduction of fungal activity significantly inhibited litter decomposition (P soil fauna have been mentioned as a key control of litter decomposition in warm deserts, biogeographic legacies and temperature limitation may constrain the importance of these organisms in temperate aridlands, particularly in the southern hemisphere.

  4. Influence of Soil Moisture on Litter Respiration in the Semiarid Loess Plateau

    Science.gov (United States)

    Zhang, Yanjun; Guo, Shengli; Liu, Qingfang; Jiang, Jishao

    2014-01-01

    Understanding the response mechanisms of litter respiration to soil moisture in water-limited semi-arid regions is of vital importance to better understanding the interplay between ecological processes and the local carbon cycle. In situ soil respiration was monitored during 2010–2012 under various conditions (normal litter, no litter, and double litter treatments) in a 30-year-old artificial black locust plantation (Robinia pseudoacacia L.) on the Loess Plateau. Litter respiration with normal and double litter treatments exhibited similar seasonal variation, with the maximum value obtained in summer (0.57 and 1.51 μmol m−2 s−1 under normal and double litter conditions, respectively) and the minimum in spring (0.27 and 0.69 μmol m−2 s−1 under normal and double litter conditions, respectively). On average, annual cumulative litter respiration was 115 and 300 g C m−2 y−1 under normal and double litter conditions, respectively. Using a soil temperature of 17°C as the critical point, the relationship between litter respiration and soil moisture was found to follow quadratic functions well, whereas the determination coefficient was much greater at high soil temperature than at low soil temperature (33–35% vs. 22–24%). Litter respiration was significantly higher in 2010 and 2012 than in 2011 under both normal litter (132–165 g C m−2 y−1 vs. 48 g C m−2 y−1) and double litter (389–418 g C m−2 y−1 vs. 93 g C m−2 y−1) conditions. Such significant interannual variations were largely ascribed to the differences in summer rainfall. Our study demonstrates that, apart from soil temperature, moisture also has significant influence on litter respiration in semi-arid regions. PMID:25474633

  5. Poultry litter and the environment: Physiochemical properties of litter and soil during successive flock rotations and after remote site deposition.

    Science.gov (United States)

    Crippen, Tawni L; Sheffield, Cynthia L; Byrd, J Allen; Esquivel, Jesus F; Beier, Ross C; Yeater, Kathleen

    2016-05-15

    The U.S. broiler meat market has grown over the past 16 years and destinations for U.S. broiler meat exports expanded to over 150 countries. This market opportunity has spurred a corresponding increase in industrialized poultry production, which due to the confined space in which high numbers of animals are housed, risks accumulating nutrients and pollutants. The purpose of this research was to determine the level of pollutants within poultry litter and the underlying soil within a production facility; and to explore the impact of spent litter deposition into the environment. The study follows a production facility for the first 2.5 years of production. It monitors the effects of successive flocks and management practices on 15 physiochemical parameters: Ca, Cu, electrical conductivity, Fe, K, Mg, Mn, moisture, Na, NO3(-)/N, organic matter, P, pH, S, and Zn. Litter samples were collected in-house, after clean-outs and during stockpiling. The soil before house placement, after the clean-outs and following litter stockpiling was monitored. Management practices markedly altered the physiochemical profiles of the litter in-house. A canonical discriminant analysis was used to describe the relationship between the parameters and sampling times. The litter profiles grouped into five clusters corresponding to time and management practices. The soil in-house exhibited mean increases in all physiochemical parameters (2-297 fold) except Fe, Mg, %M, and pH. The spent litter was followed after deposition onto a field for use as fertilizer. After 20 weeks, the soil beneath the litter exhibited increases in EC, Cu, K, Na, NO3(-)/N, %OM, P, S and Zn; while %M decreased. Understanding the impacts of industrialized poultry farms on the environment is vital as the cumulative ecological impact of this land usage could be substantial if not properly managed to reduce the risk of potential pollutant infiltration into the environment. Published by Elsevier B.V.

  6. Reciprocal effects of litter from exotic and congeneric native plant species via soil nutrients.

    Directory of Open Access Journals (Sweden)

    Annelein Meisner

    Full Text Available Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to congeneric native plant species. Here, we test how the legacy of litter from three exotic plant species affects their own performance in comparison to their congeneric natives that co-occur in the invaded habitat. We also analyzed litter effects on soil processes. In all three comparisons, soil with litter from exotic plant species had the highest respiration rates. In two out of the three exotic-native species comparisons, soil with litter from exotic plant species had higher inorganic nitrogen concentrations than their native congener, which was likely due to higher initial litter quality of the exotics. When litter from an exotic plant species had a positive effect on itself, it also had a positive effect on its native congener. We conclude that exotic plant species develop a legacy effect in soil from the invaded range through their litter inputs. This litter legacy effect results in altered soil processes that can promote both the exotic plant species and their native congener.

  7. Soil Fauna Alter the Effects of Litter Composition on Nitrogen Cycling in a Mineral Soil

    Science.gov (United States)

    Plant chemical composition and the soil community are known to influence litter and soil organic matter decomposition. Although these two factors are likely to interact, their mechanisms and outcomes of interaction are not well understood. Studies of their interactive effects are...

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

    Science.gov (United States)

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

    2007-02-01

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

  9. The influence of litter composition across the litter–soil interface on mass loss, nitrogen dynamics and the decomposer community

    Science.gov (United States)

    Many studies have investigated the influence of plant litter species composition on decomposition, but results have been context-dependent. Litter and soil are considered to constitute a decomposition continuum, but whether litter and soil ecosystems respond to litter identity an...

  10. Dynamics of microbial communities during decomposition of litter from pioneering plants in initial soil ecosystems

    Directory of Open Access Journals (Sweden)

    J. Esperschütz

    2013-07-01

    Full Text Available In initial ecosystems, concentrations of all macro- and micronutrients can be considered as extremely low. Plant litter therefore strongly influences the development of a degrader's food web and is an important source for C and N input into soil in such ecosystems. In the present study, a 13C litter decomposition field experiment was performed for 30 weeks in initial soils from a post-mining area near the city of Cottbus (Germany. Two of this region's dominant but contrasting pioneering plant species (Lotus corniculatus L. and Calamagrostis epigejos L. were chosen to investigate the effects of litter quality on the litter decomposing microbial food web in initially nutrient-poor substrates. The results clearly indicate the importance of litter quality, as indicated by its N content, its bioavailability for the degradation process and the development of microbial communities in the detritusphere and soil. The degradation of the L. corniculatus litter, which had a low C / N ratio, was fast and showed pronounced changes in the microbial community structure 1–4 weeks after litter addition. The degradation of the C. epigejos litter material was slow and microbial community changes mainly occurred between 4 and 30 weeks after litter addition to the soil. However, for both litter materials a clear indication of the importance of fungi for the degradation process was observed both in terms of fungal abundance and activity (13C incorporation activity

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

    Science.gov (United States)

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

    2015-01-01

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

  12. Combined effects of leaf litter and soil microsite on decomposition process in arid rangelands.

    Science.gov (United States)

    Carrera, Analía Lorena; Bertiller, Mónica Beatriz

    2013-01-15

    The objective of this study was to analyze the combined effects of leaf litter quality and soil properties on litter decomposition and soil nitrogen (N) mineralization at conserved (C) and disturbed by sheep grazing (D) vegetation states in arid rangelands of the Patagonian Monte. It was hypothesized that spatial differences in soil inorganic-N levels have larger impact on decomposition processes of non-recalcitrant than recalcitrant leaf litter (low and high concentration of secondary compounds, respectively). Leaf litter and upper soil were extracted from modal size plant patches (patch microsite) and the associated inter-patch area (inter-patch microsite) in C and D. Leaf litter was pooled per vegetation state and soil was pooled combining vegetation state and microsite. Concentrations of N and secondary compounds in leaf litter and total and inorganic-N in soil were assessed at each pooled sample. Leaf litter decay and soil N mineralization at microsites of C and D were estimated in 160 microcosms incubated at field capacity (16 month). C soils had higher total N than D soils (0.58 and 0.41 mg/g, respectively). Patch soil of C and inter-patch soil of D exhibited the highest values of inorganic-N (8.8 and 8.4 μg/g, respectively). Leaf litter of C was less recalcitrant and decomposed faster than that of D. Non-recalcitrant leaf litter decay and induced soil N mineralization had larger variation among microsites (coefficients of variation = 25 and 41%, respectively) than recalcitrant leaf litter (coefficients of variation = 12 and 32%, respectively). Changes in the canopy structure induced by grazing disturbance increased leaf litter recalcitrance, and reduced litter decay and soil N mineralization, independently of soil N levels. This highlights the importance of the combined effects of soil and leaf litter properties on N cycling probably with consequences for vegetation reestablishment and dynamics, rangeland resistance and resilience with implications

  13. The effect of leaf litter cover on surface runoff and soil erosion in Northern China.

    Directory of Open Access Journals (Sweden)

    Xiang Li

    Full Text Available The role of leaf litter in hydrological processes and soil erosion of forest ecosystems is poorly understood. A field experiment was conducted under simulated rainfall in runoff plots with a slope of 10%. Two common types of litter in North China (from Quercus variabilis, representing broadleaf litter, and Pinus tabulaeformis, representing needle leaf litter, four amounts of litter, and five rainfall intensities were tested. Results revealed that the litter reduced runoff and delayed the beginning of runoff, but significantly reduced soil loss (p<0.05. Average runoff yield was 29.5% and 31.3% less than bare-soil plot, and for Q. variabilis and P. tabulaeformis, respectively, and average sediment yield was 85.1% and 79.9% lower. Rainfall intensity significantly affected runoff (R = 0.99, p<0.05, and the efficiency in runoff reduction by litter decreased considerably. Runoff yield and the runoff coefficient increased dramatically by 72.9 and 5.4 times, respectively. The period of time before runoff appeared decreased approximately 96.7% when rainfall intensity increased from 5.7 to 75.6 mm h-1. Broadleaf and needle leaf litter showed similarly relevant effects on runoff and soil erosion control, since no significant differences (p≤0.05 were observed in runoff and sediment variables between two litter-covered plots. In contrast, litter mass was probably not a main factor in determining runoff and sediment because a significant correlation was found only with sediment in Q. variabilis litter plot. Finally, runoff yield was significantly correlated (p<0.05 with sediment yield. These results suggest that the protective role of leaf litter in runoff and erosion processes was crucial, and both rainfall intensity and litter characteristics had an impact on these processes.

  14. Toxicity of iron oxide nanoparticles to grass litter decomposition in a sandy soil

    Science.gov (United States)

    Rashid, Muhammad Imtiaz; Shahzad, Tanvir; Shahid, Muhammad; Imran, Muhammad; Dhavamani, Jeyakumar; Ismail, Iqbal M. I.; Basahi, Jalal M.; Almeelbi, Talal

    2017-02-01

    We examined time-dependent effect of iron oxide nanoparticles (IONPs) at a rate of 2000 mg kg-1 soil on Cynodon dactylon litter (3 g kg-1) decomposition in an arid sandy soil. Overall, heterotrophic cultivable bacterial and fungal colonies, and microbial biomass carbon were significantly decreased in litter-amended soil by the application of nanoparticles after 90 and 180 days of incubation. Time dependent effect of nanoparticles was significant for microbial biomass in litter-amended soil where nanoparticles decreased this variable from 27% after 90 days to 49% after 180 days. IONPs decreased CO2 emission by 28 and 30% from litter-amended soil after 90 and 180 days, respectively. These observations indicated that time-dependent effect was not significant on grass-litter carbon mineralization efficiency. Alternatively, nanoparticles application significantly reduced mineral nitrogen content in litter-amended soil in both time intervals. Therefore, nitrogen mineralization efficiency was decreased to 60% after 180 days compared to that after 90 days in nanoparticles grass-litter amended soil. These effects can be explained by the presence of labile Fe in microbial biomass after 180 days in nanoparticles amendment. Hence, our results suggest that toxicity of IONPs to soil functioning should consider before recommending their use in agro-ecosystems.

  15. Initial Soil Organic Matter Content Influences the Storage and Turnover of Litter-, Root- and Soil Carbon in Grasslands

    Science.gov (United States)

    Liu, L.; Xu, S.; Li, P.; Sayer, E. J.

    2017-12-01

    Grassland degradation is a worldwide problem that often leads to substantial loss of soil organic matter (SOM). Understanding how SOM content influences the stabilization of plant carbon (C) to form soil C is important to evaluate the potential of degraded grasslands to sequester additional C. We conducted a greenhouse experiment using C3 soils with six levels of SOM content and planted the C4 grass Cleistogenes squarrosa and/or added its litter to investigate how SOM content regulates the storage of new soil C derived from litter and roots, the decomposition of extant soil C, and the formation of soil aggregates. We found that microbial biomass carbon (MBC) increased with SOM content, and increased the mineralization of litter C. Both litter addition and planted treatments increased the amount of new C inputs to soil. However, litter addition had no significant impacts on the mineralization of extant soil C, but the presence of living roots significantly accelerated it. Thus, by the end of the experiment, soil C content was significantly higher in the litter addition treatments, but was not affected by planted treatments. The soil macroaggregate fraction increased with SOM content and was positively related to MBC. Overall, our study suggests that as SOM content increases, plant growth and soil microbes become more active, which allows microbes to process more plant-derived C and increases new soil C formation. The interactions between SOM content and plant C inputs should be considered when evaluating soil C turnover in degraded grasslands.

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

    Science.gov (United States)

    Scheibe, Andrea; Gleixner, Gerd

    2014-01-01

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

  17. [Effects of different types of litters on soil organic carbon mineralization].

    Science.gov (United States)

    Shi, Xue-Jun; Pan, Jian-Jun; Chen, Jin-Ying; Yang, Zhi-Qiang; Zhang, Li-Ming; Sun, Bo; Li, Zhong-Pei

    2009-06-15

    Using litter incubation experiment in laboratory, decomposition discrepancies of four typical litters from Zijin Mountain were analyzed. The results show that organic carbon mineralization rates of soil with litters all involve fast and slow decomposition stages, and the differences are that the former has shorter duration,more daily decomposition quantity while the latter is opposite. Organic carbon mineralization rates of soil with litters rapidly reached maximum in the early days of incubation, and the order is soil with Cynodon dactylon litter (CK + BMD) (23.88 +/- 0.62) mg x d(-1), soil with Pinus massoniana litter (CK+ PML) (17.93 +/- 0.99) mg x d(-1), soil with Quercus acutissima litter (CK+ QAC) (15.39 +/- 0.16) mg x d(-1) and soil with Cyclobalanopsis glauca litter (CK + CGO) (7.26 +/- 0.34) mg x d(-1), and with significant difference between each other (p litter initial chemical elements. The amount of organic carbon mineralized accumulation within three months incubation is (CK + BMD) (338.21 +/- 6.99) mg, (CK + QAC) (323.48 +/- 13.68) mg, (CK + PML) (278.34 +/- 13.91) mg and (CK + CGO) (245.21 +/- 4.58) mg. 198.17-297.18 mg CO2-C are released during litter incubation, which occupies 20.29%-31.70% of the total litter organic carbon amounts. Power curve model can describe the trends of organic carbon mineralization rate and mineralized accumulation amount,which has a good correlation with their change.

  18. The Effect of Leaf Litter Cover on Surface Runoff and Soil Erosion in Northern China

    Science.gov (United States)

    Li, Xiang; Niu, Jianzhi; Xie, Baoyuan

    2014-01-01

    The role of leaf litter in hydrological processes and soil erosion of forest ecosystems is poorly understood. A field experiment was conducted under simulated rainfall in runoff plots with a slope of 10%. Two common types of litter in North China (from Quercus variabilis, representing broadleaf litter, and Pinus tabulaeformis, representing needle leaf litter), four amounts of litter, and five rainfall intensities were tested. Results revealed that the litter reduced runoff and delayed the beginning of runoff, but significantly reduced soil loss (prunoff yield was 29.5% and 31.3% less than bare-soil plot, and for Q. variabilis and P. tabulaeformis, respectively, and average sediment yield was 85.1% and 79.9% lower. Rainfall intensity significantly affected runoff (R = 0.99, prunoff reduction by litter decreased considerably. Runoff yield and the runoff coefficient increased dramatically by 72.9 and 5.4 times, respectively. The period of time before runoff appeared decreased approximately 96.7% when rainfall intensity increased from 5.7 to 75.6 mm h−1. Broadleaf and needle leaf litter showed similarly relevant effects on runoff and soil erosion control, since no significant differences (p≤0.05) were observed in runoff and sediment variables between two litter-covered plots. In contrast, litter mass was probably not a main factor in determining runoff and sediment because a significant correlation was found only with sediment in Q. variabilis litter plot. Finally, runoff yield was significantly correlated (prunoff and erosion processes was crucial, and both rainfall intensity and litter characteristics had an impact on these processes. PMID:25232858

  19. The effect of leaf litter cover on surface runoff and soil erosion in Northern China.

    Science.gov (United States)

    Li, Xiang; Niu, Jianzhi; Xie, Baoyuan

    2014-01-01

    The role of leaf litter in hydrological processes and soil erosion of forest ecosystems is poorly understood. A field experiment was conducted under simulated rainfall in runoff plots with a slope of 10%. Two common types of litter in North China (from Quercus variabilis, representing broadleaf litter, and Pinus tabulaeformis, representing needle leaf litter), four amounts of litter, and five rainfall intensities were tested. Results revealed that the litter reduced runoff and delayed the beginning of runoff, but significantly reduced soil loss (prunoff yield was 29.5% and 31.3% less than bare-soil plot, and for Q. variabilis and P. tabulaeformis, respectively, and average sediment yield was 85.1% and 79.9% lower. Rainfall intensity significantly affected runoff (R = 0.99, prunoff reduction by litter decreased considerably. Runoff yield and the runoff coefficient increased dramatically by 72.9 and 5.4 times, respectively. The period of time before runoff appeared decreased approximately 96.7% when rainfall intensity increased from 5.7 to 75.6 mm h-1. Broadleaf and needle leaf litter showed similarly relevant effects on runoff and soil erosion control, since no significant differences (p≤0.05) were observed in runoff and sediment variables between two litter-covered plots. In contrast, litter mass was probably not a main factor in determining runoff and sediment because a significant correlation was found only with sediment in Q. variabilis litter plot. Finally, runoff yield was significantly correlated (prunoff and erosion processes was crucial, and both rainfall intensity and litter characteristics had an impact on these processes.

  20. Litter Controls Earthworm-Mediated Carbon and Nitrogen Transformations in Soil from Temperate Riparian Buffers

    OpenAIRE

    Maria Kernecker; Joann K. Whalen; Robert L. Bradley

    2014-01-01

    Nutrient cycling in riparian buffers is partly influenced by decomposition of crop, grass, and native tree species litter. Nonnative earthworms in riparian soils in southern Quebec are expected to speed the processes of litter decomposition and nitrogen (N) mineralization, increasing carbon (C) and N losses in gaseous forms or via leachate. A 5-month microcosm experiment evaluated the effect of Aporrectodea turgida on the decomposition of 3 litter types (deciduous leaves, reed canarygrass, an...

  1. Tree leaf and root traits mediate soil faunal contribution to litter decomposition across an elevational gradient

    NARCIS (Netherlands)

    Fujii, Saori; Cornelissen, Johannes H.C.; Berg, Matty P.; Mori, Akira S.

    2018-01-01

    © 2018 British Ecological Society. Plant litter decomposition is key to carbon and nutrient cycling in terrestrial ecosystems. Soil fauna are important litter decomposers, but how their contribution to decomposition changes with alterations in plant composition and climate is not well established.

  2. Reciprocal effects of litter from exotic and congeneric native plant species via soil nutrients

    NARCIS (Netherlands)

    Meisner, A.; De Boer, W.; Cornelissen, J.H.C.; Van der Putten, W.H.

    2012-01-01

    Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to

  3. Integrating plant litter quality, soil organic matter stabilization, and the carbon saturation concept.

    Science.gov (United States)

    Castellano, Michael J; Mueller, Kevin E; Olk, Daniel C; Sawyer, John E; Six, Johan

    2015-09-01

    Labile, 'high-quality', plant litters are hypothesized to promote soil organic matter (SOM) stabilization in mineral soil fractions that are physicochemically protected from rapid mineralization. However, the effect of litter quality on SOM stabilization is inconsistent. High-quality litters, characterized by high N concentrations, low C/N ratios, and low phenol/lignin concentrations, are not consistently stabilized in SOM with greater efficiency than 'low-quality' litters characterized by low N concentrations, high C/N ratios, and high phenol/lignin concentrations. Here, we attempt to resolve these inconsistent results by developing a new conceptual model that links litter quality to the soil C saturation concept. Our model builds on the Microbial Efficiency-Matrix Stabilization framework (Cotrufo et al., 2013) by suggesting the effect of litter quality on SOM stabilization is modulated by the extent of soil C saturation such that high-quality litters are not always stabilized in SOM with greater efficiency than low-quality litters. © 2015 John Wiley & Sons Ltd.

  4. Litter Controls Earthworm-Mediated Carbon and Nitrogen Transformations in Soil from Temperate Riparian Buffers

    Directory of Open Access Journals (Sweden)

    Maria Kernecker

    2014-01-01

    Full Text Available Nutrient cycling in riparian buffers is partly influenced by decomposition of crop, grass, and native tree species litter. Nonnative earthworms in riparian soils in southern Quebec are expected to speed the processes of litter decomposition and nitrogen (N mineralization, increasing carbon (C and N losses in gaseous forms or via leachate. A 5-month microcosm experiment evaluated the effect of Aporrectodea turgida on the decomposition of 3 litter types (deciduous leaves, reed canarygrass, and soybean stem residue. Earthworms increased CO2 and N2O losses from microcosms with soybean residue, by 112% and 670%, respectively, but reduced CO2 and N2O fluxes from microcosms with reed canarygrass by 120% and 220%, respectively. Litter type controlled the CO2 flux (soybean ≥ deciduous-mix litter = reed canarygrass > no litter and the N2O flux (soybean ≥ no litter ≥ reed canarygrass > deciduous-mix litter. However, in the presence of earthworms, there was a slight increase in C and N gaseous losses of C and N relative to their losses via leachate, across litter treatments. We conclude that litter type determines the earthworm-mediated decomposition effect, highlighting the importance of vegetation management in controlling C and N losses from riparian buffers to the environment.

  5. Species-specific effects of live roots and shoot litter on soil decomposer abundances do not forecast plant litter-nitrogen uptake

    DEFF Research Database (Denmark)

    Saj, Stéphane; Mikola, Juha; Ekelund, Flemming

    2009-01-01

    and bacterial- and fungal-feeding nematodes did not differ between the live plants, litter-N uptake differed, with Holcus being the most efficient compared to Plantago and Lotus. Hence, although microbes and their feeders unquestionably control N mineralization in the soil, and their growth differs among plant......Plant species produce litter of varying quality and differ in the quality and quantity of compounds they release from live roots, which both can induce different decomposer growth in the soil. To test whether differences in decomposer growth can forecast the amount of N species acquire from plant...... litter, as suggested by theory, we grew individuals of three grassland plants-Holcus lanatus, Plantago lanceolata and Lotus corniculatus-in soils into which (15)N-labelled litter of either Holcus, Plantago or Lotus was added. We measured the effects of live roots and litter of each species on soil...

  6. Litter production and its nutrient concentration in some fuelwood trees grown on sodic soil

    Energy Technology Data Exchange (ETDEWEB)

    Garg, V.K. (National Botanical Research Inst., Lucknow (India))

    1992-01-01

    Litter production was estimated in 8-year-old tree plantations of Acacia nilotica, Prosopis juliflora, Dalbergia sisso, and Terminalia arjuna planted in a monoculture tree cropping system on sodic soils of Lucknow Division, India. Mean annual litter fall of these trees amounted to 5.9, 7.4, 5.0 and 5.4 t ha[sup -1], respectively. Irrespective of tree species, the leaf litter concentrations of N, K and Ca were greater than those of P and Mg. The concentration of nutrients in leaf tissues was negatively correlated for N and Ca, with the magnitude of leaf fall in D. sissoo, but was positively correlated for Ca and Mg in A. nilotica; no such correlations were found in P. juliflora and T. arjuna. The variations in the concentration of leaf litter nutrient did not appear to be species specific but depended on adverse edaphic properties including the fertility status of sodic soil. A. nilotica and P. juliflora with bimodal patterns of litter fall return greater amounts of nutrients to the soil surface than D. sissoo and T. arjuna which have unimodal patterns of litter fall. The study indicated the potential benefit of a mixed plantation system having variable leaf fall patterns among the planted trees so providing constant litter mulch to help in conserving soil moisture. (author).

  7. Species-specific effects of live roots and shoot litter on soil decomposer abundances do not forecast plant litter-nitrogen uptake.

    Science.gov (United States)

    Saj, Stéphane; Mikola, Juha; Ekelund, Flemming

    2009-08-01

    Plant species produce litter of varying quality and differ in the quality and quantity of compounds they release from live roots, which both can induce different decomposer growth in the soil. To test whether differences in decomposer growth can forecast the amount of N species acquire from plant litter, as suggested by theory, we grew individuals of three grassland plants-Holcus lanatus, Plantago lanceolata and Lotus corniculatus-in soils into which (15)N-labelled litter of either Holcus, Plantago or Lotus was added. We measured the effects of live roots and litter of each species on soil microbes and their protozoan and nematode feeders, and to link decomposer growth and plant nutrient uptake, we measured the amount of N taken up by plants from the added litter. We hypothesised that those species that induce the highest growth of microbes, and especially that of microbial feeders, will also take up the highest amount of N from the litter. We found, however, that although numbers of bacterial-feeding Protozoa and nematodes were on average lower after addition of Holcus than Plantago or Lotus litter, N uptake was higher from Holcus litter. Further, although the effects on Protozoa and bacterial- and fungal-feeding nematodes did not differ between the live plants, litter-N uptake differed, with Holcus being the most efficient compared to Plantago and Lotus. Hence, although microbes and their feeders unquestionably control N mineralization in the soil, and their growth differs among plant species, these differences cannot predict differences in litter-N uptake among plant species. A likely reason is that for nutrient uptake, other species-specific plant traits, such as litter chemistry, root proliferation ability and competitiveness for soil N, override in significance the species-specific ability of plants to induce decomposer growth.

  8. Leaf litter is an important mediator of soil respiration in an oak-dominated forest

    Science.gov (United States)

    Jared L. DeForest; Jiquan Chen; Steve G. McNulty

    2009-01-01

    The contribution of the organic (O) horizon to total soil respiration is poorly understood even though it can represent a large source of uncertainty due to seasonal changes in microclimate and O horizon properties due to plant phenology. Our objectives were to partition the CO2 effluxes of litter layer and mineral soil from total soil...

  9. Paradoxical differences in N-dynamics between Luxembourg soils: litter quality or parent material?

    NARCIS (Netherlands)

    Kooijman, A.M.; Smit, A.

    2009-01-01

    To explore whether litter quality could alter differences in N-dynamics between soil types, we compared spruce and beech growing on soils with parent material sandstone and limestone, and beech and hornbeam on acid marl and limestone. We measured pH, organic matter content, C:N ratio, soil

  10. Paradoxical differences in N-dynamics between Luxembourg soils: Litter quality or parent material?

    NARCIS (Netherlands)

    Kooijman, A.M.; Smit, A.

    2009-01-01

    To explore whether litter quality could alter differences in N-dynamics between soil types, we compared spruce and beech growing on soils with parent material sandstone and limestone, and beech and hornbeam on acid marl and limestone. We measured pH, organic matter content, C:N ratio, soil

  11. Arctic emissions of biogenic volatile organic compounds – from plants, litter and soils

    DEFF Research Database (Denmark)

    Svendsen, Sarah Hagel

    -terpenoid BVOCs were dominating the emission profile from the soils and the magnitude of the soil emissions depended greatly on the soil water content and temperature. A warmer arctic climate will likely alter the composition of plant species, cause a thawing of permafrost soil and change soil characteristics...... in adsorbent cartridges and analyzed using gas chromatography–mass spectrometry. Ecosystem BVOC emissions were highly dominated by terpenoids but the composition of terpenoids differed between different plant species. Litter emissions were less dominated by terpenoids than the ecosystem emissions, however...... they still constituted approximately 50 % of the total emissions. I suggested that the litter emissions derived both from microbial soil processes and from stores inside the litter tissue and that the relative importance of these two sources were plant species specific. Furthermore, emissions of non...

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

    Science.gov (United States)

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

    2017-12-31

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

  13. Zinc oxide nanoparticles affect carbon and nitrogen mineralization of Phoenix dactylifera leaf litter in a sandy soil.

    Science.gov (United States)

    Rashid, Muhammad Imtiaz; Shahzad, Tanvir; Shahid, Muhammad; Ismail, Iqbal M I; Shah, Ghulam Mustafa; Almeelbi, Talal

    2017-02-15

    We investigated the impact of zinc oxide nanoparticles (ZnO NPs; 1000mgkg -1 soil) on soil microbes and their associated soil functions such as date palm (Phoenix dactylifera) leaf litter (5gkg -1 soil) carbon and nitrogen mineralization in mesocosms containing sandy soil. Nanoparticles application in litter-amended soil significantly decreased the cultivable heterotrophic bacterial and fungal colony forming units (cfu) compared to only litter-amended soil. The decrease in cfu could be related to lower microbial biomass carbon in nanoparticles-litter amended soil. Likewise, ZnO NPs also reduced CO 2 emission by 10% in aforementioned treatment but this was higher than control (soil only). Labile Zn was only detected in the microbial biomass of nanoparticles-litter applied soil indicating that microorganisms consumed this element from freely available nutrients in the soil. In this treatment, dissolved organic carbon and mineral nitrogen were 25 and 34% lower respectively compared to litter-amended soil. Such toxic effects of nanoparticles on litter decomposition resulted in 130 and 122% lower carbon and nitrogen mineralization efficiency respectively. Hence, our results entail that ZnO NPs are toxic to soil microbes and affect their function i.e., carbon and nitrogen mineralization of applied litter thus confirming their toxicity to microbial associated soil functions. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Changes in soil organic matter and net nitrogen mineralization in heathland soils, after removal, addition or replacement of litter from Erica tetralix or Molinia caerulea.

    NARCIS (Netherlands)

    Vuuren, van M.M.I.; Berendse, F.

    1993-01-01

    The effects of different litter input rates and of different types of litter on soil organic matter accumulation and net N mineralization were investigated in plant communities dominated by Erica tetralix L. or Molinia caerulea (L.) Moench. Plots in which the litter on the soil had repeatedly been

  15. Allelopathic Effects of Litter Axonopus compressus against Two Weedy Species and Its Persistence in Soil

    Directory of Open Access Journals (Sweden)

    B. Samedani

    2013-01-01

    Full Text Available This study investigated the allelopathic effect of Axonopus compressus litter on Asystasia gangetica and Pennisetum polystachion. In experiment 1 the bioassays with 0, 10, 30, and 50 g L−1 of aqueous A. compressus litter leachate were conducted. Experiment 2 was carried out by incorporating 0, 10, 20, 30, 40, and 50 g L−1 of A. compressus litter leachate into soil. In experiment 3, the fate of A. compressus litter leachate phenolics in the soil was investigated. A. compressus leachates did not affect the germination percentage of A. gangetica and P. polystachion, but delayed germination of A. gangetica seeds and decreased seed germination time of P. polystachion. A. compressus litter leachates affected weeds hypocotyl length. Hypocotyl length reductions of 18 and 31% were observed at the highest concentration (50 g L−1 compared to the control in A. gangetica and P. polystachion, respectively. When concentration of A. compressus litter leachate-amended soil increased A. gangetica and P. polystachion seedling shoot length, root length, seedling weight and chlorophyll concentration were not affected. The 5-week decomposition study of A. compressus showed that the phenolic compounds in A. compressus litter abruptly decreased about 52% after two weeks and remained steady until the end of the incubation.

  16. Evaluating litter decomposition and soil organic matter dynamics in earth system models: contrasting analysis of long-term litter decomposition and steady-state soil carbon

    Science.gov (United States)

    Bonan, G. B.; Wieder, W. R.

    2012-12-01

    Decomposition is a large term in the global carbon budget, but models of the earth system that simulate carbon cycle-climate feedbacks are largely untested with respect to litter decomposition. Here, we demonstrate a protocol to document model performance with respect to both long-term (10 year) litter decomposition and steady-state soil carbon stocks. First, we test the soil organic matter parameterization of the Community Land Model version 4 (CLM4), the terrestrial component of the Community Earth System Model, with data from the Long-term Intersite Decomposition Experiment Team (LIDET). The LIDET dataset is a 10-year study of litter decomposition at multiple sites across North America and Central America. We show results for 10-year litter decomposition simulations compared with LIDET for 9 litter types and 20 sites in tundra, grassland, and boreal, conifer, deciduous, and tropical forest biomes. We show additional simulations with DAYCENT, a version of the CENTURY model, to ask how well an established ecosystem model matches the observations. The results reveal large discrepancy between the laboratory microcosm studies used to parameterize the CLM4 litter decomposition and the LIDET field study. Simulated carbon loss is more rapid than the observations across all sites, despite using the LIDET-provided climatic decomposition index to constrain temperature and moisture effects on decomposition. Nitrogen immobilization is similarly biased high. Closer agreement with the observations requires much lower decomposition rates, obtained with the assumption that nitrogen severely limits decomposition. DAYCENT better replicates the observations, for both carbon mass remaining and nitrogen, without requirement for nitrogen limitation of decomposition. Second, we compare global observationally-based datasets of soil carbon with simulated steady-state soil carbon stocks for both models. The models simulations were forced with observationally-based estimates of annual

  17. Comparison of radionuclide levels in soil, sagebrush, plant litter, cryptogams, and small mammals

    International Nuclear Information System (INIS)

    Landeen, D.S.

    1994-09-01

    Soil, sagebrush, plant litter, cryptogam, and small mammal samples were collected and analyzed for cesium-137, strontium-90, plutonium-238, plutonium 239/240, technetium-99, and iodine-129 from 1981 to 1986 at the US Department of Energy Hanford Site in southeastern Washington State as part of site characterization and environmental monitoring activities. Samples were collected on the 200 Areas Plateau, downwind from ongoing waste management activities. Plant litter, cryptogams, and small mammals are media that are not routinely utilized in monitoring or characterization efforts for determination of radionuclide concentrations. Studies at Hanford, other US Department of Energy sites, and in eastern Europe have indicated that plant litter and cryptogams may serve as effective ''natural'' monitors of air quality. Plant litter in this study consists of fallen leaves from sagebrush and ''cryptogams'' describes that portion of the soil crust composed of mosses, lichens, algae, and fungi. Comparisons of cesium-137 and strontium-90 concentrations in the soil, sagebrush, litter, and cryptogams revealed significantly higher (p<0.05) levels in plant litter and cryptogams. Technetium-99 values were the highest in sagebrush and litter. Plutonium-238 and 239/40 and iodine-129 concentrations never exceeded 0.8 pCi/gm in all media. No evidence of any significant amounts of any radionuclides being incorporated into the small mammal community was discovered. The data indicate that plant litter and cryptogams may be better, indicators of environmental quality than soil or vegetation samples. Augmenting a monitoring program with samples of litter and cryptogams may provide a more accurate representation of radionuclide environmental uptake and/or contamination levels in surrounding ecosystems. The results of this study may be applied directly to other radioecological monitoring conducted at other nuclear sites and to the monitoring of other pollutants

  18. Impact of long-term land application of broiler litter on environmentally related soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Kingery, W.L. [Mississippi State Univ., MS (United States); Wood, C.W.; Mullins, G.L. [Auburn Univ., AL (United States)] [and others

    1994-01-01

    The largest portion of Alabama`s rapidly growing poultry industry is geographically concentrated in the Sand Mountain region of northern Alabama. The result is that large amounts of waste are applied to relatively small areas of agricultural soils. A study was conducted to determine the effects of long-term broiler waste (litter) application on environmentally related soil conditions in the region. The region has an average annual rainfall of 1325 mm, which is evenly distributed throughout the year, a thermic temperature regime, and soils in the region are of the Ultisol order. In each of four major broiler-producing counties, three pairs of sites consisting of long-term (15-28 yr) littered and nonlittered fields on matching soil series and maintained under perennial tall fescue (Festuca arundinacea Schreb.) were sampled. Soil cores were taken to 3 m or lithic contact and depth-incremented samples (0-15, 15-30, and each subsequent 30-cm interval) were analyzed for organic C, total N, NO{sub 3}-N, pH, electrical conductivity, and acid-extractable P, K, Ca, Mg, Co, and Zn. Litter application increased organic C and total N to depths of 15 and 30 cm, respectively, as compared with nonlittered soils, whereas pH was 0.5 units higher to a depth of 60 cm under littered soils. Significant accumulation of NO{sub 3}N was found in littered soils to or near bedrock. Extractable P concentrations in littered soils were more than six times greater than in nonlittered soils to a depth of 60 cm. Elevated levels of extractable K, Ca, and Mg to depths greater than 60 cm also were found as a result of long-term litter use. Extractable Cu and Zn had accumulated in littered soils to a depth of 45 cm. These findings indicate that long-term land application of broiler litter, at present rates, has altered soil chemical conditions and has created a potential for adverse environmental impacts in the Sand Mountain region of Alabama. 43 refs., 6 figs., 3 tabs.

  19. Energetic Materials Effects on Essential Soil Processes: Decomposition of Orchard Grass (Dactylis glomerata) Litter in Soil Contaminated with Energetic Materials

    Science.gov (United States)

    2014-02-01

    availabilities of their respective food sources (bacteria and fungi ), were also unaffected-or-increasing in soil with CL-20 treatments. This is...ENERGETIC MATERIALS EFFECTS ON ESSENTIAL SOIL PROCESSES: DECOMPOSITION OF ORCHARD...GRASS (DACTYLIS GLOMERATA) LITTER IN SOIL CONTAMINATED WITH ENERGETIC MATERIALS ECBC-TR-1199 Roman G. Kuperman Ronald T. Checkai Michael Simini

  20. Contribution of Topography and Incident Solar Radiation to Variation of Soil and Plant Litter at an Area with Heterogeneous Terrain

    OpenAIRE

    Felipe Cito Nettesheim; Tiago de Conto; Marcos Gervasio Pereira; Deivid Lopes Machado

    2015-01-01

    Natural processes that determine soil and plant litter properties are controlled by multiple factors. However, little attention has been given to distinguishing the effects of environmental factors from the effects of spatial structure of the area on the distribution of soil and litter properties in tropical ecosystems covering heterogeneous topographies. The aim of this study was to assess patterns of soil and litter variation in a tropical area that intercepts different levels of solar radi...

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

    Science.gov (United States)

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

    2015-04-01

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

  2. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    NARCIS (Netherlands)

    Berton Zanchi, F.; Waterloo, M.J.; Dolman, A.J.; Groenendijk, M.; Kruijt, B.

    2011-01-01

    Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and

  3. Microbial properties and litter and soil nutrients after two prescribed fires in developing savannas in an upland Missouri Ozark Forest

    Science.gov (United States)

    Felix, Jr. Ponder; Mahasin Tadros; Edward F. Loewenstein

    2009-01-01

    On some landscapes periodic fire may be necessary to develop and maintain oak-dominated savannas. We studied the effects of two annual prescribed burns to determine their effect on microbial activity and soil and litter nutrients 1 year after the last burn. Surface litter and soil from the upper 0?5 cm soil layer in three developing savannas (oak-hickory, ...

  4. Differential contribution of soil biota groups to plant litter decomposition as mediated by soil use

    Science.gov (United States)

    Falco, Liliana B.; Sandler, Rosana V.; Coviella, Carlos E.

    2015-01-01

    Plant decomposition is dependant on the activity of the soil biota and its interactions with climate, soil properties, and plant residue inputs. This work assessed the roles of different groups of the soil biota on litter decomposition, and the way they are modulated by soil use. Litterbags of different mesh sizes for the selective exclusion of soil fauna by size (macro, meso, and microfauna) were filled with standardized dried leaves and placed on the same soil under different use intensities: naturalized grasslands, recent agriculture, and intensive agriculture fields. During five months, litterbags of each mesh size were collected once a month per system with five replicates. The remaining mass was measured and decomposition rates calculated. Differences were found for the different biota groups, and they were dependant on soil use. Within systems, the results show that in the naturalized grasslands, the macrofauna had the highest contribution to decomposition. In the recent agricultural system it was the combined activity of the macro- and mesofauna, and in the intensive agricultural use it was the mesofauna activity. These results underscore the relative importance and activity of the different groups of the edaphic biota and the effects of different soil uses on soil biota activity. PMID:25780777

  5. Differential contribution of soil biota groups to plant litter decomposition as mediated by soil use

    Directory of Open Access Journals (Sweden)

    Ricardo A. Castro-Huerta

    2015-03-01

    Full Text Available Plant decomposition is dependant on the activity of the soil biota and its interactions with climate, soil properties, and plant residue inputs. This work assessed the roles of different groups of the soil biota on litter decomposition, and the way they are modulated by soil use. Litterbags of different mesh sizes for the selective exclusion of soil fauna by size (macro, meso, and microfauna were filled with standardized dried leaves and placed on the same soil under different use intensities: naturalized grasslands, recent agriculture, and intensive agriculture fields. During five months, litterbags of each mesh size were collected once a month per system with five replicates. The remaining mass was measured and decomposition rates calculated. Differences were found for the different biota groups, and they were dependant on soil use. Within systems, the results show that in the naturalized grasslands, the macrofauna had the highest contribution to decomposition. In the recent agricultural system it was the combined activity of the macro- and mesofauna, and in the intensive agricultural use it was the mesofauna activity. These results underscore the relative importance and activity of the different groups of the edaphic biota and the effects of different soil uses on soil biota activity.

  6. Litter quality as driving factor for plant nutrition via grazing of protozoa on soil microorganisms.

    Science.gov (United States)

    Koller, Robert; Robin, Christophe; Bonkowski, Michael; Ruess, Liliane; Scheu, Stefan

    2013-08-01

    Plant residues provide a major source of nitrogen (N) for plant growth. Litter N mineralization varies with litter carbon-to-nitrogen (C-to-N) ratio and presence of bacterial-feeding fauna. We assessed the effect of amoebae, major bacterial feeders in soil, on mineralization of litter of low (high quality) and high C-to-N ratio (low quality) and evaluated consequences for plant growth. We used stable isotopes to determine plant N uptake from litter and plant C partitioning. Stable isotope probing of phospholipid fatty acids was used to follow incorporation of plant C into microorganisms. Amoebae increased plant N uptake independent of litter quality and thereby the biomass of shoots and roots by 33% and 66%, respectively. Plant allocation of total (13)C to roots in low (42%) exceeded that of high-quality litter treatments (26%). Amoebae increased plant allocation of (13)C to roots by 37%. Microbial community structure and incorporation of (13)C into PLFAs varied significantly with litter quality and in the low-quality litter treatment also with the presence of amoebae. Overall, the results suggest that in particular at low nutrient conditions, root-derived C fosters the mobilization of bacterial N by protozoa, thereby increasing plant growth when microorganisms and plants compete for nutrients. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  7. Detection and quantification of ionophore antibiotics in runoff, soil and poultry litter.

    Science.gov (United States)

    Sun, Peizhe; Barmaz, Delphine; Cabrera, Miguel L; Pavlostathis, Spyros G; Huang, Ching-Hua

    2013-10-18

    Ionophore antibiotics (IPAs) are widely used as coccidiostats in poultry and other livestock industries to promote growth and prevent infections. Because most of the ingested IPAs are excreted in poultry litter, which is primarily applied as grassland fertilizer, a significant amount of IPAs can be released into the litter-soil-water environment. A robust analytical method has been developed to quantify IPAs (monensin (MON), salinomycin (SAL) and narasin (NAR)) in complex environmental compartments including surface runoff, soil and poultry litter, with success to minimize matrix interference. The method for water samples involves solid-phase extraction (SPE) followed by liquid-liquid extraction (LLE) post-clean up steps. The method for solid samples involves bi-solvent LLE. IPAs were detected by HPLC-MS, with optimized parameters to achieve the highest sensitivity. Nigericin (NIG), an IPA not used in livestock industry, is successfully applied and validated as a surrogate standard. The method recoveries were at 92-95% and 81-85% in runoff samples from unfertilized and litter-fertilized fields, respectively. For solids, the method recoveries were at 93-99% in soils, and 79-83% in poultry litter samples. SAL was detected at up to 22mg/kg and MON and NAR at up to 4mg/kg in broiler litter from different farms. Up to 183μg/kg of MON was detected in litter-fertilized soils. All three IPAs were detected in the rainfall runoff from litter-fertilized lands at concentrations up to 9μg/L. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Lindsey E. Rustad; Ivan J. Fernandez

    1998-01-01

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

  9. Long Term Effects of Poultry Litter on Soil Physical and Chemical Properties in Cotton Plots

    Science.gov (United States)

    Surrency, J.; Tsegaye, T.; Coleman, T.; Fahsi, A.; Reddy, C.

    1998-01-01

    Poultry litter and compost can alter the moisture holding capacity of a soil. These organic materials can also increase the nutrient status of a soil during the decomposition process by microbial actions. The objective of this study was to evaluate the effect of poultry litter and compost on the dielectric constant and moisture holding capacity of soil. The Delta-T theta-probe was used to measure volumetric soil water content and the apparent dielectric constant of the upper 6-cm of the soil profile. Soil texture, pH, and organic matter were also determined for each plot. Results of these analyses indicated that the pH of the soil ranged from 6.4 to 7.7 and the volumetric soil moisture content ranged from 0.06 to 0.18 cu m/cu m for the upper 6-cm of the soil profile. The effect of poultry litter and compost on soil properties resulted in an increase in the volumetric moisture content and dielectric constant of the soil due to the improvement of the soil structure.

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

    Science.gov (United States)

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

    2015-03-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  12. [Effects of mixed decomposition of Populus simonii and other tree species leaf litters on soil properties in Loess Plateau].

    Science.gov (United States)

    Li, Qian; Liu, Zeng-Wen; Du, Liang-Zhen

    2012-03-01

    In this study, the leaf litters of Populus simonii and other 11 tree species were put into soil separately or in mixture after grinding, and incubated in laboratory to analyze the effects of their decomposition on soil properties and the interactions between the litters decomposition. The decomposition of each kind of the leaf litters in soil increased the soil urease, dehydrogenase, and phosphatase activities and the soil organic matter and available N contents markedly, but had greater differences in the effects on the soil available P content and CEC. The decomposition of the leaf litters of Caragana microphylla and of Amorpha fruticosa showed obvious effects in improving soil properties. The decomposition of the mixed leaf litters of P. simonii and Pinus tabulaeformis, Platycladus orientalis, Robinia pseudoacacia, or Ulmus pumila showed interactive promotion effects on the abundance of soil microbes, and that of the mixed leaf litters of P. simonii and P. orientalis or C. microphylla showed interactive promotion effects on the soil organic matter, available P, and available K contents and soil CEC but interactive inhibition effects on the activities of most of the soil enzymes tested. The decomposition of the mixed leaf litters of P. simonii and Larix principis-rupprechtii showed interactive promotion effects on the activities of most of the soil enzymes and soil nutrient contents, while that of the mixed leaf litters of P. simonii and P. sylvestris var. mongolica showed interactive inhibition effects. Overall, the decomposition of the mixed leaf litters of P. simo- nii and U. pumila, P. tabulaeformis, L. principis-rupprechtii, or R. pseudoacacia could improve soil quality, but the mixed leaf litters of P. simonii and P. orientalis, C. microphylla, P. sylvestris var. mongolica, Hippophae rhamnoides, or A. fruticosa showed an interactive inhibition effect during their decomposition.

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

    Science.gov (United States)

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

    2012-02-01

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

  14. Some Sensitivity Studies of Chemical Transport Simulated in Models of the Soil-Plant-Litter System

    Energy Technology Data Exchange (ETDEWEB)

    Begovich, C.L.

    2002-10-28

    Fifteen parameters in a set of five coupled models describing carbon, water, and chemical dynamics in the soil-plant-litter system were varied in a sensitivity analysis of model response. Results are presented for chemical distribution in the components of soil, plants, and litter along with selected responses of biomass, internal chemical transport (xylem and phloem pathways), and chemical uptake. Response and sensitivity coefficients are presented for up to 102 model outputs in an appendix. Two soil properties (chemical distribution coefficient and chemical solubility) and three plant properties (leaf chemical permeability, cuticle thickness, and root chemical conductivity) had the greatest influence on chemical transport in the soil-plant-litter system under the conditions examined. Pollutant gas uptake (SO{sub 2}) increased with change in plant properties that increased plant growth. Heavy metal dynamics in litter responded to plant properties (phloem resistance, respiration characteristics) which induced changes in the chemical cycling to the litter system. Some of the SO{sub 2} and heavy metal responses were not expected but became apparent through the modeling analysis.

  15. Litter as seedbed: interactions between the soil, seedlings and litter of kauri (Agathis australis)

    NARCIS (Netherlands)

    Verkaik, E.

    2006-01-01

    Plants have important impacts upon soil processes such as nutrient mineralisation and organic matter dynamics. They might even enhance their own fitness by improving soil quality or by making the soil less favourable for competing species. In the latter strategy, tannins in plant foliage might be

  16. Role of litter turnover in soil quality in tropical degraded lands of Colombia.

    Science.gov (United States)

    León, Juan D; Osorio, Nelson W

    2014-01-01

    Land degradation is the result of soil mismanagement that reduces soil productivity and environmental services. An alternative to improve degraded soils through reactivation of biogeochemical nutrient cycles (via litter production and decomposition) is the establishment of active restoration models using new forestry plantations, agroforestry, and silvopastoral systems. On the other hand, passive models of restoration consist of promoting natural successional processes with native plants. The objective in this review is to discuss the role of litter production and decomposition as a key strategy to reactivate biogeochemical nutrient cycles and thus improve soil quality in degraded land of the tropics. For this purpose the results of different projects of land restoration in Colombia are presented based on the dynamics of litter production, nutrient content, and decomposition. The results indicate that in only 6-13 years it is possible to detect soil properties improvements due to litter fall and decomposition. Despite that, low soil nutrient availability, particularly of N and P, seems to be major constraint to reclamation of these fragile ecosystems.

  17. Effect of Leaf Litters and Soils on Viability of Entomopathogenic Fungi Beauveria bassiana (Bals. Vuill

    Directory of Open Access Journals (Sweden)

    LISDAR IDWAN SUDIRMAN

    2008-09-01

    Full Text Available Viability of Beauveria bassiana is extremely low due to toxic compounds in soils. This research was aimed to study the effect of four groups of media on viability of B. bassiana Bb-Pb2. The first group was leaf litters of onion, flowering white cabbage, cabbage, and chinese mustard, respectively; the second group was the soils containing decomposed residues of each plant of the first group; the third group was the mixtures of each media of both groups above (1:1, and the fourth group was natural top soil as a control. Each plastic bag filled with one kg of each medium was inoculated with ten ml of B. bassiana conidia (106/ml of concentration and incubated in open area for 8 weeks. The results showed that all leaf litters of those plants and their compost soils affected the fungal viability. The highest decreasing number of colony was found on onion's leaf litters, soil containing of decomposed onion, and the mixtures of both media. The treated B. bassiana showed significant reducing abilities of growth, conidia production and conidia germination on PDA media, except the one of control. It is suggested that the Bb-Pb2 isolate might not be effective as bioinsecticide in the soils containing either those leaf litters or composts.

  18. Effect of Leaf Litters and Soils on Viability of Entomopathogenic Fungi Beauveria bassiana (Bals. Vuill

    Directory of Open Access Journals (Sweden)

    LISDAR IDWAN SUDIRMAN

    2008-09-01

    Full Text Available Viability of Beauveria bassiana is extremely low due to toxic compounds in soils. This research was aimed to study the effect of four groups of media on viability of B. bassiana Bb-Pb2. The first group was leaf litters of onion, flowering white cabbage, cabbage, and chinese mustard, respectively; the second group was the soils containing decomposed residues of each plant of the first group; the third group was the mixtures of each media of both groups above (1:1, and the fourth group was natural top soil as a control. Each plastic bag filled with one kg of each medium was inoculated with ten ml of B. bassiana conidia (106/ml of concentration and incubated in open area for 8 weeks. The results showed that all leaf litters of those plants and their compost soils affected the fungal viability. The highest decreasing number of colony was found on onion’s leaf litters, soil containing of decomposed onion, and the mixtures of both media. The treated B. bassiana showed significant reducing abilities of growth, conidia production and conidia germination on PDA media, except the one of control. It is suggested that the Bb-Pb2 isolate might not be effective as bioinsecticide in the soils containing either those leaf litters or composts.

  19. Water, Rather than Temperature, Dominantly Impacts How Soil Fauna Affect Dissolved Carbon and Nitrogen Release from Fresh Litter during Early Litter Decomposition

    Directory of Open Access Journals (Sweden)

    Shu Liao

    2016-10-01

    Full Text Available Longstanding observations suggest that dissolved materials are lost from fresh litter through leaching, but the role of soil fauna in controlling this process has been poorly documented. In this study, a litterbag experiment employing litterbags with different mesh sizes (3 mm to permit soil fauna access and 0.04 mm to exclude fauna access was conducted in three habitats (arid valley, ecotone and subalpine forest with changes in climate and vegetation types to evaluate the effects of soil fauna on the concentrations of dissolved organic carbon (DOC and total dissolved nitrogen (TDN during the first year of decomposition. The results showed that the individual density and community abundance of soil fauna greatly varied among these habitats, but Prostigmata, Isotomidae and Oribatida were the dominant soil invertebrates. At the end of the experiment, the mass remaining of foliar litter ranged from 58% for shrub litter to 77% for birch litter, and the DOC and TDN concentrations decreased to 54%–85% and increased to 34%–269%, respectively, when soil fauna were not present. The effects of soil fauna on the concentrations of both DOC and TDN in foliar litter were greater in the subalpine forest (wetter but colder during the winter and in the arid valley (warmer but drier during the growing season, and this effect was positively correlated with water content. Moreover, the effects of fauna on DOC and TDN concentrations were greater for high-quality litter and were related to the C/N ratio. These results suggest that water, rather than temperature, dominates how fauna affect the release of dissolved substances from fresh litter.

  20. Paradoxical differences in N-dynamics between Luxembourg soils: litter quality or parent material?

    OpenAIRE

    Kooijman, A.M.; Smit, A.

    2009-01-01

    To explore whether litter quality could alter differences in N-dynamics between soil types, we compared spruce and beech growing on soils with parent material sandstone and limestone, and beech and hornbeam on acid marl and limestone. We measured pH, organic matter content, C:N ratio, soil respiration and net N-mineralization of the organic layer and the mineral topsoil in a laboratory incubation experiment and estimated gross N-mineralization and immobilization with a simulation model. Speci...

  1. Impacts of soil petroleum contamination on nutrient release during litter decomposition of Hippophae rhamnoides.

    Science.gov (United States)

    Zhang, Xiaoxi; Liu, Zengwen; Luc, Nhu Trung; Yu, Qi; Liu, Xiaobo; Liang, Xiao

    2016-03-01

    Petroleum exploitation causes contamination of shrub lands close to oil wells. Soil petroleum contamination affects nutrient release during the litter decomposition of shrubs, which influences nutrient recycling and the maintenance of soil fertility. Hence, this contamination may reduce the long-term growth and stability of shrub communities and consequently, the effects of phytoremediation. Fresh foliar litter of Hippophae rhamnoides, a potential phytoremediating species, was collected for this study. The litter was placed in litterbags and then buried in different petroleum-polluted soil media (the petroleum concentrations were 15, 30, and 45 g kg(-1) dry soil, which were considered as slightly, moderately and seriously polluted soil, respectively) for a decomposition test. The impacts of petroleum contamination on the release of nutrients (including N, P, K, Cu, Zn, Fe, Mn, Ca and Mg) were assessed. The results showed that (1) after one year of decomposition, the release of all nutrients was accelerated in the slightly polluted soil. In the moderately polluted soil, P release was accelerated, while Cu, Zn and Mn release was inhibited. In the seriously polluted soil, Cu and Zn release was accelerated, while the release of the other nutrients was inhibited. (2) The effect of petroleum on nutrient release from litter differed in different periods during decomposition; this was mainly due to changes in soil microorganisms and enzymes under the stress of petroleum contamination. (3) To maintain the nutrient cycling and the soil fertility of shrub lands, H. rhamnoides is only suitable for phytoremediation of soils containing less than 30 g kg(-1) of petroleum.

  2. Inhibitory and toxic effects of extracellular self-DNA in litter: a mechanism for negative plant-soil feedbacks?

    Science.gov (United States)

    Mazzoleni, Stefano; Bonanomi, Giuliano; Incerti, Guido; Chiusano, Maria Luisa; Termolino, Pasquale; Mingo, Antonio; Senatore, Mauro; Giannino, Francesco; Cartenì, Fabrizio; Rietkerk, Max; Lanzotti, Virginia

    2015-02-01

    Plant-soil negative feedback (NF) is recognized as an important factor affecting plant communities. The objectives of this work were to assess the effects of litter phytotoxicity and autotoxicity on root proliferation, and to test the hypothesis that DNA is a driver of litter autotoxicity and plant-soil NF. The inhibitory effect of decomposed litter was studied in different bioassays. Litter biochemical changes were evaluated with nuclear magnetic resonance (NMR) spectroscopy. DNA accumulation in litter and soil was measured and DNA toxicity was assessed in laboratory experiments. Undecomposed litter caused nonspecific inhibition of root growth, while autotoxicity was produced by aged litter. The addition of activated carbon (AC) removed phytotoxicity, but was ineffective against autotoxicity. Phytotoxicity was related to known labile allelopathic compounds. Restricted (13) C NMR signals related to nucleic acids were the only ones negatively correlated with root growth on conspecific substrates. DNA accumulation was observed in both litter decomposition and soil history experiments. Extracted total DNA showed evident species-specific toxicity. Results indicate a general occurrence of litter autotoxicity related to the exposure to fragmented self-DNA. The evidence also suggests the involvement of accumulated extracellular DNA in plant-soil NF. Further studies are needed to further investigate this unexpected function of extracellular DNA at the ecosystem level and related cellular and molecular mechanisms. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  3. Does Short-term Litter Input Manipulation Affect Soil Respiration and the Carbon-isotopic Signature of Soil Respired CO2

    Science.gov (United States)

    Cheng, X.; Wu, J.

    2016-12-01

    Global change greatly alters the quality and quantity of plant litter inputs to soils, and further impacts soil organic matter (SOM) dynamics and soil respiration. However, the process-based understanding of how soil respiration may change with future shift in litter input is not fully understood. The Detritus Input and Removal Treatment (DIRT) experiment was conducted in coniferous forest (Platycladus orientalis (Linn.) Franco) ecosystem of central China to investigate the impact of above- and belowground litter input on soil respiration and the carbon-isotopic signature of soil respired CO2. Short-term (1-2 years) litter input manipulation significantly affected soil respiration, based on annual flux values, soil respiration was 31.9%, 20.5% and 37.2% lower in no litter (NL), no root (NR) and no input (NRNL), respectively, compared to control (CK). Whereas double litter (DL) treatment increased soil respiration by 9.1% compared to CK. The recalcitrance index of carbon (RIC) and the relative abundance of fungi increased under litter removal or root exclusion treatment (NL, NR and NRNL) compared to CK. Basal soil respiration was positively related to liable C and microbial biomass and negatively related to RIC and fungi to bacteria (F: B) ratio. The carbon-isotopic signature of soil respired CO2 enriched under litter removal and no input treatment, and slightly depleted under litter addition treatment compared to CK. Our results suggest that short-term litter input manipulation can affect the soil respiration by altering substrate availability and microbial community structure, and also impact the carbon-isotopic signature of soil respired CO2 possibly duo to change in the component of soil respiration and soil microclimate.

  4. Do soil fauna really hasten litter decomposition? A meta-analysis of enclosure studies

    Czech Academy of Sciences Publication Activity Database

    Frouz, J.; Roubíčková, A.; Heděnec, P.; Tajovský, Karel

    2015-01-01

    Roč. 68, May-June (2015), s. 18-24 ISSN 1164-5563 Grant - others:GA ČR(CZ) GAP504/12/1288 Program:GA Institutional support: RVO:60077344 Keywords : Invertebrates * bioturbation * soil organic matter * carbon cycle * litter bag Subject RIV: EH - Ecology, Behaviour Impact factor: 1.951, year: 2015

  5. Nitrous oxide emissions from soil amended with low-phosphorus broiler litter

    Science.gov (United States)

    Regions of the United States with a high concentration of poultry farms have soils with excess nitrogen (N) and phosphorus (P) far beyond the agronomic requirement of crops because of recurrent land application of broiler litter. A new waste treatment technology developed by USDA-ARS, called “Quick ...

  6. Do arbuscular mycorrhizal fungi stabilize litter-derived carbon in soil?

    Czech Academy of Sciences Publication Activity Database

    Verbruggen, E.; Jansa, Jan; Hammer, E.C.; Rilling, M.C.

    2016-01-01

    Roč. 104, č. 1 (2016), s. 261-269 ISSN 0022-0477 R&D Projects: GA MŠk(CZ) LK11224 Institutional support: RVO:61388971 Keywords : isotopes * litter decomposition * plant- soil (below-ground) interactions Subject RIV: EE - Microbiology, Virology Impact factor: 5.813, year: 2016

  7. Litter Decomposition and Soil Respiration Responses to Fuel-Reduction Treatments in Piedmond Loblolly Pine Forests

    Science.gov (United States)

    Mac A. Callaham; Peter H. Anderson; Thomas A. Waldrop; Darren J. Lione; Victor B. Shelburne

    2004-01-01

    As part of the National Fire and Fire Surrogate Study, we measured the short-term effects of different fuel-management practices on leaf litter decomposition and soil respiration in loblolly pine stands on the upper Piedmont of South Carolina. These stands had been subjected to a factorial arrangement of experimental fuel-management treatments that included prescribed...

  8. Retention of dead standing plant biomass (marcescence) increases subsequent litter decomposition in the soil organic layer

    Czech Academy of Sciences Publication Activity Database

    Angst, Šárka; Cajthaml, T.; Angst, Gerrit; Šimáčková, H.; Brus, Jiří; Frouz, Jan

    2017-01-01

    Roč. 418, 1-2 (2017), s. 571-579 ISSN 0032-079X Institutional support: RVO:60077344 ; RVO:61389013 Keywords : photodegradation * C-13 CP/MAS NMR spectroscopy * litter decomposition * pyrolysis GC-MS * Calamagrostis epigeios * photo-facilitation Subject RIV: DF - Soil Science; CD - Macromolecular Chemistry (UMCH-V) OBOR OECD: Soil science; Polymer science (UMCH-V) Impact factor: 3.052, year: 2016

  9. Agroforestry systems, nutrients in litter and microbial activity in soils cultivated with coffee at high altitude

    Directory of Open Access Journals (Sweden)

    Krystal de Alcantara Notaro

    2014-04-01

    Full Text Available Agroforestry systems are an alternative option for sustainable production management. These systems contain trees that absorb nutrients from deeper layers of the soil and leaf litter that help improve the soil quality of the rough terrain in high altitude areas, which are areas extremely susceptible to environmental degradation. The aim of this study was to characterize the stock and nutrients in litter, soil activity and the population of microorganisms in coffee (Coffea arabica L. plantations under high altitude agroforestry systems in the semi-arid region of the state of Pernambuco, Brazil. Samples were collected from the surface litter together with soil samples taken at two depths (0-10 and 10-20 cm from areas each subject to one of the following four treatments: agroforestry system (AS, native forest (NF, biodynamic system (BS and coffee control (CT.The coffee plantation had been abandoned for nearly 15 years and, although there had been no management or harvesting, still contained productive coffee plants. The accumulation of litter and mean nutrient content of the litter, the soil nutrient content, microbial biomass carbon, total carbon, total nitrogen, C/N ratio, basal respiration, microbial quotient, metabolic quotient and microbial populations (total bacteria, fluorescent bacteria group, total fungi and Trichoderma spp. were all analyzed. The systems thatwere exposed to human intervention (A and BS differed in their chemical attributes and contained higher levels of nutrients when compared to NF and CT. BS for coffee production at high altitude can be used as a sustainable alternative in the high altitude zones of the semi-arid region in Brazil, which is an area that is highly susceptible to environmental degradation.

  10. Impact of Poultry Litter Cake, Cleanout, and Bedding following Chemical Amendments on Soil C and N Mineralization

    OpenAIRE

    Watts, Dexter B.; Smith, Katy E.; Torbert, H. A.

    2012-01-01

    Poultry litter is a great alternative N source for crop production. However, recent poultry litter management changes, and increased chemical amendment use may impact its N availability. Thus, research was initiated to evaluate the effect that broiler cake and total cleanout litter amended with chemical additives have on C and N mineralization. A 35-day incubation study was carried out on a Hartsells fine sandy loam (fine-loamy, siliceous, subactive, thermic Typic Hapludults) soil common to t...

  11. 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

  12. Phosphorus runoff from waste water treatment biosolids and poultry litter applied to agricultural soils.

    Science.gov (United States)

    White, John W; Coale, Frank J; Sims, J Thomas; Shober, Amy L

    2010-01-01

    Differences in the properties of organic phosphorus (P) sources, particularly those that undergo treatment to reduce soluble P, can affect soil P solubility and P transport in surface runoff. This 2-yr field study investigated soil P solubility and runoff P losses from two agricultural soils in the Mid-Atlantic region after land application of biosolids derived from different waste water treatment processes and poultry litter. Phosphorus speciation in the biosolids and poultry litter differed due to treatment processes and significantly altered soil P solubility and dissolved reactive P (DRP) and bioavailable P (FeO-P) concentrations in surface runoff. Runoff total P (TP) concentrations were closely related to sediment transport. Initial runoff DRP and FeO-P concentrations varied among the different biosolids and poultry litter applied. Over time, as sediment transport declined and DRP concentrations became an increasingly important component of runoff FeO-P and TP, total runoff P was more strongly influenced by the type of biosolids applied. Throughout the study, application of lime-stabilized biosolids and poultry litter increased concentrations of soil-soluble P, readily desorbable P, and soil P saturation, resulting in increased DRP and FeO-P concentrations in runoff. Land application of biosolids generated from waste water treatment processes that used amendments to reduce P solubility (e.g., FeCl(3)) did not increase soil P saturation and reduced the potential for DRP and FeO-P transport in surface runoff. These results illustrate the importance of waste water treatment plant process and determination of specific P source coefficients to account for differential P availability among organic P sources.

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

    International Nuclear Information System (INIS)

    Thomas, W.A.

    1975-01-01

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

  14. Heavy metal concentrations in ground beetles, leaf litter, and soil of a forest ecosystem.

    Science.gov (United States)

    Jelaska, Lucija Serić; Blanusa, Maja; Durbesić, Paula; Jelaska, Sven D

    2007-01-01

    The objective of this study was to quantify the relationships between heavy metal concentrations in soil, leaf litter, and ground beetles at four sampling sites of a forest ecosystem in Medvednica Nature Park, Croatia. Ground beetles were sampled by pitfall trapping. Specimens were dry-ashed and soil and beetle samples digested with nitric acid. Lead, cadmium, copper, zinc, manganese, and iron were analyzed using atomic absorption spectrometry. Statistically significant differences between plots were found for lead, cadmium, and iron in ground beetles. Correlations between ground beetles and soil or leaf litter were positive for lead and cadmium concentrations and negative for iron concentration. Differences in species metal concentrations were recorded. Higher concentrations of all studied metals were found in female beetles. However, a significant difference between sexes was found only for manganese. Significant differences in species metal concentrations were found for species that differ in feeding strategies and age based on breeding season and emergence of young adults.

  15. Mineralization and carbon turnover in subarctic heath soil as affected by warming and additional litter

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Michelsen, Anders; Baath, Erland

    2007-01-01

    Arctic soil carbon (C) stocks are threatened by the rapidly advancing global warming. In addition to temperature, increasing amounts of leaf litter fall following from the expansion of deciduous shrubs and trees in northern ecosystems may alter biogeochemical cycling of C and nutrients. Our aim w...... on C and N transformations during field incubation suggest that microbial activity is an important control on the carbon balance of arctic soils under climate change.......Arctic soil carbon (C) stocks are threatened by the rapidly advancing global warming. In addition to temperature, increasing amounts of leaf litter fall following from the expansion of deciduous shrubs and trees in northern ecosystems may alter biogeochemical cycling of C and nutrients. Our aim...

  16. Species identities, not functional groups, explain the effects of earthworms on litter carbon-derived soil respiration

    Science.gov (United States)

    Soil respiration is frequently measured as a surrogate for biological activities and is important in soil carbon cycling. The heterotrophic component of soil respiration is primarily driven by microbial decomposition of leaf litter and soil organic matter, and is partially controlled by resource ava...

  17. Inhibitory and toxic effects of extracellular self-DNA in litter : A mechanism for negative plant-soil feedbacks?

    NARCIS (Netherlands)

    Mazzoleni, Stefano; Bonanomi, Giuliano; Incerti, Guido; Chiusano, Maria Luisa; Termolino, Pasquale; Mingo, Antonio; Senatore, Mauro; Giannino, Francesco; Cartenì, Fabrizio; Rietkerk, Max; Lanzotti, Virginia

    2015-01-01

    Plant-soil negative feedback (NF) is recognized as an important factor affecting plant communities. The objectives of this work were to assess the effects of litter phytotoxicity and autotoxicity on root proliferation, and to test the hypothesis that DNA is a driver of litter autotoxicity and

  18. Litter decomposition rate and soil organic matter quality in a patchwork heathland of Southern Norway

    Science.gov (United States)

    Certini, G.; Vestgarden, L. S.; Forte, C.; Tau Strand, L.

    2014-07-01

    Norwegian heathland soils, although scant and shallow, are major reservoirs of carbon (C). We aimed at assessing whether vegetation cover and, indirectly, its driving factor soil drainage are good proxies for soil organic matter (SOM) composition and dynamics in a typical heathland area of Southern Norway consisting in a patchwork of three different types of vegetation, dominated by Calluna, Molinia, or Sphagnum. Such vegetation covers were clearly associated to microtopographic differences, which in turn dictated differences in soil moisture regime, Calluna growing in the driest sites, Sphagnum in the wettest, and Molinia in sites with intermediate moisture. Litter decomposition was followed over a period of 1 year, by placing litterbags filled with biomass from each dominant species under each type of vegetation cover. The composition of the living biomass, the bulk SOM and some extractable fractions of SOM were investigated by chemical methods and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Litter decomposition was faster for Molinia and Calluna, irrespective of the vegetation cover of the site where they were placed. Sphagnum litter decomposed very slowly, especially under Calluna, where the soil environment is by far more oxidising than under itself. In terms of SOM quality, Calluna covered areas showed the greatest differences from the others, in particular a much higher contribution from lipids and aliphatic biopolymers, apparently related to biomass composition. Our findings showed that in the studied environment litter decomposition rate and SOM composition are actually dependent on vegetation cover and/or soil drainage. On this basis, monitoring changes in the patchwork of vegetation types in boreal heathlands could be a reliable cost-effective way to account for modifications in the SOM potential to last induced by climate change.

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

    Science.gov (United States)

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

    2018-04-01

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

  20. Solar ultraviolet radiation alters alder and birch litter chemistry that in turn affects decomposers and soil respiration.

    Science.gov (United States)

    Kotilainen, Titta; Haimi, Jari; Tegelberg, Riitta; Julkunen-Tiitto, Riitta; Vapaavuori, Elina; Aphalo, Pedro Jose

    2009-10-01

    Solar ultraviolet (UV)-A and UV-B radiation were excluded from branches of grey alder (Alnus incana) and white birch (Betula pubescens) trees in a field experiment. Leaf litter collected from these trees was used in microcosm experiments under laboratory conditions. The aim was to evaluate the effects of the different UV treatments on litter chemical quality (phenolic compounds, C, N and lignin) and the subsequent effects of these changes on soil fauna and decomposition processes. We measured the decomposition rate of litter, growth of woodlice (Porcellio scaber), soil microbial respiration and abundance of nematodes and enchytraeid worms. In addition, the chemical quality of woodlice feces was analyzed. The exclusion of both UV-A and UV-B had several effects on litter chemistry. Exclusion of UV-B radiation decreased the C content in litter in both tree species. In alder litter, UV exclusion affected concentration of phenolic groups variably, whereas in birch litter there were no significant differences in phenolic compounds. Moreover, further effects on microbial respiration and chemical quality of woodlice feces were apparent. In both tree species, microbial CO(2) evolution was lower in soil with litter produced under exclusion of both UV-A and UV-B radiation when compared to soil with control litter. The N content was higher in the feces of woodlice eating alder litter produced under exclusion of both UV-A and UV-B compared to the control. In addition, there were small changes in the concentration of individual phenolic compounds analyzed from woodlice feces. Our results demonstrate that both UV-A and UV-B alter litter chemistry which in turn affects decomposition processes.

  1. Plant litter decomposition and carbon sequestration for arable soils. Final report of works. April 2005

    International Nuclear Information System (INIS)

    Recous, S.; Barrois, F.; Coppens, F.; Garnier, P.; Grehan, E.; Balesdent, J.; Dambrine, E.; Zeller, B.; Loiseau, P.; Personeni, E.

    2002-01-01

    The general objective of this project was to contribute to the evaluation of land use and management impacts on C sequestration and nitrogen dynamics in soils. The land used through the presence/absence of crops and their species, and the land management through tillage, localisation of crop residues, fertilizer applications,... are important factors that affect the dynamics of organic matters in soils, particularly the mineralization of C and N, the losses to the atmosphere and hydrosphere, the retention of carbon into the soil. This project was conducted by four research groups, three of them having expertise in nutrient cycling of three major agro-ecosystems (arable crops, grasslands, forests) and the fourth one having expertise in modelling long term effects of land use on C storage into the soils. Within this common project one major objective was to better understand the fate of plant litter entering the soil either as above litter or as root litter. The focus was put on two factors that particularly affect decomposition: the initial biochemical quality of plant litter, and the location of the decomposing litter. One innovative aspect of the project was the use of stable isotope as 13 C for carbon, based on the use of enriched or depleted 13 C material, the only option to assess the dynamics of 'new' C entering the soil on the short term, in order to reveal the effects of decomposition factors. Another aspect was the simultaneous study of C and N. The project consisted in experiments relevant for each agro-ecosystem, in forest, grassland and arable soils for which interactions between residue quality and nitrogen availability on the one hand, residue quality and location on the other hand, was investigated. A common experiment was set up to investigate the potential degradability of the various residue used (beech leaf rape straw, young rye, Lolium and dactylic roots) in a their original soils and in a single soil was assessed. Based on these experiments, the

  2. Phosphorus release behaviors of poultry litter biochar as a soil amendment

    International Nuclear Information System (INIS)

    Wang, Yue; Lin, Yingxin; Chiu, Pei C.; Imhoff, Paul T.; Guo, Mingxin

    2015-01-01

    Phosphorus (P) may be immobilized and consequently the runoff loss risks be reduced if poultry litter (PL) is converted into biochar prior to land application. Laboratory studies were conducted to examine the water extractability of P in PL biochar and its release kinetics in amended soils. Raw PL and its biochar produced through 400 °C pyrolysis were extracted with deionized water under various programs and measured for water extractable P species and contents. The materials were further incubated with a sandy loam at 20 g kg −1 soil and intermittently leached with water for 30 days. The P release kinetics were determined from the P recovery patterns in the water phase. Pyrolysis elevated the total P content from 13.7 g kg −1 in raw PL to 27.1 g kg −1 in PL biochar while reduced the water-soluble P level from 2.95 g kg −1 in the former to 0.17 g kg −1 in the latter. The thermal treatment transformed labile P in raw PL to putatively Mg/Ca phosphate minerals in biochar that were water-unextractable yet proton-releasable. Orthophosphate was the predominant form of water-soluble P in PL biochar, with condensed phosphate (e.g., pyrophosphate) as a minor form and organic phosphate in null. Release of P from PL biochar in both water and neutral soils was at a slower and steadier rate over a longer time period than from raw PL. Nevertheless, release of P from biochar was acid-driven and could be greatly promoted by the media acidity. Land application of PL biochar at soil pH-incorporated rates and frequency will potentially reduce P losses to runoffs and minimize the adverse impact of waste application on aquatic environments. - Highlights: • The predominant portion of P in poultry litter biochar is water insoluble. • Poultry litter P was immobilized by forming Ca/Mg (pyro)phosphates in biochar. • Release of P from biochar was slower and steadier than from raw poultry litter. • Soil pH greatly influenced the P release patterns of poultry litter biochar

  3. Phosphorus release behaviors of poultry litter biochar as a soil amendment

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yue [Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716 (United States); Lin, Yingxin [Department of Agriculture and Natural Resources, Delaware State University, Dover, DE 19901 (United States); Chiu, Pei C.; Imhoff, Paul T. [Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716 (United States); Guo, Mingxin, E-mail: mguo@desu.edu [Department of Agriculture and Natural Resources, Delaware State University, Dover, DE 19901 (United States)

    2015-04-15

    Phosphorus (P) may be immobilized and consequently the runoff loss risks be reduced if poultry litter (PL) is converted into biochar prior to land application. Laboratory studies were conducted to examine the water extractability of P in PL biochar and its release kinetics in amended soils. Raw PL and its biochar produced through 400 °C pyrolysis were extracted with deionized water under various programs and measured for water extractable P species and contents. The materials were further incubated with a sandy loam at 20 g kg{sup −1} soil and intermittently leached with water for 30 days. The P release kinetics were determined from the P recovery patterns in the water phase. Pyrolysis elevated the total P content from 13.7 g kg{sup −1} in raw PL to 27.1 g kg{sup −1} in PL biochar while reduced the water-soluble P level from 2.95 g kg{sup −1} in the former to 0.17 g kg{sup −1} in the latter. The thermal treatment transformed labile P in raw PL to putatively Mg/Ca phosphate minerals in biochar that were water-unextractable yet proton-releasable. Orthophosphate was the predominant form of water-soluble P in PL biochar, with condensed phosphate (e.g., pyrophosphate) as a minor form and organic phosphate in null. Release of P from PL biochar in both water and neutral soils was at a slower and steadier rate over a longer time period than from raw PL. Nevertheless, release of P from biochar was acid-driven and could be greatly promoted by the media acidity. Land application of PL biochar at soil pH-incorporated rates and frequency will potentially reduce P losses to runoffs and minimize the adverse impact of waste application on aquatic environments. - Highlights: • The predominant portion of P in poultry litter biochar is water insoluble. • Poultry litter P was immobilized by forming Ca/Mg (pyro)phosphates in biochar. • Release of P from biochar was slower and steadier than from raw poultry litter. • Soil pH greatly influenced the P release patterns

  4. The inflow of Cs-137 in soil with root litter and root exudates of Scots pine

    Science.gov (United States)

    Shcheglov, Alexey; Tsvetnova, Olga; Popova, Evgenia

    2017-04-01

    In the model experiment on evaluation of Cs-137 inflow in the soil with litter of roots and woody plants root exudates on the example of soil and water cultures of Scots pine (Pinus sylvestris L.) was shown, that through 45 days after the deposit Cs-137 solution on pine needles (specific activity of solution was 3.718*106 Bk) of the radionuclide in all components of model systems has increased significantly: needles, small branches and trunk by Cs-137 surface contamination during the experiment; roots as a result of the internal distribution of the radionuclide in the plant; soil and soil solution due to the of receipt Cs-137 in the composition of root exudates and root litter. Over 99% of the total reserve of Cs-137 accumulated in the components of the soil and water systems, accounted for bodies subjected to external pollution (needles and small branches) and soil solution, haven't been subjected to surface contamination. At the same contamination of soil and soil solution by Cs-137 in the model experiment more than a> 99.9% was due to root exudates

  5. Enhanced litter input rather than changes in litter chemistry drive soil carbon and nitrogen cycles under elevated CO2: a microcosm study

    Science.gov (United States)

    Lingli Lui; John S. King; Fitzgerald L. Booker; Christian P. Giardina; H. Lee Allen; Shuijin Hu

    2009-01-01

    Elevated CO2 has been shown to stimulate plant productivity and change litter chemistry. These changes in substrate availability may then alter soil microbial processes and possibly lead to feedback effects on N availability. However, the strength of this feedback, and even its direction, remains unknown. Further, uncertainty remains whether...

  6. Effect of petroleum on decomposition of shrub-grass litters in soil in Northern Shaanxi of China.

    Science.gov (United States)

    Zhang, Xiaoxi; Liu, Zengwen; Yu, Qi; Luc, Nhu Trung; Bing, Yuanhao; Zhu, Bochao; Wang, Wenxuan

    2015-07-01

    The impacts of petroleum contamination on the litter decomposition of shrub-grass land would directly influence nutrient cycling, and the stability and function of ecosystem. Ten common shrub and grass species from Yujiaping oil deposits were studied. Litters from these species were placed into litterbags and buried in petroleum-contaminated soil with 3 levels of contamination (slight, moderate and serious pollution with petroleum concentrations of 15, 30 and 45 g/kg, respectively). A decomposition experiment was then conducted in the lab to investigate the impacts of petroleum contamination on litter decomposition rates. Slight pollution did not inhibit the decomposition of any litters and significantly promoted the litter decomposition of Hippophae rhamnoides, Caragana korshinskii, Amorpha fruticosa, Ziziphus jujuba var. spinosa, Periploca sepium, Medicago sativa and Bothriochloa ischaemum. Moderate pollution significantly inhibited litter decomposition of M. sativa, Coronilla varia, Artemisia vestita and Trrifolium repens and significantly promoted the litter decomposition of C. korshinskii, Z. jujuba var. spinosa and P. sepium. Serious pollution significantly inhibited the litter decomposition of H. rhamnoides, A. fruticosa, B. ischaemum and A. vestita and significantly promoted the litter decomposition of Z. jujuba var. spinosa, P. sepium and M. sativa. In addition, the impacts of petroleum contamination did not exhibit a uniform increase or decrease as petroleum concentration increased. Inhibitory effects of petroleum on litter decomposition may hinder the substance cycling and result in the degradation of plant communities in contaminated areas. Copyright © 2015. Published by Elsevier B.V.

  7. Toxicity to woodlice of zinc and lead oxides added to soil litter

    Science.gov (United States)

    Beyer, W.N.; Anderson, A.

    1985-01-01

    Previous studies have shown that high concentrations of metals in soil are associated with reductions in decomposer populations. We have here determined the relation between the concentrations of lead and zinc added as oxides to soil litter and the survival and reproduction of a decomposer population under controlled conditions. Laboratory populations of woodlice (Porcellio scaber Latr) were fed soil litter treated with lead or zinc at concentrations that ranged from 100 to 12,800 ppm. The survival of the adults, the maximum number of young alive, and the average number of young alive, were recorded over 64 weeks. Lead at 12,800 ppm and zinc at 1,600 ppm or more had statistically significant (p zinc have reduced populations of decomposers in contaminated forest soil litter, and concentrations are similar to those reported to be associated with reductions in natural populations of decomposers. Poisoning of decomposers may disrupt nutrient cycling, reduce the numbers of invertebrates available to other wildlife for food, and contribute to the contamination of food chains.

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

    Science.gov (United States)

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

    2008-12-01

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

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

    International Nuclear Information System (INIS)

    Schlesinger, W.H.; Lichter, J.

    2001-01-01

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

  10. The Arbuscular Mycorrhizal Fungus Funneliformis mosseae Alters Bacterial Communities in Subtropical Forest Soils during Litter Decomposition

    Directory of Open Access Journals (Sweden)

    Heng Gui

    2017-06-01

    Full Text Available Bacterial communities and arbuscular mycorrhizal fungi (AMF co-occur in the soil, however, the interaction between these two groups during litter decomposition remains largely unexplored. In order to investigate the effect of AMF on soil bacterial communities, we designed dual compartment microcosms, where AMF (Funneliformis mosseae was allowed access (AM to, or excluded (NM from, a compartment containing forest soil and litterbags. Soil samples from this compartment were analyzed at 0, 90, 120, 150, and 180 days. For each sample, Illumina sequencing was used to assess any changes in the soil bacterial communities. We found that most of the obtained operational taxonomic units (OTUs from both treatments belonged to the phylum of Proteobacteria, Acidobacteria, and Actinobacteria. The community composition of bacteria at phylum and class levels was slightly influenced by both time and AMF. In addition, time and AMF significantly affected bacterial genera (e.g., Candidatus Solibacter, Dyella, Phenylobacterium involved in litter decomposition. Opposite to the bacterial community composition, we found that overall soil bacterial OTU richness and diversity are relatively stable and were not significantly influenced by either time or AMF inoculation. OTU richness at phylum and class levels also showed consistent results with overall bacterial OTU richness. Our study provides new insight into the influence of AMF on soil bacterial communities at the genus level.

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

    Science.gov (United States)

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

    2013-07-01

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

  12. The effects of high-tannin leaf litter from transgenic poplars on microbial communities in microcosm soils.

    Directory of Open Access Journals (Sweden)

    Richard S. Winder

    2013-09-01

    Full Text Available The impacts of leaf litter from genetically-modified hybrid poplar accumulating high levels of condensed tannins (proanthocyanidins were examined in soil microcosms consisting of moss growing on sieved soil. Moss preferentially proliferated in microcosms with lower tannin content; DGGE detected increased fungal diversity in microcosms with low-tannin litter. The proportion of cloned rDNA sequences from Actinobacteria decreased with litter addition while Bacteroidetes, Chloroflexi, Cyanobacteria, and α-Proteobacteria significantly increased. β–Proteobacteria were proportionally more numerous at high tannin levels. Tannins had no significant impact on overall diversity of bacterial communities analyzed with various estimators. There was an increased proportion of N-fixing bacteria corresponding to the addition of litter with low tannin levels. The addition of litter increased the proportion of Ascomycota/Basidiomycota. Dothideomycetes, Pucciniomycetes, and Tremellomycetes also increased and Agaricomycetes decreased. Agaricomycetes and Sordariomycetes were significantly more abundant in controls, whereas Pucciniomycetes increased in soil with litter from transformed trees (P = 0.051. Richness estimators and diversity indices revealed no significant difference in the composition of fungal communities; PCoA partitioned the fungal communities into three groups: (i those with higher amounts of added tannin from both transformed and untransformed treatments, (ii those corresponding to soils without litter, and (iii those corresponding to microcosms with litter added from trees transformed only with a β-glucuronidase (GUS control vector. While the litter from transformed poplars had significant effects on soil microbe communities, the observed impacts reflected known impacts on soil processes associated with tannins, and were similar to changes that would be expected from natural variation in tannin levels.

  13. The effects of high-tannin leaf litter from transgenic poplars on microbial communities in microcosm soils.

    Science.gov (United States)

    Winder, Richard S; Lamarche, Josyanne; Constabel, C Peter; Hamelin, Richard C

    2013-01-01

    The impacts of leaf litter from genetically modified hybrid poplar accumulating high levels of condensed tannins (proanthocyanidins) were examined in soil microcosms consisting of moss growing on sieved soil. Moss preferentially proliferated in microcosms with lower tannin content; DGGE (denaturing gradient gel electrophoresis) detected increased fungal diversity in microcosms with low-tannin litter. The proportion of cloned rDNA sequences from Actinobacteria decreased with litter addition while Bacteroidetes, Chloroflexi, Cyanobacteria, and α-Proteobacteria significantly increased. β-Proteobacteria were proportionally more numerous at high-tannin levels. Tannins had no significant impact on overall diversity of bacterial communities analyzed with various estimators. There was an increased proportion of N-fixing bacteria corresponding to the addition of litter with low-tannin levels. The addition of litter increased the proportion of Ascomycota/Basidiomycota. Dothideomycetes, Pucciniomycetes, and Tremellomycetes also increased and Agaricomycetes decreased. Agaricomycetes and Sordariomycetes were significantly more abundant in controls, whereas Pucciniomycetes increased in soil with litter from transformed trees (P = 0.051). Richness estimators and diversity indices revealed no significant difference in the composition of fungal communities; PCoA (principal coordinate analyses) partitioned the fungal communities into three groups: (i) those with higher amounts of added tannin from both transformed and untransformed treatments, (ii) those corresponding to soils without litter, and (iii) those corresponding to microcosms with litter added from trees transformed only with a β-glucuronidase control vector. While the litter from transformed poplars had significant effects on soil microbe communities, the observed impacts reflected known impacts on soil processes associated with tannins, and were similar to changes that would be expected from natural variation in

  14. Contribution of Topography and Incident Solar Radiation to Variation of Soil and Plant Litter at an Area with Heterogeneous Terrain

    Directory of Open Access Journals (Sweden)

    Felipe Cito Nettesheim

    2015-06-01

    Full Text Available Natural processes that determine soil and plant litter properties are controlled by multiple factors. However, little attention has been given to distinguishing the effects of environmental factors from the effects of spatial structure of the area on the distribution of soil and litter properties in tropical ecosystems covering heterogeneous topographies. The aim of this study was to assess patterns of soil and litter variation in a tropical area that intercepts different levels of solar radiation throughout the year since its topography has slopes predominantly facing opposing geographic directions. Soil data (pH, C, N, P, H+Al, Ca, Mg, K, Al, Na, sand, and silt and plant litter data (N, K, Ca, P, and Mg were gathered together with the geographic coordinates (to model the spatial structure of 40 sampling units established at two sites composed of slopes predominantly facing northwest and southeast (20 units each. Soil and litter chemical properties varied more among slopes within similar geographic orientations than between the slopes facing opposing directions. Both the incident solar radiation and the spatial structure of the area were relevant in explaining the patterns detected in variation of soil and plant litter. Individual contributions of incident solar radiation to explain the variation in the properties evaluated suggested that this and other environmental factors may play a particularly relevant role in determining soil and plant litter distribution in tropical areas with heterogeneous topography. Furthermore, this study corroborates that the spatial structure of the area also plays an important role in the distribution of soil and litter within this type of landscape, which appears to be consistent with the action of water movement mechanisms in such areas.

  15. [Litter decomposition and nutrient release in Acacia mangium plantations established on degraded soils of Colombia].

    Science.gov (United States)

    Castellanos-Barliza, Jeiner; León Peláez, Juan Diego

    2011-03-01

    Several factors control the decomposition in terrestrial ecosystems such as humidity, temperature, quality of litter and microbial activity. We investigated the effects of rainfall and soil plowing prior to the establishment of Acacia mangium plantations, using the litterbag technique, during a six month period, in forests plantations in Bajo Cauca region, Colombia. The annual decomposition constants (k) of simple exponential model, oscillated between 1.24 and 1.80, meanwhile k1 y k2 decomposition constants of double exponential model were 0.88-1.81 and 0.58-7.01. At the end of the study, the mean residual dry matter (RDM) was 47% of the initial value for the three sites. We found a slow N, Ca and Mg release pattern from the A. mangium leaf litter, meanwhile, phosphorus (P) showed a dominant immobilization phase, suggesting its low availability in soils. Chemical leaf litter quality parameters (e.g. N and P concentrations, C/N, N/P ratios and phenols content) showed an important influence on decomposition rates. The results of this study indicated that rainfall plays an important role on the decomposition process, but not soil plowing.

  16. [Contributions of soil fauna to litter decomposition in alpine/subalpine forests].

    Science.gov (United States)

    Liu, Rui-Long; Li, Wei-Min; Yang, Wan-Qin; Tan, Bo; Wang, Wen-Jun; Xu, Zhen-Feng; Wu, Fu-Zhong

    2013-12-01

    A field experiment was conducted using the litterbag method to quantify the contribution of soil fauna to litter mass loss of Salix paraplesia, Sabina saltuaria, Betula albosinensis and Abies faxoniana during different key periods of the decomposition process of the first year (from November 2011 to October 2012). The results showed that the mass loss rate showed S. paraplesia > B. albosinensis > A. faxoniana > S. saltuaria, and the rate in the growing season was greater than in the freeze-thaw season. The contribution rate of soil fauna to the mass decomposition displayed as S. saltuaria (26.7%) > A. faxoniana (18.8%) > B. albosinensis (15.7%) > S. paraplesia (13.2%), which was higher in the freeze-thaw season than in the growing season for litter of B. albo-sinensis and A. faxoniana while vice versa for litter of B. albosinensis and A. faxoniana. The contribution of soil fauna was mainly related to organic C, P and N/P in the freeze-thaw season, while N, C/N, lignin and lignin/cellulose in the growing season.

  17. Bacterial diversity in agricultural soils during litter decomposition

    NARCIS (Netherlands)

    Dilly, O.; Bloem, J.; Vos, A.; Munch, J.C.

    2004-01-01

    Denaturing gradient gel electrophoresis (DGGE) of amplified fragments of genes coding for 16S rRNA was used to study the development of bacterial communities during decomposition of crop residues in agricultural soils. Ten strains were tested, and eight of these strains produced a single band.

  18. Effects of litter addition and warming on soil carbon, nutrient pools and microbial communities in a subarctic heath ecosystem

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Michelsen, Anders; Jonasson, Sven Evert

    2008-01-01

    in the uppermost 5 cm soil, while decreasing the pool of total P per unit area of the organic profile and having no significant effects on N concentrations or pools. Microbial biomass C and N were unaffected by the treatments, while the microbial biomass P increased significantly with litter addition. Soil...... proportion of biomarkers for Gram-positive bacteria. The combined warming plus litter addition treatment decreased the soil water content in the uppermost 5 cm soil, which was a likely reason for many interactions between the effects of warming and litter addition. The soil organic matter quality...... of the combined treatment was also clearly different from the control based on a near-infrared reflectance (NIR) spectroscopic analysis, implying that the treatment altered the composition of soil organic matter. However, it appears that the biological processes and the microbial community composition responded...

  19. Impact of Poultry Litter Cake, Cleanout, and Bedding following Chemical Amendments on Soil C and N Mineralization

    Directory of Open Access Journals (Sweden)

    Dexter B. Watts

    2012-01-01

    Full Text Available Poultry litter is a great alternative N source for crop production. However, recent poultry litter management changes, and increased chemical amendment use may impact its N availability. Thus, research was initiated to evaluate the effect that broiler cake and total cleanout litter amended with chemical additives have on C and N mineralization. A 35-day incubation study was carried out on a Hartsells fine sandy loam (fine-loamy, siliceous, subactive, thermic Typic Hapludults soil common to the USA Appalachian Plateau region. Three poultry litter components (broiler cake, total cleanout, and bedding material from a broiler house were evaluated and compared to a soil control. Chemical amendments lime (CaCO3, gypsum (CaSO4, aluminum sulfate (AlSO4, and ferrous sulfate (FeSO4 were added to the poultry litter components to determine their impact on C and N mineralization. Litter component additions increased soil C mineralization in the order of broiler cake > total cleanout > bedding > soil control. Although a greater concentration of organic C was observed in the bedding, broiler cake mineralized the most C, which can be attributed to differences in the C : N ratio between treatments. Chemical amendment in addition to the manured soil also impacted C mineralization, with AlSO4 generally decreasing mineralization. Nitrogen mineralization was also significantly affected by poultry litter component applications. Broiler cake addition increased N availability followed by total cleanout compared to soil control, while the bedding resulted in net N immobilization. Chemical amendments impacted N mineralization primarily in the broiler cake amended soil where all chemical amendments decreased mineralization compared to the no chemical amendment treatment. This short-term study (35-day incubation indicates that N availability to crops may be different depending on the poultry litter component used for fertilization and chemical amendment use which could

  20. Hydrolytic and ligninolytic enzyme activities in the Pb contaminated soil inoculated with litter-decomposing fungi.

    Science.gov (United States)

    Kähkönen, Mika A; Lankinen, Pauliina; Hatakka, Annele

    2008-06-01

    The impact of Pb contamination was tested to five hydrolytic (beta-glucosidase, beta-xylosidase, beta-cellobiosidase, alpha-glucosidase and sulphatase) and two ligninolytic (manganese peroxidase, MnP and laccase) enzyme activities in the humus layer in the forest soil. The ability of eight selected litter-degrading fungi to grow and produce extracellular enzymes in the heavily Pb (40 g Pb of kg ww soil(-1)) contaminated and non-contaminated soil in the non-sterile conditions was also studied. The Pb content in the test soil was close to that of the shooting range at Hälvälä (37 g Pb of kg ww soil(-1)) in Southern Finland. The fungi were Agaricus bisporus, Agrocybe praecox, Gymnopus peronatus, Gymnopilus sapineus, Mycena galericulata, Gymnopilus luteofolius, Stropharia aeruginosa and Stropharia rugosoannulata. The Pb contamination (40 g Pb of kg ww soil(-1)) was deleterious to all five studied hydrolytic enzyme activities after five weeks of incubation. All five hydrolytic enzyme activities were significantly higher in the soil than in the extract of the soil indicating that a considerable part of enzymes were particle bound in the soils. Hydrolytic enzyme activities were higher in the non-contaminated soil than in the Pb contaminated soil. Fungal inocula increased the hydrolytic enzyme activities beta-cellobiosidase and beta-glucosidase in non-contaminated soils. All five hydrolytic enzyme activities were similar with fungi and without fungi in the Pb contaminated soil. This was in line that Pb contamination (40 g Pb of kg ww soil(-1)) depressed the growth of all fungi compared to those grown without Pb in the soil. Laccase and MnP activities were low in both Pb contaminated and non-contaminated soil cultures. MnP activities were higher in soil cultures containing Pb than without Pb. Our results showed that Pb in the shooting ranges decreased fungal growth and microbial functioning in the soil.

  1. Soil mineral composition matters: response of microbial communities to phenanthrene and plant litter addition in long-term matured artificial soils.

    Science.gov (United States)

    Babin, Doreen; Vogel, Cordula; Zühlke, Sebastian; Schloter, Michael; Pronk, Geertje Johanna; Heister, Katja; Spiteller, Michael; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2014-01-01

    The fate of polycyclic aromatic hydrocarbons (PAHs) in soil is determined by a suite of biotic and abiotic factors, and disentangling their role in the complex soil interaction network remains challenging. Here, we investigate the influence of soil composition on the microbial community structure and its response to the spiked model PAH compound phenanthrene and plant litter. We used long-term matured artificial soils differing in type of clay mineral (illite, montmorillonite) and presence of charcoal or ferrihydrite. The soils received an identical soil microbial fraction and were incubated for more than two years with two sterile manure additions. The matured artificial soils and a natural soil were subjected to the following spiking treatments: (I) phenanthrene, (II) litter, (III) litter + phenanthrene, (IV) unspiked control. Total community DNA was extracted from soil sampled on the day of spiking, 7, 21, and 63 days after spiking. Bacterial 16S rRNA gene and fungal internal transcribed spacer amplicons were quantified by qPCR and subjected to denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed that the bacterial community composition, which was strongly shaped by clay minerals after more than two years of incubation, changed in response to spiked phenanthrene and added litter. DGGE and qPCR showed that soil composition significantly influenced the microbial response to spiking. While fungal communities responded only in presence of litter to phenanthrene spiking, the response of the bacterial communities to phenanthrene was less pronounced when litter was present. Interestingly, microbial communities in all artificial soils were more strongly affected by spiking than in the natural soil, which might indicate the importance of higher microbial diversity to compensate perturbations. This study showed the influence of soil composition on the microbiota and their response to phenanthrene and litter, which may increase our understanding of

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

    Science.gov (United States)

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

    2017-12-01

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

  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. Introducing litter quality to the ecosystem model LPJ-GUESS: Effects on short- and long-term soil carbon dynamics

    Science.gov (United States)

    Portner, Hanspeter; Wolf, Annett; Rühr, Nadine; Bugmann, Harald

    2010-05-01

    Many biogeochemical models have been applied to study the response of the carbon cycle to changes in climate, whereby the process of carbon uptake (photosynthesis) has usually gained more attention than the equally important process of carbon release by respiration. The decomposition of soil organic matter is driven by a combination of factors like soil temperature, soil moisture and litter quality. We have introduced dependence on litter substrate quality to heterotrophic soil respiration in the ecosystem model LPJ-GUESS [Smith et al.(2001)]. We were interested in differences in model projections before and after the inclusion of the dependency both in respect to short- and long-term soil carbon dynamics. The standard implementation of heterotrophic soil respiration in LPJ-GUESS is a simple carbon three-pool model whose decay rates are dependent on soil temperature and soil moisture. We have added dependence on litter quality by coupling LPJ-GUESS to the soil carbon model Yasso07 [Tuomi et al.(2008)]. The Yasso07 model is based on an extensive number of measurements of litter decomposition of forest soils. Apart from the dependence on soil temperature and soil moisture, the Yasso07 model uses carbon soil pools representing different substrate qualities: acid hydrolyzable, water soluble, ethanol soluble, lignin compounds and humus. Additionally Yasso07 differentiates between woody and non-woody litter. In contrary to the reference implementation of LPJ-GUESS, in the new model implementation, the litter now is divided according to its specific quality and added to the corresponding soil carbon pool. The litter quality thereby differs between litter source (leaves, roots, stems) and plant functional type (broadleaved, needleleaved, grass). The two contrasting model implementations were compared and validated at one specific CarboEuropeIP site (Lägern, Switzerland) and on a broader scale all over Switzerland. Our focus lay on the soil respiration for the years 2006

  5. Soil Biochemical Changes Induced by Poultry Litter Application and Conservation Tillage under Cotton Production Systems

    Directory of Open Access Journals (Sweden)

    Seshadri Sajjala

    2012-07-01

    Full Text Available Problems arising from conventional tillage (CT systems (such as soil erosion, decrease of organic matter, environmental damage etc. have led many farmers to the adoption of no-till (NT systems that are more effective in improving soil physical, chemical and microbial properties. Results from this study clearly indicated that NT, mulch tillage (MT, and winter rye cover cropping systems increased the activity of phosphatase, β-glucosidase and arylsulfatase at a 0–10 cm soil depth but decreased the activity of these enzymes at 10–20 cm. The increase in enzyme activity was a good indicator of intensive soil microbial activity in different soil management practices. Poultry litter (PL application under NT, MT, and rye cropping system could be considered as effective management practices due to the improvement in carbon (C content and the biochemical quality at the soil surface. The activities of the studied enzymes were highly correlated with soil total nitrogen (STN soil organic carbon (SOC at the 0–10 cm soil depth, except for acid phosphatase where no correlation was observed. This study revealed that agricultural practices such as tillage, PL, and cover crop cropping system have a noticeable positive effect on soil biochemical activities under cotton production.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  8. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    Directory of Open Access Journals (Sweden)

    Antônio Ocimar Manzi

    2011-04-01

    Full Text Available Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and groundwater chemistry and soil CO2 respiration were studied in forests on sandy soils, whereas drought sensitivity of poorly-drained valley soils was investigated in an artificial drainage experiment. Slightly changes in litter decomposition or water chemistry were observed as a consequence of artificial drainage. Riparian plots did experience higher litter decomposition rates than campina forest. In response to a permanent lowering of the groundwater level from 0.1 m to 0.3 m depth in the drainage plot, topsoil carbon and nitrogen contents decreased substantially. Soil CO2 respiration decreased from 3.7±0.6 µmol m-2 s-1 before drainage to 2.5±0.2 and 0.8±0.1 µmol m-2 s-1 eight and 11 months after drainage, respectively. Soil respiration in the control plot remained constant at 3.7±0.6 µmol m-2 s-1. The above suggests that more frequent droughts may affect topsoil carbon and nitrogen content and soil respiration rates in the riparian ecosystem, and may induce a transition to less diverse campinarana or short-statured campina forest that covers areas with strongly-leached sandy soil.

  9. Short communication: A laboratory study to validate the impact of the addition of Alnus nepalensis leaf litter on carbon and nutrients mineralization in soil

    OpenAIRE

    GAURAV MISHRA; KRISHNA GIRI; ANTARA DUTTA

    2016-01-01

    Abstract. Mishra G, Giri K, Dutta A, Hazarika S and Borgohain P. 2015. A laboratory study to validate the impact of the addition of Alnus nepalensis leaf litter on carbon and nutrients mineralization in soil. Nusantara Bioscience 8: 5-7. Plant litter or residues can be used as soil amendment to maintain the carbon stock and soil fertility. The amount and rate of mineralization depends on biochemical composition of plant litter. Alnus nepalensis (Alder) is known for its symbiotic nitrogen fixa...

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

    Science.gov (United States)

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

    2015-05-15

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

  11. A Greener Arctic: Vascular Plant Litter Input in Subarctic Peat Bogs Changes Soil Invertebrate Diets and Decomposition Patterns

    Science.gov (United States)

    Krab, E. J.; Berg, M. P.; Aerts, R.; van Logtestijn, R. S. P.; Cornelissen, H. H. C.

    2014-12-01

    Climate-change-induced trends towards shrub dominance in subarctic, moss-dominated peatlands will most likely have large effects on soil carbon (C) dynamics through an input of more easily decomposable litter. The mechanisms by which this increase in vascular litter input interacts with the abundance and diet-choice of the decomposer community to alter C-processing have, however, not yet been unraveled. We used a novel 13C tracer approach to link invertebrate species composition (Collembola), abundance and species-specific feeding behavior to C-processing of vascular and peat moss litters. We incubated different litter mixtures, 100% Sphagnum moss litter, 100% Betula leaf litter, and a 50/50 mixture of both, in mesocosms for 406 days. We revealed the transfer of C from the litters to the soil invertebrate species by 13C labeling of each of the litter types and assessed 13C signatures of the invertebrates Collembola species composition differed significantly between Sphagnum and Betula litter. Within the 'single type litter' mesocosms, Collembola species showed different 13C signatures, implying species-specific differences in diet choice. Surprisingly, the species composition and Collembola abundance changed relatively little as a consequence of Betula input to a Sphagnum based system. Their diet choice, however, changed drastically; species-specific differences in diet choice disappeared and approximately 67% of the food ingested by all Collembola originated from Betula litter. Furthermore, litter decomposition patterns corresponded to these findings; mass loss of Betula increased from 16.1% to 26.2% when decomposing in combination with Sphagnum, while Sphagnum decomposed even slower in combination with Betula litter (1.9%) than alone (4.7%). This study is the first to empirically show that collective diet shifts of the peatland decomposer community from mosses towards vascular plant litter may drive altered decomposition patterns. In addition, we showed that

  12. Soil macrofauna and litter nutrients in three tropical tree plantations on a disturbed site in Puerto Rico.

    Science.gov (United States)

    Matthew W. Warren; Xiaoming Zou

    2002-01-01

    Tree plantations are increasingly common in tropical landscapes due to their multiple uses. Plantations vary in structure and composition, and these variations may alter soil fauna communities. Recent studies have demonstrated the important role of soil fauna in the regulation of plant litter decomposition in the tropics. However, little is known about how plantation...

  13. White poplar (Populus alba L. - Litter impact on chemical and biochemical parameters related to nitrogen cycle in contaminated soils

    Directory of Open Access Journals (Sweden)

    Paula Madejon

    2014-04-01

    Full Text Available Aim of study: The aim of this study was to determine the effect of litter from Populus alba on chemical and biochemical properties related to the N cycle in soils with different pH values and trace element contents. We hypothesized that this litter would influence several parameters related to the N cycle and consequently to soil health.Area of study: we collected two reforested contaminated soils of different pH values (AZ pH 7.23 and DO pH = 2.66 and a non-contaminated soil (RHU pH 7.19.Materials and methods: Soil samples were placed in 2,000 cm3 microcosms and were incubated for 40 weeks in controlled conditions. Each soil was mixed with its corresponding litter, and soils without litter were also tested for comparison. Ammonium (NH4+-N and nitrate (NO3–-N content, potential nitrification rate (PNR, microbial biomass nitrogen (MBN, protease activity, and several chemical properties such as pH, available trace element concentrations (extracted with 0.01 M CaCl2 were determined at different times of incubation.Main results: Values of available trace elements did not vary during the incubation and were always higher in acid soil. In neutral soils litter presence increased values of Kjeldahl-N, NO3–-N content, potential nitrification rate (PNR, microbial biomass nitrogen (MBN and protease activity. Presence of trace elements in neutral soils did not alter the parameters studied. However, acidic pH and high content of available trace elements strongly affected NH4+-N andNO3–-N, microbial biomass N and protease activity.Research highlights: Our results showed the negative effect of the acidity and trace element availability in parameters related with the N-cycle.Key words: microbial biomass N; protease activity; soil pH; N mineralization; nitrification; phytoremediation.

  14. The effect of soil macrofauna on litter decomposition and soil organic matter accumulation during soil formation in spoil heaps after brown coal mining: a preliminary results

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan

    2002-01-01

    Roč. 21, č. 4 (2002), s. 363-369 ISSN 1335-342X R&D Projects: GA ČR GA526/01/1055 Institutional research plan: CEZ:AV0Z6066911 Keywords : soil formation * microbial respiration * litter bag test Subject RIV: EH - Ecology, Behaviour Impact factor: 0.246, year: 2002

  15. Distribution of black carbon in Ponderosa pine litter and soils following the High Park wildfire

    Science.gov (United States)

    Boot, C. M.; Haddix, M.; Paustian, K.; Cotrufo, M. F.

    2014-12-01

    Black carbon (BC), the heterogeneous product of burned biomass, is a critical component in the global carbon cycle, yet timescales and mechanisms for incorporation into the soil profile are not well understood. The High Park Fire, which took place in northwestern Colorado in the summer of 2012, provided an opportunity to study the effects of both fire intenstiy and geomorphology on properties of carbon (C), nitrogen (N), and BC in the Cache La Poudre River drainage. We sampled montane Ponderosa pine litter, 0-5 cm soils, and 5-15 cm soils four months post-fire in order to examine the effects of slope and burn intensity on %C, C stocks, %N and black carbon (g kg-1 C, and g m-2). We developed and implemented the benzene polycarboxylic acid (BPCA) method for quantifying BC. With regard to slope, we found that steeper slopes had higher C : N than shallow slopes, but that there was no difference in black carbon content or stocks. BC content was greatest in the litter in burned sites (19 g kg-1 C), while BC stocks were greatest in the 5-15 cm subsurface soils (23 g m-2). At the time of sampling, none of the BC deposited on the land surface post-fire had been incorporated into to either the 0-5 cm or 5-15 cm soil layers. The ratio of B5CA : B6CA (less condensed to more condensed BC) indicated there was significantly more older, more processed BC at depth. Total BC soil stocks were relatively low compared to other fire-prone grassland and boreal forest systems, indicating most of the BC produced in this system is likely transported off the surface through erosion events. Future work examining mechanisms for BC transport will be required for understanding the role BC plays in the global carbon cycle.

  16. White popular (Populus alba L.) - Litter impact on chemical and biochemical parameters related to nitrogen cycle in contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Ciadamidaro, L.; Madejon, P.; Cabrera, F.; Madejon, E.

    2014-06-01

    Aim of study: The aim of this study was to determine the effect of litter from Populus alba on chemical and biochemical properties related to the N cycle in soils with different pH values and trace element contents. We hypothesized that this litter would influence several parameters related to the N cycle and consequently to soil health. Area of study: we collected two reforested contaminated soils of different pH values (AZ pH 7.23 and DO pH 2.66) and a non-contaminated soil (RHU pH 7.19). Materials and methods: Soil samples were placed in 2,000 cm{sup 3} microcosms and were incubated for 40 weeks in controlled conditions. Each soil was mixed with its corresponding litter, and soils without litter were also tested for comparison. Ammonium (NH{sub 4}{sup 4}+-N) and nitrate (NO{sub 3}{sup -} -N) content, potential nitrification rate (PNR), microbial biomass nitrogen (MBN), protease activity, and several chemical properties such as pH, available trace element concentrations (extracted with 0.01 M CaCl{sub 2}) were determined at different times of incubation. Main results: Values of available trace elements did not vary during the incubation and were always higher in acid soil. In neutral soils litter presence increased values of Kjeldahl-N, NO{sub 3} –-N content, potential nitrification rate (PNR), microbial biomass nitrogen (MBN) and protease activity. Presence of trace elements in neutral soils did not alter the parameters studied. However, acidic pH and high content of available trace elements strongly affected NH{sub 4}{sup +}-N and NO{sub 3}{sup -} -N, microbial biomass N and protease activity. Research highlights: Our results showed the negative effect of the acidity and trace element availability in parameters related with the N-cycle. (Author)

  17. Litter Production and Decomposition Rate in the Reclaimed Mined Land under Albizia and Sesbania Stands and Their Effects on some Soil Chemical Properties

    Directory of Open Access Journals (Sweden)

    Hery Suhartoyo

    2011-01-01

    Full Text Available Vegetation establishment is considered as a critical step of mined land rehabilitation. The growing plants do not only prevent soil erosion, but also play important roles in soil ecosystem development. Their litterfall is the main process of transferring organic matter and nutrients from aboveground tree biomass to soil. Thus, its quantification would aid in understanding biomass and nutrient dynamics of the ecosystem. This study was aimed to investigate the litter production and its decomposition rate in a reclaimed mined land using albizia and sesbania, and their effects on some soil properties. The litter under each stand was biweekly collected for four months. At the same time litter samples were decomposed in mesh nylon bags in soils and the remaining litters were biweekly measured. Soil samples were taken from 0-15 cm depths from each stand for analyses of soil organic C, total N, and cation exchange capacity (CEC. The results demonstrated that total litter production under albizia (10.58 t ha-1 yr-1 was almost twice as much as that under sesbania stands (5.43 t ha-1 yr-1. Albizia litter was dominated by leaf litter (49.26% and least as understory vegetation (23.31%, whereas sesbania litter was more evenly distributed among litter types. Decomposition rates of all litters were fastest in the initial stage and then gradually decreased. Sesbania leaf litters decomposed fastest, while albizia twigs slowest. Differences in the litter production and decomposition rates of the two species had not sufficiently caused significant effects on organic-C, total N, and CEC of the soils after one year of revegetation.

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

    Science.gov (United States)

    Fahey, T.; Yavitt, J. B.

    2012-12-01

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

  19. Effects of long-term poultry litter application on phosphorus soil chemistry and runoff water quality.

    Science.gov (United States)

    Reiter, Mark S; Daniel, Tommy C; DeLaune, Paul B; Sharpley, Andrew N; Lory, John A

    2013-11-01

    Continuous application of poultry litter (PL) significantly changes many soil properties, including soil test P (STP); Al, Fe, and Ca concentrations; and pH, which can affect the potential for P transport in surface runoff water. We conducted rainfall simulations on three historically acidic silt loam soils in Arkansas, Missouri, and Virginia to establish if long-term PL applications would affect soil inorganic P fractions and the resulting dissolved reactive P (DRP) in runoff water. Soil samples (0-5 cm depth) were taken to find sites ranging in Mehlich-3 STP from 20 to 1154 mg P kg. Simulated rainfall events were conducted on 3-m plots at 6.7 cm h, and runoff was collected for 30 min. Correlation between Mehlich-3 and runoff DRP indicated a linear relationship to 833 mg Mehlich-3 P kg. As Mehlich-3 STP increased, a concomitant increase in soil pH and Ca occurred on all soils. Soil P fractionation demonstrated that, as Mehlich-3 STP generally increased above 450 mg P kg (from high to very high), the easily soluble and loosely bound P fractions decreased by 3 to 10%. Water-insoluble complexes of P bound to Al and Ca were the main drivers in the reduction of DRP in runoff, accounting for up to 43 and 38% of total P, respectively. Basing runoff DRP concentration projections solely on Mehlich-3 STP may overestimate runoff P losses from soils receiving long-term PL applications due to dissolution of water-insoluble Ca-P compounds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  20. Effects of Plant Functional Group Loss on Soil Microbial Community and Litter Decomposition in a Steppe Vegetation.

    Science.gov (United States)

    Xiao, Chunwang; Zhou, Yong; Su, Jiaqi; Yang, Fan

    2017-01-01

    Globally, many terrestrial ecosystems are experiencing a rapid loss of biodiversity. Continued improvements in our understanding of interrelationships between plant diversity and soil microbes are critical to address the concern over the consequences of the decline in biodiversity on ecosystem functioning and services. By removing forbs, or grasses, or, to an extreme scenario, both forbs and grasses in a steppe vegetation in Inner Mongolia, we studied how plant functional group (PFG) loss affects soil microbial community composition using phospholipid fatty acid analysis (PLFA) and litter decomposition using a litter-bag method. PFG loss significantly decreased above- and below-ground plant biomass, soil microbial biomass carbon (SMBC) and nitrogen (SMBN), but had no effect on the ratio of SMBC to SMBN. Although the ratio of fungal to bacterial PLFAs remained unaffected, PFG loss significantly reduced the amount of bacterial, fungal, and total PLFAs. PFG loss decreased litter monthly mass loss and decay constant, and such decrease was significant when both forbs and grasses were removed. Our results provide robust evidence that PFG loss in grassland ecosystem can lead to a rapid response of soil microbial activity which may affect litter decomposition and soil nutrient cycling, suggesting that the assessment of plant-microbe interactions in soils is an integral component of ecosystem response to biodiversity loss.

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

    Science.gov (United States)

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

  2. Decomposition of litter and soil organic matter - Can we distinguish a mechanism for soil organic matter buildup ?

    International Nuclear Information System (INIS)

    Berg, B.; Johansson, M.B.; McClaugherty, C.; Virzo de Santo, A.; Ekbohm, G.

    1995-01-01

    This synthesis paper presents a model for estimating the buildup of soil organic matter in various types of coniferous forests. The knowledge used was obtained from a well-studied forest with good litterfall data, decomposition information and validation measurements of the soil organic matter layer. By constructing a simple model for litterfall, and the information on maximum decomposition levels for litter, we could estimate the annual increase in soil organic matter and extend this to encompass stand age. The validation measurement and the estimated amount of soil organic matter differed by about 8 or 26% over a 120-yr period, depending on the litterfall model. The estimated increased storage of soil organic matter as a consequence of climate change was found to be drastic. We thus found that the soil organic matter layer would grow about four times as fast as a result of the needle component only. This estimate was based on a comparison between latitudes with a difference of 17 degrees. 35 refs, 7 figs, 3 tabs

  3. Nitrogen mineralization and nitrous oxide emissions in a sandy soil amended with low-phosphorus broiler litter

    Science.gov (United States)

    Recurrent land application of broiler litter in regions with a high concentration of poultry farms result in soils with phosphorus (P) far beyond the agronomic requirement of crops. A new waste treatment technology developed by USDA-ARS, called “Quick Wash”, chemically extracts and recovers P from b...

  4. INTERACTIVE EFFECTS OF CO2 AND O3 ON A PONDEROSA PINE PLANT/LITTER/SOIL MESOCOSM

    Science.gov (United States)

    To study individual and combined impacts of two important atmospheric trace gases, CO2 and O3, on C and N cycling in forest ecosystems; a four-year experiment using a small-scale ponderosa pine (Pinus ponderosa Laws.) seedling/soil/litter system was initiated in April, 1998. Th...

  5. Composition of fungal and bacterial communities in forest litter and soil is largely determined by dominant trees

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Michaela; Šnajdr, Jaroslav; Baldrian, Petr

    2015-01-01

    Roč. 84, č. 1 (2015), s. 53-64 ISSN 0038-0717 R&D Projects: GA MŠk LD12050; GA ČR GAP504/12/1288; GA ČR GA13-06763S Institutional support: RVO:61388971 Keywords : Litter * Bacteria * Forest soil Subject RIV: EE - Microbiology, Virology Impact factor: 4.152, year: 2015

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

    Directory of Open Access Journals (Sweden)

    E. V. J. Tanner

    2016-11-01

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

  7. Effects of belowground litter addition, increased precipitation and clipping on soil carbon and nitrogen mineralization in a temperate steppe

    OpenAIRE

    Ma, L.; Guo, C.; Xin, X.; Yuan, S.; Wang, R.

    2013-01-01

    Soil carbon (C) and nitrogen (N) cycling are sensitive to changes in environmental factors and play critical roles in the responses of terrestrial ecosystems to natural and anthropogenic perturbations. This study was conducted to quantify the effects of belowground particulate litter (BPL) addition, increased precipitation and their interactions on soil C and N mineralization in two adjacent sites where belowground photosynthate allocation was manipulated through vegetation ...

  8. Production of cellulases by fungal cultures isolated from forest litter soil

    Directory of Open Access Journals (Sweden)

    A. Sri Lakshmi

    2012-06-01

    Full Text Available The aims of this study were the isolation and screening of fungal cultures from forest litter soil for cellulases production. In the present study, four fungal cultures were isolated and identified. Among these fungal cultures, three belonged to the genus Aspergillus and one belonged to the genus Pencillium. These fungal cultures were tested to find their ability to produce cellulases, that catalyze the degradation of cellulose, which is a linear polymer made of glucose subunits linked by beta-1, 4 glycosidic bonds. The fungal isolate 3 (Aspergillus sp. was noticed to show maximum zone of hydrolysis of carboxy-methyl cellulose and produce higher titers of cellulases including exoglucanase, endoglucanase and beta -D-glucosidase. The activities of the cellulases were determined by Filter paper assay (FPA, Carboxy-methly cellulase assay (CMCase and beta -D-glucosidase assay respectively. The total soluble sugar and extracellular protein contents of the fungal filtrates were also determined.

  9. Mineral cycling in soil and litter arthropod food chains. Annual progress report, February 1, 1983-January 31, 1984

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1983-01-01

    This annual report describes progress in research on the influence of soil fauna on the general process of terrestrial decomposition. The major goal is to investigate the regulation of decomposition by soil arthropods. Methods have included radioactive tracer measurements of food chain dynamics, rates of nutrient or mineral element flow during decomposition, and simulation modeling. This year's report describes significant progress in defining the influence of soil arthropods in stimulating microbial immobilization of nutrients. Preliminary efforts to define the importance of the soil-litter macroarthropods are also reported

  10. [Contribution of soil fauna to litter decomposition of Abies faxoniana and Rhododendron lapponicum across an alpine timberline ecotone in Western Sichuan, China.

    Science.gov (United States)

    Wang, Li Feng; He, Run Lian; Yang, Lin; Chen, Ya Mei; Liu, Yang; Zhang, Jian

    2016-11-18

    Soil fauna is an important biological factor in regulation litter decomposition. In order to quantify the contributions of soil fauna to the mass losses of litter of two dominant species fir (Abies faxoniana) and rhododendron (Rhododendron lapponicum) in the alpine timberline ecotone (coniferous forest-timberline-alpine meadow) of western Sichuan, China, a field litterbag experiment was conducted from May 2013 to November 2014. Samples of air-dried leaf litter were placed in nylon litterbags of two different mesh sizes, i.e. 3.00 mm (with the soil animals) and 0.04 mm (excluded the soil animals). The results showed that the decomposition rate of A. faxoniana (k: 0.209-0.243) was higher than that of R. lapponicum (k: 0.173-0.189) across the timberline ecotone. Soil fauna had significant contributions to litter decomposition of two species, the contributions of soil fauna to mass loss showed a decreasing trend with increasing altitude. From the coniferous forest to the alpine meadow, the mass losses caused by soil fauna for the fir litter accounted for 15.2%, 13.2% and 9.8%, respectively and that for the rhododendron litter accounted for 20.1%, 17.5% and 12.4%, respectively. Meanwhile, the daily average contributions caused by soil fauna for the fir and rhododendron litter decomposition accounted for 0.17%, 0.13%, 0.12% and 0.26%, 0.25%, 0.23%, respectively. Relatively, soil fauna had more influence on alpine rhododendron decomposition. Two-way ANOVA showed that species, altitude and their interaction had significant impact on the litter mass loss and decomposition rate caused by soil fauna. The daily average contribution caused by soil fauna for the fir and rhododendron litter decomposition accounted for 0.25% and 0.44% in the first growing season, then 0.10% and 0.19% in the second growing season, both were higher than that of snow-covered season (0.07% and 0.12%). Regression analysis showed that the environmental factors (daily average temperature, freezing and

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

    Science.gov (United States)

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

    2011-11-01

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

  12. Plant litter effects on soil nutrient availability and vegetation dynamics: changes that occur when annual grasses invade shrub-steppe communities

    Science.gov (United States)

    Sheel Bansal; Roger L. Sheley; Bob Blank; Edward A. Vasquez

    2014-01-01

    Changes in the quantity and quality of plant litter occur in many ecosystems as they are invaded by exotic species, which impact soil nutrient cycling and plant community composition. Such changes in sagebrush-steppe communities are occurring with invasion of annual grasses (AG) into a perennial grass (PG) dominated system. We conducted a 5-year litter manipulation...

  13. Plant community and litter composition in temperate deciduous woodlots along two field gradients of soil Ni, Cu and Co concentrations

    International Nuclear Information System (INIS)

    Hale, Beverley; Robertson, Paul

    2016-01-01

    Perennial plant communities in the proximity of metal smelters and refineries may receive substantial inputs of base metal particulate as well as sulphate from the co-emission of sulphur dioxide. The Ni refinery at Port Colborne (Canada) operated by Inco (now Vale Canada Ltd.) emitted Ni, Co and Cu, along with sulphur dioxide, between 1918 and 1984. The objectives were to determine if vascular plant community composition, including standing litter, in twenty-one woodlots on clay or organic soil, were related to soil Ni concentration which decreased in concentration with distance from the Ni refinery. The soil Ni concentration in the clay woodlots ranged from 16 to 4130 mg Ni/kg, and in the organic woodlots, ranged from 98 to 22,700 mg Ni/kg. The concentrations of Co and Cu in the soils were also elevated, and highly correlated with soil Ni concentration. In consequence, each series of woodlots constituted a ‘fixed ratio ray’ of metal mixture exposure. For each of the woodlots, there were 16 independent measurements of ‘woodlot status’ which were correlated with elevated soil Ni concentration. Of the 32 combinations, there were eight linear correlations with soil Ni concentration, considerably more than would be expected by chance alone at a p-value of 0.05. With the exception of mean crown rating for shrubs at the clay sites, the correlations were consistent with the hypothesis that increased soil metal concentrations would be correlated with decreased diversity, plant community health or fitness, and increased accumulation of litter. Only five of the eight linear correlations were from the organic woodlots, suggesting that the observations were not confounded with soil type nor range in soil metal concentrations. - Highlights: • Temperate woodlots on organic or clay soils with gradient of soil Ni were studied. • Soil Ni ranged up to 4100 mg/kg on clay and up to 22,700 mg/kg on organic. • Most indices of plant community status were not correlated

  14. Plant litter chemistry alters the content and composition of organic carbon associated with soil mineral and aggregate fractions in invaded ecosystems.

    Science.gov (United States)

    Tamura, Mioko; Suseela, Vidya; Simpson, Myrna; Powell, Brian; Tharayil, Nishanth

    2017-10-01

    Through the input of disproportionate quantities of chemically distinct litter, invasive plants may potentially influence the fate of organic matter associated with soil mineral and aggregate fractions in some of the ecosystems they invade. Although context dependent, these native ecosystems subjected to prolonged invasion by exotic plants may be instrumental in distinguishing the role of plant-microbe-mineral interactions from the broader edaphic and climatic influences on the formation of soil organic matter (SOM). We hypothesized that the soils subjected to prolonged invasion by an exotic plant that input recalcitrant litter (Japanese knotweed, Polygonum cuspidatum) would have a greater proportion of plant-derived carbon (C) in the aggregate fractions, as compared with that in adjacent soil inhabited by native vegetation that input labile litter, whereas the soils under an invader that input labile litter (kudzu, Pueraria lobata) would have a greater proportion of microbial-derived C in the silt-clay fraction, as compared with that in adjacent soils that receive recalcitrant litter. At the knotweed site, the higher C content in soils under P. cuspidatum, compared with noninvaded soils inhabited by grasses and forbs, was limited to the macroaggregate fraction, which was abundant in plant biomarkers. The noninvaded soils at this site had a higher abundance of lignins in mineral and microaggregate fractions and suberin in the macroaggregate fraction, partly because of the greater root density of the native species, which might have had an overriding influence on the chemistry of the above-ground litter input. At the kudzu site, soils under P. lobata had lower C content across all size fractions at a 0-5 cm soil depth despite receiving similar amounts of Pinus litter. Contrary to our prediction, the noninvaded soils receiving recalcitrant Pinus litter had a similar abundance of plant biomarkers across both mineral and aggregate fractions, potentially because of

  15. The influence of land use systems on soil and surface litter fauna in the western region of Santa Catarina

    Directory of Open Access Journals (Sweden)

    Marie Luise Carolina Bartz

    Full Text Available The aim of this study was to evaluate the abundance of soil and surface litter fauna in the western region of Santa Catarina state, southern Brazil, in the following land use systems (LUS: no-tillage crops (NT, integrated crop-livestock (ICL, pasture (PA, Eucalyptus plantation (EP and native forest fragments (NF. Sampling was done in three counties in the western region of Santa Catarina: Xanxerê, Chapecó and São Miguel do Oeste, in two seasons (winter and summer. The evaluation of soil/litter fauna in each LUS was performed by installing nine "pitfall traps" per sampling grid (3 x 3. The counties are true replicas. The soil for the chemical attributes was collected at the same sampling points for soil fauna. Altogether, 17 taxa were identified in the five LUS. The presence of groups of fauna was influenced by the type of soil management used. The LUS NF and EP provide better soil conditions for the development of a higher diversity of soil fauna groups compared to other LUS, which showed varying degrees of human intervention, regardless of the sampling season (winter or summer. However, annual crop systems NT and ICL groups showed greater richness and total abundance when compared to the perennial systems (EP and PA. Principal component analysis is an important tool in the study of biological indicators of sustainability because it allows use of soil attributes (chemical and physical as explanatory environmental variables, which helps in the interpretation of ecological data.

  16. Microbial communities in litter and soil - particles size fractionation, C- and N-pools and soil enzymes

    International Nuclear Information System (INIS)

    Stemmer, M.; Gerzabek, M.H.; Pichlmayer, F.; Kandeler, E.

    1995-08-01

    In this study we try to correlate C and N pool investigations to enzyme activities in particle size fractions of soils. Soil incubations in the lab (for one year) simulate two different conventional tillage treatments : (i) soil mixed with maize straw (GSF-mixed) and (ii) soil with maize straw lying on the top (home-mixed). The control soil is incubated without any amendment. The separation of the particle size fractions (2000 - 200 μm, 200 - 63 μm, 63 - 2 μm, 2 - 0.1 μm and 0.1 - 0 μm) is realized by a combination of wet-sieving and centrifugation. To disrupt aggregates we use a defined low-energy ultrasonication, which partly preserves microaggregates. The decomposition of organic C during the incubation can be observed clearly, the small amount of N in the added maize straw complicates the analysis. The isotopic measurements of δ13C and δ15N provide valuable additional informations in this context. Both enzymes, saccharase and xylanase, seem to react in a more sensitive way on the incorporation of the maize litter, than the chemical analysis of the pools. The saccharase activity, which seems to be a sensitive indicator for microbial biomass, shows different behaviour between the mix- and top-treatment. The xylanase activity is mainly located in the coarse sand fraction, this extracellular enzyme might be adsorbed by the particulate organic matter. The transfer of adhering coatings and small particles of the added maize to small sized particles during the fractionation procedure and the 'passive role' of the silt fraction, which could be due to the used method, are nonexpected results. (author)

  17. Transformation of leaf litter by insect herbivory in the Subarctic: Consequences for soil biogeochemistry under global change

    Science.gov (United States)

    Kristensen, J. A.; Metcalfe, D. B.; Rousk, J.

    2017-12-01

    Climate warming may increase insect herbivore ranges and outbreak intensities in arctic ecosystems. Thorough understanding of the implications of these changes for ecosystem processes is essential to make accurate predictions of surface-atmosphere carbon (C) feedbacks. Yet, we lack a comprehensive understanding of the impacts of herbivore outbreaks on soil microbial underpinnings of C and nitrogen (N) fluxes. Here, we investigate the growth responses of heterotrophic soil decomposers and C and N mineralisation to simulated defoliator outbreaks in Subarctic birch forests. In microcosms, topsoil was incubated with leaf litter, insect frass, mineral N and combinations of the three; all was added in equal amounts of N. A higher fraction of added C and N was mineralised during outbreaks (frass addition) relative to non-outbreak years (litter addition). However, under high mineral N-availability in the soil of the kind likely under longer periods of enhanced insect herbivory (litter+mineral N), the mineralised fraction of added C decreased while the mineralised fraction of N increased substantially, which suggest a shift towards more N-mining of the organic substrates. This shift was accompanied by higher fungal dominance, and may facilitate soil C-accumulation assuming constant quality of C-inputs. Thus, long-term increases of insect herbivory, of the kind observed in some areas and projected by some models, may facilitate higher ecosystem C-sink capacity in this Subarctic ecosystem.

  18. Short communication: A laboratory study to validate the impact of the addition of Alnus nepalensis leaf litter on carbon and nutrients mineralization in soil

    Directory of Open Access Journals (Sweden)

    GAURAV MISHRA

    2016-04-01

    Full Text Available Abstract. Mishra G, Giri K, Dutta A, Hazarika S and Borgohain P. 2015. A laboratory study to validate the impact of the addition of Alnus nepalensis leaf litter on carbon and nutrients mineralization in soil. Nusantara Bioscience 8: 5-7. Plant litter or residues can be used as soil amendment to maintain the carbon stock and soil fertility. The amount and rate of mineralization depends on biochemical composition of plant litter. Alnus nepalensis (Alder is known for its symbiotic nitrogen fixation and capability to restore fertility of degraded lands. A laboratory incubation experiment was conducted for 60 days under controlled conditions to validate the carbon and nutrients mineralization potential of alder litter. Soil fertility indicators, i.e. soil organic carbon (SOC, available nitrogen (N, available phosphorus (P, and available potassium (K were analyzed using standard procedures. Significant differences were observed in the soil properties after addition of litter. Nutrient composition of alder litter was found superior by providing significantly higher organic matter and helped in better nutrient cycling. Therefore, alder based land use system may be replicated in other degraded lands or areas for productivity enhancement which is important for sustaining biodiversity and soil fertility.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-11-01

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

  20. Microbial Composition in Decomposing Pine Litter Shifts in Response to Common Soil Secondary Minerals

    Science.gov (United States)

    Welty-Bernard, A. T.; Heckman, K.; Vazquez, A.; Rasmussen, C.; Chorover, J.; Schwartz, E.

    2011-12-01

    A range of environmental and biotic factors have been identified that drive microbial community structure in soils - carbon substrates, redox conditions, mineral nutrients, salinity, pH, and species interactions. However, soil mineralogy has been largely ignored as a candidate in spite of recent studies that indicate that minerals have a substantial impact on soil organic matter stores and subsequent fluxes from soils. Given that secondary minerals and organic colloids govern a soil's biogeochemical activity due to surface area and electromagnetic charge, we propose that secondary minerals are a strong determinant of the communities that are responsible for process rates. To test this, we created three microcosms to study communities during decomposition using pine forest litter mixed with two common secondary minerals in soils (goethite and gibbsite) and with quartz as a control. Changes in bacterial and fungal communities were tracked over the 154-day incubation by pyrosequencing fragments of the bacterial 16S and fungal 18S rRNA genes. Ordination using nonmetric multidimensional scaling showed that bacterial communities separated on the basis of minerals. Overall, a single generalist - identified as an Acidobacteriaceae isolate - dominated all treatments over the course of the experiment, representing roughly 25% of all communities. Fungal communities discriminated between the quartz control alone and mineral treatments as a whole. Again, several generalists dominated the community. Coniochaeta ligniaria dominated communities with abundances ranging from 29 to 40%. The general stability of generalist populations may explain the similarities between treatment respiration rates. Variation between molecular fingerprints, then, were largely a function of unique minor members with abundances ranging from 0.01 to 8%. Carbon availability did not surface as a possible mechanism responsible for shifts in fingerprints due to the relatively large mass of needles in the

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

    Science.gov (United States)

    Hall, S. J.; Hammel, K.

    2017-12-01

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

  2. Organic Carbon Accumulation in Topsoil Following Afforestation with Willow: Emphasis on Leaf Litter Decomposition and Soil Organic Matter Quality

    Directory of Open Access Journals (Sweden)

    Benoit Lafleur

    2015-03-01

    Full Text Available Short-rotation intensive cultures (SRICs of willows can potentially sequester carbon (C in soil. However, there is limited information regarding the factors governing soil organic C (Corg accumulation following afforestation. The objectives of this study were to: (i determine whether willow leads to Corg accumulation in the topsoil (0–10 cm two to six years after establishment in five SRICs located along a large climatic/productivity gradient in southern Quebec, and (ii assess the influence of leaf litter decomposition and soil organic matter (OM quality on Corg accumulation in the topsoil. Topsoil Corg concentrations and pools under SRICs were, on average, 25% greater than reference fields, and alkyls concentrations were higher under SRICs. On an annualized basis, Corg accumulation rates in the topsoil varied between 0.4 and 4.5 Mg ha−1 yr−1. Estimated annual litterfall C fluxes were in the same order of magnitude, suggesting that SRICs can accumulate Corg in the topsoil during early years due to high growth rates. Leaf litter decomposition was also related to Corg accumulation rates in the topsoil. It was positively correlated to growing season length, degree-days, and growing season average air and topsoil temperature (r > 0.70, and negatively correlated to topsoil volumetric water content (r = −0.55. Leaf litter decomposition likely occurred more quickly than that of plants in reference fields, and as it progressed, OM became more decay resistant, more stable and accumulated as Corg in the topsoil.

  3. Soil respiration as affected by long-term broiler litter application to a udult in the ozark highlands.

    Science.gov (United States)

    McMullen, Richard L; Brye, Kristofor R; Gbur, Edward E

    2015-01-01

    The United States produced 8.4 billion broiler chickens () and an estimated 10.1 to 14.3 million Mg of broiler litter (BL) in 2012. Arkansas' production of 1 billion broilers in 2012 produced an estimated 1.2 to 1.7 million Mg of BL, most of which was concentrated in the Ozark Highlands region of northwest Arkansas. Increased CO release from soils associated with agricultural practices has generated concerns regarding the contribution of certain agricultural management practices to global warming. The objectives of this study were to evaluate the effects of long-term (>6 yr) BL application to a Udult on soil respiration and annual C emissions and to determine the predictability of soil respiration based on soil temperature and moisture in the Ozark Highlands region of northwest Arkansas. Soil respiration was measured routinely between May 2009 and May 2012 in response to annual BL application rates of 0, 5.6, and 11.2 Mg dry litter ha that began in 2003. Soil respiration varied ( 0.05) by BL application rate but differed ( < 0.01) among study years. Multiple regression indicated that soil respiration could be reasonably predicted using 2-cm-depth soil temperature (T) and the product of T and VWC as predictors ( = 0.52; < 0.01). Results indicate that organic amendments, such as BL, can stimulate release of CO from the soil to the atmosphere, potentially negatively affecting atmospheric greenhouse gas concentrations; thus, there may be application rates above which the benefits of organic amendments may be diminished by adverse environmental effects. Improved BL management strategies are needed to lessen the loss of CO from BL-amended soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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

    International Nuclear Information System (INIS)

    Haberhauer, G.; Gerzabek, M.H.

    1999-06-01

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

  5. Carbon dioxide efflux from soil with poultry litter applications in conventional and conservation tillage systems in northern Alabama.

    Science.gov (United States)

    Roberson, T; Reddy, K C; Reddy, S S; Nyakatawa, E Z; Raper, R L; Reeves, D W; Lemunyon, J

    2008-01-01

    Increased CO2 release from soils resulting from agricultural practices such as tillage has generated concerns about contributions to global warming. Maintaining current levels of soil C and/or sequestering additional C in soils are important mechanisms to reduce CO2 in the atmosphere through production agriculture. We conducted a study in northern Alabama from 2003 to 2006 to measure CO2 efflux and C storage in long-term tilled and non-tilled cotton (Gossypium hirsutum L.) plots receiving poultry litter or ammonium nitrate (AN). Treatments were established in 1996 on a Decatur silt loam (clayey, kaolinitic thermic, Typic Paleudults) and consisted of conventional-tillage (CT), mulch-tillage (MT), and no-tillage (NT) systems with winter rye [Secale cereale (L.)] cover cropping and AN and poultry litter (PL) as nitrogen sources. Cotton was planted in 2003, 2004, and 2006. Corn was planted in 2005 as a rotation crop using a no-till planter in all plots, and no fertilizer was applied. Poultry litter application resulted in higher CO2 emission from soil compared with AN application regardless of tillage system. In 2003 and 2006, CT (4.39 and 3.40 micromol m(-2) s(-1), respectively) and MT (4.17 and 3.39 micromol m(-2) s(-1), respectively) with PL at 100 kg N ha(-1) (100 PLN) recorded significantly higher CO2 efflux compared with NT with 100 PLN (2.84 and 2.47 micromol m(-2) s(-1), respectively). Total soil C at 0- to 15-cm depth was not affected by tillage but significantly increased with PL application and winter rye cover cropping. In general, cotton produced with NT conservation tillage in conjunction with PL and winter rye cover cropping reduced CO2 emissions and sequestered more soil C compared with control treatments.

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

    Science.gov (United States)

    Yang, Zhao; Yang, Xiao-Dong

    2011-11-01

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

  7. Effect of climate-related change in vegetation on leaf litter consumption and energy storage by Gammarus pulex from Continental or Mediterranean populations.

    Directory of Open Access Journals (Sweden)

    Natacha Foucreau

    Full Text Available As a consequence of global warming, it is important to characterise the potential changes occurring for some functional processes through the intra-specific study of key species. Changes in species distribution, particularly when key or engineer species are affected, should contribute to global changes in ecosystem functioning. In this study, we examined the potential consequences induced by global warming on ecosystem functioning in term of organic matter recycling. We compared consumption of leaf litter by some shredder populations (Gammarus pulex between five tree species inhabiting continental (i.e., the northern region of the Rhône River Valley and/or Mediterranean (i.e., the southern region of the Rhône River Valley conditions. To consider any potential adaptation of the gammarid population to vegetation in the same climate conditions, three populations of the key shredder Gammarus pulex from the northern region and three from the southern region of the Rhône River Valley were used. We experimentally compared the effects of the geographical origin of both the gammarid populations and the leaf litter species on the shredding activity and the physiological state of animals (through body triglyceride content. This study demonstrated that leaf toughness is more important than geographical origin for determining shredder leaf litter consumption. The overall consumption rate of the gammarid populations from the southern region of Rhône Valley was much higher than that of the populations from the northern region, but no clear differences between the origins of the leaf litter (i.e., continental vs. Mediterranean were observed. The northwards shift of G. pulex populations adapted to warmer conditions might significantly modify organic matter recycling in continental streams. As gammarid populations can demonstrate local adaptations to certain leaf species as a trophic resource, changes in riparian vegetation associated with climate change

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

    Science.gov (United States)

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

    2014-12-01

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

  9. Comparative effects of sulfuric and nitric acid rain on litter decomposition and soil microbial community in subtropical plantation of Yangtze River Delta region.

    Science.gov (United States)

    Liu, Xin; Zhang, Bo; Zhao, Wenrui; Wang, Ling; Xie, Dejin; Huo, Wentong; Wu, Yanwen; Zhang, Jinchi

    2017-12-01

    Acid rain is mainly caused by dissolution of sulfur dioxide and nitrogen oxides in the atmosphere, and has a significant negative effect on ecosystems. The relative composition of acid rain is changing gradually from sulfuric acid rain (SAR) to nitric acid rain (NAR) with the rapidly growing amount of nitrogen deposition. In this study, we investigated the impact of simulated SAR and NAR on litter decomposition and the soil microbial community over four seasons since March 2015. Results first showed that the effects of acid rain on litter decomposition and soil microbial were positive in the early period of the experiment, except for SAR on soil microbes. Second, soil pH with NAR decreased more rapidly with the amount of acid rain increased in summer than with SAR treatments. Only strongly acid rain (both SAR and NAR) was capable of depressing litter decomposition and its inhibitory effect was stronger on leaf than on fine root litter. Meanwhile, NAR had a higher inhibitory effect on litter decomposition than SAR. Third, in summer, autumn and winter, PLFAs were negatively impacted by the increased acidity level resulting from both SAR and NAR. However, higher acidity level of NAR (pH=2.5) had the strongest inhibitory impact on soil microbial activity, especially in summer. In addition, Gram-negative bacteria (cy19:0) and fungi (18:1ω9) were more sensitive to both SAR and NAR, and actinomycetes was more sensitive to SAR intensity. Finally, soil total carbon, total nitrogen and pH were the most important soil property factors affecting soil microbial activity, and high microbial indices (fungi/bacteria) with high soil pH. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect litter decomposition and soil microbial in subtropical forest of China. Copyright © 2017. Published by Elsevier B.V.

  10. Toward a Simple Framework for Understanding the Influence of Litter Quality on Vertical and Horizontal Patterns of Soil Organic Matter Pools

    Science.gov (United States)

    Craig, M.; Phillips, R.

    2016-12-01

    Decades of research have revealed that plant litter quality fundamentally influences soil organic matter (SOM) properties. Yet we lack the predictive frameworks necessary to up-scale our understanding of these dynamics in biodiverse systems. Given that ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) plants are thought to differ in their litter quality, we ask whether this dichotomy represents a framework for understanding litter quality effects on SOM in temperate forests. To do this, we sampled soils from 250 spatially referenced locations within a 25-Ha plot where 28,000 trees had been georeferenced, and analyzed spatial patterns of plant and SOM properties. We then examined the extent to which the dominance of AM- versus EM-trees relates to 1) the quality of litter inputs to forest soils and 2) the horizontal and vertical distribution of SOM fractions. We found that leaf litters produced by EM-associated trees were generally of lower quality, having a lower concentration of soluble compounds and higher C:N. Concomitant with this, we observed higher soil C:N under EM trees. Interestingly, this reflected greater N storage in AM-dominated soils rather than greater C storage in EM-dominated soils. These patterns were driven by the storage of SOM in N-rich fractions in AM-dominated soils. Specifically, trees with high litter quality were associated with greater amounts of deep and mineral-associated SOM; pools that are generally considered stable. Our results support the recent contention that high-quality plant inputs should lead to the formation of stable SOM and suggest that the AM-EM framework may provide a way forward for representing litter quality effects on SOM in earth system models.

  11. Mineral cycling in soil and litter arthropod food chains. Progress report, 1985

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1985-01-01

    Research progress in the following areas is briefly summarized: (1) microarthropod effects on microbial immobilization of nutrients during decomposition; and (2) effects of arthropods on decomposition rates of unconfined leaf litter

  12. Single and Combined Effects of Pesticide Seed Dressings and Herbicides on Earthworms, Soil Microorganisms, and Litter Decomposition.

    Science.gov (United States)

    Van Hoesel, Willem; Tiefenbacher, Alexandra; König, Nina; Dorn, Verena M; Hagenguth, Julia F; Prah, Urša; Widhalm, Theresia; Wiklicky, Viktoria; Koller, Robert; Bonkowski, Michael; Lagerlöf, Jan; Ratzenböck, Andreas; Zaller, Johann G

    2017-01-01

    Seed dressing, i.e., the treatment of crop seeds with insecticides and/or fungicides, aiming to protect seeds from pests and diseases, is widely used in conventional agriculture. During the growing season, those crop fields often receive additional broadband herbicide applications. However, despite this broad utilization, very little is known on potential side effects or interactions between these different pesticide classes on soil organisms. In a greenhouse pot experiment, we studied single and interactive effects of seed dressing of winter wheat ( Triticum aestivum L. var. Capo ) with neonicotinoid insecticides and/or strobilurin and triazolinthione fungicides and an additional one-time application of a glyphosate-based herbicide on the activity of earthworms, soil microorganisms, litter decomposition, and crop growth. To further address food-web interactions, earthworms were introduced to half of the experimental units as an additional experimental factor. Seed dressings significantly reduced the surface activity of earthworms with no difference whether insecticides or fungicides were used. Moreover, seed dressing effects on earthworm activity were intensified by herbicides (significant herbicide × seed dressing interaction). Neither seed dressings nor herbicide application affected litter decomposition, soil basal respiration, microbial biomass, or specific respiration. Seed dressing did also not affect wheat growth. We conclude that interactive effects on soil biota and processes of different pesticide classes should receive more attention in ecotoxicological research.

  13. Effect of Litter Fall on Soil Nutrient Content and pH, and its Consequences in View of Climate Change (Síkf

    OpenAIRE

    TÓTH, János Attila; NAGY, Péter Tamás; KRAKOMPERGER, Zsolt; VERES, Zsuzsa; KOTROCZÓ, Zsolt; KINCSES, Sándorné; FEKETE, István; PAPP, Mária; LAJTHA, Kate

    2011-01-01

    In the DIRT (Detritus Input and Removal Treatment) field experiments established at theSíkfkút Site (North Hungary) in October 2000, an experiment was initiated to study the long-termeffects of litter quality and quantity on pH and nutrient content (organic carbon, N forms, PO43–, K+,Mg2+, Ca2+) of soil in a Quercetum petraeae-cerris forest. An eight-year litter manipulationdemonstrated a close connection between the changes in pH and Mg2+ and Ca2+ concentration. Thedecline of litter producti...

  14. 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)

  15. Survival of generic E. coli and Listeria spp. populations in dairy compost- and poultry litter compost-amended soils in the Northeastern United States

    Science.gov (United States)

    Introduction:The FDA FSMA standards stipulate composting conditions that meet acceptable treatments for use of manure/poultry litter-based biological soil amendments of animal origin (BSAAO). Application of FSMA-compliant BSAAO to soils for production of fresh produce is expected to result in reduc...

  16. Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1978-October 31, 1979

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1979-01-01

    Research on soil and litter arthropod food chains, concerning measurement of nutrient flow using radioisotope techniques and investigations of the role of soil arthropods as regulators of the ecosystem-level processes of decomposition and mineralization of nutrients is described. Laboratory measurements of radiotracer turnover by predaceous macroarthropods are reported, as well as the status of research with microarthropod turnover of radioactive tracers. Implications of results are evaluated in context of current understanding of nutrient flows along arthropod food chains. The interactions of soil fauna and mycorrhizal fungi are also under investigation. Field work has been completed on granitic outcrop projects, and a synthesis of results is summarized. Input-output budgets revealed that granitic outcrop island ecosystems are essentially in balance as regards nutrient flows. The ecosystems showed a strong resistance component of stability, as opposed to resilience, following an applied chemical perturbation and a natural one

  17. Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1975--October 31, 1976

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1976-01-01

    Progress is described in radioisotope measurement of nutrient element flow in soil-litter arthropod food chains. Two models of accumulation (Goldstein-Elwood, Reichle-Crossley) were tested experimentally and found to yield equivalent predictions of 134 Cs and 85 Sr movement through arthropod populations. Radioisotope retention studies were used to compare trophic strategies of soil tipulids from arctic tundra and temperate forest. Arctic tipulids were found to compensate for low temperatures with enhanced assimilation and slower turnover of nutrients. Electron microprobe analysis is being used to measure elemental content of soil microarthropods. Concentrations as high as 70,000 ppm of Ca are reported for oribatid mites. Improved measurements of input-output nutrient concentrations are reported for island ecosystems on granitic outcrops, which are being subjected to experimental alteration in studies of ecosystem function

  18. Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1978-October 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Crossley, Jr, D A

    1979-07-15

    Research on soil and litter arthropod food chains, concerning measurement of nutrient flow using radioisotope techniques and investigations of the role of soil arthropods as regulators of the ecosystem-level processes of decomposition and mineralization of nutrients is described. Laboratory measurements of radiotracer turnover by predaceous macroarthropods are reported, as well as the status of research with microarthropod turnover of radioactive tracers. Implications of results are evaluated in context of current understanding of nutrient flows along arthropod food chains. The interactions of soil fauna and mycorrhizal fungi are also under investigation. Field work has been completed on granitic outcrop projects, and a synthesis of results is summarized. Input-output budgets revealed that granitic outcrop island ecosystems are essentially in balance as regards nutrient flows. The ecosystems showed a strong resistance component of stability, as opposed to resilience, following an applied chemical perturbation and a natural one (drought).

  19. Elevated UV-B radiation incident on Quercus robur leaf canopies enhances decomposition of resulting leaf litter in soil

    International Nuclear Information System (INIS)

    Newsham, K.K.; Greenslade, P.D.; Kennedy, V.H.; McLeod, A.R.

    1999-01-01

    We examined whether the exposure of Quercus robur L. to elevated UV-B radiation (280–315 nm) during growth would influence leaf decomposition rate through effects on litter quality. Saplings were exposed for eight months at an outdoor facility in the UK to a 30% elevation above the ambient level of erythemally weighted UV-B radiation under UV-B treatment arrays of fluorescent lamps filtered with cellulose diacetate, which transmitted both UV-B and UV-A (315–400 nm) radiation. Saplings were exposed to elevated UV-A alone under control arrays of lamps filtered with polyester and to ambient radiation under unenergised arrays of lamps. Abscised leaves from saplings were enclosed in 1 mm2 mesh nylon bags, placed in a Quercus–Fraxinus woodland and were sampled at 0.11, 0.53, 1.10 and 1.33 years for dry weight loss, chemical composition and saprotrophic fungal colonization. At abscission, litters from UV-A control arrays had ≈ 7.5% higher lignin/nitrogen ratios than those from UV-B treatment and ambient arrays (P < 0.06). Dry weight loss of leaves treated with elevated UV-B radiation during growth was 2.5% and 5% greater than that of leaves from UV-A control arrays at 0.53 and 1.33 years, respectively. Litter samples from UV-B treatment arrays lost more nitrogen and phosphorus than samples from ambient arrays and more carbon than samples from UV-A control arrays. The annual fractional weight loss of litter from UV-B treatment arrays was 8% and 6% greater than that of litter from UV-A control and ambient arrays, respectively. Regression analyses indicated that the increased decomposition rate of UV-B treated litters was associated with enhanced colonization of leaves by basidiomycete fungi, the most active members of the soil fungal community, and that the frequency of these fungi was negatively associated with the initial lignin/nitrogen ratio of leaves. (author)

  20. Effects of land cover change on litter decomposition and soil greenhouse gas fluxes in subtropical Hong Kong

    Science.gov (United States)

    Ngar Wong, Chun; Lai, Derrick Yuk Fo

    2017-04-01

    Nowadays, over 50% of the world's population live in urbanized areas and the level of urbanization varies substantially across countries. Intense human activities and management associated with urbanization can alter the microclimate and biogeochemical processes in urban areas, which subsequently affect the provision of ecosystem services and functions. Litter decomposition and soil greenhouse gas (GHG) exchange play an important role in governing nutrient cycling and future climate change, respectively. Yet, the effects of urbanization on these two biogeochemical processes remain uncertain and not well understood, especially in subtropical and high-density cities. This study aims to examine the effects of urbanization on decomposition and GHG fluxes among four land covers- natural forest, urban forest, farmland and roadside planter, in Hong Kong based on litterbag experiment and closed chamber measurements for one full year. Litter decomposition rate was significantly lower in farmland than in other land cover types. Significant differences in CO2 emission were detected among the four land cover types (pmean N2O fluxes, respectively. The emission of CO2 was positively correlated with soil potassium content, while CH4 and N2O flux increased markedly with soil temperature and nitrate nitrogen content, respectively. The results obtained in this study will enhance our understanding on urban ecosystem and be useful for recommending sustainable management strategies for conservation of ecosystem services in urban areas.

  1. Influence of poultry litter and double cropping on soybean yield

    Science.gov (United States)

    Continuous cultivation of mono-cropping systems coupled with inorganic fertilizer consumption has led to a decline in soil fertility, negatively influencing crop yields. Poultry litter application and double cropping are two management practices that could be used with conservation tillage to increa...

  2. Test of validity of a dynamic soil carbon model using data from leaf litter decomposition in a West African tropical forest

    Science.gov (United States)

    Guendehou, G. H. S.; Liski, J.; Tuomi, M.; Moudachirou, M.; Sinsin, B.; Mäkipää, R.

    2013-05-01

    We evaluated the applicability of the dynamic soil carbon model Yasso07 in tropical conditions in West Africa by simulating the litter decomposition process using as required input into the model litter mass, litter quality, temperature and precipitation collected during a litterbag experiment. The experiment was conducted over a six-month period on leaf litter of five dominant tree species, namely Afzelia africana, Anogeissus leiocarpa, Ceiba pentandra, Dialium guineense and Diospyros mespiliformis in a semi-deciduous vertisol forest in Southern Benin. Since the predictions of Yasso07 were not consistent with the observations on mass loss and chemical composition of litter, Yasso07 was fitted to the dataset composed of global data and the new experimental data from Benin. The re-parameterized versions of Yasso07 had a good predictive ability and refined the applicability of the model in Benin to estimate soil carbon stocks, its changes and CO2 emissions from heterotrophic respiration as main outputs of the model. The findings of this research support the hypothesis that the high variation of litter quality observed in the tropics is a major driver of the decomposition and needs to be accounted in the model parameterization.

  3. Toxicological benchmarks for screening potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process

    International Nuclear Information System (INIS)

    Will, M.E.; Suter, G.W. II.

    1994-09-01

    One of the initial stages in ecological risk assessments for hazardous waste sites is the screening of contaminants to determine which of them are worthy of further consideration as open-quotes contaminants of potential concern.close quotes This process is termed open-quotes contaminant screening.close quotes It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to soil- and litter-dwelling invertebrates, including earthworms, other micro- and macroinvertebrates, or heterotrophic bacteria and fungi. This report presents a standard method for deriving benchmarks for this purpose, sets of data concerning effects of chemicals in soil on invertebrates and soil microbial processes, and benchmarks for chemicals potentially associated with United States Department of Energy sites. In addition, literature describing the experiments from which data were drawn for benchmark derivation. Chemicals that are found in soil at concentrations exceeding both the benchmarks and the background concentration for the soil type should be considered contaminants of potential concern

  4. Toxicological benchmarks for screening potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process

    Energy Technology Data Exchange (ETDEWEB)

    Will, M.E.; Suter, G.W. II

    1994-09-01

    One of the initial stages in ecological risk assessments for hazardous waste sites is the screening of contaminants to determine which of them are worthy of further consideration as {open_quotes}contaminants of potential concern.{close_quotes} This process is termed {open_quotes}contaminant screening.{close_quotes} It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to soil- and litter-dwelling invertebrates, including earthworms, other micro- and macroinvertebrates, or heterotrophic bacteria and fungi. This report presents a standard method for deriving benchmarks for this purpose, sets of data concerning effects of chemicals in soil on invertebrates and soil microbial processes, and benchmarks for chemicals potentially associated with United States Department of Energy sites. In addition, literature describing the experiments from which data were drawn for benchmark derivation. Chemicals that are found in soil at concentrations exceeding both the benchmarks and the background concentration for the soil type should be considered contaminants of potential concern.

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

    Science.gov (United States)

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

    2017-04-18

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

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

    Science.gov (United States)

    Phil Kersten; Dan Cullen

    2013-01-01

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

  7. 17-β estradiol and testosterone mineralization and incorporation into organic matter in broiler litter-amended soils.

    Science.gov (United States)

    Durant, Michelle B; Hartel, Peter G; Cabrera, Miguel L; Vencill, William K

    2012-01-01

    The presence of the hormones estradiol and testosterone in the environment is of concern because they adversely affect vertebrate sexual characteristics. Land spreading broiler litter introduces these hormones into the environment. We conducted two studies. The first study determined the mineralization of C-labeled estradiol and testosterone at three water potentials and three temperatures in four broiler litter-amended soils. With a few exceptions, the mineralization of each hormone either stayed the same or increased with increasing water content (both hormones) and increasing (estradiol) or decreasing (testosterone) temperature. Mineralization was dependent on soil type. The second study determined the incorporation of C-labeled estradiol and testosterone into (i) three soil organic matter (SOM) fractions (fulvic acid, humic acid, and humin) at two water potentials, two temperatures, and one sampling time, and (ii) at one water potential, one temperature, and seven sampling times. As time increased, higher temperature and water potential decreased percentages of C estradiol and testosterone in water- and acetone-soluble fractions and increased percentages in SOM fractions. However, the distribution of the two hormones in SOM fractions differed. For estradiol, higher temperature and water potential increased the percentage in all three SOM fractions. For testosterone, higher temperature and water potential increased the percentage of hormone in fulvic acid and humin. Although the mineralization studies suggest the potential for these hormones to still have environmental effects, the incorporation of the two hormones into SOM suggest that land spreading these hormones may actually be less of an environmental concern. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. The Microbial Efficiency-Matrix Stabilization (MEMS) framework integrates plant litter decomposition with soil organic matter stabilization: do labile plant inputs form stable soil organic matter?

    Science.gov (United States)

    Cotrufo, M Francesca; Wallenstein, Matthew D; Boot, Claudia M; Denef, Karolien; Paul, Eldor

    2013-04-01

    The decomposition and transformation of above- and below-ground plant detritus (litter) is the main process by which soil organic matter (SOM) is formed. Yet, research on litter decay and SOM formation has been largely uncoupled, failing to provide an effective nexus between these two fundamental processes for carbon (C) and nitrogen (N) cycling and storage. We present the current understanding of the importance of microbial substrate use efficiency and C and N allocation in controlling the proportion of plant-derived C and N that is incorporated into SOM, and of soil matrix interactions in controlling SOM stabilization. We synthesize this understanding into the Microbial Efficiency-Matrix Stabilization (MEMS) framework. This framework leads to the hypothesis that labile plant constituents are the dominant source of microbial products, relative to input rates, because they are utilized more efficiently by microbes. These microbial products of decomposition would thus become the main precursors of stable SOM by promoting aggregation and through strong chemical bonding to the mineral soil matrix. © 2012 Blackwell Publishing Ltd.

  9. Diffusional limits to the consumption of atmospheric methane by soils

    Science.gov (United States)

    Striegl, Robert G.

    1993-01-01

    Net transport of atmospheric gases into and out of soil systems is primarily controlled by diffusion along gas partial pressure gradients. Gas fluxes between soil and the atmosphere can therefore be estimated by a generalization of the equation for ordinary gaseous diffusion in porous unsaturated media. Consumption of CH4 by methylotrophic bacteria in the top several centimeters of soil causes the uptake of atmospheric CH4 by aerated soils. The capacity of the methylotrophs to consume CH4 commonly exceeds the potential of CH4 to diffuse from the atmosphere to the consumers. The maximum rate of uptake of atmospheric CH4 by soil is, therefore, limited by diffusion and can be calculated from soil physical properties and the CH4 concentration gradient. The CH4 concentration versus depth profile is theoretically described by the equation for gaseous diffusion with homogeneous chemical reaction in porous unsaturated media. This allows for calculation of the in situ rate of CH4 consumption within specified depth intervals.

  10. Bioremediation of gasoline contaminated soil by a bacterial consortium amended with poultry litter, coir pith and rhamnolipid biosurfactant

    International Nuclear Information System (INIS)

    Rahman, K.S.M.; Banat, I.M.; Thahira, J.; Thayumanavan, T.; Lakshmanaperumalsamy, P.

    2002-01-01

    The aim of the present study was to find methods for enhancing rates of hydrocarbon biodegradation in gasoline contaminated soil by ex situ bioremediation. Red soil (RS) was treated with gasoline-spilled soil (GS) from a gasoline station and different combinations of amendments were prepared using (i) mixed bacterial consortium (MC), (ii) poultry litter (PL), (iii) coir pith (CP) and (iv) rhamnolipid biosurfactant (BS) produced by Pseudomonas sp. DS10-129. The study was conducted for a period of 90 days during which bacterial growth, hydrocarbon degradation and growth parameters of Phaseolus aureus RoxB including seed germination, chlorophyll content, shoot and root length were measured. Approximately 67% and 78% of the hydrocarbons were effectively degraded within 60 days in soil samples amended with RS + GS + MC + PL + CP + BS at 0.1% and 1%. Maximum percentage of seed germination, shoot length, root length and chlorophyll content in P. aureus were recorded after 60 days in the above amendments. Further incubation to 90 days did not exhibit significant improvements. Statistical analysis using analysis of variance (ANOVA) and Duncan's multiple range test (DMRT) revealed that the level of amendments, incubation time and combination of amendments significantly influenced bacterial growth, hydrocarbon degradation, seed germination and chlorophyll content at a 1% probability level. All tested additives MC, PL, CP and rhamnolipid BS had significant positive effects on the bioremediation of GS. (author)

  11. How does litter cover, litter diversity and fauna affect sediment discharge and runoff?

    Science.gov (United States)

    Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Scholten, Thomas

    2013-04-01

    significantly with litter cover. The reduction of sediment discharge was positively related to biodiversity. At level 1, sediment discharge was reduced by 45 percent compared to the bare soil plots. At biodiversity level 4, sediment discharge amounts only 28 percent compared to bare ground. This biodiversity effect could be explained by a better overlap and gap filling of leaves of different litter species in a way that overland flow below the litter cover on the soil surface was less erosive at higher biodiversity levels. No strong correlation was found between sediment discharge or runoff and fauna indicating that litter decomposition in such subtropical systems is mainly driven by microbiological processes rather than macrofaunistical processes like litter consumption by diplopods and collembola. A negative correlation of sediment discharge and runoff volume over time during the rainfall events was found. These preliminary findings will now undergo a more detailed analysis using linear mixed effect models to understand the utterly part of litter cover diversity in soil erosion and to give more information about the mechanisms involved.

  12. Carex sempervirens tussocks induce spatial heterogeneity in litter decomposition, but not in soil properties, in a subalpine grassland in the Central Alps

    Science.gov (United States)

    Fei-Hai Yu; Martin Schutz; Deborah S. Page-Dumroese; Bertil O. Krusi; Jakob Schneller; Otto Wildi; Anita C. Risch

    2011-01-01

    Tussocks of graminoids can induce spatial heterogeneity in soil properties in dry areas with discontinuous vegetation cover, but little is known about the situation in areas with continuous vegetation and no study has tested whether tussocks can induce spatial heterogeneity in litter decomposition. In a subalpine grassland in the Central Alps where vegetation cover is...

  13. Incorporation of 13C labeled Pinus ponderosa needle and fine root litter into soil organic matter measured by Py-GC/MS-C-IRMS

    Science.gov (United States)

    Mambelli, S.; Gleixner, G.; Dawson, T. E.; Bird, J. A.; Torn, M. S.

    2006-12-01

    Developing effective strategies for enhancing C storage in soils requires understanding the influence of plant C quality. In turn, plant C quality impacts the decay continuum between plant residue and humified, stable SOM. This remains one of the least understood aspects of soil biogeochemistry. We investigated the initial phase of incorporation of 13C labeled Pinus ponderosa needle and fine root litter into SOM. The two litter types were placed in separate microcosms in the A horizon in a temperate conifer soil. Curie-point pyrolysis-gas chromatography coupled with on-line mass spectrometry and isotope ratio mass spectrometry (Py-GC/MS-C- IRMS) were used to determine the identity and the 13C enrichment of pyrolysis products (fragments of carbohydrates, lignin, proteins and lipids). We compared the two initial litter types, needles and fine roots, to samples of the bulk soil (A horizon, < 2mm) and soil humin fraction (from chemical solubility) obtained from each microcosm 1.5y after litter addition. Pyrolysis of plant material and SOM produced 56 suitable products for isotopic analysis; of them, 15 occurred in both the litter and bulk soil, 7 in both the litter and the humin fraction and 9 in both bulk soil and the humin fraction. The pyrolysis products found in common in the plant and soil were related either to polysaccharides or were non-specific and could have originated from various precursors. The data suggest that the majority of plant inputs, both from needles or fine roots, were degraded very rapidly. In the humin fraction, the most recalcitrant pool of C in soil, with a measured turnover time of 260y (this soil), only products from the fragmentation of polysaccharides and alkyl-benzene compounds were found. Comparisons of the enrichment normalized by input level suggest little difference between the incorporation of C from needles versus fine roots into SOM. The most enriched fragments in the humin fraction were products from polysaccharides degradation

  14. Changes in plant functional groups, litter quality, and soil carbon and nitrogen mineralization with sheep grazing in an Inner Mongolian Grassland

    Science.gov (United States)

    Barger, N.N.; Ojima, D.S.; Belnap, J.; Shiping, W.; Yanfen, W.; Chen, Z.

    2004-01-01

    This study reports on changes in plant functional group composition, litter quality, and soil C and N mineralization dynamics from a 9-year sheep grazing study in Inner Mongolia. Addressed are these questions: 1) How does increasing grazing intensity affect plant community composition? 2) How does increasing grazing intensity alter soil C and N mineralization dynamics? 3) Do changes in soil C and N mineralization dynamics relate to changes in plant community composition via inputs of the quality or quantity of litter? Grazing plots were set up near the Inner Mongolia Grassland Ecosystem Research Station (IMGERS) with 5 grazing intensities: 1.3, 2.7, 4.0, 5.3, and 6.7 sheep ha -1??yr-1. Plant cover was lower with increasing grazing intensity, which was primarily due to a dramatic decline in grasses, Carex duriuscula, and Artemisia frigida. Changes in litter mass and percentage organic C resulted in lower total C in the litter layer at 4.0 and 5.3 sheep ha-1??yr-1 compared with 2.7 sheep ha -1??yr-1. Total litter N was lower at 5.3 sheep ha-1??yr-1 compared with 2.7 sheep ha -1??yr-1. Litter C:N ratios, an index of litter quality, were significantly lower at 4.0 sheep ha-1??yr -1 relative to 1.3 and 5.3 sheep ha-1??yr -1. Cumulative C mineralized after 16 days decreased with increasing grazing intensity. In contrast, net N mineralization (NH4+ + NO3-) after a 12-day incubation increased with increasing grazing intensity. Changes in C and N mineralization resulted in a narrowing of CO2-C:net Nminratios with increasing grazing intensity. Grazing explained 31% of the variability in the ratio of CO 2-C:net Nmin. The ratio of CO2-C:net N min was positively correlated with litter mass. Furthermore, there was a positive correlation between litter mass and A. frigida cover. Results suggest that as grazing intensity increases, microbes become more C limited resulting in decreased microbial growth and demand for N.

  15. Wettability of poultry litter biochars at variable pyrolysis temperatures and their impact on soil wettability and water retention relationships

    Science.gov (United States)

    Yi, S. C.; Witt, B.; Guo, M.; Chiu, P.; Imhoff, P. T.

    2012-12-01

    To reduce the impact of poultry farming on greenhouse gas emissions, poultry farming waste - poultry litter - can be converted to biofuel and biochar through slow-pyrolysis, with the biochar added to agricultural soil for nutrient enrichment and carbon sequestration. While biochars from source materials other than poultry litter have been shown to sequester carbon and increase soil fertility, there is considerable variability in biochar behavior - even with biochars created from the same source material. This situation is exacerbated by our limited understanding of how biochars alter physical, chemical, and biological processes in agricultural soils. The focus of this work is to develop a mechanistic understanding of how poultry litter (PL) biochars affect the hydrology, microbial communities, N2O emissions, and nitrogen cycling in agricultural soils. The initial focus is on the impact of PL biochar on soil hydrology. PL from Perdue AgriRecycle, LLC (Seaford, Delaware) was used to produce biochars at pyrolysis temperatures from 300°C to 600°C. To explore the impact of these biochars on soil wettability, the PL biochars were mixed with a 30/40 Accusand in mass fractions from 0% to 100%. The water contact angle was then measured using a goniometer on these sand/biochar mixtures using the sessile drop method and a single layer of sample particles. The PL biochars produced at temperatures between 300°C to 400°C were hydrophobic, while those pyrolized at > 400°C were hydrophilic. Water contact angles for samples with 100% biochar varied systematically with pyrolysis temperature, decreasing from 101.12° to 20.57° as the pyrolysis temperature increased from 300 to 600°C. Even for small amounts of hydrophobic biochar added to the hydrophilic sand, the contact angle of the mixture was altered: for sand/biochar mixtures containing only 2% hydrophobic PL biochar by weight, the contact angle of the mixture increased from ~ 8° (0% biochar) to 20° (2% biochar). For

  16. [Litter decomposition and soil faunal diversity of two understory plant debris in the alpine timberline ecotone of western Sichuan in a snow cover season].

    Science.gov (United States)

    He, Run-lian; Chen, Ya-mei; Deng, Chang-chun; Yan, Wan-qin; Zhang, Jian; Liu, Yang

    2015-03-01

    In order to understand the relationship between litter decomposition and soil fauna diversity during snow cover season, litterbags with plant debris of Actinothuidium hookeri, Cystopteris montana, two representative understory plants in the alpine timberline ecotone, and their mixed litter were incubated in the dark coniferous forest, timberline and alpine meadow, respectively. After a snow cover season, the mass loss and soil fauna in litterbags were investigated. After decomposition with a snow cover season, alpine meadow showed the highest mass loss of plant debris in comparison with coniferous forest and timberline, and the mass loss of A. hookeri was more significant. The mixture of two plants debris accelerated the mass loss, especially in the timberline. A total of 968 soil invertebrates, which belonged to 5 classes, 10 orders and 35 families, were captured in litterbags. Acarina and Collembola were the dominant groups in plant debris. The numbers of individuals and groups of soil faunal communities in litter of timberline were higher than those of alpine meadow and dark coniferous forest. Canonical correspondence analysis (CCA) indicated that the groups of soil animals were related closely with the average temperature, and endemic species such as Isoptera and Geophilomorpha were observed only in coniferous forest, while Hemiptera and Psocoptera only in.the alpine meadow. The diversity of soil faunal community was more affected by plant debris varieties in the timberline than in the coniferous forest and alpine meadow. Multiple regression analysis indicated that the average temperature and snow depth explained 30.8% of the variation of litter mass loss rate, soil animals explained 8.3%, and altogether explained 34.1%. Snow was one of the most critical factors impacting the decomposition of A. hookeri and C. montana debris in the alpine timberline ecotone.

  17. Repeated soil application of organic waste amendments reduces draught force and fuel consumption for soil tillage

    DEFF Research Database (Denmark)

    Peltrea, Clément; Nyord, Tavs; Bruun, Sander

    2015-01-01

    Abstract Soil application of organic waste products (OWP) can maintain or increase soil organic carbon (SOC) content, which in turn could lead to increased porosity and potentially to reduced energy use for soil tillage. Only a few studies have addressed the effect of SOC content on draught force...... for soil tillage, and this still needs to be addressed for fields that receive diverse types of organic waste of urban, agricultural and agro-industrial origin. The objective of this study was to determine the effect of changes in SOC induced by repeated soil application of OWP on draught force for soil...... tillage and tractor fuel consumption. Draught force was measured for tillage with conventional spring tillage tines, as well as bulk density, soil texture and SOC content in the CRUCIAL field experiment, Denmark in which diverse types of OWP had been applied annually for 11 years. The OWP included...

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

    Science.gov (United States)

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

    2015-09-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Yan Peng

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

  1. Uranium in soil, forest litter and living plant material above three uranium mineralizations in Northern Sweden

    International Nuclear Information System (INIS)

    Ek, John

    1982-01-01

    In order to investigate the feasibility of biogeochemical sampling media in uranium exploration, samples from the most common trees and low bushes together with forest litter were collected over the areas of three uranium mineralizations in Northern Sweden and analyzed for uranium. The results were compared with uranium content of the till and its radioactivity. The average uranium content was low for all sample types and considerably lower in the ash of the organic sample types compared to that of the till. No sample type showed any tendency of having higher uranium concentration above mineralizations compared to background areas. These results suggest that, under conditions prevailing in Sweden, the investigated sample types are not suitable for uranium exploration

  2. Response of detritus food web and litter quality to elevated CO2 and crop cultivars and their feedback to soil functionality

    Science.gov (United States)

    Hu, Zhengkun; Chen, Xiaoyun; Zhu, Chunwu; Bonkowski, Michael; Hu, Shuijin; Li, Huixin; Hu, Feng; Liu, Manqiang

    2017-04-01

    Elevated atmospheric CO2 concentrations (eCO2) often increase plant growth and alter the belowground detritus soil food web. Interactions with agriculture management may further modify soil process and the associated ecosystem functionality. Little attention, however, has been directed toward assessing the responses of soil food web and their feedback to soil functionality, particularly in wetland agroecosystems. We report results from a long-term free air CO2 enrichment (FACE) experiment in a rice paddy field that examined the responses of detritus food webs to eCO2 (200 ppm higher than ambient CO2 (aCO2)) of two rice cultivars with distinctly weak and strong responses to eCO2. Soil detritus food web components, including soil microbes and microfauna, soil environment as well as resources availability variables, were determined at the rice ripening stage. To obtain the information of soil functionality, indicated by litter decomposition and enzyme activities, we adopted a reciprocal transplant approach that fully manipulate the factors of litter straw and food web components for the incubation of 120 days. Results about the field investigation showed that eCO2 lead to a higher C/N ratio of litter and soil compared to aCO2, especially for the strong responsive cultivar. eCO2-induced enhanced carbon input stimulated the fungal decomposition pathway by increasing fungal biomass, fungi: bacteria ratio and fungivorous nematode. Results from the manipulative incubation experiment showed eCO2-induced lower quality of straw decreased cumulative C mineralization, but changes in detritus food web induced by eCO2 and strongly responsive cultivar lead to an increased CO2 respiration coincidently within each straw type, mainly due to the adaption to the high C/N ratio environment which increased their functional breadth. Based on SEMs and curves of carbon mineralization rate, soil communities showed significant effects on C release at the early stage through mediating enzyme

  3. CARBOHYDRATE USE AND ASSIMILATION BY LITTER AND SOIL FUNGI ASSESSED BY CARBON ISOTOPES AND BIOLOG ASSAYS

    Science.gov (United States)

    Soil fungi are integral to decomposition in forests, yet identification of probable functional roles of different taxa is problematic. Here, we compared carbohydrate assimilation patterns derived from stable isotope analyses on cultures with those produced from cultures on Biolo...

  4. Copper concentration of vineyard soils as a function of pH variation and addition of poultry litter

    Directory of Open Access Journals (Sweden)

    Gilmar Ribeiro Nachtigall

    2007-11-01

    Full Text Available Copper (Cu concentration was evaluated as a function of pH variation and addition of poultry litter to a Dystrophic Lithic Udorthent and a Humic Dystrudept from the state of Rio Grande do Sul, Brazil, cultivated with vines treated with successive applications of Cu-based product. Samples were collected from the surface layer (0 to 10 cm. Soluble Cu concentration was determined using DTPA and Mehlich III as extractants, and exchangeable Cu was determined in CaCl2. The availability of Cu was mainly affected by the soil pH. CaCl2 extractant had the best correlation with Cu concentration in contaminated soils, according to treatments applied. The addition of poultry litter did not reduce Cu availability in these soils. Total soil Cu content varied between 1,300 and 1,400 mg kg-1 in both soils. Copper available fractions, extracted by DTPA, CaCl2 and Mehlich III, averaged 35, 0.2 and 63%, respectively, of the total Cu present in the soil.Avaliaram-se os teores de Cu em função da variação do pH e da adição de cama-de-frango de dois solos com elevados teores deste elemento. Foram coletadas amostras da camada superficial (0 a 10 cm de um typical dystrophic Lithic Udorthent - LU (Neossolo Litólico distrófico típico e de um Humic Dystrudept - HD (Cambissolo Húmico alumínico típico da região da Serra do RS, cultivados com parreirais que receberam aplicações sucessivas de produtos à base de Cu. Foram determinados os teores de Cu solúvel em DTPA e pelo método Mehlich III, além do Cu trocável em CaCl2. A disponibilidade de Cu foi afetada principalmente pelo pH do solo. O extrator CaCl2 foi o que melhor se correlacionou com os teores de Cu em solos contaminados em função dos tratamentos aplicados. A adição de cama-de-frango não diminuiu a disponibilidade de Cu destes solos. Os teores de Cu total variaram entre 1.300 e 1.400 mg kg-1 nos dois solos. Considerando os teores totais de Cu nos solos, as frações "disponíveis", extra

  5. Metals in Soil and Runoff from a Piedmont Hay Field Amended with Broiler Litter and Flue Gas Desulfurization Gypsum.

    Science.gov (United States)

    Schomberg, Harry H; Endale, Dinku M; Jenkins, Michael B; Chaney, Rufus L; Franklin, Dorcas H

    2018-03-01

    Flue gas desulfurization gypsum (FGDG) from coal-fired power plants is readily available for agricultural use in many US regions. Broiler litter (BL) provides plant available N, P, and K but can be a source of unwanted As, Cu, and Zn. As a source of Ca and S, FGDG can reduce losses of P and other elements in runoff from BL-amended areas. Rainfall simulation plots (2.0 m) were established on a Piedmont Cecil soil growing 'Coastal' bermudagrass ( L.) for hay. Accumulation and transport of As, Cu, Cd, Cr, Hg, Pb, and Zn were evaluated after annual BL applications (13.5 Mg ha) with four FGDG rates (0, 2.2, 4.5, 9.0 Mg ha) and two FGDG treatments (0 and 9 Mg ha) without BL. Runoff As concentrations were sixfold greater with BL than without ( ≤ 0.01) and were similar to BL with FGDG at 2.2, 4.5 or 9.0 Mg ha ( ≤ 0.10). Runoff concentrations of target elements did not increase where FGDG was applied alone. After three annual applications of FGDG and BL, soil concentrations of As, Cr, Pb, Hg, and Cu were well below levels of environmental concern. Our findings indicate that runoff losses of As from BL application are not reduced with FGDG but support other research indicating no identifiable environmental risks from FGDG beneficial use in agricultural systems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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

    Science.gov (United States)

    Choi, Sung-Deuk

    2014-02-01

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

  7. Scots pine litter decomposition along drainage succession and soil nutrient gradients in peatland forests, and the effects of inter-annual weather variation

    Science.gov (United States)

    Raija Laiho; Jukka Laine; Carl C. Trettin; Leena Finér

    2004-01-01

    Peatlands form a large carbon (C) pool but their C sink is labile and susceptible to changes in climate and land-use. Some pristine peatlands are forested, and others have the potential: the amount of arboreal vegetation is likely to increase if soil water levels are lowered as a consequence of climate change. On those sites tree litter dynamics may be crucial for the...

  8. EFFECTS OF CO2 AND O3 IN PONDEROSA PINE PLANT/LITTER/SOIL MESOCOSMS

    Science.gov (United States)

    Forested ecosysems are subjected to interacting conditions whose joint impacts may be quite different from those from single factors. To understand the impacts of CO2 and O3 on forest ecosystems, in April 1998, we initiated a four-year study of a Ponderosa pine seedling/soil/lit...

  9. Soil fauna and plant litter decomposition in tropical and subalpine forests

    Science.gov (United States)

    G. Gonzalez; T.R. Seastedt

    2001-01-01

    The decomposition of plant residues is influenced by their chemical composition, the physical-chemical environment, and the decomposer organisms. Most studies interested in latitudinal gradients of decomposition have focused on substrate quality and climate effects on decomposition, and have excluded explicit recognition of the soil organisms involved in the process....

  10. Drivers of yeast community composition in the litter and soil of a temperate forest

    Czech Academy of Sciences Publication Activity Database

    Mašínová, Tereza; Bahnmann, Barbara Doreen; Větrovský, Tomáš; Tomšovský, M.; Merunková, K.; Baldrian, Petr

    2017-01-01

    Roč. 93, č. 2 (2017), s. 1-10, č. článku 223. ISSN 0168-6496 R&D Projects: GA ČR GA13-06763S Institutional support: RVO:61388971 Keywords : yeast ecology * soil microbiology * metagenomics Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.720, year: 2016

  11. Phosphorus leaching from soil cores from a twenty-year study evaluating alum treatment of poultry litter

    Science.gov (United States)

    Adding alum (aluminum sulfate) to poultry litter is a best management practice (BMP) used to stabilize phosphorus (P) in less soluble forms, reducing non-point source P runoff. However, little research has been conducted on the effects of alum-treated poultry litter on P leaching. The objective of...

  12. Density-dependent microbial turnover improves soil carbon model predictions of long-term litter manipulations

    Science.gov (United States)

    Georgiou, Katerina; Abramoff, Rose; Harte, John; Riley, William; Torn, Margaret

    2017-04-01

    Climatic, atmospheric, and land-use changes all have the potential to alter soil microbial activity via abiotic effects on soil or mediated by changes in plant inputs. Recently, many promising microbial models of soil organic carbon (SOC) decomposition have been proposed to advance understanding and prediction of climate and carbon (C) feedbacks. Most of these models, however, exhibit unrealistic oscillatory behavior and SOC insensitivity to long-term changes in C inputs. Here we diagnose the sources of instability in four models that span the range of complexity of these recent microbial models, by sequentially adding complexity to a simple model to include microbial physiology, a mineral sorption isotherm, and enzyme dynamics. We propose a formulation that introduces density-dependence of microbial turnover, which acts to limit population sizes and reduce oscillations. We compare these models to results from 24 long-term C-input field manipulations, including the Detritus Input and Removal Treatment (DIRT) experiments, to show that there are clear metrics that can be used to distinguish and validate the inherent dynamics of each model structure. We find that widely used first-order models and microbial models without density-dependence cannot readily capture the range of long-term responses observed across the DIRT experiments as a direct consequence of their model structures. The proposed formulation improves predictions of long-term C-input changes, and implies greater SOC storage associated with CO2-fertilization-driven increases in C inputs over the coming century compared to common microbial models. Finally, we discuss our findings in the context of improving microbial model behavior for inclusion in Earth System Models.

  13. Elevated CO2 and Tree Species Affect Microbial  Activity and Associated Aggregate Stability in Soil  Amended with Litter

    Directory of Open Access Journals (Sweden)

    Salwan M. J. Al‐Maliki

    2017-03-01

    Full Text Available (1 Elevated atmospheric CO2 (eCO2 may affect organic inputs to woodland soils with potential consequences for C dynamics and associated aggregation; (2 The Bangor Free Air Concentration Enrichment experiment compared ambient (330 ppmv and elevated (550 ppmv CO2 regimes over four growing seasons (2005–2008 under Alnus glutinosa, Betula pendula and Fagus sylvatica. Litter from the experiment (autumn 2008 and Lumbricus terrestris were added to mesocosm soils. Microbial properties and aggregate stability were investigated in soil and earthworm casts. Soils taken from the field experiment in spring 2009 were also investigated; (3 eCO2 litter had lower N and higher C:N ratios. F. sylvatica and B. pendula litter had lower N and P than A. glutinosa; F. sylvatica had higher cellulose. In mesocosms, eCO2 litter decreased respiration, mineralization constant (respired C:total organic C and soluble carbon in soil but not earthworm casts; microbial‐C and fungal hyphal length differed by species (A. glutinosa = B. pendula > F. sylvatica not CO2 regime. eCO2 increased respiration in field aggregates but increased stability only under F. sylvatica; (4 Lower litter quality under eCO2 may restrict its initial decomposition, affecting C stabilization in aggregates. Later resistant materials may support microbial activity and increase aggregate stability. In woodland, C and soil aggregation dynamics may alter under eCO2, but outcomes may be influenced by tree species and earthworm activity.

  14. Long-term nitrogen addition leads to loss of species richness due to litter accumulation and soil acidification in a temperate steppe.

    Science.gov (United States)

    Fang, Ying; Xun, Fen; Bai, Wenming; Zhang, Wenhao; Li, Linghao

    2012-01-01

    Although community structure and species richness are known to respond to nitrogen fertilization dramatically, little is known about the mechanisms underlying specific species replacement and richness loss. In an experiment in semiarid temperate steppe of China, manipulative N addition with five treatments was conducted to evaluate the effect of N addition on the community structure and species richness. Species richness and biomass of community in each plot were investigated in a randomly selected quadrat. Root element, available and total phosphorus (AP, TP) in rhizospheric soil, and soil moisture, pH, AP, TP and inorganic N in the soil were measured. The relationship between species richness and the measured factors was analyzed using bivariate correlations and stepwise multiple linear regressions. The two dominant species, a shrub Artemisia frigida and a grass Stipa krylovii, responded differently to N addition such that the former was gradually replaced by the latter. S. krylovii and A. frigida had highly-branched fibrous and un-branched tap root systems, respectively. S. krylovii had higher height than A. frigida in both control and N added plots. These differences may contribute to the observed species replacement. In addition, the analysis on root element and AP contents in rhizospheric soil suggests that different calcium acquisition strategies, and phosphorus and sodium responses of the two species may account for the replacement. Species richness was significantly reduced along the five N addition levels. Our results revealed a significant relationship between species richness and soil pH, litter amount, soil moisture, AP concentration and inorganic N concentration. Our results indicate that litter accumulation and soil acidification accounted for 52.3% and 43.3% of the variation in species richness, respectively. These findings would advance our knowledge on the changes in species richness in semiarid temperate steppe of northern China under N

  15. Plant litter functional diversity effects on litter mass loss depend on the macro-detritivore community.

    Science.gov (United States)

    Patoine, Guillaume; Thakur, Madhav P; Friese, Julia; Nock, Charles; Hönig, Lydia; Haase, Josephine; Scherer-Lorenzen, Michael; Eisenhauer, Nico

    2017-11-01

    A better understanding of the mechanisms driving litter diversity effects on decomposition is needed to predict how biodiversity losses affect this crucial ecosystem process. In a microcosm study, we investigated the effects of litter functional diversity and two major groups of soil macro-detritivores on the mass loss of tree leaf litter mixtures. Furthermore, we tested the effects of litter trait community means and dissimilarity on litter mass loss for seven traits relevant to decomposition. We expected macro-detritivore effects on litter mass loss to be most pronounced in litter mixtures of high functional diversity. We used 24 leaf mixtures differing in functional diversity, which were composed of litter from four species from a pool of 16 common European tree species. Earthworms, isopods, or a combination of both were added to each litter combination for two months. Litter mass loss was significantly higher in the presence of earthworms than in that of isopods, whereas no synergistic effects of macro-detritivore mixtures were found. The effect of functional diversity of the litter material was highest in the presence of both macro-detritivore groups, supporting the notion that litter diversity effects are most pronounced in the presence of different detritivore species. Species-specific litter mass loss was explained by nutrient content, secondary compound concentration, and structural components. Moreover, dissimilarity in N concentrations increased litter mass loss, probably because detritivores having access to nutritionally diverse food sources. Furthermore, strong competition between the two macro-detritivores for soil surface litter resulted in a decrease of survival of both macro-detritivores. These results show that the effects of litter functional diversity on decomposition are contingent upon the macro-detritivore community and composition. We conclude that the temporal dynamics of litter trait diversity effects and their interaction with

  16. Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1975--October 31, 1976. [/sup 134/Cs, /sup 85/Sr

    Energy Technology Data Exchange (ETDEWEB)

    Crossley, D.A. Jr.

    1976-07-31

    Progress is described in radioisotope measurement of nutrient element flow in soil-litter arthropod food chains. Two models of accumulation (Goldstein-Elwood, Reichle-Crossley) were tested experimentally and found to yield equivalent predictions of /sup 134/Cs and /sup 85/Sr movement through arthropod populations. Radioisotope retention studies were used to compare trophic strategies of soil tipulids from arctic tundra and temperate forest. Arctic tipulids were found to compensate for low temperatures with enhanced assimilation and slower turnover of nutrients. Electron microprobe analysis is being used to measure elemental content of soil microarthropods. Concentrations as high as 70,000 ppm of Ca are reported for oribatid mites. Improved measurements of input-output nutrient concentrations are reported for island ecosystems on granitic outcrops, which are being subjected to experimental alteration in studies of ecosystem function.

  17. Effects of soil development time and litter quality on soil carbon sequestration: Assessing soil carbon saturation with a field transplant experiment along a post-mining chronosequence

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan

    2017-01-01

    Roč. 28, č. 2 (2017), s. 664-672 ISSN 1085-3278 Institutional support: RVO:60077344 Keywords : soil organic matter fractions * carbon sequestration * carbon saturation * mining * reclamation Subject RIV: DF - Soil Science OBOR OECD: Soil science Impact factor: 9.787, year: 2016

  18. Influence of moisture conditions and mineralization of soil solution on structure of litter macrofauna of the deciduous forests of Ukraine steppe zone

    Directory of Open Access Journals (Sweden)

    V. V. Brygadyrenko

    2015-02-01

    Full Text Available The accounting of litter mesofauna was carried out in the territory of Dnipropetrovsk, Zaporizhzhya, Nikolaev,Donetsk regions of Ukrainein the natural forest ecosystems in 2001–2014. 339 forest ecosystems were surveyed; xeromesophilic conditions of moistening were characteristic for 47 trial sites, mesophilic conditions – for 99 sites, hygro-mesophilic conditions – for 50 sites, meso-hygrophilic conditions – for 89 sites, hygrophilic conditions – for 54 sites; trophotope C was represented by 35 trial sites, Dc – by 44, Dac – by 76, Dn – by 128, De – by 37, E – by 19 forest ecosystems, accordingly. The relative number of saprophages reaches maximum values in hygro-mesophilic, meso-hygrophilic and hygrophilic conditions, and minimum values – in mesophilic conditions of moistening. The share of rare species is maximum in hygro-mesophilic conditions of moistening. The minimum quantity of mass species is also observed in conditions of hygro-mesophilic and meso-hygrophilic deciduous forests. With the growth of moistening of the soil, quantity of species of Carabidae, Formicidae and other dominant families remains without significant changes. The relative number of Formicidae is maximum in xeromesophilic and mesophilic conditions of soil moistening. In these hygrotopes, as well as in hygro-mesophilic conditions of moistening the Julidae numbers are maximum. The Isopoda percent in mesofauna significantly grows in meso-hygrophilic and hygrophilic conditions of moistening. The share of other dominant taxonomical groups in the structure of litter mesofauna remains without significant changes in numbers. In the majority of the analysed hygrotopes 7–8 families are withing the structure of dominants. In the conditions of salinization (trophotopes De and E, and also on light sandy loam soils, the numbers of litter mesofauna decrease. Share of saprophages is minimum in trophotopes Dc and E, while it increases in trophotopes C, Dac, Dn

  19. The role of .i.Armadillidium vulgare./i. (Isopoda: Oniscidea) in litter decomposition and soil organic matter stabilization

    Czech Academy of Sciences Publication Activity Database

    Špaldoňová, Alexandra; Frouz, Jan

    2014-01-01

    Roč. 83, November (2014), s. 186-192 ISSN 0929-1393 Grant - others:GA ČR(CZ) GAP504/12/1288 Program:GA Institutional support: RVO:60077344 Keywords : feces * litter decomposition * microbial respiration * priming effect * terrestrial isopods * TMAH-Py-GC MS Subject RIV: EH - Ecology, Behaviour Impact factor: 2.644, year: 2014

  20. Metals in soil and runoff from a piedmont hayfield amended with broiler litter and flue gas desulfurization gypsum

    Science.gov (United States)

    Flue gas desulfurization gypsum (FGDG) from coal-fired power plants is available for agricultural use in many US regions. Broiler litter (BL) provides plant available N, P, and K but may be a source of unwanted arsenic (As), copper (Cu), and zinc (Zn). FGDG provides Ca and S and can reduce runoff lo...

  1. EFFECTS OF FERTILIZER TYPE (CHICKEN LITTER VS. INORGANIC FERTILIZER) AND CATTLE GRAZING ON THE SOIL MICROBIAL COMMUNITY

    Science.gov (United States)

    Pasture plots included unharvested, hayed, light and heavy cattle grazing pressure, fertilized with either inorganic N-P-K or broiler litter. Total phospholipid fatty acids (PLFAs) followed a seasonal trend and were higher in grazed plots than hayed & unharvested plots. Fungi a...

  2. Early stage litter decomposition across biomes

    Science.gov (United States)

    Ika Djukic; Sebastian Kepfer-Rojas; Inger Kappel Schmidt; Klaus Steenberg Larsen; Claus Beier; Björn Berg; Kris Verheyen; Adriano Caliman; Alain Paquette; Alba Gutiérrez-Girón; Alberto Humber; Alejandro Valdecantos; Alessandro Petraglia; Heather Alexander; Algirdas Augustaitis; Amélie Saillard; Ana Carolina Ruiz Fernández; Ana I. Sousa; Ana I. Lillebø; Anderson da Rocha Gripp; André-Jean Francez; Andrea Fischer; Andreas Bohner; Andrey Malyshev; Andrijana Andrić; Andy Smith; Angela Stanisci; Anikó Seres; Anja Schmidt; Anna Avila; Anne Probst; Annie Ouin; Anzar A. Khuroo; Arne Verstraeten; Arely N. Palabral-Aguilera; Artur Stefanski; Aurora Gaxiola; Bart Muys; Bernard Bosman; Bernd Ahrends; Bill Parker; Birgit Sattler; Bo Yang; Bohdan Juráni; Brigitta Erschbamer; Carmen Eugenia Rodriguez Ortiz; Casper T. Christiansen; E. Carol Adair; Céline Meredieu; Cendrine Mony; Charles A. Nock; Chi-Ling Chen; Chiao-Ping Wang; Christel Baum; Christian Rixen; Christine Delire; Christophe Piscart; Christopher Andrews; Corinna Rebmann; Cristina Branquinho; Dana Polyanskaya; David Fuentes Delgado; Dirk Wundram; Diyaa Radeideh; Eduardo Ordóñez-Regil; Edward Crawford; Elena Preda; Elena Tropina; Elli Groner; Eric Lucot; Erzsébet Hornung; Esperança Gacia; Esther Lévesque; Evanilde Benedito; Evgeny A. Davydov; Evy Ampoorter; Fabio Padilha Bolzan; Felipe Varela; Ferdinand Kristöfel; Fernando T. Maestre; Florence Maunoury-Danger; Florian Hofhansl; Florian Kitz; Flurin Sutter; Francisco Cuesta; Francisco de Almeida Lobo; Franco Leandro de Souza; Frank Berninger; Franz Zehetner; Georg Wohlfahrt; George Vourlitis; Geovana Carreño-Rocabado; Gina Arena; Gisele Daiane Pinha; Grizelle González; Guylaine Canut; Hanna Lee; Hans Verbeeck; Harald Auge; Harald Pauli; Hassan Bismarck Nacro; Héctor A. Bahamonde; Heike Feldhaar; Heinke Jäger; Helena C. Serrano; Hélène Verheyden; Helge Bruelheide; Henning Meesenburg; Hermann Jungkunst; Hervé Jactel; Hideaki Shibata; Hiroko Kurokawa; Hugo López Rosas; Hugo L. Rojas Villalobos; Ian Yesilonis; Inara Melece; Inge Van Halder; Inmaculada García Quirós; Isaac Makelele; Issaka Senou; István Fekete; Ivan Mihal; Ivika Ostonen; Jana Borovská; Javier Roales; Jawad Shoqeir; Jean-Christophe Lata; Jean-Paul Theurillat; Jean-Luc Probst; Jess Zimmerman; Jeyanny Vijayanathan; Jianwu Tang; Jill Thompson; Jiří Doležal; Joan-Albert Sanchez-Cabeza; Joël Merlet; Joh Henschel; Johan Neirynck; Johannes Knops; John Loehr; Jonathan von Oppen; Jónína Sigríður Þorláksdóttir; Jörg Löffler; José-Gilberto Cardoso-Mohedano; José-Luis Benito-Alonso; Jose Marcelo Torezan; Joseph C. Morina; Juan J. Jiménez; Juan Dario Quinde; Juha Alatalo; Julia Seeber; Jutta Stadler; Kaie Kriiska; Kalifa Coulibaly; Karibu Fukuzawa; Katalin Szlavecz; Katarína Gerhátová; Kate Lajtha; Kathrin Käppeler; Katie A. Jennings; Katja Tielbörger; Kazuhiko Hoshizaki; Ken Green; Lambiénou Yé; Laryssa Helena Ribeiro Pazianoto; Laura Dienstbach; Laura Williams; Laura Yahdjian; Laurel M. Brigham; Liesbeth van den Brink; Lindsey Rustad; al. et

    2018-01-01

    Through litter decomposition enormous amounts of carbon is emitted to the atmosphere. Numerous large-scale decomposition experiments have been conducted focusing on this fundamental soil process in order to understand the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly based on site-specific litter and methodologies...

  3. Decontamination of Petroleum-Contaminated Soils Using The Electrochemical Technique: Remediation Degree and Energy Consumption.

    Science.gov (United States)

    Streche, Constantin; Cocârţă, Diana Mariana; Istrate, Irina-Aura; Badea, Adrian Alexandru

    2018-02-19

    Currently, there are different remediation technologies for contaminated soils, but the selection of the best technology must be not only the treatment efficiency but also the energy consumption (costs) during its application. This paper is focused on assessing energy consumption related to the electrochemical treatment of polluted soil with petroleum hydrocarbons. In the framework of a research project, two types of experiments were conducted using soil that was artificially contaminated with diesel fuel at the same level of contamination. The experimental conditions considered for each experiment were: different amounts of contaminated soils (6 kg and 18 kg, respectively), the same current intensity level (0.25A and 0.5A), three different contamination degrees (1%, 2.5% and 5%) and the same time for application of the electrochemical treatment. The remediation degree concerning the removal of petroleum hydrocarbons from soil increased over time by approximately 20% over 7 days. With regard to energy consumption, the results revealed that with an increase in the quantity of treated soil of approximately three times, the specific energy consumption decreased from 2.94 kWh/kg treated soil to 1.64 kWh/kg treated soil.

  4. The natural abundance of 15N in litter and soil profiles under six temperate tree species: N cycling depends on tree species traits and site fertility

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Nilsson, Lars Ola; Schmidt, Inger Kappel

    2013-01-01

    We investigated the influence of tree species on the natural 15N abundance in forest stands under elevated ambient N deposition.We analysed δ15N in litter, the forest floor and three mineral soil horizons along with ecosystem N status variables at six sites planted three decades ago with five Eur...... to nitrate leaching or other N transformation processes....... species leached more nitrate.The δ15N pattern reflected tree species related traits affecting the N cycling as well as site fertility and former land use, and possibly differences in N leaching. The tree species δ15N patterns reflected fractionation caused by uptake of N through mycorrhiza rather than due...

  5. Effects of terrestrial isopods (Crustacea: Oniscidea on leaf litter decomposition processes

    Directory of Open Access Journals (Sweden)

    Khaleid F. Abd El-Wakeil

    2015-03-01

    Full Text Available The leaf litter decomposition is carried out by the combined action of microorganisms and decomposer invertebrates such as earthworms, diplopods and isopods. The present work aimed to evaluate the impact of terrestrial isopod on leaf litter decomposition process. In Lab experimental food sources from oak and magnolia leaves litter were prepared. Air dried leaf litter were cut to 9 mm discs and sterilized in an autoclave then soaked in distilled water or water percolated through soil and left to decompose for 2, 4 and 6 weeks. 12 groups from two isopods species Porcellio scaber and Armadillidium vulgare, were prepared with each one containing 9 isopods. They were fed individually on the prepared food for 2 weeks. The prepared food differed in Carbon stable isotope ratio (δ13C, C%, N% and C/N ratios. At the end of the experiment, isopods were dissected and separated into gut, gut content and rest of the body. The δ13C for the prepared food, faecal pellets, remaining food, gut content, gut and rest of isopod were compared. The feeding activities of the two isopods were significantly different among isopods groups. Consumption and egestion ratios of magnolia leaf were higher than oak leaf. P. scaber consumed and egested litter higher than A. vulgare. The present results suggested that the impact of isopods and decomposition processes is species and litter specific.

  6. Mineral cycling in soil and litter arthropod food chains. Three-year progress report, November 1, 1980-January 31, 1984

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1984-01-01

    This report summarizes our analysis of trophic dynamics in soil fauna including their impact on the decomposition process, investigation of relationships between soil fauna and microflora, development and testing of models describing these processes, and documentation of rates of movement of nutrients along soil arthropod food chains

  7. Using Capacitance Sensors for the Continuous Measurement of the Water Content in the Litter Layer of Forest Soil

    Directory of Open Access Journals (Sweden)

    Mioko Ataka

    2014-01-01

    Full Text Available Little is known about the wetting and drying processes of the litter layer (L layer, likely because of technical difficulties inherent in nondestructive water content (WC monitoring. We developed a method for continuously measuring the WC of leaf litter (the “LWC method” in situ using capacitance sensors. To test variants of this approach, five (for the LWC_5 or ten (for the LWC_10 method Quercus serrata leaves were attached around capacitance sensors. The output voltage used for each LWC method was linearly correlated with the gravimetric WC (LWC_5: R2=0.940; LWC_10: R2=0.942, producing different slopes for each calibration line. For in situ continuous measurements of WC in the L layer, two sensors were used, one placed on top of the L layer and the other at the boundary between the L and mineral layers. The average continuous WC of the L layer was then calculated from the output voltage of the two sensors and the calibration function, and this value was linearly correlated with the gravimetric WC (R2=0.697. However, because the L layer characteristics (e.g., thickness, water-holding capacity, and species composition may differ among study sites, appropriate approaches for measuring this layer’s moisture properties may be needed.

  8. Carbon turnover in topsoil and subsoil: The microbial response to root litter additions and different environmental conditions in a reciprocal soil translocation experiment

    Science.gov (United States)

    Preusser, Sebastian; Poll, Christian; Marhan, Sven; Kandeler, Ellen

    2017-04-01

    At the global scale, soil organic carbon (SOC) represents the largest active terrestrial organic carbon (OC) pool. Carbon dynamics in subsoil, however, vary from those in topsoil with much lower C concentrations in subsoil than in topsoil horizons, although more than 50 % of SOC is stored in subsoils below 30 cm soil depth. In addition, microorganisms in subsoil are less abundant, more heterogeneously distributed and the microbial communities have a lower diversity than those in topsoil. Especially in deeper soil, the impact of changes in habitat conditions on microorganisms involved in carbon cycling are largely unexplored and consequently the understanding of microbial functioning is limited. A reciprocal translocation experiment allowed us to investigate the complex interaction effects of altered environmental and substrate conditions on microbial decomposer communities in both topsoil and subsoil habitats under in situ conditions. We conducted this experiment with topsoil (5 cm soil depth) and subsoil (110 cm) samples of an acid and sandy Dystric Cambisol from a European beech (Fagus sylvatica L.) forest in Lower Saxony, Germany. In total 144 samples were buried into three depths (5 cm, 45 cm and 110 cm) and 13C-labelled root litter was added to expose the samples to different environmental conditions and to increase the substrate availability, respectively. Samples were taken in three month intervals up to a maximum exposure time of one year to follow the temporal development over the experimental period. Analyses included 13Cmic and 13C PLFA measurements to investigate the response of microbial abundance, community structure and 13C-root decomposition activity under the different treatments. Environmental conditions in the respective soil depths such as soil temperature and water content were recorded throughout the experimental period. All microbial groups (gram+ and gram- bacteria, fungi) showed highest relative 13C incorporation in 110 cm depth and samples

  9. Advances of study on atmospheric methane oxidation (consumption) in forest soil

    Institute of Scientific and Technical Information of China (English)

    WANG Chen-rui; SHI Yi; YANG Xiao-ming; WU Jie; YUE Jin

    2003-01-01

    Next to CO2, methane (CH4) is the second important contributor to global warming in the atmosphere and global atmospheric CH4 budget depends on both CH4 sources and sinks. Unsaturated soil is known as a unique sink for atmospheric CH4 in terrestrial ecosystem. Many comparison studies proved that forest soil had the biggest capacity of oxidizing atmospheric CH4 in various unsaturated soils. However, up to now, there is not an overall review in the aspect of atmospheric CH4 oxidation (consumption) in forest soil. This paper analyzed advances of studies on the mechanism of atmospheric CH4 oxidation, and related natural factors (Soil physical and chemical characters, temperature and moisture, ambient main greenhouse gases concentrations, tree species, and forest fire) and anthropogenic factors (forest clear-cutting and thinning, fertilization, exogenous aluminum salts and atmospheric deposition, adding biocides, and switch of forest land use) in forest soils. It was believed that CH4 consumption rate by forest soil was limited by diffusion and sensitive to changes in water status and temperature of soil. CH4 oxidation was also particularly sensitive to soil C/N, Ambient CO2, CH4 and N2O concentrations, tree species and forest fire. In most cases, anthropogenic disturbances will decrease atmospheric CH4 oxidation, thus resulting in the elevating of atmospheric CH4. Finally, the author pointed out that our knowledge of atmospheric CH4 oxidation (consumption) in forest soil was insufficient. In order to evaluate the contribution of forest soils to atmospheric CH4 oxidation and the role of forest played in the process of global environmental change, and to forecast the trends of global warming exactly, more researchers need to studies further on CH4 oxidation in various forest soils of different areas.

  10. Laboratory and field evaluation of broiler litter nitrogen mineralization.

    Science.gov (United States)

    Sistani, K R; Adeli, A; McGowen, S L; Tewolde, H; Brink, G E

    2008-05-01

    Two studies were conducted for this research. First, a laboratory incubation to quantify broiler litter N mineralization with the following treatments: two soil moisture regimes, constant at 60% water fill pore space (WFPS) and fluctuating (60-30% WFPS), three soil types, Brooksville silty clay loam, Ruston sandy loam from Mississippi, and Catlin silt loam from Illinois. Second, a field incubation study to quantify broiler litter N mineralization using similar soils and litter application rates as the laboratory incubation. Broiler litter was applied at an equivalent rate of 350 kg total N ha(-1) for both studies except for control treatments. Subsamples were taken at different timing for both experiments for NO3-N and NH4-N determinations. In the laboratory experiment, soil moisture regimes had no significant impact on litter-derived inorganic N. Total litter-derived inorganic N across all treatments increased from 23 mg kg(-1) at time 0, to 159 mg kg(-1) at 93 d after litter application. Significant differences were observed among the soil types. Net litter-derived inorganic N was greater for Brooksville followed by Ruston and Catlin soils. For both studies and all soils, NH4-N content decreased while NO3-N content increased indicating a rapid nitrification of the mineralized litter N. Litter mineralization in the field study followed the same trend as the laboratory study but resulted in much lower net inorganic N, presumably due to environmental conditions such as precipitation and temperature, which may have resulted in more denitrification and immobilization of mineralized litter N. Litter-derived inorganic N from the field study was greater for Ruston than Brooksville. Due to no impact by soil moisture regimes, additional studies are warranted in order to develop predictive relationships to quantify broiler litter N availability.

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

    Science.gov (United States)

    Roger W. Perry; Virginia L. McDaniel

    2015-01-01

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

  12. Mineral cycling in soil and litter arthropod food chains. Progress report, November 1, 1979-October 31, 1980

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1980-01-01

    Recent progress and current status are reported for research concerned with mineral element dynamics in soil arthropod food chains. Research is performed within the larger context of terrestrial decomposition systems, in which soil arthropods may act as regulators of nutrient dynamics during decomposition. Research is measuring rates of nutrient accumulation and excretion by using radioactive tracer techniques with radioactive analogs of nutrients. Experimental measurement of radioactive tracer excretion and nutrient element pools are reported for soil microarthropods, using new methods of counting and microprobe elemental analysis. Research on arthropod-fungal relations is utilizing high-efficiency extraction followed by dissection of 13 x 13 cm soil blocks. A two-component excretion model is reported for Cobalt-60 in earthworms (Eisenia foetida), demonstrating that no assimilation of cobalt occurs from the mineral soil fraction but is entirely from organic matter. Collection of data sets on soil arthropod communities and abundances is completed

  13. Role of carboxydobacteria in consumption of atmospheric carbon monoxide by soil

    Energy Technology Data Exchange (ETDEWEB)

    Conrad, R. (Max-Planck-Institut fuer Chemie, Mainz, Germany); Meyer, O.; Seiler, W.

    1981-08-01

    The carbon monoxide consumption rates of the carboxydobacteria Pseudomonas (Seliberia) carboxydohydrogena, P. carboxydovorans, and P. carboxydoflava were measured at high (50%) and low (0.5 ..mu..l liter/sup -1/) mixing ratios of CO in air. CO was only consumed when the bacteria had been grown under CO-autotrophic conditions. At low cell densities the CO comsumption rates measured at low CO mixing ratios were similar in cell suspensions and in mixtures of bacteria in soil. CO consumption observed in natural soil (loess, eolian sand, chernozem) as well as in suspensions or soil mixtures of carboxydobacteria showed Michaelis-Menten kinetics. Considering the difference of the K/sub m/, values and the observed V/sub max/ values, carboxydobacteria cannot contribute significantly to the consumption of atmospheric CO.

  14. Plant litter decomposition and carbon sequestration for arable soils. Final report of works. April 2005; Biodegradation des litieres et sequestration du carbone dans les ecosystemes cultives et perennes. Rapport final des travaux Avril 2005

    Energy Technology Data Exchange (ETDEWEB)

    Recous, S.; Barrois, F.; Coppens, F.; Garnier, P.; Grehan, E. [Institut National de Recherches Agronomiques (INRA), Unite d' Agronomie Laon-Reims-Mons (France); Balesdent, J. [CNRS-CEA-Univ.de la Mediterranee, UMR 6191, Lab. d' Ecologie Microbienne de la Rhizosphere, 13 - Saint Paul lez Durance (France); Dambrine, E.; Zeller, B. [Institut National de Recherches Agronomiques (INRA), Unite Biogeochimie des Ecosystemes Forestiers, 54 - Nancy (France); Loiseau, P.; Personeni, E. [Institut National de Recherches Agronomiques (INRA), Unite d' Agronomie, 63 - Clermont-Ferrand (France)

    2002-07-01

    The general objective of this project was to contribute to the evaluation of land use and management impacts on C sequestration and nitrogen dynamics in soils. The land used through the presence/absence of crops and their species, and the land management through tillage, localisation of crop residues, fertilizer applications,... are important factors that affect the dynamics of organic matters in soils, particularly the mineralization of C and N, the losses to the atmosphere and hydrosphere, the retention of carbon into the soil. This project was conducted by four research groups, three of them having expertise in nutrient cycling of three major agro-ecosystems (arable crops, grasslands, forests) and the fourth one having expertise in modelling long term effects of land use on C storage into the soils. Within this common project one major objective was to better understand the fate of plant litter entering the soil either as above litter or as root litter. The focus was put on two factors that particularly affect decomposition: the initial biochemical quality of plant litter, and the location of the decomposing litter. One innovative aspect of the project was the use of stable isotope as {sup 13}C for carbon, based on the use of enriched or depleted {sup 13}C material, the only option to assess the dynamics of 'new' C entering the soil on the short term, in order to reveal the effects of decomposition factors. Another aspect was the simultaneous study of C and N. The project consisted in experiments relevant for each agro-ecosystem, in forest, grassland and arable soils for which interactions between residue quality and nitrogen availability on the one hand, residue quality and location on the other hand, was investigated. A common experiment was set up to investigate the potential degradability of the various residue used (beech leaf rape straw, young rye, Lolium and dactylic roots) in a their original soils and in a single soil was assessed. Based on

  15. Atividade microbiana de solo e serapilheira em áreas povoadas com Pinus elliottii e Terminalia ivorensis Microbial activity of soil and litter in areas with forest stands of Pinus elliottii e Terminalia ivorensis

    Directory of Open Access Journals (Sweden)

    André Mundstock Xavier de Carvalho

    2008-12-01

    Full Text Available No Brasil, as espécies Pinus elliottii e Terminalia ivorensis vêm sendo indicadas para reflorestamento. No entanto, pouco se sabe sobre as características ecológicas destas florestas, o ciclo de nutrientes e suas conseqüências sobre a produtividade e sustentabilidade sob condições tropicais. Visando melhor compreender a dinâmica do C nestes ecossistemas, objetivou-se neste trabalho avaliar a atividade microbiana do solo, serapilheira e da mistura solo + serapilheira em povoamentos florestais de P. elliottii e T. ivorensis. Amostras de solos e serapilheira foram incubadas e a atividade microbiana avaliada por meio da evolução de CO2. Ao final da incubação, a respiração acumulada foi superior para a serapilheira de T. ivorensis. Os demais substratos com serapilheira não diferiram entre si, mas diferiram do solo sob T. ivorensis, que, por sua vez, diferiu do solo sob P. elliottii. Nas condições testadas, a incorporação de solo à serapilheira, bem como a incorporação alternada de solo de um povoamento à serapilheira de outro, não promoveu aumentos significativos na respiração da serapilheira, mostrando que as características químicas da própria serapilheira alteram mais fortemente sua velocidade de degradação que as características químicas e microbianas do solo onde é incorporada.In Brazil, the species Pinus elliottii and Terminalia ivorensis are being recommended for reforestation. However, little is known about the ecological characteristics of such forests, the nutrient cycle and possible consequences on yields and sustainability under tropical conditions. For a better understanding of the C dynamic in these ecosystems, this study aimed to evaluate the microbial activity of soil, litter, and the mixture of soil + litter in forest stands of P. elliottii and T. ivorensis. Samples of soil, litter and mixture were incubated and the microbial activity was evaluated on the basis of CO2 released. At the end of

  16. The uptake of radionuclides from inadvertent consumption of soil by grazing animals

    International Nuclear Information System (INIS)

    Green, N.; Dodd, N.J.

    1988-01-01

    Investigations of the transfer to man of artificially-produced radionuclides through food chains have shown that the inadvertent consumption of soil by grazing animals can give variations in estimates of transfer coefficients, especially for radionuclides that are poorly absorbed by plant roots. Even small masses of soil adhering to herbage or directly ingested can make a significant contribution to the intake inventory in terms of activity. Although the activity concentrations of soil-contaminated herbage are elevated, the radionuclides associated with the soil may not necessarily be in a form which is easily absorbed by the animal. Attempts must be made, therefore, to quantify soil intake and the subsequent radionuclide uptake by this mechanism. A field investigation of the uptake of radionuclides by farm animals grazing near the Sellafield nuclear reprocessing plant has been pursued. The aims of the study were to estimate the transfer to muscle and other tissues. This paper describes the methods used to estimate both the soil intake and the consequent availability of radionuclides associated with the soil. The measurements were used to evaluate the contribution to tissue content of inadvertent consumption of soil by cows and sheep. 10 refs.; 2 tabs

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

    Science.gov (United States)

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

    2015-09-22

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

  18. The partitioning of litter carbon during litter decomposition under different rainfall patterns: a laboratory study

    Science.gov (United States)

    Yang, X.; Szlavecz, K. A.; Langley, J. A.; Pitz, S.; Chang, C. H.

    2017-12-01

    Quantifying litter C into different C fluxes during litter decomposition is necessary to understand carbon cycling under changing climatic conditions. Rainfall patterns are predicted to change in the future, and their effects on the fate of litter carbon are poorly understood. Soils from deciduous forests in Smithsonian Environmental Research Center (SERC) in Maryland, USA were collected to reconstruct soil columns in the lab. 13C labeled tulip poplar leaf litter was used to trace carbon during litter decomposition. Top 1% and the mean of 15-minute historical precipitation data from nearby weather stations were considered as extreme and control rainfall intensity, respectively. Both intensity and frequency of rainfall were manipulated, while the total amount was kept constant. A pulse of CO2 efflux was detected right after each rainfall event in the soil columns with leaf litter. After the first event, CO2 efflux of the control rainfall treatment soils increased to threefold of the CO2 efflux before rain event and that of the extreme treatment soils increased to fivefold. However, in soils without leaf litter, CO2 efflux was suppressed right after rainfall events. After each rainfall event, the leaf litter contribution to CO2 efflux first showed an increase, decreased sharply in the following two days, and then stayed relatively constant. In soil columns with leaf litter, the order of cumulative CO2 efflux was control > extreme > intermediate. The order of cumulative CO2 efflux in the bare soil treatment was extreme > intermediate > control. The order of volume of leachate from different treatments was extreme > intermediate > control. Our initial results suggest that more intense rainfall events result in larger pulses of CO2, which is rarely measured in the field. Additionally, soils with and without leaf litter respond differently to precipitation events. This is important to consider in temperate regions where leaf litter cover changes throughout the year

  19. THE FATE OF TANNINS IN CORSICAN PINE LITTER

    NARCIS (Netherlands)

    Nierop, K.G.J.; Verstraten, J.M.

    2006-01-01

    Tannins are ubiquitous in higher plants and therefore also in litter and soils where they affect many biogeochemical processes. Despite this well recognized role, the fate of tannins in litter and mineral soils is hardly known as often only trace amounts, if any, of tannins are measured. In this

  20. The consumption of atmospheric methane by soil in a simulated future climate

    Directory of Open Access Journals (Sweden)

    C. L. Curry

    2009-11-01

    Full Text Available A recently developed model for the consumption of atmospheric methane by soil (Curry, 2007 is used to investigate the global magnitude and distribution of methane uptake in a simulated future climate. In addition to solving the one-dimensional diffusion-reaction equation, the model includes a parameterization of biological CH4 oxidation that is sensitive to soil temperature and moisture content, along with specified reduction factors for land cultivation and wetland fractional coverage. Under the SRES emission scenario A1B, the model projects an 8% increase in the global annual mean CH4 soil sink by 2100, over and above the 15% increase expected from increased CH4 concentration alone. While the largest absolute increases occur in cool temperate and subtropical forest ecosystems, the largest relative increases in consumption (>40% are seen in the boreal forest, tundra and polar desert environments of the high northern latitudes. Methane uptake at mid- to high northern latitudes increases year-round in 2100, with a 68% increase over present-day values in June. This increase is primarily due to enhanced soil diffusivity resulting from lower soil moisture produced by increased evaporation and reduced snow cover. At lower latitudes, uptake is enhanced mainly by elevated soil temperatures and/or reduced soil moisture stress, with the dominant influence determined by the local climate.

  1. Mineral cycling in soil and litter arthropod food chains. Progress report, November 1, 1980-October 31, 1981

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1980-01-01

    Progress and current status are reported for research projects concerned with mineral element and nutrient dynamics in soil arthropod food chains. Research is performed within the larger context of terrestrial decomposition, in which soil arthropods may act as regulators of nutrient dynamics during decomposition. Research is measuring rates of nutrient accumulation and excretion by using radioactive tracer analogs of nutrients. This year, emphasis has been placed on field work in which soil arthropod population size and nutrients inputs were varied experimentally. The presence of microarthropods in field microcosms increased the mineralization of N and P in each case, but rates were not correlated with arthropod densities. Experiments recently started are using both arthropod and microfloral inhibitors, in open systems on the forest floor, with the objective of quantifying arthropod enhancement of microbial immobilization of nutrients

  2. Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1977--October 31, 1978

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1978-01-01

    Progress is reported in projects dealing with radioisotope measurement of nutrient flow in soil arthropod food chains, the role of soil arthropods as regulators of the terrestrial decomposition process, and field projects investigating the response to perturbation by island ecosystems on granitic outcrops. Radioisotopes in combination with system modeling techniques are being used to estimate nutrient flow rates in food chains of soil arthropods, and help to evaluate their impact on the decomposition process. Field work on granitic outcrop ecosystems has been completed. Evaluations of input-output budgets showed that the ecosystems are essentially in balance. They showed a strong resistance component of stability, as opposed to resilience, as far as chemical perturbations and drought are concerned

  3. Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1976--October 31, 1977

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1977-01-01

    Progress has been made in two sub-projects related to the radioisotope measurement of nutrient flow in soil arthropod food chains and the influence of soil arthropods as regulators of decomposition in ecological systems. Radioisotopes were utilized to evaluate models describing nutrient accumulation by arthropods. Radionuclide turnover rates and nutrient contents of microarthropods are being measured. A field experiment in granitic outcrop areas is nearing completion. This work will describe nutrient input-output budgets for island ecosystems which occur on outcrops. Experimental perturbations are being used to evaluate importance of ecosystem components in system maintenance

  4. Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Soil and Litter Invertebrates and Heterotrophic Process

    Energy Technology Data Exchange (ETDEWEB)

    Will, M.E.

    1994-01-01

    This report presents a standard method for deriving benchmarks for the purpose of ''contaminant screening,'' performed by comparing measured ambient concentrations of chemicals. The work was performed under Work Breakdown Structure 1.4.12.2.3.04.07.02 (Activity Data Sheet 8304). In addition, this report presents sets of data concerning the effects of chemicals in soil on invertebrates and soil microbial processes, benchmarks for chemicals potentially associated with United States Department of Energy sites, and literature describing the experiments from which data were drawn for benchmark derivation.

  5. Camerobiid mites (Acariformes: Raphignathina: Camerobiidae inhabiting epiphytic bromeliads and soil litter of tropical dry forest with analysis of setal homology in the genus Neophyllobius

    Directory of Open Access Journals (Sweden)

    Ricardo Paredes-León

    2016-06-01

    Full Text Available A survey of the camerobiid mites living on epiphytic bromeliads and the forest floor of a Mexican tropical dry forest was carried out. We found three new species of the genus Neophyllobius, which are described in this paper; the first two, namely N. cibyci sp. nov. and N. tepoztlanensis sp. nov., were both found inhabiting bromeliads (Tillandsia spp. and living on two tree species (Quercus obtusata and Sapium macrocarpum; the third, N. tescalicola sp. nov., was found in soil and litter under Q. obtusata. These three new species can be differentiated from other species in the genus by a combination of morphological characters in adult females, mainly those setae on femora and genua I. The idiosoma and leg setal ontogeny of a camerobiid mite is presented for the first time in this paper, illustrating chaetotaxic notations and their relative positions in N. cibyci sp. nov. larva, protonymph and adults (female and male, and establishing setal homologies among instars. Setal homology with other species in the cohort Raphignathina is briefly discussed. Additionally, a compilation and an identification key to all known species of camerobiid mites in Mexico is provided.

  6. PERFORMANCE, CARCASS YIELD AND LITTER QUALITY OF BROILERS RAISED ON LITTERS TREATED WITH MICRO-ORGANISMS

    Directory of Open Access Journals (Sweden)

    Dayane Prado da Cruz

    2013-03-01

    Full Text Available The present paper aimed at evaluating the effect of adding beneficial micro-organisms to the litters on litter quality, performance and carcass yield for broilers. A total of 240 one-day chicks were used, and randomly distributed in blocks with four treatments and four replications. The following treatments were carried out in the housing: Treatment 1 – Control with weekly spraying of water on the litters; Treatment 2 – Litter treated with a mixture of inoculated and fermented meal by micro-organisms and weekly spraying of water; Treatment 3 – Litter treated by weekly spraying of micro-organisms; Treatment 4 – Litter treated with the same mixture of meals from treatment two and weekly spraying of micro-organisms. Performance was evaluated by the feed consumption, weight gain, feed conversion, viability and carcass, breast and leg yield. From litter samples, pH, dry matter, ashes and nitrogen were evaluated. No differences were found among the treatments. In the conditions the animals were raised, it can be concluded that the treatment on the litter does not affect performance, carcass yield and quality of the litter for broilers.

  7. Toxicological benchmarks for potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process

    Energy Technology Data Exchange (ETDEWEB)

    Will, M.E.; Suter, G.W. II

    1995-09-01

    An important step in ecological risk assessments is screening the chemicals occur-ring on a site for contaminants of potential concern. Screening may be accomplished by comparing reported ambient concentrations to a set of toxicological benchmarks. Multiple endpoints for assessing risks posed by soil-borne contaminants to organisms directly impacted by them have been established. This report presents benchmarks for soil invertebrates and microbial processes and addresses only chemicals found at United States Department of Energy (DOE) sites. No benchmarks for pesticides are presented. After discussing methods, this report presents the results of the literature review and benchmark derivation for toxicity to earthworms (Sect. 3), heterotrophic microbes and their processes (Sect. 4), and other invertebrates (Sect. 5). The final sections compare the benchmarks to other criteria and background and draw conclusions concerning the utility of the benchmarks.

  8. Effects of pulse current on energy consumption and removal of heavy metals during electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Sun, Tian R.; Ottosen, Lisbeth M.

    2012-01-01

    industrially polluted soils were performed. At a current density of 0.1mA/cm2 in soil 1 and 0.2mA/cm2 in soil 2, there was no difference on energy consumption and removal of heavy metals between pulse current and constant current experiments, but at higher current experiments (i.e., 0.2mA/cm2 in soil 1 and 0......The aims of this paper were to investigate the possibility for energy saving when using a pulsed electric field during electrodialytic soil remediation (EDR) and the effect of the pulsed current on removal of heavy metals. Eight experiments with constant and pulse current in the different.......8mA/cm2 in soil 2) the energy was saved 67% and 60% and the removal of heavy metals was increased 17–76% and 31–51% by pulse current in soil 1 and soil 2, respectively. When comparing the voltage drop at different parts of EDR cells, it was found that the voltage drop of the area across cation...

  9. Microbiological Safety of Chicken Litter or Chicken Litter-Based Organic Fertilizers: A Review

    Directory of Open Access Journals (Sweden)

    Zhao Chen

    2014-01-01

    Full Text Available Chicken litter or chicken litter-based organic fertilizers are usually recycled into the soil to improve the structure and fertility of agricultural land. As an important source of nutrients for crop production, chicken litter may also contain a variety of human pathogens that can threaten humans who consume the contaminated food or water. Composting can inactivate pathogens while creating a soil amendment beneficial for application to arable agricultural land. Some foodborne pathogens may have the potential to survive for long periods of time in raw chicken litter or its composted products after land application, and a small population of pathogenic cells may even regrow to high levels when the conditions are favorable for growth. Thermal processing is a good choice for inactivating pathogens in chicken litter or chicken litter-based organic fertilizers prior to land application. However, some populations may become acclimatized to a hostile environment during build-up or composting and develop heat resistance through cross-protection during subsequent high temperature treatment. Therefore, this paper reviews currently available information on the microbiological safety of chicken litter or chicken litter-based organic fertilizers, and discusses about further research on developing novel and effective disinfection techniques, including physical, chemical, and biological treatments, as an alternative to current methods.

  10. Transfer of arsenic from poultry feed to poultry litter: A mass balance study.

    Science.gov (United States)

    Gupta, Sanjay K; Le, X Chris; Kachanosky, Gary; Zuidhof, Martin J; Siddique, Tariq

    2018-07-15

    Roxarsone (rox), an arsenic (As) containing organic compound, is a common feed additive used in poultry production. To determine if As present in rox is excreted into the poultry litter without any retention in chicken meat for safe human consumption, the transference of As from the feed to poultry excreta was assessed using two commercial chicken strains fed with and without dietary rox. The results revealed that both the strains had similar behaviour in growth (chicken weight; 2.17-2.25kg), feed consumption (282-300kgpen -1 initially containing 102 chicken) and poultry litter production (73-81kgpen -1 ) during the growth phase of 35days. Our mass balance calculations showed that chickens ingested 2669-2730mg As with the feed and excreted out 2362-2896mg As in poultry litter during the growth period of 28days when As containing feed was used, yielding As recovery between 86 and 108%. Though our complementary studies show that residual arsenic species in rox-fed chicken meat may have relevance to human exposure, insignificant retention of total As in the chicken meat substantiates our mass balance results. The results are important in evaluating the fate of feed additive used in poultry production and its potential environmental implications if As containing poultry litter is applied to soil for crop production. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Mineral cycling in soil and litter arthropod food chains. Progress report, November 1, 1981-January 31, 1983

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1982-01-01

    Progress is reported for research projects on nutrient dynamics during terrestrial decomposition, as influenced by soil arthropods. Radioactive tracers are used as analogs of nutrients, to measure material movement along food chains and dynamics of processes during decomposition. Forest floor systems from which arthropods were excluded, or in which microfloral activity was depressed, trapped incoming nutrients from canopy throughfall at different rates. Faunal stimulation of microfloral activities could not be demonstrated, but drought conditions disturbed the experiment. Turnover measurements for radionuclides in collembolans are also reported, and compared with information on mites and other arthropods

  12. Nitrous oxide production and consumption potential in an agricultural and a forest soil

    DEFF Research Database (Denmark)

    Yu, Kewei; Struwe, Sten; Kjøller, Annelise

    2008-01-01

    Both a laboratory incubation experiment using soils from an agricultural field and a forest and field measurements at the same locations were conducted to determine nitrous oxide (N2O) production and consumption (reduction) potentials using the acetylene (C2H2) inhibition technique. Results from...... measurements show that average N2O emission rates were 0.56 and 0.59 kg N ha-1 in the agricultural field and forest, respectively. When C2H2 was provided in the field measurements, N2O emission rates from the agricultural field and forest increased by 38 and 51%, respectively. Nitrous oxide consumption under...

  13. Throughfall-mediated alterations to soil microbial community structure in a forest plot of homogenous soil texture, litter, and plant species composition

    Science.gov (United States)

    Van Stan, John; Rosier, Carl; Moore, Leslie; Gay, Trent; Reichard, James; Wu, Tiehang; Kan, Jinjun

    2015-04-01

    Identifying spatiotemporal influences on soil microbial community (SMC) structure is critical to our understanding of patterns in biogeochemical cycling and related ecological services (e.g., plant community structure, water quality, response to environmental change). Since forest canopy structure alters the spatiotemporal patterning of precipitation water and solute supplies to soils (via "throughfall"), is it possible that changes in SMC structure could arise from modifications in canopy elements? Our study investigates this question by monitoring throughfall water and dissolved ion supply to soils beneath a continuum of canopy structure: from large gaps (0% cover), to bare Quercus virginiana Mill. (southern live oak) canopy (~50-70%), to heavy Tillandsia usneoides L. (Spanish moss) canopy (>90% cover). Throughfall water supply diminished with increasing canopy cover, yet increased washoff/leaching of Na+, Cl-, PO43-, and SO42- from the canopy to the soils. Presence of T. usneoides diminished throughfall NO3-, but enhanced NH4+, concentrations supplied to subcanopy soils. The mineral soil horizon (0-10 cm) sampled in triplicate from locations receiving throughfall water and solutes from canopy gaps, bare canopy, and T. usneoides-laden canopy significantly differed in soil chemistry parameters (pH, Ca2+, Mg2+, CEC). Polymerase Chain Reaction-Denaturant Gradient Gel Electrophoresis (PCR-DGGE) banding patterns beneath similar canopy covers (experiencing similar throughfall dynamics) also produced high similarities per ANalyses Of SIMilarity (ANO-SIM), and clustered together when analyzed by Nonmetric Multidimensional Scaling (NMDS). These results suggest that modifications of forest canopy structures are capable of affecting mineral-soil horizon SMC structure via throughfall when canopies' biomass distribution is highly heterogeneous. As SMC structure, in many instances, relates to functional diversity, we suggest that future research seek to identify functional

  14. Genotypic diversity of an invasive plant species promotes litter decomposition and associated processes.

    Science.gov (United States)

    Wang, Xiao-Yan; Miao, Yuan; Yu, Shuo; Chen, Xiao-Yong; Schmid, Bernhard

    2014-03-01

    Following studies that showed negative effects of species loss on ecosystem functioning, newer studies have started to investigate if similar consequences could result from reductions of genetic diversity within species. We tested the influence of genotypic richness and dissimilarity (plots containing one, three, six or 12 genotypes) in stands of the invasive plant Solidago canadensis in China on the decomposition of its leaf litter and associated soil animals over five monthly time intervals. We found that the logarithm of genotypic richness was positively linearly related to mass loss of C, N and P from the litter and to richness and abundance of soil animals on the litter samples. The mixing proportion of litter from two sites, but not genotypic dissimilarity of mixtures, had additional effects on measured variables. The litter diversity effects on soil animals were particularly strong under the most stressful conditions of hot weather in July: at this time richness and abundance of soil animals were higher in 12-genotype litter mixtures than even in the highest corresponding one-genotype litter. The litter diversity effects on decomposition were in part mediated by soil animals: the abundance of Acarina, when used as covariate in the analysis, fully explained the litter diversity effects on mass loss of N and P. Overall, our study shows that high genotypic richness of S. canadensis leaf litter positively affects richness and abundance of soil animals, which in turn accelerate litter decomposition and P release from litter.

  15. Web Application for Coastal Area Planning through Analysis of Landslide and Soil Consumption

    Science.gov (United States)

    Panizzoni, Giulio; Debiasi, Alberto; Eccher, Matteo; De Amicis, Raffaele

    2016-04-01

    Global warming and rapid climatic changes are producing dramatic effects on coastal area of Mediterranean countries. Italian coastal areas are one of the most urbanized zones of the south western Europe and the extensive use of soil is causing a consistent impact on the hydrogeological context. Moreover, soil consumption combined with extreme meteorological events, facilitates the occurrence of hazardous landslide events. Environmental policy makers and data managers in territorial planning need to face such emergency situation with appropriate tools. We present an application service with the aim of advising user through environmental analysis of Landslide and Soil Consumption impact. This service wants also to improve the sharing of environmental harmonized datasets/metadata across different organizations and the creation of a collaborative environment where the stakeholders and environmental experts can share their data and work cooperatively. We developed a set of processing services providing functionalities to assess impact of landslide on territory and impact of land take and soil sealing. Among others, the service is able to evaluate environmental impacts of landslide events on Cultural Heritage sites. We have also designed a 3D WebGL client customized to execute the processing services and visualize their outputs. It provides high usability in terms of navigation and data visualization. In this way the service provides not only a Spatial Data Infrastructure to access and visualize data but a complete Decision Support Systems for a more effective environmental planning of coastal area.

  16. [Effects of soil wetting pattern on the soil water-thermal environment and cotton root water consumption under mulched drip irrigation].

    Science.gov (United States)

    Li, Dong-wei; Li, Ming-si; Liu, Dong; Lyu, Mou-chao; Jia, Yan-hui

    2015-08-01

    Abstract: To explore the effects of soil wetting pattern on soil water-thermal environment and water consumption of cotton root under mulched drip irrigation, a field experiment with three drip intensities (1.69, 3.46 and 6.33 L · h(-1)), was carried out in Shihezi, Xinjiang Autonomous Region. The soil matric potential, soil temperature, cotton root distribution and water consumption were measured during the growing period of cotton. The results showed that the main factor influencing the soil temperature of cotton under plastic mulch was sunlight. There was no significant difference in the soil temperature and root water uptake under different treatments. The distribution of soil matrix suction in cotton root zone under plastic mulch was more homogeneous under ' wide and shallow' soil wetting pattern (W633). Under the 'wide and shallow' soil wetting pattern, the average difference of cotton root water consumption between inner row and outer row was 0.67 mm · d(-1), which was favorable to the cotton growing trimly at both inner and outer rows; for the 'narrow and deep' soil wetting pattern (W169), the same index was 0.88 mm · d(-1), which was unfavorable to cotton growing uniformly at both inner and outer rows. So, we should select the broad-shallow type soil wetting pattern in the design of drip irrigation under mulch.

  17. Use of natural zeolite-supplemented litter increased broiler production

    African Journals Online (AJOL)

    The aim of this study was to ascertain the influence of natural zeolite, consisting mainly of clinoptilolite and mordenite, as a component of the litter material in broiler houses on the performance of the broilers and on some litter characteristics. Live weight gain, feed consumption, feed efficiency, viability and leg and body ...

  18. Long-term effects of alum-treated litter, untreated litter and NH4NO3 application on phosphorus speciation, distribution and reactivity in soils using K-edge XANES and chemical fractionation

    Science.gov (United States)

    Whereas soil test information on the fertility and chemistry of soils has been important to elaborate safe and sound agricultural practices, microscopic information can give a whole extra dimension to understand the chemical processes occurring in soils. The objective of this study was to evaluate t...

  19. Marine Anthropogenic Litter

    OpenAIRE

    Bergmann, Melanie; Gutow, Lars; Klages, Michael

    2015-01-01

    This book describes how manmade litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habitats and food webs worldwide. The book illustrates how advanced technologies from deep-sea research, microbiology and mathematic modelling as well as classic beach litter counts by volunteers co...

  20. Trees as templates for tropical litter arthropod diversity.

    Science.gov (United States)

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

    2010-09-01

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

  1. 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.

  2. [Contribution of soil water at various depths to water consumption of rainfed winter wheat in the Loess tableland, China].

    Science.gov (United States)

    Cheng, Li Ping; Liu, Wen Zhao

    2017-07-18

    Soil water and stem water were collected in jointing and heading stages of the rainfed winter wheat in the Changwu Loess tableland, and the stable isotopic compositions of hydrogen and oxygen in water samples were measured to analyze the contribution of soil water at various depths to water consumption of winter wheat. The results showed that the isotopes were enriched in soil and wheat stem water in comparison with that in precipitation. Under the condition of no dry layer in soil profile, the contributions to wheat water consumption in jointing and heading stages were 5.4% and 2.6% from soil water at 0-30 cm depth, 73.4% and 67.3% at 60-90 cm depth (the main water source for winter wheat), and 7.9% and 13.5% below 120 cm depth, respectively. With the wheat growth, the contribution of soil water below the depth of 90 cm increased. It was concluded that soil evaporation mainly consumed soil water in 0-30 cm depth and wheat transpiration mainly consumed soil water below 60 cm depth in the experimental period. In the production practice, it is necessary to increase rainwater storage ratio during the summer fallow period, and apply reasonable combination of nitrogen and phosphorus fertilizers in order to increase soil moisture before wheat sowing, promote the wheat root developing deep downwards and raise the deep soil water utilization ratio.

  3. Amending triple superphosphate with chicken litter biochar improves phosphorus availability

    Directory of Open Access Journals (Sweden)

    Audrey Asap

    2018-04-01

    Full Text Available The reaction of H2PO42- and HPO4- with Al and Fe in acid soils to form a precipitate reduces P availability. Chicken litter biochar has been used to improve soil P availability for maize production but with limited information on optimum rates of biochar and Triple Superphosphate (TSP to increase P availability. This study determined the optimum amount of chicken litter biochar and TSP that could increase P availability. Different rates of chicken litter biochar and TSP were evaluated in an incubation study for 30, 60, and 90 days. Selected soil chemical properties before and after incubation were determined using standard procedures. Soil pH, total P, available P, and water soluble P increased in treatments with 75% and 50% biochar. Total acidity, exchangeable Al3+, and Fe2+ were significantly reduced by the chicken litter biochar. The chicken litter biochar also increased soil CEC and exchangeable cations (K, Ca, Mg and Na. The use of 75% and 50% of 5 t ha-1 biochar with 25% TSP of the existing recommendation can be used to increase P availability whilst minimizing soil Al and Fe content. This rates can be used to optimize chicken litter biochar and TSP use in acid soils for crop production especially maize and short term vegetables.

  4. The global stoichiometry of litter nitrogen mineralization

    Science.gov (United States)

    Stefano Manzoni; Robert B. Jackson; John A. Trofymow; Amilcare Porporato

    2008-01-01

    Plant residue decomposition and the nutrient release to the soil play a major role in global carbon and nutrient cycling. Although decomposition rates vary strongly with climate, nitrogen immobilization into litter and its release in mineral forms are mainly controlled by the initial chemical composition of the residues. We used a data set of ~2800 observations to show...

  5. Utilization of poultry litter for pesticide bioremediation

    Science.gov (United States)

    Agricultural chemical products such as pesticides have been used to increase crop production, especially in undeveloped countries. Poultry litter, the combination of feces and bedding materials, has also been used as an alternative to improve soil quality for crop production. However, information re...

  6. DNA barcoding survey of Trichoderma diversity in soil and litter of the Colombian lowland Amazonian rainforest reveals Trichoderma strigosellum sp. nov. and other species

    NARCIS (Netherlands)

    Lopez-Quintero, C.A.; Atanasova, L.; Franco-Molano, A.E.; Gams, W.; Komon-Zelazowska, M.; Theelen, B.; Muller, W.H.; Boekhout, T.; Druzhinina, I.

    2013-01-01

    The diversity of Trichoderma (Hypocreales, Ascomycota) colonizing leaf litter as well as the rhizosphere of Garcinia macrophylla (Clusiaceae) was investigated in primary and secondary rain forests in Colombian Amazonia. DNA barcoding of 107 strains based on the internal transcribed spacers 1 and 2

  7. Metal and nutrient dynamics in decomposing tree litter on a metal contaminated site

    International Nuclear Information System (INIS)

    Van Nevel, Lotte; Mertens, Jan; Demey, Andreas; De Schrijver, An; De Neve, Stefaan; Tack, Filip M.G.; Verheyen, Kris

    2014-01-01

    In a forest on sandy, metal polluted soil, we examined effects of six tree species on litter decomposition rates and accompanied changes in metal (Cd, Zn) and nutrient (base cations, N, C) amounts. Decomposition dynamics were studied by means of a litterbag experiment lasting for 30 months. The decomposition peak occurred within the first year for all tree species, except for aspen. During litter decomposition, high metal litter types released part of their accumulated metals, whereas low metal litter types were characterized by a metal enrichment. Base cations, N and C were released from all litter types. Metal release from contaminated litter might involve risks for metal dispersion towards the soil. On the other hand, metal enrichment of uncontaminated litter may be ecologically relevant as it can be easily transported or serve as food source. - Highlights: • Litter decomposition peak occurred within the first year for all tree species, except for aspen. • Base cations, N and C were released from all litter types during decomposition. • Cd and Zn were released from the high metal litter types. • Low metal litter types were characterized by a net Cd and Zn enrichment. • Metal and nutrient releases were reflected in topsoil characteristics. - Litter decomposition rates, as well as enrichment and release dynamics of metals and nutrients in decomposing litter were divergent under the different tree species

  8. Links between plant litter chemistry, species diversity, and below-ground ecosystem function.

    Science.gov (United States)

    Meier, Courtney L; Bowman, William D

    2008-12-16

    Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics of plant species diversity. We amended native soils with litter mixtures containing up to 4 alpine plant species, and we used 9 litter chemical traits to evaluate the chemical composition (i.e., the identity and quantity of compounds) and chemical diversity of the litter mixtures. The chemical composition of the litter mixtures was the strongest predictor of soil respiration, net N mineralization, and microbial biomass N. Soil respiration and net N mineralization rates were also significantly correlated with the chemical diversity of the litter mixtures. In contrast, soil C and N cycling rates were poorly correlated with plant species richness, and there was no relationship between species richness and the chemical diversity of the litter mixtures. These results indicate that the composition and diversity of chemical compounds in litter are potentially important functional traits affecting decomposition, and simple metrics like plant species richness may fail to capture variation in these traits. Litter chemical traits therefore provide a mechanistic link between organisms, species diversity, and key components of below-ground ecosystem function.

  9. Nutrient dynamics and tree growth of silvopastoral systems: impact of poultry litter.

    Science.gov (United States)

    Blazier, Michael A; Gaston, Lewis A; Clason, Terry R; Farrish, Kenneth W; Oswald, Brian P; Evans, Hayden A

    2008-01-01

    Fertilizing pastures with poultry litter has led to an increased incidence of nutrient-saturated soils, particularly on highly fertilized, well drained soils. Applying litter to silvopastures, in which loblolly pine (Pinus taeda L.) and bahiagrass (Paspalum notatum) production are integrated, may be an ecologically desirable alternative for upland soils of the southeastern USA. Integrating subterranean clover (Trifolium subterraneum) into silvopastures may enhance nutrient retention potential. This study evaluated soil nutrient dynamics, loblolly pine nutrient composition, and loblolly pine growth of an annually fertilized silvopasture on a well drained soil in response to fertilizer type, litter application rate, and subterranean clover. Three fertilizer treatments were applied annually for 4 yr: (i) 5 Mg litter ha(-1) (5LIT), (ii) 10 Mg litter ha(-1) (10LIT), and (iii) an inorganic N, P, K pasture blend (INO). Litter stimulated loblolly pine growth, and neither litter treatment produced soil test P concentrations above runoff potential threshold ranges. However, both litter treatments led to accumulation of several nutrients (notably P) in upper soil horizons relative to INO and unfertilized control treatments. The 10LIT treatment may have increased N and P leaching potential. Subterranean clover kept more P sequestered in the upper soil horizon and conferred some growth benefits to loblolly pine. Thus, although these silvopasture systems had a relatively high capacity for nutrient use and retention at this site, litter should be applied less frequently than in this study to reduce environmental risks.

  10. Environmentally friendly animal litter

    Science.gov (United States)

    Chett, Boxley; McKelvie, Jessica

    2013-08-20

    A method of making an animal litter that includes geopolymerized ash, wherein, the animal litter is made from a quantity of a pozzolanic ash mixed with a sufficient quantity of water and an alkaline activator to initiate a geopolymerization reaction that forms geopolymerized ash. After the geopolymerized ash is formed, it is dried, broken into particulates, and sieved to a desired size. These geopolymerized ash particulates are used to make a non-clumping or clumping animal litter. Odor control may be accomplished with the addition of a urease inhibitor, pH buffer, an odor eliminating agent, and/or fragrance.

  11. Cadmium transfer from contaminated soils to the human body through rice consumption in southern Jiangsu Province, China.

    Science.gov (United States)

    Li, Tianyuan; Chang, Qing; Yuan, Xuyin; Li, Jizhou; Ayoko, Godwin A; Frost, Ray L; Chen, Hongyan; Zhang, Xinjian; Song, Yinxian; Song, Wenzhi

    2017-06-21

    Consumption of crops grown in cadmium-contaminated soils is an important Cd exposure route to humans. The present study utilizes statistical analysis and in vitro digestion experiments to uncover the transfer processes of Cd from soils to the human body through rice consumption. Here, a model was created to predict the levels of bioaccessible Cd in rice grains using phytoavailable Cd quantities in the soil. During the in vitro digestion, a relatively constant ratio between the total and bioaccessible Cd in rice was observed. About 14.89% of Cd in soils was found to be transferred into rice grains and up to 3.19% could be transferred from rice grains to the human body. This model was able to sufficiently predict rice grain cadmium concentrations based on CaCl 2 extracted zinc and cadmium concentrations in soils (R 2 = 0.862). The bioaccessible Cd concentration in rice grains was also able to be predicted using CaCl 2 extracted cadmium from soil (R 2 = 0.892). The models established in this study demonstrated that CaCl 2 is a suitable indicator of total rice Cd concentrations and bioaccessible rice grain Cd concentrations. The chain model approach proposed in this study can be used for the fast and accurate evaluation of human Cd exposure through rice consumption based on the soil conditions in contaminated regions.

  12. The global stoichiometry of litter nitrogen mineralization.

    Science.gov (United States)

    Manzoni, Stefano; Jackson, Robert B; Trofymow, John A; Porporato, Amilcare

    2008-08-01

    Plant residue decomposition and the nutrient release to the soil play a major role in global carbon and nutrient cycling. Although decomposition rates vary strongly with climate, nitrogen immobilization into litter and its release in mineral forms are mainly controlled by the initial chemical composition of the residues. We used a data set of approximately 2800 observations to show that these global nitrogen-release patterns can be explained by fundamental stoichiometric relationships of decomposer activity. We show how litter quality controls the transition from nitrogen accumulation into the litter to release and alters decomposers' respiration patterns. Our results suggest that decomposers lower their carbon-use efficiency to exploit residues with low initial nitrogen concentration, a strategy used broadly by bacteria and consumers across trophic levels.

  13. Influence of litter layer removal on the soil thermal regime of a pine forest in a mediterranean climate Influência da manta morta no regime térmico de um solo sob pinus num clima do tipo mediterrâneo

    Directory of Open Access Journals (Sweden)

    José Alexandre Varanda Andrade

    2010-10-01

    Full Text Available The removal of the litter layer in Portuguese pine forests would reduce fire hazard, but on the other hand this practice would influence the thermal regime of the soil, hence affecting soil biological activity, litter decomposition and nutrient dynamics. Temperature profiles of a sandy soil (Haplic Podzol under a pine forest were measured with thermocouples at depths to 16 cm, with and without litter layer. The litter layer acted as a thermal insulator, reducing the amplitude of the periodic temperature variation in the mineral soil underneath and increasing damping depths, particularly at low soil water contents. At the mineral soil surface the reduction of amplitudes was about 2.5 ºC in the annual cycle and 5 to 6.7 ºC in the daily cycle, depending on the soil water content. When soil was both cold and wet, mean daily soil temperatures were higher (about 1 - 1.5 ºC under the litter layer. Improved soil thermal conditions under the litter layer recommend its retention as a forest management practice to follow in general.A remoção da manta morta nos pinhais portugueses pode reduzir o risco de incêndio florestal, mas essa prática pode influenciar o regime térmico do solo, alterando dessa forma a atividade biológica, a decomposição da manta morta e a dinâmica de nutrientes. Num solo arenoso (Haplic Podzol sob pinus foram medidos perfis térmicos com termopares a várias profundidades até 16 cm, com ou sem manta morta. A manta morta atuou como um isolador térmico, reduzindo a amplitude da variação periódica da temperatura na camada de solo subjacente e aumentando as profundidades de amortecimento, sobretudo em teores baixos de umidade do solo. Na superfície do solo mineral a redução das amplitudes foi de cerca de 2,5 ºC no ciclo anual e de 5 a 6,7 ºC no ciclo diário, dependendo da umidade do solo. A manta morta aumentou em cerca de 1-1,5 ºC as temperaturas médias diárias do solo mineral quando este se encontrava mais frio

  14. LBA-ECO TG-07 Litter Decomposition, Tapajos National Forest, Para, Brazil: 2000-2001

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this study was to determine the effects of soil phosphorus (P) status on litter decomposition rates using two factors: soil texture (with associated...

  15. Effect of different types of litter material for rearing broilers.

    Science.gov (United States)

    Swain, B K; Sundaram, R N

    2000-07-01

    1. Coir dust was evaluated as broiler litter in comparison with sawdust and rice husk using 135 commercial broilers. Forty-five broiler chicks were reared to 42 d on a 50 mm layer of each of these litters. 2. Birds reared on coir dust showed no difference in food consumption, body weight gain, food conversion efficiency production number and survivability in comparison to those reared on saw dust and rice husk. 3. It was concluded that coir dust is suitable as broiler litter when cheaply available.

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

    Science.gov (United States)

    Grizelle Gonzalez; Timothy R. Seastedt; Zugeily Donato

    2003-01-01

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

  17. Morphogenetic Litter Types of Bog Spruce Forests

    Directory of Open Access Journals (Sweden)

    T. T. Efremova

    2015-02-01

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

  18. Allelopathic activity and chemical constituents of walnut (Juglans regia) leaf litter in walnut-winter vegetable agroforestry system.

    Science.gov (United States)

    Wang, Qian; Xu, Zheng; Hu, Tingxing; Rehman, Hafeez Ur; Chen, Hong; Li, Zhongbin; Ding, Bo; Hu, Hongling

    2014-01-01

    Walnut agroforestry systems have many ecological and economic benefits when intercropped with cool-season species. However, decomposing leaf litter is one of the main sources of allelochemicals in such systems. In this study, lettuce (Lactuca sativa var. angustata) was grown in the soil incorporated with walnut leaf litter to assess its allelopathic activity. Lettuce growth and physiological processes were inhibited by walnut leaf litter, especially during early growth stage (1-2 euphylla period) or with large amount of litter addition. The plants treated by small amount of leaf litter recovered their growth afterwards, while the inhibition for 180 g leaf litter persisted until harvest. Twenty-eight compounds were identified in the leaf litter, and several of them were reported to be phytotoxic, which may be responsible for the stress induced by walnut leaf litter. Thus, for highest economic value of vegetables such as lettuce, excessive incorporation of leaf litter should be discouraged.

  19. Incorporation of microplastics from litter into burrows of Lumbricus terrestris

    NARCIS (Netherlands)

    Huerta Lwanga, Esperanza; Gertsen, H.F.; Gooren, H.; Peters, P.; Salanki, T.E.; Ploeg, van der M.; Besseling, E.; Koelmans, A.A.; Geissen, V.

    2017-01-01

    Pollution caused by plastic debris is an urgent environmental problem. Here, we assessed the effects of microplastics in the soil surface litter on the formation and characterization of burrows built by the anecic earthworm Lumbricus terrestris in soil and quantified the amount of microplastics that

  20. Changes in eucalypt litter quality during the first three months of field decomposition in a Congolese plantation

    OpenAIRE

    Ngao, Jérôme; Bernhard Reversat, France; Loumeto, J. J.

    2009-01-01

    In fast-growing tree plantations, decomposition of leaf litter is considered as a key process of soil fertility. A three-month field experiment, spanning both rainy and dry seasons, was conducted to determine how changes in litter decomposition affect the main parameters of litter quality-namely, the concentrations of phenolic and non-phenolic carbon (C) compounds, nitrogen (N), and fibres, and the litter C mineralization rate. This Study was conducted to test (1) if these changes vary accord...

  1. Application of biochar to soil reduces cancer risk via rice consumption: a case study in Miaoqian village, Longyan, China.

    Science.gov (United States)

    Khan, Sardar; Reid, Brian J; Li, Gang; Zhu, Yong-Guan

    2014-07-01

    Consumption of rice contaminated with potentially toxic elements (PTEs) is a major pathway for human exposure to PTEs. This is particularly true in China's so called "Cancer Villages". In this study, sewage sludge biochar (SSBC) was applied to soil (at 5% and 10%) to suppress PTE phytoavailability and as a consequence to reduce PTE levels in rice grown in mining impacted paddy soils. Risk assessment indicated that SSBC addition (10%) markedly (P≤0.05) decreased the daily intake, associated with the consumption of rice, of PTEs (As, Cd, Co, Cu, Mn, Pb and Zn by: 68, 42, 55, 29, 43, 38 and 22%, respectively). In treatments containing SSBC (10%) the health quotient (HQ) indices for PTEs (except for As, Cu and Mn) were iAs (AsIII+AsV) associated with the consumption of rice was significantly (P≤0.01) reduced by 66%. These findings suggest that SSBC could be a useful soil amendment to mitigating PTE exposure, through rice consumption, in China's "Cancer Villages". Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Ecological restoration of litter in mined areas

    Science.gov (United States)

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

    2016-04-01

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

  3. The susceptibility of soil enzymes to inhibition by leaf litter tannins is dependent on the tannin chemistry, enzyme class and vegetation history.

    Science.gov (United States)

    Triebwasser, Daniella J; Tharayil, Nishanth; Preston, Caroline M; Gerard, Patrick D

    2012-12-01

    By inhibiting soil enzymes, tannins play an important role in soil carbon (C) and nitrogen (N) mineralization. The role of tannin chemistry in this inhibitory process, in conjunction with enzyme classes and isoforms, is less well understood. Here, we compared the inhibition efficiencies of mixed tannins (MTs, mostly limited to angiosperms) and condensed tannins (CTs, produced mostly by gymnosperms) against the potential activity of β-glucosidase (BG), N-acetyl-glucosaminidase (NAG), and peroxidase in two soils that differed in their vegetation histories. Compared with CTs, MTs exhibited 50% more inhibition of almond (Prunus dulcis) BG activity and greater inhibition of the potential NAG activity in the gymnosperm-acclimatized soils. CTs exhibited lower BG inhibition in the angiosperm-acclimated soils, whereas both types of tannins exhibited higher peroxidase inhibition in the angiosperm soils than in gymnosperm soils. At all of the tested tannin concentrations, irrespective of the tannin type and site history, the potential peroxidase activity was inhibited two-fold more than the hydrolase activity and was positively associated with the redox-buffering efficiency of tannins. Our finding that the inhibitory activities and mechanisms of MTs and CTs are dependent on the vegetative history and enzyme class is novel and furthers our understanding of the role of tannins and soil isoenzymes in decomposition. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  4. Effects of tree leaf litter, deer fecal pellets, and soil properties on growth of an introduced earthworm (Lumbricus terrestris): Implications for invasion dynamics

    Science.gov (United States)

    Kassidy N. Yatso; Erik A. Lilleskov

    2016-01-01

    Invasive earthworm communities are expanding into previously earthworm-free forests of North America, producing profound ecosystem changes. Lumbricus terrestris is an invasive anecic earthworm that consumes a large portion of the detritus on the soil surface, eliminating forest floor organic horizons and reducing soil organic matter. Two mesocosm...

  5. Understanding Litter Input Controls on Soil Organic Matter Turnover and Formation are Essential for Improving Carbon-Climate Feedback Predictions for Arctic, Tundra Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Wallenstein, Matthew [Colorado State Univ., Fort Collins, CO (United States)

    2017-12-05

    The Arctic region stored vast amounts of carbon (C) in soils over thousands of years because decomposition has been limited by cold, wet conditions. Arctic soils now contain roughly as much C that is contained in all other soils across the globe combined. However, climate warming could unlock this oil C as decomposition accelerates and permafrost thaws. In addition to temperature-driven acceleration of decomposition, several additional processes could either counteract or augment warming-induced SOM losses. For example, increased plant growth under a warmer climate will increase organic matter inputs to soils, which could fuel further soil decomposition by microbes, but will also increase the production of new SOM. Whether Arctic ecosystems store or release carbon in the future depends in part on the balance between these two counteracting processes. By differentiating SOM decomposition and formation and understanding the drivers of these processes, we will better understand how these systems function. We did not find evidence of priming under current conditions, defined as an increase in the decomposition of native SOM stocks. This suggests that decomposition is unlikely to be further accelerated through this mechanism. We did find that decomposition of native SOM did occur when nitrogen was added to these soils, suggesting that nitrogen limits decomposition in these systems. Our results highlight the resilience and extraordinary C storage capacity of these soils, and suggest shrub expansion may partially mitigate C losses from decomposition of old SOM as Arctic soils warm.

  6. Litter Quality of Populus Species as Affected by Free-Air CO2

    OpenAIRE

    Vermue, E.; Buurman, P.; Hoosbeek, M.R.

    2009-01-01

    The effect of elevated CO2 and nitrogen fertilization on the molecular chemistry of litter of three Populus species and associated soil organic matter (SOM) was investigated by pyrolysis-gas chromatography/mass spectrometry. The results are based on 147 quantified organic compounds in 24 litter samples. Litter of P. euramerica was clearly different from that of P. nigra and P. alba. The latter two had higher contents of proteins, polysaccharides, and cutin/cutan, while the former had higher c...

  7. Urea Hydrolysis and Calcium Carbonate Precipitation in Gypsum-Amended Broiler Litter.

    Science.gov (United States)

    Burt, Christopher D; Cabrera, Miguel L; Rothrock, Michael J; Kissel, D E

    2018-01-01

    Broiler () litter is subject to ammonia (NH) volatilization losses. Previous work has shown that the addition of gypsum to broiler litter can increase nitrogen mineralization and decrease NH losses due to a decrease in pH, but the mechanisms responsible for these effects are not well understood. Therefore, three laboratory studies were conducted to evaluate the effect of gypsum addition to broiler litter on (i) urease activity at three water contents, (ii) calcium carbonate precipitation, and (iii) pH. The addition of gypsum to broiler litter increased ammonium concentrations ( litter pH by 0.43 to 0.49 pH units after 5 d ( litter only increased on Day 0 for broiler litter with low (0.29 g HO g) and high (0.69 g HO g) water contents, and on Day 3 for litter with medium (0.40 g HO g) water content ( litter with gypsum also caused an immediate decrease in litter pH (0.22 pH units) due to the precipitation of calcium carbonate (CaCO) from gypsum-derived calcium and litter bicarbonate. Furthermore, as urea was hydrolyzed, more urea-derived carbon precipitated as CaCO in gypsum-treated litter than in untreated litter ( litter with gypsum favors the precipitation of CaCO, which buffers against increases in litter pH that are known to facilitate NH volatilization. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. Characterization and production and consumption processes of N2O emitted from temperate agricultural soils determined via isotopomer ratio analysis

    Science.gov (United States)

    Toyoda, Sakae; Yano, Midori; Nishimura, Sei-Ichi; Akiyama, Hiroko; Hayakawa, Atsushi; Koba, Keisuke; Sudo, Shigeto; Yagi, Kazuyuki; Makabe, Akiko; Tobari, Yoshifumi; Ogawa, Nanako O.; Ohkouchi, Naohiko; Yamada, Keita; Yoshida, Naohiro

    2011-06-01

    Isotopomer ratios of N2O (bulk nitrogen and oxygen isotope ratios, δ15Nbulk and δ18O, and intramolecular 15N site preference, SP) are useful parameters that characterize sources of this greenhouse gas and also provide insight into production and consumption mechanisms. We measured isotopomer ratios of N2O emitted from typical Japanese agricultural soils (Fluvisols and Andisols) planted with rice, wheat, soybean, and vegetables, and treated with synthetic (urea or ammonium) and organic (poultry manure) fertilizers. The results were analyzed using a previously reported isotopomeric N2O signature produced by nitrifying/denitrifying bacteria and a characteristic relationship between δ15Nbulk and SP during N2O reduction by denitrifying bacteria. Relative contributions from nitrification (hydroxylamine oxidation) and denitrification (nitrite reduction) to gross N2O production deduced from the analysis depended on soil type and fertilizer. The contribution from nitrification was relatively high (40%-70%) in Andisols amended with synthetic ammonium fertilizer, while denitrification was dominant (50%-90%) in the same soils amended with poultry manure during the period when N2O production occurred in the surface layer. This information on production processes is in accordance with that obtained from flux/concentration analysis of N2O and soil inorganic nitrogen. However, isotopomer analysis further revealed that partial reduction of N2O was pronounced in high-bulk density, alluvial soil (Fluvisol) compared to low-bulk density, volcanic ash soil (Andisol), and that the observed difference in N2O flux between normal and pelleted manure could have resulted from a similar mechanism with different rates of gross production and gross consumption. The isotopomeric analysis is based on data from pure culture bacteria and would be improved by further studies on in situ biological processes in soils including those by fungi. When flux/concentration-weighted average isotopomer

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

    Science.gov (United States)

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

    2009-01-01

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

  10. Litter drives ecosystem and plant community changes in cattail invasion.

    Science.gov (United States)

    Farrer, Emily C; Goldberg, Deborah E

    2009-03-01

    Invaded systems are commonly associated with a change in ecosystem processes and a decline in native species diversity; however, many different causal pathways linking invasion, ecosystem change, and native species decline could produce this pattern. The initial driver of environmental change may be anthropogenic, or it may be the invader itself; and the mechanism behind native species decline may be the human-induced environmental change, competition from the invader, or invader-induced environmental change (non-trophic effects). We examined applicability of each of these alternate pathways in Great Lakes coastal marshes invaded by hybrid cattail (Typha x glauca). In a survey including transects in three marshes, we found that T. x glauca was associated with locally high soil nutrients, low light, and large amounts of litter, and that native diversity was highest in areas of shallow litter depth. We tested whether live T. x glauca plants or their litter induced changes in the environment and in diversity with a live plant and litter transplant experiment. After one year, Typha litter increased soil NH4+ and N mineralization twofold, lowered light levels, and decreased the abundance and diversity of native plants, while live Typha plants had no effect on the environment or on native plants. This suggests that T. x glauca, through its litter production, can cause the changes in ecosystem processes that we commonly attribute to anthropogenic nutrient loading and that T. x glauca does not displace native species through competition for resources, but rather affects them non-trophically through its litter. Moreover, because T. x glauca plants were taller when grown with their own litter, we suggest that this invader may produce positive feedbacks and change the environment in ways that benefit itself and may promote its own invasion.

  11. Trace metals accumulation in soil irrigated with polluted water and assessment of human health risk from vegetable consumption in Bangladesh.

    Science.gov (United States)

    Islam, Md Atikul; Romić, Davor; Akber, Md Ali; Romić, Marija

    2018-02-01

    Trace metals accumulation in soil irrigated with polluted water and human health risk from vegetable consumption was assessed based on the data available in the literature on metals pollution of water, soil, sediment and vegetables from the cites of Bangladesh. The quantitative data on metal concentrations, their contamination levels and their pollution sources have not been systematically gathered and studied so far. The data on metal concentrations, sources, contamination levels, sample collection and analytical tools used were collected, compared and discussed. The USEPA-recommended method for health risk assessment was used to estimate human risk from vegetable consumption. Concentrations of metals in water were highly variable, and the mean concentrations of Cd, Cr, Cu and As in water were found to be higher than the FAO irrigation water quality standard. In most cases, mean concentrations of metals in soil were higher than the Bangladesh background value. Based on geoaccumulation index (I geo ) values, soils of Dhaka city are considered as highly contaminated. The I geo shows Cd, As, Cu, Ni, Pb and Cr contamination of agricultural soils and sediments of the cities all over the Bangladesh. Polluted water irrigation and agrochemicals are identified as dominant sources of metals in agricultural soils. Vegetable contamination by metals poses both non-carcinogenic and carcinogenic risks to the public. Based on the results of the pollution and health risk assessments, Cd, As, Cr, Cu, Pb and Ni are identified as the priority control metals and the Dhaka city is recommended as the priority control city. This study provides quantitative evidence demonstrating the critical need for strengthened wastewater discharge regulations in order to protect residents from heavy metal discharges into the environment.

  12. The influence of biopreparations on the reduction of energy consumption and CO2 emissions in shallow and deep soil tillage.

    Science.gov (United States)

    Naujokienė, Vilma; Šarauskis, Egidijus; Lekavičienė, Kristina; Adamavičienė, Aida; Buragienė, Sidona; Kriaučiūnienė, Zita

    2018-06-01

    The application of innovation in agriculture technologies is very important for increasing the efficiency of agricultural production, ensuring the high productivity of plants, production quality, farm profitability, the positive balance of used energy, and the requirements of environmental protection. Therefore, it is a scientific problem that solid and soil surfaces covered with plant residue have a negative impact on the work, traction resistance, energy consumption, and environmental pollution of tillage machines. The objective of this work was to determine the dependence of the reduction of energy consumption and CO 2 gas emissions on different biopreparations. Experimental research was carried out in a control (SC1) and seven different biopreparations using scenarios (SC2-SC8) using bacterial and non-bacterial biopreparations in different consistencies (with essential and mineral oils, extracts of various grasses and sea algae, phosphorus, potassium, humic and gibberellic acids, copper, zinc, manganese, iron, and calcium), estimating discing and plowing as the energy consumption parameters of shallow and deep soil tillage machines, respectively. CO 2 emissions were determined by evaluating soil characteristics (such as hardness, total porosity and density). Meteorological conditions such average daily temperatures (2015-20.3 °C; 2016-16.90 °C) and precipitations (2015-6.9 mm; 2016-114.9 mm) during the month strongly influenced different results in 2015 and 2016. Substantial differences between the averages of energy consumption identified in approximately 62% of biological preparation combinations created usage scenarios. Experimental research established that crop field treatments with biological preparations at the beginning of vegetation could reduce the energy consumption of shallow tillage machines by up to approximately 23%, whereas the energy consumption of deep tillage could be reduced by up to approximately 19.2% compared with the control

  13. Microbiological and chemical properties of litter from different chicken types and production systems

    International Nuclear Information System (INIS)

    Omeira, N.; Barbour, E.K.; Nehme, P.A.; Hamadeh, S.K.; Zurayk, R.; Bashour, I.

    2006-01-01

    in the litter from free-range broilers and layers compared to that in the litter from intensively managed systems (P = 0.0439). Staphylococcus species in the litter as well as cadmium concentrations seem to be the most critical parameters presenting risks on the environment and on human health. Based on the lowest coliform counts (an indication of water pollution), the high nutrient levels and the low cadmium values, litter from intensively managed layers appears as the most suitable for application on agricultural soils

  14. Microbiological and chemical properties of litter from different chicken types and production systems

    Energy Technology Data Exchange (ETDEWEB)

    Omeira, N. [Department of Land and Water Resources, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon); Barbour, E.K. [Department of Animal Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon)]. E-mail: eb01@aub.edu.lb; Nehme, P.A. [Department of Land and Water Resources, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon); Hamadeh, S.K. [Department of Animal Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon); Zurayk, R. [Department of Land and Water Resources, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon); Bashour, I. [Department of Land and Water Resources, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon)

    2006-08-15

    in the litter from free-range broilers and layers compared to that in the litter from intensively managed systems (P = 0.0439). Staphylococcus species in the litter as well as cadmium concentrations seem to be the most critical parameters presenting risks on the environment and on human health. Based on the lowest coliform counts (an indication of water pollution), the high nutrient levels and the low cadmium values, litter from intensively managed layers appears as the most suitable for application on agricultural soils.

  15. Microbiological and chemical properties of litter from different chicken types and production systems.

    Science.gov (United States)

    Omeira, N; Barbour, E K; Nehme, P A; Hamadeh, S K; Zurayk, R; Bashour, I

    2006-08-15

    free-range broilers and layers compared to that in the litter from intensively managed systems (P=0.0439). Staphylococcus species in the litter as well as cadmium concentrations seem to be the most critical parameters presenting risks on the environment and on human health. Based on the lowest coliform counts (an indication of water pollution), the high nutrient levels and the low cadmium values, litter from intensively managed layers appears as the most suitable for application on agricultural soils.

  16. Litter Quality of Populus Species as Affected by Free-Air CO2

    NARCIS (Netherlands)

    Vermue, E.; Buurman, P.; Hoosbeek, M.R.

    2009-01-01

    The effect of elevated CO2 and nitrogen fertilization on the molecular chemistry of litter of three Populus species and associated soil organic matter (SOM) was investigated by pyrolysis-gas chromatography/mass spectrometry. The results are based on 147 quantified organic compounds in 24 litter

  17. The freezer defrosting: global warming and litter decomposition rates in cold biomes. Essay review.

    NARCIS (Netherlands)

    Aerts, R.

    2006-01-01

    1 Decomposition of plant litter, a key component of the global carbon budget, is hierarchically controlled by the triad: climate > litter quality > soil organisms. Given the sensitivity of decomposition to temperature, especially in cold biomes, it has been hypothesized that global warming will lead

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

    Science.gov (United States)

    Scott, Neal A; Binkley, Dan

    1997-07-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  20. Influence of host plants and soil diluents on arbuscular mycorrhizal fungus propagation for on-farm inoculum production using leaf litter compost and agrowastes

    Science.gov (United States)

    Arbuscular mycorrhizal (AM) fungi (Claroideoglomus etunicatum NNT10, C. etunicatum PBT03 and Funneliformis mosseae RYA08) were propagated using different culture materials (sterile sandy soil by itself or mixed 1:1 (v/v) with clay-brick granules, rice husk charcoal, or vermiculite) and host plants (...

  1. A medium-spatial scale distribution pattern of Pseudoscorpionida (Arachnida in a gradient of topography (altitude and inclination, soil factors, and litter in a central Amazonia forest reserve, Brazil

    Directory of Open Access Journals (Sweden)

    N. O. Aguiar

    Full Text Available In Amazonia, nothing is known about the distribution of the invertebrates on a medium-spatial scale pattern. In a trail system of 64 km² at Ducke Reserve, we sampled 72 transects using the hand-sorting method and Berlese-Tullgren extraction. The reserve possesses ecosystems of "terra-firme" forest and the trail system represents a gradient of topographic soil factors and vegetation, avoiding categorizations. Considering the abundance and diversity of Pseudoscorpionida, we investigated the relation of the community to environmental factors tested (topography, clay percentage, litter, and soil pH, to the two major drainage basins of the reserve, and if these invertebrates can be used as biological indicators to monitor changes. We registered two species for the first time in the reserve, increasing the known diversity to 17 species. The lack of correlation with the predictor variables and the large home range, indicate that pseudoscorpions are not good biological indicators in the reserve. As the eastern and western watersheds are not separate management units for the community, our results show that they are generalist predators. In spite of our results and lack of knowledge concerning their biology, life history and taxonomy, pseudoscorpions are cosmopolitan and easy to find and measure. Compared with previous studies in the reserve, they have a consistent pattern of abundance and diversity throughout the years showing the stability of the community which can be checked mainly by comparison with environmental changes that would occur in the reserve. An investigation on a medium-spatial scale pattern and over a long-term period including other habitats, and also other predictor variables, like humidity, the structure of the vegetation and canopy closure, will be necessary to reinforce the observed tendencies.

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

    Directory of Open Access Journals (Sweden)

    Rodrigo Camara

    2018-03-01

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

  3. Large litter sizes

    DEFF Research Database (Denmark)

    Sandøe, Peter; Rutherford, K.M.D.; Berg, Peer

    2012-01-01

    This paper presents some key results and conclusions from a review (Rutherford et al. 2011) undertaken regarding the ethical and welfare implications of breeding for large litter size in the domestic pig and about different ways of dealing with these implications. Focus is primarily on the direct...... possible to achieve a drop in relative piglet mortality and the related welfare problems. However, there will be a growing problem with the need to use foster or nurse sows which may have negative effects on both sows and piglets. This gives rise to new challenges for management....

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

    Directory of Open Access Journals (Sweden)

    Lori D. Bothwell

    2014-12-01

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

  5. Plant litter chemistry and mycorrhizal roots promote a nitrogen feedback in a temperate forest.

    Science.gov (United States)

    Nina Wurzburger; Ronald L. Hendrick

    2009-01-01

    1. Relationships between mycorrhizal plants and soil nitrogen (N) have led to the speculation that the chemistry of plant litter and the saprotrophy of mycorrhizal symbionts can function together to...

  6. Isotopic Discrimination During Leaf Litter Decomposition

    Science.gov (United States)

    Ngao, J.; Rubino, M.

    2006-12-01

    Methods involving stable isotopes have been successfully applied since decades in various research fields. Tracing 13C natural abundance in ecosystem compartments greatly enhanced the understanding of the C fluxes in the plant-soil-atmosphere C exchanges when compartments present different C isotopic signatures (i.e. atmospheric CO2 vs photosynthetic leaves, C3 vs C4; etc.). However, the assumption that no isotopic discrimination occurs during respiration is commonly made in numbers of C isotope-based ecological studies. Furthermore, verifications of such assumption are sparse and not enough reliable. The aim of our study is to assess the potential isotopic discrimination that may occur during litter decomposition. Leaf litter from an Arbutus unedo (L.) stand (Tolfa, Italy) was incubated in 1L jars, under constant laboratory conditions (i.e. 25 ° C and 135% WC). During the entire incubation period, gravimetric mass loss, litter respiration rates and the isotopic composition of respired CO2 are monitored at regular intervals. Data from 7 months of incubation will be presented and discussed. After two months, the litter mass loss averaged 16% of initial dry mass. During the same time-period, the respiration rate decreased significantly by 58% of the initial respiration rate. Isotopic compositions of respired CO2 ranged between -27.95‰ and - 25.69‰. Mean values did not differ significantly among the sampling days, in spite of an apparent enrichment in 13C of respired CO2 with time. The significance of these isotopic enrichment will be determined at a longer time scale. They may reveal both/either a direct microbial discrimination during respiration processes and/or a use of different litter compounds as C source along time. Further chemical and compound-specific isotopic analysis of dry matter will be performed in order to clarify these hypotheses. This work is part of the "ALICE" project, funded by the European Union's Marie Curie Fellowship Actions that aims to

  7. Rate of litter decomposition and microbial activity in an area of Caatinga

    Directory of Open Access Journals (Sweden)

    Patrícia Carneiro Souto

    2013-12-01

    Full Text Available In order to evaluate the decomposition of litter and microbial activity in an area of preserved Caatinga, an experiment was conducted in the Natural Heritage Private Reserve Tamanduá Farm in Santa Terezinha county, State of Paraiba. The decomposition rate was determined by using litter bags containing 30 g of litter, which were arranged on the soil surface in September 2003 and 20 bags were taken each month until September 2005. The collected material was oven dried and weighed to assess weight loss compared to initial weight. Microbial activity was estimated monthly by the quantification of carbon dioxide (CO2 released into the edaphic breathing process from the soil surface, and captured by KOH solution. Weight loss of litter after one year was 41.19% and, after two years, was 48.37%, indicating a faster decomposition in the first year. Data analysis showed the influence of season on litter decomposition and temperature on microbial activity.

  8. Litter mercury deposition in the Amazonian rainforest

    International Nuclear Information System (INIS)

    Fostier, Anne Hélène; Melendez-Perez, José Javier; Richter, Larissa

    2015-01-01

    The objective of this work was to assess the flux of atmospheric mercury transferred to the soil of the Amazonian rainforest by litterfall. Calculations were based on a large survey of published and unpublished data on litterfall and Hg concentrations in litterfall samples from the Amazonian region. Litterfall based on 65 sites located in the Amazon rainforest averaged 8.15 ± 2.25 Mg ha"−"1 y"−"1. Average Hg concentrations were calculated from nine datasets for fresh tree leaves and ten datasets for litter, and a median concentration of 60.5 ng Hg g"−"1 was considered for Hg deposition in litterfall, which averaged 49 ± 14 μg m"−"2 yr"−"1. This value was used to estimate that in the Amazonian rainforest, litterfall would be responsible for the annual removing of 268 ± 77 Mg of Hg, approximately 8% of the total atmospheric Hg deposition to land. The impact of the Amazon deforestation on the Hg biogeochemical cycle is also discussed. - Highlights: • Based on published data we estimated the litterfall in the Amazonian rainforest. • All the published data on Hg concentration in leaves and litter from the region and some unpublished data are presented. • We calculated the litter mercury deposition. • We estimated the contribution of dry, wet and litter Hg deposition in the Amazonian rainforest. • We also discussed the impact of Amazon deforestation on the Hg biogeochemical cycle. - The Amazonian rainforest is responsible for removing at least 268 Mg Hg y"−"1, 8% of the total atmospheric mercury deposition to land.

  9. Titration and Spectroscopic Measurements of Poultry Litter pH Buffering Capacity.

    Science.gov (United States)

    Cassity-Duffey, Kate; Cabrera, Miguel; Mowrer, Jake; Kissel, David

    2015-07-01

    The pH value of poultry litter is affected by nitrification, mineralization, and the addition of acidifying chemicals, all acting on the poultry litter pH buffering capacity (pHBC). Increased understanding of poultry litter pHBC will aid in modeling NH volatilization from surface-applied poultry litter as well as estimating rates of alum applications. Our objectives were to (i) determine the pHBC of a wide range of poultry litters; (ii) assess the accuracy of near-infrared reflectance spectroscopy (NIRS) for determining poultry litter pHBC; and (iii) demonstrate the use of poultry litter pHBC to increase the accuracy of alum additions. Litter pHBC was determined by titration and calculated from linear and sigmoidal curves. For the 37 litters measured, linear pHBC ranged from 187 to 537 mmol (pH unit) kg dry litter. The linear and sigmoidal curves provided accurate predictions of pHBC, with most > 0.90. Results from NIRS analysis showed that the linear pHBC expressed on an "as is" water content basis had a NIRS coefficient of calibration (developed using a modified partial least squares procedure) of 0.90 for the 37 poultry litters measured. Using the litter pHBC, an empirical model was derived to determine the amount of alum needed to create a target pH. The model performed well in the range of pH 6.5 to 7.5 (RMSE = 0.07) but underpredicted the amount of alum needed to reach pH litter, which prevented its hydrolysis. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  10. Changes in chemical composition of litter during decomposition: a review of published 13C NMR spectra

    Czech Academy of Sciences Publication Activity Database

    Cepáková, Šárka; Frouz, Jan

    2015-01-01

    Roč. 15, č. 3 (2015), s. 805-815 ISSN 0718-9516 Grant - others:GAJU(CZ) GAJU/04-146/2013P; GA ČR(CZ) GAP504/12/1288 Program:GA Institutional support: RVO:60077344 Keywords : 13C CPMAS NMR * litter decomposition * litter quality * soil organic matter Subject RIV: DF - Soil Science Impact factor: 1.600, year: 2015

  11. Links between plant litter chemistry, species diversity, and below-ground ecosystem function

    OpenAIRE

    Meier, Courtney L.; Bowman, William D.

    2008-01-01

    Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics...

  12. Above and belowground controls on litter decomposition in semiarid ecosystems: effects of solar radiation, water availability and litter quality

    Science.gov (United States)

    Austin, A. T.; Araujo, P. I.; Leva, P. E.; Ballare, C. L.

    2008-12-01

    The integrated controls on soil organic matter formation in arid and semiarid ecosystems are not well understood and appear to stem from a number of interacting controls affecting above- and belowground carbon turnover. While solar radiation has recently been shown to have an important direct effect on carbon loss in semiarid ecosystems as a result of photochemical mineralization of aboveground plant material, the mechanistic basis for photodegradative losses is poorly understood. In addition, there are large potential differences in major controls on above- and belowground decomposition in low rainfall ecosystems. We report on a mesocosm and field study designed to examine the relative importance of different wavelengths of solar radiation, water availability, position of senescent material above- and belowground and the importance of carbon litter quality in determining rates of abiotic and biotic decomposition. In a factorial experiment of mesocosms, we incubated leaf and root litter simultaneously above- and belowground and manipulated water availability with large and small pulses. Significant interactions between position-litter type and position-pulse sizes demonstrated interactive controls on organic mass loss. Aboveground decomposition showed no response to pulse size or litter type, as roots and leaves decomposed equally rapidly under all circumstances. In contrast, belowground decomposition was significantly altered by litter type and water pulses, with roots decomposing significantly slower and small water pulses reducing belowground decomposition. In the field site, using plastic filters which attenuated different wavelengths of natural solar radiation, we found a highly significant effect of radiation exclusion on mass loss and demonstrated that both UV-A and short-wave visible light can have important impacts on photodegradative carbon losses. The combination of position and litter quality effects on litter decomposition appear to be critical for the

  13. Production of nitrous oxide and consumption of methane by forest soils

    Science.gov (United States)

    Keller, M.; Wofsy, S. C.; Kaplan, W. A.; Mcelroy, M. B.; Goreau, T. J.

    1983-01-01

    Soils in an Amazonian rainforest are observed to release N2O at a rate larger than the global mean by about a factor of 20. Emissions from a New England hardwood forest are approximately 30 times smaller then Brazilian values. Atmospheric methane is consumed by soils in both systems. Tropical forests would provide a major source of atmospheric N2O if the Brazilian results are representative.

  14. Facilitative and Inhibitory Effect of Litter on Seedling Emergence and Early Growth of Six Herbaceous Species in an Early Successional Old Field Ecosystem

    Directory of Open Access Journals (Sweden)

    Qiang Li

    2014-01-01

    Full Text Available In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m−2, litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter. Puccinellia tenuiflora and Chloris virgata will acquire more emergence benefits under high litter amount. It is predicted that Chloris virgata will dominate further in this natural succession old field ecosystem with litter accumulation. Artificial P. tenuiflora seeds addition may be required to accelerate old field succession toward matured grassland.

  15. Facilitative and inhibitory effect of litter on seedling emergence and early growth of six herbaceous species in an early successional old field ecosystem.

    Science.gov (United States)

    Li, Qiang; Yu, Pujia; Chen, Xiaoying; Li, Guangdi; Zhou, Daowei; Zheng, Wei

    2014-01-01

    In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m(-2), litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter. Puccinellia tenuiflora and Chloris virgata will acquire more emergence benefits under high litter amount. It is predicted that Chloris virgata will dominate further in this natural succession old field ecosystem with litter accumulation. Artificial P. tenuiflora seeds addition may be required to accelerate old field succession toward matured grassland.

  16. Litter cover as an index of nitrogen availability in rehabilitated mine sites

    International Nuclear Information System (INIS)

    Todd, M.C.L.; Grierson, P.F.; Adams, M.A.

    2000-01-01

    The spatial heterogeneity of litter cover and bioavailability of nitrogen within a 9-year-old rehabilitated bauxite mine in south Western Australia was examined. Three replicate plots (6 m by 6 m) were each divided into 100 quadrats. Litter cover, vegetation distribution, and projected foliage cover were mapped, and litter (overstorey leaves, understorey leaves, and other assorted fractions) and soil (depth: 0-5, 5-10, and 10-30 cm) were sampled from within each quadrat. Litter distribution reflected projected foliage cover, and accumulated within microtopographic depressions. Distribution of soil nitrate (NO 3 - ) reflected the distribution of litter. The 15 N natural abundance (δ 15 N) values of soil (0-5 cm) and the understorey litter fraction were significantly correlated (R 2 = 0.529, P 13 C) of soil (0-5 cm) was significantly correlated with the distribution of the assorted litter fraction (R 2 0.296, P < 0.05). It is concluded that site preparation practices that effect microtopography, such as contour ripping and revegetation along contours, will have a significant impact on nitrogen (N) distribution and bioavailability within rehabilitated mine sites. Copyright (2000) CSIRO Australia

  17. Decomposition of Phragmites australis litter retarded by invasive Solidago canadensis in mixtures: an antagonistic non-additive effect

    Science.gov (United States)

    Zhang, Ling; Zhang, Yaojun; Zou, Jianwen; Siemann, Evan

    2014-06-01

    Solidago canadensis is an aggressive invader in China. Solidago invasion success is partially attributed to allelopathic compounds release and more benefits from AM fungi, which potentially makes the properties of Solidago litter different from co-occurring natives. These properties may comprehensively affect litter decomposition of co-occurring natives. We conducted a field experiment to examine litter mixing effects in a Phragmites australis dominated community invaded by Solidago in southeast China. Solidago had more rapid mass and N loss rate than Phragmites when they decomposed separately. Litter mixing decreased N loss rate in Phragmites litter and increased that of Solidago. Large decreases in Phragmites mass loss and smaller increases in Solidago mass loss caused negative non-additive effect. Solidago litter extracts reduced soil C decomposition and N processes, suggested an inhibitory effect of Solidago secondary compounds. These results are consistent with the idea that nutrient transfer and secondary compounds both affected litter mixtures decomposition.

  18. A test of the hierarchical model of litter decomposition

    DEFF Research Database (Denmark)

    Bradford, Mark A.; Veen, G. F.; Bonis, Anne

    2017-01-01

    Our basic understanding of plant litter decomposition informs the assumptions underlying widely applied soil biogeochemical models, including those embedded in Earth system models. Confidence in projected carbon cycle-climate feedbacks therefore depends on accurate knowledge about the controls...... regulating the rate at which plant biomass is decomposed into products such as CO2. Here we test underlying assumptions of the dominant conceptual model of litter decomposition. The model posits that a primary control on the rate of decomposition at regional to global scales is climate (temperature...

  19. Effect of pulse current on energy consumption and removal of heavy metals during electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Sun, Tian Ran

    pathways to unacceptable dosages, leading to intolerable adverse effects on both public health and the environment. In the last decades, soil and water remediation have gained growing awareness, as the necessity becomes clearer for development of such techniques for elimination of the negative impact from......: transport of water (electroosmosis) and ions (electromigration), with electromigration being the most important transport process when treating heavy metal contaminated soils. Electrodialytic remediation (EDR), one of the enhanced electrochemical remediation techniques, is developed at the Technical...... compartments. Therefore no current is wasted for carrying ions from one electrode compartment to the other. The EDR technique has been tested for decontamination of a variety of different heavy metal polluted particulate materials: mine tailings, soil, different types of fly ashes, sewage sludge, freshwater...

  20. Influence of tropical leaf litter on nitrogen mineralization and community structure of ammonia-oxidizing bacteria

    Directory of Open Access Journals (Sweden)

    Diallo, MD.

    2015-01-01

    Full Text Available Description of the subject. The present study concerns the relationships among leaf litter decomposition, substrate quality, ammonia-oxidizing bacteria (AOB community composition and nitrogen (N availability. Decomposition of organic matter affects the biogeochemical cycling of carbon (C and N. Since the composition of the soil microbial community can alter the physiological capacity of the community, it is timely to study the litter quality effect on N dynamic in ecosystems. Objectives. The aim of this study was to determine the influence of leaf litter decomposition on N mineralization. The specific objectives of this study were to evaluate the influence of the litter biochemistry of five plants species (Faidherbia albida A.Chev., Azadirachta indica A.Juss., Casuarina equisetifolia L., Andropogon gayanus Kunth and Eragrostis tremula Hochst. ex Steud. on N mineralization in a tropical ferrous soil (Lixisol, nitrification, and genetic diversity of ammonia-oxidizing bacteria. Denaturing gradient gel electrophoresis (DGGE of amplified fragments of genes coding for 16S rRNA was used to study the development of bacterial communities during decomposition of leaf litter in soils. Method. Community structure of AOB was determined at two time periods: day 0 and day 140. Ten strains were tested and each of these strains produced a single band. Thus, DGGE DNA band patterns were used to estimate bacterial diversity. Plant secondary compounds such as polyphenols are purported to influence nutrient cycling by affecting organic matter degradation, mineralization rates, N availability and humus formation. In a laboratory study, we investigated the influence of six phenolic acids (ferulic, gallic, vanillic, syringic, p-coumaric and p-HBA acids commonly found in the plant residues on N mineralization and NH4+ and NO3- production in soils. Results. The results showed that litter type did affect soil nitrification. Faidherbia albida litter was associated with

  1. Environmentally-friendly animal litter

    Energy Technology Data Exchange (ETDEWEB)

    Boxley, Chett; McKelvie, Jessica

    2012-08-28

    An animal litter composition including geopolymerized ash particulates having a network of repeating aluminum-silicon units is described herein. Generally, the animal litter is made from a quantity of a pozzolanic ash mixed with a sufficient quantity of water and an alkaline activator to initiate a geopolymerization reaction that forms geopolymerized ash. After the geopolymerized ash is formed, it is dried, broken into particulates, and sieved to a desired size. These geopolymerized ash particulates are used to make a non-clumping or clumping animal litter. Odor control is accomplished with the addition of a urease inhibitor, pH buffer, an odor eliminating agent, and/or fragrance.

  2. Environmentally-friendly animal litter

    Science.gov (United States)

    Boxley, Chett; McKelvie, Jessica

    2013-09-03

    An animal litter composition that includes geopolymerized ash particulates having a network of repeating aluminum-silicon units is described herein. Generally, the animal litter is made from a quantity of a pozzolanic ash mixed with an alkaline activator to initiate a geopolymerization reaction that forms geopolymerized ash. This geopolymerization reaction may occur within a pelletizer. After the geopolymerized ash is formed, it may be dried and sieved to a desired size. These geopolymerized ash particulates may be used to make a non-clumping or clumping animal litter or other absorbing material. Aluminum sulfate, clinoptilolite, silica gel, sodium alginate and mineral oil may be added as additional ingredients.

  3. Effects of elevated CO2 on litter chemistry and subsequent invertebrate detritivore feeding responses.

    Directory of Open Access Journals (Sweden)

    Matthew W Dray

    Full Text Available Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presented eight invertebrate species from aquatic and terrestrial ecosystems with litter from Alnus glutinosa (common alder or Betula pendula (silver birch trees propagated under ambient (380 ppm or elevated (ambient +200 ppm CO2 concentrations. Alder litter was largely unaffected by CO2 enrichment, but birch litter from leaves grown under elevated CO2 had reduced nitrogen concentrations and greater C/N ratios. Invertebrates were provided individually with either (i two litter discs, one of each CO2 treatment ('choice', or (ii one litter disc of each CO2 treatment alone ('no-choice'. Consumption was recorded. Only Odontocerum albicorne showed a feeding preference in the choice test, consuming more ambient- than elevated-CO2 birch litter. Species' responses to alder were highly idiosyncratic in the no-choice test: Gammarus pulex and O. albicorne consumed more elevated-CO2 than ambient-CO2 litter, indicating compensatory feeding, while Oniscus asellus consumed more of the ambient-CO2 litter. No species responded to CO2 treatment when fed birch litter. Overall, these results show how elevated atmospheric CO2 can alter litter chemistry, affecting invertebrate feeding behaviour in species-specific ways. The data highlight the need for greater species-level information when predicting changes to detrital processing-a key ecosystem function-under atmospheric change.

  4. Stoichiometric controls of nitrogen and phosphorus cycling in decomposing beech leaf litter.

    Science.gov (United States)

    Mooshammer, Maria; Wanek, Wolfgang; Schnecker, Jörg; Wild, Birgit; Leitner, Sonja; Hofhansl, Florian; Blöchl, Andreas; Hämmerle, Ieda; Frank, Alexander H; Fuchslueger, Lucia; Keiblinger, Katharina M; Zechmeister-Boltenstern, Sophie; Richter, Andreas

    2012-04-01

    Resource stoichiometry (C:N:P) is an important determinant of litter decomposition. However, the effect of elemental stoichiometry on the gross rates of microbial N and P cycling processes during litter decomposition is unknown. In a mesocosm experiment, beech (Fagus sylvatica L.) litter with natural differences in elemental stoichiometry (C:N:P) was incubated under constant environmental conditions. After three and six months, we measured various aspects of nitrogen and phosphorus cycling. We found that gross protein depolymerization, N mineralization (ammonification), and nitrification rates were negatively related to litter C:N. Rates of P mineralization were negatively correlated with litter C:P. The negative correlations with litter C:N were stronger for inorganic N cycling processes than for gross protein depolymerization, indicating that the effect of resource stoichiometry on intracellular processes was stronger than on processes catalyzed by extracellular enzymes. Consistent with this, extracellular protein depolymerization was mainly limited by substrate availability and less so by the amount of protease. Strong positive correlations between the interconnected N and P pools and the respective production and consumption processes pointed to feed-forward control of microbial litter N and P cycling. A negative relationship between litter C:N and phosphatase activity (and between litter C:P and protease activity) demonstrated that microbes tended to allocate carbon and nutrients in ample supply into the production of extracellular enzymes to mine for the nutrient that is more limiting. Overall, the study demonstrated a strong effect of litter stoichiometry (C:N:P) on gross processes of microbial N and P cycling in decomposing litter; mineralization of N and P were tightly coupled to assist in maintaining cellular homeostasis of litter microbial communities.

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

    Directory of Open Access Journals (Sweden)

    Han Li

    2016-01-01

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

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

    Science.gov (United States)

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

    2018-07-01

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

  7. Natural carbon isotopes used to study methane consumption and production in soil

    DEFF Research Database (Denmark)

    Ambus, Per; Andersen, Bertel Lohmann; Kemner, Marianne

    2002-01-01

    Changes in the isotopic composition of carbon can be used to reveal simultaneous occurrence of methane production and oxidation in soil. The method is conducted in laboratory jar experiments as well as in the field by using flux chambers. Simultaneous occurrence of production and oxidation of met...

  8. Using column experiments to examine transport of As and other trace elements released from poultry litter: Implications for trace element mobility in agricultural watersheds.

    Science.gov (United States)

    Oyewumi, Oluyinka; Schreiber, Madeline E

    2017-08-01

    Trace elements are added to poultry feed to control infection and improve weight gain. However, the fate of these trace elements in poultry litter is poorly understood. Because poultry litter is applied as fertilizer in many agricultural regions, evaluation of the environmental processes that influence the mobility of litter-derived trace elements is critical for predicting if trace elements are retained in soil or released to water. This study examined the effect of dissolved organic carbon (DOC) in poultry litter leachate on the fate and transport of litter-derived elements (As, Cu, P and Zn) using laboratory column experiments with soil collected from the Delmarva Peninsula (Mid-Atlantic, USA), a region of intense poultry production. Results of the experiments showed that DOC enhanced the mobility of all of the studied elements. However, despite the increased mobility, 60-70% of Zn, As and P mass was retained within the soil. In contrast, almost all of the Cu was mobilized in the litter leachate experiments, with very little retention in soil. Overall, our results demonstrate that the mobility of As, Cu, Zn and P in soils which receive poultry litter application is strongly influenced by both litter leachate composition, specifically organic acids, and adsorption to soil. Results have implications for understanding fate and transport of trace elements released from litter application to soil water and groundwater, which can affect both human health and the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Methanogen community composition and rates of methane consumption in Canadian High Arctic permafrost soils.

    Science.gov (United States)

    Allan, J; Ronholm, J; Mykytczuk, N C S; Greer, C W; Onstott, T C; Whyte, L G

    2014-04-01

    Increasing permafrost thaw, driven by climate change, has the potential to result in organic carbon stores being mineralized into carbon dioxide (CO2) and methane (CH4) through microbial activity. This study examines the effect of increasing temperature on community structure and metabolic activity of methanogens from the Canadian High Arctic, in an attempt to predict how warming will affect microbially controlled CH4 soil flux. In situ CO2 and CH4 flux, measured in 2010 and 2011 from ice-wedge polygons, indicate that these soil formations are a net source of CO2 emissions, but a CH4 sink. Permafrost and active layer soil samples were collected at the same sites and incubated under anaerobic conditions at warmer temperatures, with and without substrate amendment. Gas flux was measured regularly and indicated an increase in CH4 flux after extended incubation. Pyrosequencing was used to examine the effects of an extended thaw cycle on methanogen diversity and the results indicate that in situ methanogen diversity, based on the relative abundance of the 16S ribosomal ribonucleic acid (rRNA) gene associated with known methanogens, is higher in the permafrost than in the active layer. Methanogen diversity was also shown to increase in both the active layer and permafrost soil after an extended thaw. This study provides evidence that although High Arctic ice-wedge polygons are currently a sink for CH4, higher arctic temperatures and anaerobic conditions, a possible result of climate change, could result in this soil becoming a source for CH4 gas flux. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. Soil quality is key for planning and managing urban allotments intended for the sustainable production of home-consumption vegetables.

    Science.gov (United States)

    Bretzel, F; Calderisi, M; Scatena, M; Pini, R

    2016-09-01

    The growing importance of urban allotments in planning and managing urban areas is due to the combined positive effects on ecosystem services, the economy and human well-being, especially of groups of the urban population that can be vulnerable (e.g. the elderly, immigrants, low-income families). Some studies have highlighted the potential risk of contamination by metals of vegetables grown in urban areas and the lack of appropriate site-specific risk assessments. However, surveys are still lacking on the possibilities of using urban soil as a good substrate to produce vegetables for home consumption. We assessed the soil quality in two areas in Pisa (Italy), one intended for urban horticulture and the other already cultivated for that purpose. We analysed the soils for the main chemical and physical characteristics (texture, bulk density, water stability index, pH, cation exchange capacity, organic carbon, total nitrogen, phosphorous) and elements (Pb, Cu, Ni, Cr, Zn, Cd, As, K, Al and Mn). Our results showed that both areas had physical and chemical heterogeneity due to the effects of urbanization and to the different cultivation techniques employed. The metal content was lower than the guidelines limits, and the soil conditions (pH = 8) greatly reduced the metal mobility. Copper concentration in some of the cultivated area samples was higher than the limits, representing a possible stress factor for the microbial biodiversity and fauna. Our findings demonstrate that site-specific surveys are necessary before planning urban cultivation areas, and educating urban gardeners regarding sustainable cultivation techniques is a priority for a safe environment.

  11. Incorporation of microplastics from litter into burrows of Lumbricus terrestris.

    Science.gov (United States)

    Huerta Lwanga, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A; Geissen, Violette

    2017-01-01

    Pollution caused by plastic debris is an urgent environmental problem. Here, we assessed the effects of microplastics in the soil surface litter on the formation and characterization of burrows built by the anecic earthworm Lumbricus terrestris in soil and quantified the amount of microplastics that was transported and deposited in L. terrestris burrows. Worms were exposed to soil surface litter treatments containing microplastics (Low Density Polyethylene) for 2 weeks at concentrations of 0%, 7%, 28%, 45% and 60%. The latter representing environmentally realistic concentrations found in hot spot soil locations. There were significantly more burrows found when soil was exposed to the surface treatment composed of 7% microplastics than in all other treatments. The highest amount of organic matter in the walls of the burrows was observed after using the treatments containing 28 and 45% microplastics. The highest microplastic bioturbation efficiency ratio (total microplastics (mg) in burrow walls/initial total surface litter microplastics (mg)) was found using the concentration of 7% microplastics, where L. terrestris introduced 73.5% of the surface microplastics into the burrow walls. The highest burrow wall microplastic content per unit weight of soil (11.8 ± 4.8 g kg- 1 ) was found using a concentration of 60% microplastics. L. terrestris was responsible for size-selective downward transport when exposed to concentrations of 7, 28 and 45% microplastics in the surface litter, as the fraction ≤50 μm microplastics in burrow walls increased by 65% compared to this fraction in the original surface litter plastic. We conclude that the high biogenic incorporation rate of the small-fraction microplastics from surface litter into burrow walls causes a risk of leaching through preferential flow into groundwater bodies. Furthermore, this leaching may have implications for the subsequent availability of microplastics to terrestrial organisms or for the transport

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

    Science.gov (United States)

    Criquet, Stéven

    2002-07-01

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

  13. Identifying Sources of Marine Litter

    OpenAIRE

    VEIGA Joana Mira; FLEET David; KINSEY Sue; NILSSON Per; VLACHOGIANNI Thomais; WERNER Stefanie; GALGANI Francois; THOMPSON Richard; DAGEVOS Jeroen; GAGO Jesus; SOBRAL Paula; CRONIN Richard

    2016-01-01

    Marine litter is a global problem causing harm to marine wildlife, coastal communities and maritime activities. It also embodies an emerging concern for human health and safety. The reduction of marine litter pollution poses a complex challenge for humankind, requiring adjustments in human behaviour as well as in the different phases of the life-cycle of products and across multiple economic sectors. The Marine Strategy Framework Directive (MSFD) requires European Member States to monitor...

  14. Effects of land use change on soil carbon storage and water consumption in an oasis-desert ecotone.

    Science.gov (United States)

    Lü, Yihe; Ma, Zhimin; Zhao, Zhijiang; Sun, Feixiang; Fu, Bojie

    2014-06-01

    Land use and ecosystem services need to be assessed simultaneously to better understand the relevant factors in sustainable land management. This paper analyzed land use changes in the middle reach of the arid Heihe River Basin in northwest China over the last two decades and their impacts on water resources and soil organic carbon (SOC) storage. The results indicated that from 1986 to 2007: (1) cropland and human settlements expanded by 45.0 and 17.6%, respectively, at the expense of 70.1, 35.7, and 4.1% shrinkage on woodland, grassland, and semi-shrubby desert; (2) irrigation water use was dominant and increased (with fluctuations) at an average rate of 8.2%, while basic human water consumption increased monotonically over a longer period from 1981 to 2011 at a rate of 58%; and (3) cropland expansion or continuous cultivation led to a significant reduction of SOC, while the land use transition from grassland to semi-shrubby desert and the progressive succession of natural ecosystems such as semi-shrubby desert and grassland, in contrast, can bring about significant carbon sequestration benefits. The increased water consumption and decreased SOC pool associated with some observed land use changes may induce and aggravate potential ecological risks for both local and downstream ecosystems, including water resource shortages, soil quality declines, and degeneration of natural vegetation. Therefore, it is necessary to balance socioeconomic wellbeing and ecosystem services in land use planning and management for the sustainability of socio-ecological systems across spatiotemporal scales, especially in resource-poor arid environments.

  15. Effects of Land Use Change on Soil Carbon Storage and Water Consumption in an Oasis-Desert Ecotone

    Science.gov (United States)

    Lü, Yihe; Ma, Zhimin; Zhao, Zhijiang; Sun, Feixiang; Fu, Bojie

    2014-06-01

    Land use and ecosystem services need to be assessed simultaneously to better understand the relevant factors in sustainable land management. This paper analyzed land use changes in the middle reach of the arid Heihe River Basin in northwest China over the last two decades and their impacts on water resources and soil organic carbon (SOC) storage. The results indicated that from 1986 to 2007: (1) cropland and human settlements expanded by 45.0 and 17.6 %, respectively, at the expense of 70.1, 35.7, and 4.1 % shrinkage on woodland, grassland, and semi-shrubby desert; (2) irrigation water use was dominant and increased (with fluctuations) at an average rate of 8.2 %, while basic human water consumption increased monotonically over a longer period from 1981 to 2011 at a rate of 58 %; and (3) cropland expansion or continuous cultivation led to a significant reduction of SOC, while the land use transition from grassland to semi-shrubby desert and the progressive succession of natural ecosystems such as semi-shrubby desert and grassland, in contrast, can bring about significant carbon sequestration benefits. The increased water consumption and decreased SOC pool associated with some observed land use changes may induce and aggravate potential ecological risks for both local and downstream ecosystems, including water resource shortages, soil quality declines, and degeneration of natural vegetation. Therefore, it is necessary to balance socioeconomic wellbeing and ecosystem services in land use planning and management for the sustainability of socio-ecological systems across spatiotemporal scales, especially in resource-poor arid environments.

  16. Increased site fertility and litter decomposition rate in high-pollution sites in the San Bernardino Mountains

    Science.gov (United States)

    Mark E. Fenn

    1991-01-01

    Some possible factors causing enhanced litter decomposition in high-pollution sites in the San Bernardino Mountains of southern California were investigated. Nitrogen concentration of soil, as well as foliage and litter of ponderosa pine (Pinus ponderosa Laws.) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.) were greater in...

  17. Phosphorus transformation in poultry litter and litter-treated Oxisol of Brazil assessed by 31P-NMR and wet chemical fractionation

    Directory of Open Access Journals (Sweden)

    César Roriz de Souza

    2012-11-01

    Full Text Available Large quantities of poultry litter are being produced in Brazil, which contain appreciable amounts of phosphorus (P that could be of environmental concern. To assess the immediate environmental threat, five poultry litters composed of diverse bedding material were incubated for 43 days under greenhouse conditions. The litters consisted of: coffee bean husk (CH; wood chips (WC; rice husk (RH; ground corn cobs (CC and ground napier grass (NG (Pennisetum purpureum Schum., in which the change in forms of soluble P was evaluated using 31P NMR spectroscopy. On average, 80.2 and 19.8 % of the total P in the extract, respectively, accounted for the inorganic and organic forms before incubation and 48 % of the organic P was mineralized to inorganic P in 43 days of incubation. Wide variation in the organic P mineralization rate (from 82 % -WC to 4 % - NG was observed among litters. Inorganic orthophosphate (99.9 % and pyrophosphate (0.1 % were the only inorganic P forms, whereas the organic P forms orthophosphate monoesters (76.3 % and diester (23.7 % were detected. Diester P compounds were mineralized almost completely in all litters, except in the CH litter, within the incubation period. Pyrophosphates contributed with less than 0.5% and remained unaltered during the incubation period. Wood-chip litter had a higher organic P (40 % content and a higher diester: monoester ratio; it was therefore mineralized rapidly, within the first 15 days, achieving steady state by the 29th day. Distinct mineralization patterns were observed in the litter when incubated with a clayey Oxisol. The substantial decrease observed in the organic P fraction (Po of the litter types followed the order: CH (45 % > CC (25 % > RH (13 % ≈ NG (12 % > WC (5 %, whereas the Pi fraction increased. Incubation of RH litter in soil slowed down the mineralization of organic P.

  18. Early-stage changes in natural (13)C and (15)N abundance and nutrient dynamics during different litter decomposition.

    Science.gov (United States)

    Gautam, Mukesh Kumar; Lee, Kwang-Sik; Song, Byeong-Yeol; Lee, Dongho; Bong, Yeon-Sik

    2016-05-01

    Decomposition, nutrient, and isotopic (δ(13)C and δ(15)N) dynamics during 1 year were studied for leaf and twig litters of Pinus densiflora, Castanea crenata, Erigeron annuus, and Miscanthus sinensis growing on a highly weathered soil with constrained nutrient supply using litterbags in a cool temperate region of South Korea. Decay constant (k/year) ranged from 0.58 to 1.29/year, and mass loss ranged from 22.36 to 58.43 % among litter types. The results demonstrate that mass loss and nutrient dynamics of decomposing litter were influenced by the seasonality of mineralization and immobilization processes. In general, most nutrients exhibited alternate phases of rapid mineralization followed by gradual immobilization, except K, which was released throughout the field incubation. At the end of study, among all the nutrients only N and P showed net immobilization. Mobility of different nutrients from decomposing litter as the percentage of initial litter nutrient concentration was in the order of K > Mg > Ca > N ≈ P. The δ(13)C (0.32-6.70 ‰) and δ(15)N (0.74-3.90 ‰) values of residual litters showed nonlinear increase and decrease, respectively compared to initial isotopic values during decomposition. Litter of different functional types and chemical quality converged toward a conservative nutrient use strategy through mechanisms of slow decomposition and slow nutrient mobilization. Our results indicate that litter quality and season, are the most important regulators of litter decomposition in these forests. The results revealed significant relationships between litter decomposition rates and N, C:N ratio and P, and seasonality (temperature). These results and the convergence of different litters towards conservative nutrient use in these nutrient constrained ecosystems imply optimization of litter management because litter removal can have cascading effects on litter decomposition and nutrient availability in these systems.

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

    Science.gov (United States)

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

    2007-08-01

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

  20. Quantifying the effect of plant growth on litter decomposition using a novel, triple-isotope label approach

    Science.gov (United States)

    Ernakovich, J. G.; Baldock, J.; Carter, T.; Davis, R. A.; Kalbitz, K.; Sanderman, J.; Farrell, M.

    2017-12-01

    Microbial degradation of plant detritus is now accepted as a major stabilizing process of organic matter in soils. Most of our understanding of the dynamics of decomposition come from laboratory litter decay studies in the absence of plants, despite the fact that litter decays in the presence of plants in many native and managed systems. There is growing evidence that living plants significantly impact the degradation and stabilization of litter carbon (C) due to changes in the chemical and physical nature of soils in the rhizosphere. For example, mechanistic studies have observed stimulatory effects of root exudates on litter decomposition, and greenhouse studies have shown that living plants accelerate detrital decay. Despite this, we lack a quantitative understanding of the contribution of living plants to litter decomposition and how interactions of these two sources of C build soil organic matter (SOM). We used a novel triple-isotope approach to determine the effect of living plants on litter decomposition and C cycling. In the first stage of the experiment, we grew a temperate grass commonly used for forage, Poa labillardieri, in a continuously-labelled atmosphere of 14CO2 fertilized with K15NO3, such that the grass biomass was uniformly labelled with 14C and 15N. In the second stage, we constructed litter decomposition mescososms with and without a living plant to test for the effect of a growing plant on litter decomposition. The 14C/15N litter was decomposed in a sandy clay loam while a temperate forage grass, Lolium perenne, grew in an atmosphere of enriched 13CO2. The fate of the litter-14C/15N and plant-13C was traced into soil mineral fractions and dissolved organic matter (DOM) over the course of nine weeks using four destructive harvests of the mesocosms. Our preliminary results suggest that living plants play a major role in the degradation of plant litter, as litter decomposition was greater, both in rate and absolute amount, for soil mesocosms

  1. Contribution of soil, water and food consumption to metal exposure of children from geological enriched environments in the coastal zone of Lake Victoria, Kenya.

    NARCIS (Netherlands)

    Oyoo-Okoth, E.; Admiraal, W.; Osano, O.; Manguya-Lusega, D; Ngure, V.; Kraak, M.H.S.; Chepkirui-Boit, V.; Makwali, J.

    2013-01-01

    Geologically enriched environments may contain high concentrations of some metals. In areas where industrial exposures remain superficial, children may be exposed to these geological metals through soil, drinking water and consumption of food locally grown. The aim of this study was to assess the

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Daniel Bini

    2013-02-01

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

  4. Decomposition of Arachis pintoi and Hyparrhenia rufa litters in monoculture and intercropped systems under lowland soil Decomposição da serrapilheira de Arachis pintoi e Hyparrhenia rufa em sistemas de monocultura e consórcio sob solo de várzea

    Directory of Open Access Journals (Sweden)

    Christiane Abreu de Oliveira

    2003-09-01

    Full Text Available Tropical grasslands under lowland soils are generally underutilized and the litter of forage legumes may be used to recover these degraded pastures. The objective of this work was to study the dynamics of litter decomposition of Arachis pintoi (pinto peanut, Hyparrhenia rufa (thatching grass and a mixture of both species in a lowland soil. These treatments were analyzed in three areas: grass monoculture, legume monoculture and legume intercropped with the grass during the dry and wet seasons. Litter bags containing the legume, grass or a mixture of both species were incubated to estimate the decomposition rate and microorganism colonization. Decomposition constants (K and litter half-lives (T1/2 were estimated by an exponential model whereas number of microorganisms in specific media were determined by plate dilution. The decomposition rate, release of nutrients and microorganisms number, especially bacteria, increased when pinto peanut was added to thatching grass, influenced by favorable lignin/N and C/N ratios in legume litter. When pinto peanut litter was incubated in the grass plots, 50% N and P was released within about 135 days in the dry season and in the wet season, the equivalent release occurred within 20 days. These results indicate that A. pintoi has a great potential for nutrient recycling via litter and can be used to recover degraded areas.Pastagens tropicais sobre solos de várzea são geralmente subutilizadas. A serrapilheira de leguminosas forrageiras pode ser usada para a recuperação destas pastagens. O objetivo deste trabalho foi estudar a dinâmica de decomposição de Arachis pintoi (arachis, Hyparrhenia rufa (capim jaraguá e da mistura destas espécies, em solo de várzea. Estes tratamentos foram analisados em três áreas: monocultivo da gramínea; monocultivo da leguminosa e no consórcio entre as espécies durante as estações seca e chuvosa. Sacos de decomposição contendo a serrapilheira da leguminosa ou da

  5. Carbon input belowground is the major C flux contributing to leaf litter mass loss

    DEFF Research Database (Denmark)

    Rubino, Mauro; Dungait; Evershed

    2010-01-01

    and analysed for their total C and 13C content. Gas chromatography (GC), GC–mass spectrometry (MS) and GC-combustion-isotope ratio (GC/C/IRMS) were used to analyse phospholipid fatty acids (PLFA) extracted from soil samples to identify the groups of soil micro-organisms that had incorporated litter-derived C...... and to determine the quantity of C incorporated by the soil microbial biomass (SMB). By the end of the experiment, the litter had lost about 80% of its original weight. The fraction of litter C lost as an input into the soil (67 ± 12% of the total C loss) was found to be twice as much as the fraction released...

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

    Science.gov (United States)

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

    2005-01-01

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

  7. Influence of tropical leaf litter on nitrogen mineralization and community structure of ammonia-oxidizing bacteria

    OpenAIRE

    Diallo, M. D.; Guisse, A.; Sall, S. N.; Dick, R. P.; Assigbetsé, Komi; Dieng, A. L.; Chotte, Jean-Luc

    2015-01-01

    Description of the subject. The present study concerns the relationships among leaf litter decomposition, substrate quality, ammonia-oxidizing bacteria (AOB) community composition and nitrogen (N) availability. Decomposition of organic matter affects the biogeochemical cycling of carbon (C) and N. Since the composition of the soil microbial community can alter the physiological capacity of the community, it is timely to study the litter quality effect on N dynamic in ecosystems. Objectives. T...

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

    OpenAIRE

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

    2016-01-01

    International audience; The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely un- known. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the function- ing of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black a...

  9. Insight into litter decomposition driven by nutrient demands of symbiosis system through the hypha bridge of arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Kong, Xiangshi; Jia, Yanyan; Song, Fuqiang; Tian, Kai; Lin, Hong; Bei, Zhanlin; Jia, Xiuqin; Yao, Bei; Guo, Peng; Tian, Xingjun

    2018-02-01

    Arbuscular mycorrhizal fungi (AMF) play an important role in litter decomposition. This study investigated how soil nutrient level affected the process. Results showed that AMF colonization had no significant effect on litter decomposition under normal soil nutrient conditions. However, litter decomposition was accelerated significantly under lower nutrient conditions. Soil microbial biomass in decomposition system was significantly increased. Especially, in moderate lower nutrient treatment (condition of half-normal soil nutrient), litters exhibited the highest decomposition rate, AMF hypha revealed the greatest density, and enzymes (especially nitrate reductase) showed the highest activities as well. Meanwhile, the immobilization of nitrogen (N) in the decomposing litter remarkably decreased. Our results suggested that the roles AMF played in ecosystem were largely affected by soil nutrient levels. At normal soil nutrient level, AMF exhibited limited effects in promoting decomposition. When soil nutrient level decreased, the promoting effect of AMF on litter decomposition began to appear, especially on N mobilization. However, under extremely low nutrient conditions, AMF showed less influence on decomposition and may even compete with decomposer microorganisms for nutrients.

  10. Using column experiments to examine transport of As and other trace elements released from poultry litter: Implications for trace element mobility in agricultural watersheds

    International Nuclear Information System (INIS)

    Oyewumi, Oluyinka; Schreiber, Madeline E.

    2017-01-01

    Trace elements are added to poultry feed to control infection and improve weight gain. However, the fate of these trace elements in poultry litter is poorly understood. Because poultry litter is applied as fertilizer in many agricultural regions, evaluation of the environmental processes that influence the mobility of litter-derived trace elements is critical for predicting if trace elements are retained in soil or released to water. This study examined the effect of dissolved organic carbon (DOC) in poultry litter leachate on the fate and transport of litter-derived elements (As, Cu, P and Zn) using laboratory column experiments with soil collected from the Delmarva Peninsula (Mid-Atlantic, USA), a region of intense poultry production. Results of the experiments showed that DOC enhanced the mobility of all of the studied elements. However, despite the increased mobility, 60–70% of Zn, As and P mass was retained within the soil. In contrast, almost all of the Cu was mobilized in the litter leachate experiments, with very little retention in soil. Overall, our results demonstrate that the mobility of As, Cu, Zn and P in soils which receive poultry litter application is strongly influenced by both litter leachate composition, specifically organic acids, and adsorption to soil. Results have implications for understanding fate and transport of trace elements released from litter application to soil water and groundwater, which can affect both human health and the environment. - Highlights: • Column experiments examined fate of trace elements derived from poultry litter leachate in soils from Delaware, USA. • Influent solutions included poultry litter leachate and simulated solution without DOC. • Results showed increased mobility of litter-derived As, Cu, Zn and P in solution in the presence of DOC. • Mass balance showed all of Cu mass remained in solution but most (60–70%) of the Zn, As and P mass was associated with soil. • Study results show that DOC

  11. Processes controlling the production of aromatic water-soluble organic matter during litter decomposition

    NARCIS (Netherlands)

    Klotzbücher, T.; Kaiser, K.; Filley, T.R.; Kalbitz, K.

    2013-01-01

    Dissolved organic matter (DOM) plays a fundamental role for many soil processes. For instance, production, transport, and retention of DOM control properties and long-term storage of organic matter in mineral soils. Production of water-soluble compounds during the decomposition of plant litter is a

  12. Interactions between plants, litter and microbes in cycling of nitrogen and phosphorus in the arctic

    DEFF Research Database (Denmark)

    Jonasson, Sven Evert; Castro, Jorge; Michelsen, Anders

    2006-01-01

    but increased phosphorus (P) mineralization, while litter addition decreased N and increased P mineralization but without any effect on plant and microbial N and P sequestration. Incubations of soils with plants increased N mobilization to the soil inorganic plus plant pools several-fold as compared to the net...

  13. Nutrient Dynamics and Litter Decomposition in Leucaena ...

    African Journals Online (AJOL)

    Nutrient contents and rate of litter decomposition were investigated in Leucaena leucocephala plantation in the University of Agriculture, Abeokuta, Ogun State, Nigeria. Litter bag technique was used to study the pattern and rate of litter decomposition and nutrient release of Leucaena leucocephala. Fifty grams of oven-dried ...

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

    Directory of Open Access Journals (Sweden)

    Jinsong Wang

    2015-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Kai Yue

    2016-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  17. Microbial plant litter decomposition in aquatic and terrestrial boreal systems along a natural fertility gradient

    Science.gov (United States)

    Soares, A. Margarida P. M.; Kritzberg, Emma S.; Rousk, Johannes

    2017-04-01

    Plant litter decomposition is a global ecosystem process, with a crucial role in carbon and nutrient cycling. The majority of litter processing occurs in terrestrial systems, but an important fraction also takes place in inland waters. Among environmental factors, pH impacts the litter decomposition through its selective influence on microbial decomposers. Fungal communities are less affected by pH than bacteria, possibly owing to a wider pH tolerance by this group. On the other hand, bacterial pH optima are constrained to a narrower range of pH values. The microbial decomposition of litter is universally nutrient limited; but few comparisons exist between terrestrial and aquatic systems. We investigated the microbial colonisation and decomposition of plant litter along a fertility gradient, which varied in both pH and N availability in both soil and adjacent water. To do this we installed litterbags with birch (Betula pendula) in streams and corresponding soils in adjacent riparian areas in a boreal system, in Krycklan, Sweden. During the four months covering the ice-free growth season we monitored the successional dynamics of fungal (acetate incorporation into ergosterol) and bacterial growth (thymidine incorporation), microbial respiration in leaf litter, and quantitative and qualitative changes in litter over time. We observed that bacterial growth rates were initially higher in litter decomposing in streams than those in soils, but differences between terrestrial and aquatic bacterial production converged towards the end of the experiment. In litter bags installed in soils, bacterial growth was lower at sites with more acidic pH and lower N availability, while aquatic bacteria were relatively unaffected by the fertility level. Fungal growth rates were two-fold higher for litter decomposing in streams than in soils. In aquatic systems, fungal growth was initially lower in low fertility sites, but differences gradually disappeared over the time course. Fungal

  18. Estoque de serapilheira e fertilidade do solo em pastagem degradada de Brachiaria decumbens após implantação de leguminosas arbustivas e arbóreas forrageiras Soil litter stock and fertility after planting leguminous shrubs and forage trees on degraded signal grass pasture

    Directory of Open Access Journals (Sweden)

    André Barbosa Silva

    2013-04-01

    secondary effects on soil fertility, such as acidification or nutrient movement from deeper to the surface soil layers. This study evaluated the soil litter stock and fertility of degraded Brachiaria decumbens pastures after planting leguminous shrubs and forage trees. For this purpose, we sampled (March 2010 degraded Brachiaria decumbens pasture planted in July 2008 in an intercropping experiment with sabiá (Mimosa caesalpiniaefolia, leucaena (Leucaena leucocephala, mororó (Bauhinia cheilantha and gliricidia (Gliricidia sepium, as well as N-fertilized and unfertilized brachiaria. Soil and litter was sampled (layers 0-10, 10-20 and 20-40 cm in three transects, at alternating points covered by grasses and by legumes, totaling seven composite samples per plot to determine soil pH, P, K , Ca, Mg, and Al and calculate sum of bases, effective cation exchange capacity and aluminum saturation. Litter was visually separated in legumes, grasses and unidentified material to quantify dry matter, organic matter, N, P, C, acid-detergent fiber, and lignin. The use of legumes increased the levels of total N in litter and reduced the C: N ratios, especially of gliricidia and sabiá, although the lignin levels in the latter were high. There was a significant effect of legume soil cover, with no differences between them, on pH and K (layer 0-10 cm and on pH, K and Al (layer 10-20 cm.

  19. Análise comparativa das características da serrapilheira e do solo em cafezais (Coffea arabica L. cultivados em sistema agroflorestal e em monocultura, na Zona da Mata MG Comparative analysis of litter and soil characteristics under coffee (Coffea arabica L. crop in agroforestry and monoculture systems

    Directory of Open Access Journals (Sweden)

    Mônica Matoso Campanha

    2007-10-01

    Full Text Available O aporte de serrapilheira em sistemas agroflorestais pode melhorar as características químicas e físicas do solo, diminuir a erosão e permitir a manutenção da umidade no solo por mais tempo. Isso faz dele um sistema alternativo de produção de café em regiões com solos propensos à degradação. Este trabalho teve como objetivo realizar uma análise comparativa da quantidade e teor de nutrientes da serrapilheira e das características de fertilidade e do teor de umidade dos solos, em cafeeiros cultivados sob sistemas agroflorestal e solteiro. A pesquisa foi realizada na Zona da Mata mineira, durante o período compreendido entre janeiro de 1999 e maio de 2000. O sistema agroflorestal contribuiu com 6,1 Mg ha-1 ano-1 de matéria seca de serrapilheira, no entanto o solteiro aportou 4,5 Mg ha-1 ano-1, ressaltando-se que esta última apresentou teor mais elevado de macronutrientes. O solo do sistema agroflorestal exibiu maior teor de umidade de 20-40 cm, maior capacidade de troca de cátions e soma de bases trocáveis, maior teor de K, Ca, Mg, Cu e Zn em ambos os horizontes do solo e menor índice de saturação de alumínio e alumínio trocável na camada mais profunda do que o solo sob a monocultura. No cultivo solteiro, o solo apresentou maior teor de P e de matéria orgânica, tanto na camada superficial quanto na profunda.Coffee plants in agroforestry systems is an alternative to full sunlight cultivation, presenting the potential benefits of enhancing soil chemical and physical characteristics, reducing soil erosion, besides maintaining soil moisture for longer periods. This research aimed at comparing the quantity and nutrient concentration in the litter, soil fertility and soil moisture in coffee crops under full sunlight monocrop and in agroforestry systems, at the Zona da Mata, Minas Gerais, Brazil. The research was carried out between January 1999 and May 2000. The agroforestry system, contributed with 6.1 Mg ha-1 year-1 of

  20. Elevated UV-B radiation increased the decomposition of Cinnamomum camphora and Cyclobalanopsis glauca leaf litter in subtropical China

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xinzhang Z.; Zhang, Huiling L.; Jiang, Hong; Yu, Shuquan Q. [Zhejiang Agriculture and Forestry Univ., Lin' an (China). The Nurturing Station for the State Key Lab. of Subtropical Silviculture; Zhejiang Agriculture and Forestry Univ., Lin' an (China). Zhejiang Provincial Key Lab. of Carbon Cycling and Carbon Sequestration in Forest Ecosystems; Chang, Scott X. [Alberta Univ., Edmonton (Canada). Dept. of Renewable Resources; Peng, Changhui H. [Quebec Univ., Montreal (Canada). Inst. of Environment Sciences

    2012-03-15

    Ultraviolet-B (UV-B) radiation reaching the earth's surface has been increasing due to ozone depletion and can profoundly influence litter decomposition and nutrient cycling in terrestrial ecosystems. The role of UV-B radiation in litter decomposition in humid environments is poorly understood; we thus investigated the effect of UV-B radiation on litter decomposition and nitrogen (N) release in a humid subtropical ecosystem in China. We conducted a field-based experiment using the litterbag method to study litter decomposition and N release under ambient and elevated (31% above ambient) UV-B radiation, using the leaf litter of two common tree species, Cinnamomum camphora and Cyclobalanopsis glauca, native to subtropical China. Elevated UV-B radiation significantly increased the decomposition rate of C. camphora and C. glauca leaf litter by 16.7% and 27.8%, respectively, and increased the N release from the decomposing litter of C. glauca but not C. camphora. Elevated UV-B radiation significantly accelerated the decomposition of litter of two native tree species and the N release from the decomposition litter of C. glauca in humid subtropical China, which has implications for soil carbon flux and forest productivity. (orig.)

  1. Influence of nitrogen additions on litter decomposition, nutrient dynamics, and enzymatic activity of two plant species in a peatland in Northeast China.

    Science.gov (United States)

    Song, Yanyu; Song, Changchun; Ren, Jiusheng; Tan, Wenwen; Jin, Shaofei; Jiang, Lei

    2018-06-01

    Nitrogen (N) availability affects litter decomposition and nutrient dynamics, especially in N-limited ecosystems. We investigated the response of litter decomposition to N additions in Eriophorum vaginatum and Vaccinium uliginosum peatlands. These two species dominate peatlands in Northeast China. In 2012, mesh bags containing senesced leaf litter of Eriophorum vaginatum and Vaccinium uliginosum were placed in N addition plots and sprayed monthly for two years with NH 4 NO 3 solution at dose rates of 0, 6, 12, and 24gNm -2 year -1 (CK, N1, N2 and N3, respectively). Mass loss, N and phosphorus (P) content, and enzymatic activity were measured over time as litter decomposed. In the control plots, V. uliginosum litter decomposed faster than E. vaginatum litter. N1, N2, and N3 treatments increased the mass losses of V. uliginosum litter by 6%, 9%, and 4% respectively, when compared with control. No significant influence of N additions was found on the decomposition of E. vaginatum litter. However, N and P content in E. vaginatum litter and V. uliginosum litter significantly increased with N additions. Moreover, N additions significantly promoted invertase and β-glucosidase activity in E. vaginatum and V. uliginosum litter. However, only in V. uliginosum litter was polyphenol oxidase activity significantly enhanced. Our results showed that initial litter quality and polyphenol oxidase activity influence the response of plant litter to N additions in peatland ecosystems. Increased N availability may change peatland soil N and P cycling by enhancing N and P immobilization during litter decomposition. Copyright © 2018 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Jaeeun Sohng

    2014-10-01

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

  3. [Effects of deep plowing time during the fallow period on water storage-consumption characteristics and wheat yield in dry-land soil.

    Science.gov (United States)

    Dang, Jian You; Pei, Xue Xia; Zhang, Ding Yi; Wang, Jiao Ai; Zhang, Jing; Wu, Xue Ping

    2016-09-01

    Through a three-year field trail, effects of deep plowing time during the fallow period on water storage of 0-200 cm soil before sowing, water consumption of growth period, and growth and development of wheat were investigated. Results demonstrated that soil water storage (SWS) of the fallow period was influenced by deep plowing time, precipitation, and rainfall distribution. With postponing the time of deep plowing in the fallow period, SWS was increased firstly, and then decreased. SWS with deep plowing in early or middle of August was 23.9-45.8 mm more than that with deep plowing in mid-July. It would benefit SWS when more precipitation occurred in the fallow period or more rainfall was distributed in August and September. Deep plowing at a proper time could facilitate SWS, N and P absorption of wheat, and the number of stems before winter and the spike number. The yield of wheat with deep plowing in early or middle August was 3.67%-18.2% higher than that with deep plowing in mid-July, and it was positively correlated with water storage of 0-200 cm soil during the fallow period and SWS of each soil layer during the wheat growth period. However, this correlation coefficient would be weakened by adequate rainfall in spring, the critical growing period for wheat. The time of deep plowing mainly affected the water consumption at soil layer of 60-140 cm during wheat growth. Under current farming conditions of south Shanxi, the increased grain yield of wheat could be achieved by combining the measures of high wheat stubble and wheat straw covering for holding soil water and deep plowing between the Beginning of Autumn (August 6th) and the Limit of Heat (August 21st) for promoting soil water penetration characteristics to improve the number of stems before winter and spike.

  4. Solar radiation uncorks the lignin bottleneck on plant litter decomposition in terrestrial ecosystems

    Science.gov (United States)

    Austin, A.; Ballare, C. L.; Méndez, M. S.

    2015-12-01

    Plant litter decomposition is an essential process in the first stages of carbon and nutrient turnover in terrestrial ecosystems, and together with soil microbial biomass, provide the principal inputs of carbon for the formation of soil organic matter. Photodegradation, the photochemical mineralization of organic matter, has been recently identified as a mechanism for previously unexplained high rates of litter mass loss in low rainfall ecosystems; however, the generality of this process as a control on carbon cycling in terrestrial ecosystems is not known, and the indirect effects of photodegradation on biotic stimulation of carbon turnover have been debated in recent studies. We demonstrate that in a wide range of plant species, previous exposure to solar radiation, and visible light in particular, enhanced subsequent biotic degradation of leaf litter. Moreover, we demonstrate that the mechanism for this enhancement involves increased accessibility for microbial enzymes to plant litter carbohydrates due to a reduction in lignin content. Photodegradation of plant litter reduces the structural and chemical bottleneck imposed by lignin in secondary cell walls. In litter from woody plant species, specific interactions with ultraviolet radiation obscured facilitative effects of solar radiation on biotic decomposition. The generalized positive effect of solar radiation exposure on subsequent microbial activity is mediated by increased accessibility to cell wall polysaccharides, which suggests that photodegradation is quantitatively important in determining rates of mass loss, nutrient release and the carbon balance in a broad range of terrestrial ecosystems.

  5. Seasonal climate manipulations have only minor effects on litter decomposition rates and N dynamics but strong effects on litter P dynamics of sub-arctic bog species.

    Science.gov (United States)

    Aerts, R; Callaghan, T V; Dorrepaal, E; van Logtestijn, R S P; Cornelissen, J H C

    2012-11-01

    Litter decomposition and nutrient mineralization in high-latitude peatlands are constrained by low temperatures. So far, little is known about the effects of seasonal components of climate change (higher spring and summer temperatures, more snow which leads to higher winter soil temperatures) on these processes. In a 4-year field experiment, we manipulated these seasonal components in a sub-arctic bog and studied the effects on the decomposition and N and P dynamics of leaf litter of Calamagrostis lapponica, Betula nana, and Rubus chamaemorus, incubated both in a common ambient environment and in the treatment plots. Mass loss in the controls increased in the order Calamagrostis Litter chemistry showed within each incubation environment only a few and species-specific responses. Compared to the interspecific differences, they resulted in only moderate climate treatment effects on mass loss and these differed among seasons and species. Neither N nor P mineralization in the litter were affected by the incubation environment. Remarkably, for all species, no net N mineralization had occurred in any of the treatments during 4 years. Species differed in P-release patterns, and summer warming strongly stimulated P release for all species. Thus, moderate changes in summer temperatures and/or winter snow addition have limited effects on litter decomposition rates and N dynamics, but summer warming does stimulate litter P release. As a result, N-limitation of plant growth in this sub-arctic bog may be sustained or even further promoted.

  6. Effects of top-dressing recycled broiler litter on litter production, litter characteristics, and nitrogen mass balance.

    Science.gov (United States)

    Coufal, C D; Chavez, C; Niemeyer, P R; Carey, J B

    2006-03-01

    Top-dressing is a method of broiler litter management in which a thin layer of new, clean litter material is spread over the top of previously used litter prior to placement of a new flock. This fresh layer of bedding material increases the absorptive capacity of the litter and decreases litter caking. Although this practice has been widely used in the poultry industry for many years, no research has been conducted to quantify the effects the practice has on broiler performance, litter production rates, and nutrient content, or the ability of broiler litter to retain manure N and prevent volatilization. An experiment was conducted to quantify these parameters under simulated commercial conditions in a research facility. Nine consecutive flocks of broilers were reared on recycled broiler litter that had previously been used for 9 flocks. Control pens received no litter treatment whereas top-dressed pens received a thin layer of new rice hulls (1 to 2 cm) before the placement of each flock. Nitrogen loss was calculated using the mass balance method. Average broiler performance was not different between the top-dressed and control pens. Top-dressing of litter significantly (P dressed pens compared with control pens. As a result, litter C:N ratios were significantly higher for pens with top-dressed litter. Differences in N loss between the treatments were not consistent. Average N loss for all flocks was 10.61 and 11.92 g of N/kg of marketed broiler for control and top-dressed pens, respectively, or 20.1 and 22.5% of N inputs, respectively. Based on this experiment, top-dressing of recycled broiler litter would not be recommended as a strategy to reduce the volatilization of N from broiler rearing facilities and, in fact, may actually increase N loss.

  7. Measurement of broiler litter production rates and nutrient content using recycled litter.

    Science.gov (United States)

    Coufal, C D; Chavez, C; Niemeyer, P R; Carey, J B

    2006-03-01

    It is important for broiler producers to know litter production rates and litter nutrient content when developing nutrient management plans. Estimation of broiler litter production varies widely in the literature due to factors such as geographical region, type of housing, size of broiler produced, and number of flocks reared on the same litter. Published data for N, P, and K content are also highly variable. In addition, few data are available regarding the rate of production, characteristics, and nutrient content of caked litter (cake). In this study, 18 consecutive flocks of broilers were reared on the same litter in experimental pens under simulated commercial conditions. The mass of litter and cake produced was measured after each flock. Samples of all litter materials were analyzed for pH, moisture, N, P, and K. Average litter and cake moisture content were 26.4 and 46.9%, respectively. Significant variation in litter and cake nutrient content was observed and can largely be attributed to ambient temperature differences. Average litter, cake, and total litter (litter plus cake) production rates were 153.3, 74.8, and 228.2 g of dry litter material per kg of live broiler weight (g/kg) per flock, respectively. Significant variation in litter production rates among flocks was also observed. Cumulative litter, cake, and total litter production rates after 18 flocks were 170.3, 78.7, and 249.0 g/kg, respectively. The data produced from this research can be used by broiler producers to estimate broiler litter and cake production and the nutrient content of these materials.

  8. Leaf area index from litter collection: impact of specific leaf area variability within a beech stand

    Energy Technology Data Exchange (ETDEWEB)

    Bouriaud, O. [Inst. National de la Recherche Agronomique, Centre de Recherches Forestieres de Nancy, Champenoux (France); Soudani, K. [Univ. Paris-Sud XI, Dept. d' Ecophysiologie Vegetale, Lab. Ecologie Systematique et Evolution, Orsay Cedex (France); Breda, N. [Inst. National de la Recherche Agronomique, Centre de Recherches Forestieres de Nancy, Champenoux (France)

    2003-06-01

    Litter fall collection is a direct method widely used to estimate leaf area index (LAI) in broad-leaved forest stands. Indirect measurements using radiation transmittance and gap fraction theory are often compared and calibrated against litter fall, which is considered as a reference method, but few studies address the question of litter specific leaf area (SLA) measurement and variability. SLA (leaf area per unit of dry weight, m{sup 2}{center_dot}g{sup -1}) is used to convert dry leaf litter biomass (g .m{sup -}2) into leaf area per ground unit area (m{sup 2}{center_dot}m{sup -2}). We paid special attention to this parameter in two young beech stands (dense and thinned) in northeastern France. The variability of both canopy (closure, LAI) and site conditions (soil properties, vegetation) was investigated as potential contributing factors to beech SLA variability. A systematic description of soil and floristic composition was performed and three types of soil were identified. Ellenberg's indicator values were averaged for each plot to assess nitrogen soil content. SLA of beech litter was measured three times during the fall in 23 plots in the stands (40 ha). Litter was collected bimonthly in square-shaped traps (0.5 m{sup 2}) and dried. Before drying, 30 leaves per plot and for each date were sampled, and leaf length, width, and area were measured with the help of a LI-COR areameter. SLA was calculated as the ratio of cumulated leaf area to total dry weight of the 30 leaves. Leaves characteristics per plot were averaged for the three dates of litter collection. Plant area index (PAI), estimated using the LAI-2000 plant canopy analyser and considering only the upper three rings, ranged from 2.9 to 8.1. Specific leaf area of beech litter was also highly different from one plot to the other, ranging from 150 to 320 cm{sup 2}{center_dot}g{sup -1}. Nevertheless, no relationship was found between SLA and stand canopy closure or PAI On the contrary, a significant

  9. Leaf area index from litter collection: impact of specific leaf area variability within a beech stand

    International Nuclear Information System (INIS)

    Bouriaud, O.; Soudani, K.; Breda, N.

    2003-01-01

    Litter fall collection is a direct method widely used to estimate leaf area index (LAI) in broad-leaved forest stands. Indirect measurements using radiation transmittance and gap fraction theory are often compared and calibrated against litter fall, which is considered as a reference method, but few studies address the question of litter specific leaf area (SLA) measurement and variability. SLA (leaf area per unit of dry weight, m 2 ·g -1 ) is used to convert dry leaf litter biomass (g .m - 2) into leaf area per ground unit area (m 2 ·m -2 ). We paid special attention to this parameter in two young beech stands (dense and thinned) in northeastern France. The variability of both canopy (closure, LAI) and site conditions (soil properties, vegetation) was investigated as potential contributing factors to beech SLA variability. A systematic description of soil and floristic composition was performed and three types of soil were identified. Ellenberg's indicator values were averaged for each plot to assess nitrogen soil content. SLA of beech litter was measured three times during the fall in 23 plots in the stands (40 ha). Litter was collected bimonthly in square-shaped traps (0.5 m 2 ) and dried. Before drying, 30 leaves per plot and for each date were sampled, and leaf length, width, and area were measured with the help of a LI-COR areameter. SLA was calculated as the ratio of cumulated leaf area to total dry weight of the 30 leaves. Leaves characteristics per plot were averaged for the three dates of litter collection. Plant area index (PAI), estimated using the LAI-2000 plant canopy analyser and considering only the upper three rings, ranged from 2.9 to 8.1. Specific leaf area of beech litter was also highly different from one plot to the other, ranging from 150 to 320 cm 2 ·g -1 . Nevertheless, no relationship was found between SLA and stand canopy closure or PAI On the contrary, a significant relationship between SLA and soil properties was observed. Both SLA

  10. Longevity of contributions to SOC stocks from roots and aboveground plant litter below a Miscanthus plantation

    Science.gov (United States)

    Robertson, Andrew; Smith, Pete; Davies, Christian; Bottoms, Emily; McNamara, Niall

    2013-04-01

    Miscanthus is a lignocellulosic crop that uses the Hatch-Slack (C4) photosynthetic pathway as opposed to most C3 vegetation native to the UK. Miscanthus can be grown for a number of practical end-uses but recently interest has increased in its viability as a bioenergy crop; both providing a renewable source of energy and helping to limit climate change by improving the carbon (C) budgets associated with energy generation. Recent studies have shown that Miscanthus plantations may increase stocks of soil organic carbon (SOC), however the longevity and origin of this 'new' SOC must be assessed. Consequently, we combined an input manipulation experiment with physio-chemical soil fractionation to quantify new SOC and CO2 emissions from Miscanthus roots, decomposing plant litter and soil individually. Further, fractionation of SOC from the top 30 cm gave insight into the longevity of that SOC. In January 2009 twenty-five 2 m2 plots were set up in a three-year old 11 hectare Miscanthus plantation in Lincolnshire, UK; with five replicates of five treatments. These treatments varied plant input to the soil by way of controlled exclusion techniques. Treatments excluded roots only ("No Roots"), surface litter only ("No Litter"), both roots and surface litter ("No Roots or Litter") or had double the litter amount added to the soil surface ("Double Litter"). A fifth treatment was a control with undisturbed roots and an average amount of litter added. Monthly measurements of CO2 emissions were taken at the soil surface from each treatment between March 2009 and March 2013, and soil C from the top 30 cm was monitored in all plots over the same period. Miscanthus-derived SOC was determined using the isotopic discrimination between C4 plant matter and C3 soil, and soil fractionation was then used to establish the longevity of that Miscanthus-derived SOC. Ongoing results for CO2 emissions indicate a strong seasonal variation; litter decomposition forms a large portion of the CO2

  11. Seasonal climate manipulations have only minor effects on litter decomposition rates and N dynamics but strong effects on litter P dynamics of sub-arctic bog species.

    NARCIS (Netherlands)

    Aerts, R.; Callaghan, T.V.; Dorrepaal, E.; van Logtestijn, R.S.P; Cornelissen, J.H.C.

    2012-01-01

    Litter decomposition and nutrient mineralization in high-latitude peatlands are constrained by low temperatures. So far, little is known about the effects of seasonal components of climate change (higher spring and summer temperatures, more snow which leads to higher winter soil temperatures) on

  12. Marine litter prediction by artificial intelligence

    International Nuclear Information System (INIS)

    Balas, Can Elmar; Ergin, Aysen; Williams, Allan T.; Koc, Levent

    2004-01-01

    Artificial intelligence techniques of neural network and fuzzy systems were applied as alternative methods to determine beach litter grading, based on litter surveys of the Antalya coastline (the Turkish Riviera). Litter measurements were categorized and assessed by artificial intelligence techniques, which lead to a new litter categorization system. The constructed neural network satisfactorily predicted the grading of the Antalya beaches and litter categories based on the number of litter items in the general litter category. It has been concluded that, neural networks could be used for high-speed predictions of litter items and beach grading, when the characteristics of the main litter category was determined by field studies. This can save on field effort when fast and reliable estimations of litter categories are required for management or research studies of beaches--especially those concerned with health and safety, and it has economic implications. The main advantages in using fuzzy systems are that they consider linguistic adjectival definitions, e.g. many/few, etc. As a result, additional information inherent in linguistic comments/refinements and judgments made during field studies can be incorporated in grading systems

  13. Marine litter prediction by artificial intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Balas, Can Elmar; Ergin, Aysen; Williams, Allan T.; Koc, Levent

    2004-03-01

    Artificial intelligence techniques of neural network and fuzzy systems were applied as alternative methods to determine beach litter grading, based on litter surveys of the Antalya coastline (the Turkish Riviera). Litter measurements were categorized and assessed by artificial intelligence techniques, which lead to a new litter categorization system. The constructed neural network satisfactorily predicted the grading of the Antalya beaches and litter categories based on the number of litter items in the general litter category. It has been concluded that, neural networks could be used for high-speed predictions of litter items and beach grading, when the characteristics of the main litter category was determined by field studies. This can save on field effort when fast and reliable estimations of litter categories are required for management or research studies of beaches--especially those concerned with health and safety, and it has economic implications. The main advantages in using fuzzy systems are that they consider linguistic adjectival definitions, e.g. many/few, etc. As a result, additional information inherent in linguistic comments/refinements and judgments made during field studies can be incorporated in grading systems.

  14. Association between litterers' profile and littering behavior: A chi-square approach

    Science.gov (United States)

    Asmui, Mas'udah; Zaki, Suhanom Mohd; Wahid, Sharifah Norhuda Syed; Mokhtar, Noorsuraya Mohd; Harith, Siti Suhaila

    2017-05-01

    Littering is not a novelty, yet a prolonged issue. The solutions have been discussed for a long time; however this issue still remains unresolved. Littering is commonly associated with littering behavior and awareness. The littering behavior is normally influenced by the litter profile such as gender, family income, education level and age. Jengka Street market, which is located in Pahang, is popularly known as a trade market. It offers diversities of wet and dry goods and is awaited by local residents and tourists. This study analyzes association between litterers' profile and littering behavior. Littering behavior is measured based on factors of trash bin facilities, awareness campaign and public littering behavior. 114 respondents were involved in this study with 62 (54.39%) are female aged more than 18 years old and majority of these female respondents are diploma holders. In addition, 78.95% of the respondents have family income below than RM3,000.00 per month. Based on the data analysis, it was found that first-time visitors littered higher than frequent visitors, lack of providing trash bin facilities contributes to positive littering behavior and there is a significant association between litterers' age and littering behavior by using chi-square approach.

  15. MENINGKATKAN PRODUKSI AYAM PEDAGING MELALUI PENGATURAN PROPORSI SEKAM, PASIR DAN KAPUR SEBAGAI LITTER

    Directory of Open Access Journals (Sweden)

    Muharlien Muharlien

    2012-04-01

    AND QUICKLIME AS LITTER. ABSTRACT The aim of the research was to study the correct proportion among rice hull, sand and quicklime for increasing broiler production performances. The results of research expected can be used as consideration and information for  broiler rearing by using the correct proportion of rice hull, sand and quicklime of litter to increase broiler production. The material of the research was 72 broilers, Lohman Strain of 2 weeks old and body weight was 424,74 ± 42,46 g. The research method was experimentally with Completely Randomized Design (CRD. Variables observed were feed consumption, body weight  gain and feed conversion. The data were analysis with Analysis of Variance and if there were any significant difference would  be continued with Least Significant Differences (LSD. The result of this research indicated that difference proportion of rice hull, sand and quicklime in litter had significant effect (P<0,05 on feed consumption and daily gain but had no significant effect on feed conversion. Feed consumption  (3236,13 ± 47,75 g and body weight gain  (2174,42 ± 98,60 g and feed conversion (1.81 – 1.85. The conclusion used of litter which consist of 50 % rice hull, 33 % sand and 17 % quicklime can increase feed consumption and  body weight of broiler. It was  suggested that on rearing broiler by using litter with  proportion of 50 % rice hull,  33 % sand and 17 % quicklime.   Keyword : Broiler, feed consumption, daily gain, feed conversion,  and litter.

  16. Effects of dietary coarsely ground corn and 3 bedding floor types on broiler live performance, litter characteristics, gizzard and proventriculus weight, and nutrient digestibility.

    Science.gov (United States)

    Xu, Y; Lin, Y M; Stark, C R; Ferket, P R; Williams, C M; Brake, J

    2017-07-01

    The effects of zero or 50% dietary coarsely ground corn (CC) in pelleted and screened grower and finisher diets on broilers reared on 3 bedding floor types (plastic net [NET], new pine wood shavings litter [NEW], or old pine wood shavings litter [OLD]) on broiler live performance, litter characteristics, gizzard and proventriculus weight, and apparent ileal digestibility (AID) were studied in a 2 × 3 factorial arrangement of treatments. Fine corn was produced with a hammermill (271 μm) and CC with a roller mill (1145 μm). Utilization of CC reduced milling cost by 9.47 cents per MT with similar nutrient content of screened pellets. The 50% CC treatment exhibited improved (P ≤ 0.05) feed intake at 42 d (2.5%) and 49 d (3.0%), and BW (5.4%) and FCR from 28 d (1.4%). Birds on NEW litter exhibited improved (P litter birds exhibited increased (P ≤ 0.05) gizzard weight at 28 d and 49 d and decreased proventriculus weight as compared to NET at 49 days. The 50% CC treatment exhibited decreased (P ≤ 0.05) litter moisture at 35 and 42 d, litter N at 35 and 49 d, and litter pH at 49 days. OLD litter birds exhibited greater (P litter N at 14, 35, and 49 d, as well as litter moisture, pH, and ammonia concentration at 49 days. The 50% CC group also exhibited improved AID of nitrogen (P Broilers fed pelleted and screened diets containing 50% CC exhibited improved live performance and reduced litter moisture while use of NEW litter resulted in a somewhat similar effect, which indicated that consumption of NEW litter also facilitated gastric development and function. © 2017 Poultry Science Association Inc.

  17. Vegetation exerts a greater control on litter decomposition than climate warming in peatlands.

    Science.gov (United States)

    Ward, Susan E; Orwin, Kate H; Ostle, Nicholas J; Briones, J I; Thomson, Bruce C; Griffiths, Robert I; Oakley, Simon; Quirk, Helen; Bardget, Richard D

    2015-01-01

    Historically, slow decomposition rates have resulted in the accumulation of large amounts of carbon in northern peatlands. Both climate warming and vegetation change can alter rates of decomposition, and hence affect rates of atmospheric CO2 exchange, with consequences for climate change feedbacks. Although warming and vegetation change are happening concurrently, little is known about their relative and interactive effects on decomposition processes. To test the effects of warming and vegetation change on decomposition rates, we placed litter of three dominant species (Calluna vulgaris, Eriophorum vaginatum, Hypnum jutlandicum) into a peatland field experiment that combined warming.with plant functional group removals, and measured mass loss over two years. To identify potential mechanisms behind effects, we also measured nutrient cycling and soil biota. We found that plant functional group removals exerted a stronger control over short-term litter decomposition than did approximately 1 degrees C warming, and that the plant removal effect depended on litter species identity. Specifically, rates of litter decomposition were faster when shrubs were removed from the plant community, and these effects were strongest for graminoid and bryophyte litter. Plant functional group removals also had strong effects on soil biota and nutrient cycling associated with decomposition, whereby shrub removal had cascading effects on soil fungal community composition, increased enchytraeid abundance, and increased rates of N mineralization. Our findings demonstrate that, in addition to litter quality, changes in vegetation composition play a significant role in regulating short-term litter decomposition and belowground communities in peatland, and that these impacts can be greater than moderate warming effects. Our findings, albeit from a relatively short-term study, highlight the need to consider both vegetation change and its impacts below ground alongside climatic effects when

  18. Soils

    Science.gov (United States)

    Emily Moghaddas; Ken Hubbert

    2014-01-01

    When managing for resilient forests, each soil’s inherent capacity to resist and recover from changes in soil function should be evaluated relative to the anticipated extent and duration of soil disturbance. Application of several key principles will help ensure healthy, resilient soils: (1) minimize physical disturbance using guidelines tailored to specific soil types...

  19. Heavy metal accumulation in soils, plants, and hair samples: an assessment of heavy metal exposure risks from the consumption of vegetables grown on soils previously irrigated with wastewater.

    Science.gov (United States)

    Massaquoi, Lamin Daddy; Ma, Hui; Liu, Xue Hui; Han, Peng Yu; Zuo, Shu-Mei; Hua, Zhong-Xian; Liu, Dian-Wu

    2015-12-01

    It is common knowledge that soils irrigated with wastewater accumulate heavy metals more than those irrigated with cleaner water sources. However, little is known on metal concentrations in soils and cultivars after the cessation of wastewater use. This study assessed the accumulation and health risk of heavy metals 3 years post-wastewater irrigation in soils, vegetables, and farmers' hair. Soils, vegetables, and hair samples were collected from villages previously irrigating with wastewater (experimental villages) and villages with no history of wastewater irrigation (control villages). Soil samples were digested in a mixture of HCL/HNO3/HCLO4/HF. Plants and hair samples were digested in HNO3/HCLO4 mixture. Inductive coupled plasma-optical emission spectrometer (ICP-OES) was used to determine metal concentrations of digested extracts. Study results indicate a persistence of heavy metal concentration in soils and plants from farms previously irrigated with wastewater. In addition, soils previously irrigated with wastewater were severely contaminated with cadmium. Hair metal concentrations of farmers previously irrigating with wastewater were significantly higher (P metal concentrations in hair samples of farmers previously irrigating with wastewater were not associated with current soil metal concentrations. The study concludes that there is a persistence of heavy metals in soils and plants previously irrigated with wastewater, but high metal concentrations in hair samples of farmers cannot be associated with current soil metal concentrations.

  20. Cigarette Litter: Smokers’ Attitudes and Behaviors

    Directory of Open Access Journals (Sweden)

    Julia C. Cartwright

    2012-06-01

    Full Text Available Cigarette butts are consistently the most collected items in litter clean-up efforts, which are a costly burden to local economies. In addition, tobacco waste may be detrimental to our natural environment. The tobacco industry has conducted or funded numerous studies on smokers’ littering knowledge and behavior, however, non-industry sponsored research is rare. We sought to examine whether demographics and smokers’ knowledge and beliefs toward cigarette waste as litter predicts littering behavior. Smokers aged 18 and older (n = 1,000 were interviewed about their knowledge and beliefs towards cigarette waste as litter. Respondents were members of the Research Now panel, an online panel of over three million respondents in the United States. Multivariate logistic regressions were conducted to determine factors significantly predictive of ever having littered cigarette butts or having littered cigarette butts within the past month (p-value < 0.05. The majority (74.1% of smokers reported having littered cigarette butts at least once in their life, by disposing of them on the ground or throwing them out of a car window. Over half (55.7% reported disposing of cigarette butts on the ground, in a sewer/gutter, or down a drain in the past month. Those who did not consider cigarette butts to be litter were over three and half times as likely to report having ever littered cigarette butts (OR = 3.68, 95%CI = 2.04, 6.66 and four times as likely to have littered cigarette butts in the past month (OR = 4.00, 95%CI = 2.53, 6.32. Males were significantly more likely to have littered cigarette butts in the past month compared to females (OR = 1.49, 95%CI = 1.14, 1.94. Holding the belief that cigarette butts are not litter was the only belief in this study that predicted ever or past-month littering of cigarette waste. Messages in anti-cigarette-litter campaigns should emphasize that cigarette butts are not just litter but are toxic

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

    Science.gov (United States)

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

    2014-01-01

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

  2. Runoff water quality from broiler litter-amended tall fescue in response to natural precipitation in the Ozark Highlands.

    Science.gov (United States)

    Menjoulet, B C; Brye, K R; Pirani, A L; Haggard, B E; Gbur, E E

    2009-01-01

    The Arkansas poultry industry produced more than 1.2 billion broiler chickens (Gallus gallus domesticus) and generated approximately 1.3 million Mg of broiler litter in 2002. High transportation costs of relocating broiler litter have led to annual land applications near poultry houses, increasing concern for potential surface water contamination from runoff. The objective of this study was to evaluate the effect of broiler litter application rate on runoff water quality in response to natural precipitation. Six plots (1.5 by 6.0 m), located on a Captina silt loam (finesilty, siliceous, active, mesic Typic Fragiudult), were amended with fresh broiler litter at 0, 5.6, and 11.2 Mg ha(-1) (control, low, and high litter treatments, respectively) once annually for 4 yr (May 2003 through April 2007). Runoff collected after each runoff-producing event was analyzed for soluble nutrients and metals. Cumulative runoff did not differ among litter treatments over the 4-yr study. At times, flow-weighted mean (FWM) concentrations of As from all litter treatments exceeded the maximum contaminant level for drinking water (0.01 mg As L(-1)). Four-year FWM Fe concentrations and runoff losses were greater (P precipitation is temporally variable, evaluating runoff water quality in response to natural precipitation over several years is key to ascertaining the long-term impacts of surface-applied soil amendments like broiler litter.

  3. Segregation and Alteration of Phenolic and Aliphatic Components of Root and Leaf Litter by Detritivores and Microbes

    Science.gov (United States)

    Filley, T. R.; Altmann, J.; Szlavecz, K. A.; Kalbitz, K.; Gamblin, D.; Nierop, K.

    2012-12-01

    The physical and microbial transformation of plant detritus in the litter layer and soil is accompanied by chemical separation of progressively soluble fractions and their movement into the rhizosphere driving subsequent soil processes. We investigated the combined action of specific detritivores, microbial decay, and leaching on the chemical separation of plant aromatic and aliphatic components from root, wood, and leaf tissue using 13C-TMAH thermochemolysis. This method enabled the simultaneous analysis of hydrolyzable tannin and lignin fragments, substituted fatty acids, and condensed tannin composition and revealed process-specific chemical transformations to plant secondary compounds. Long-term incubation and field sampling demonstrated how plant residues are progressively leached of the water soluble, oxidized fragments generated through decay. The residues appeared only slightly altered, in the case of brown rot wood, or enriched in aliphatic fragments, in the case of leaf and root tissue. Water extractable fractions were always selectively dominated by polyphenolics, either as demethylated lignin or tannins, and nearly devoid of aliphatic materials, despite high concentrations in the starting materials. Additionally, for plant materials with high tannin contents, such as pine needles, consumption and passage through some arthropod guts revealed what appeared to be microbially-mediated methylation of phenols, and a loss of tannins in leachates. These findings are indications for an in-situ phenol detoxification mechanism. This research provides important information regarding the links between biochemical decay and the chemical nature of organic matter removed and remaining in the soil profile.

  4. Fossil energy consumption and greenhouse gas emissions, including soil carbon effects, of producing agriculture and forestry feedstocks

    Science.gov (United States)

    Christina E. Canter; Zhangcai Qin; Hao Cai; Jennifer B. Dunn; Michael Wang; D. Andrew Scott

    2017-01-01

    The GHG emissions and fossil energy consumption associated with producing potential biomass sup­ply in the select BT16 scenarios include emissions and energy consumption from biomass production, harvest/collection, transport, and pre-processing activities to the reactor throat. Emissions associated with energy, fertilizers, and...

  5. Composition of organic matter in earthworm casts depending on litter quality

    Science.gov (United States)

    Ellerbrock, R. H.; Gerke, H. H.; Schrader, S.; Leue, M.

    2009-04-01

    Earthworms contribute to decomposition and stabilization of organic matter (OM) in soil. The digestion during intestinal passage inside worms may lead to a change in the composition of OM. It is largely unknown if and how the type of litter the earthworm is feeding on is affecting the OM composition in the casts. Fourier Transform infrared spectroscopy (FTIR) is used to determine the hydrophobic CH- (A) and the hydrophilic CO- (B) functional groups in OM. The objective was to compare the A/B- ratios of litter samples with that of (i) the corresponding casts of the primary decomposer Lumbricus terrestris and (ii) the water contact angles of ground cast samples and at intact cast surfaces. Litter from 10 different plant species including leaves of birch, beech, oak, spruce, pear, mustard and wheat straw (3 replicates) was offered separately to L. terrestris in microcosms containing a Luvisol soil. The OM composition of litter and that of casts, collected from the soil surface after 4-weeks was analyzed with FTIR (DRIFT technique). The A/B ratio of casts was generally increased as compared to that of the soil. For most litter types, the A/B ratio of cast was relatively similar except for casts from birch (Betula pendula) and pear (Pyrus communis) where the OM show a 3-times higher A/B ratio as compared to wheat (Triticum aestivum) or beech (Fagus sylvatica) casts. The higher A/B ratios seem to be related to the relative higher C/N ratios in the casts from Betula pendula and Pyrus communis feeding experiments. The results indicate that digestion of litter by the worm may change OM composition. The assumption that earthworm casts may enrich hydrophobic OM components could be verified only partly. However particulate and soluble OM fractions in the earthworm casts could have contributed to such differentiation.

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

    Directory of Open Access Journals (Sweden)

    Johanna B Boberg

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

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

    Science.gov (United States)

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

    2002-08-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  9. Major mechanisms contributing to the macrofauna-mediated slow down of litter decomposition

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Špaldoňová, A.; Lhotáková, Z.; Cajthaml, T.

    2015-01-01

    Roč. 91, December (2015), s. 23-31 ISSN 0038-0717 Grant - others:GA ČR(CZ) GAP504/12/1288 Program:GA Institutional support: RVO:60077344 Keywords : alkalinization * Bibio * CN ratio * litter decomposition * mineralization * pyrolysis Subject RIV: DF - Soil Science Impact factor: 4.152, year: 2015

  10. Decomposition of Metrosideros polymorpha leaf litter along elevational gradients in Hawaii

    Science.gov (United States)

    Paul G. Scowcroft; Douglas R. Turner; Peter M. Vitousek

    2000-01-01

    We examined interactions between temperature, soil development, and decomposition on three elevational gradients, the upper and lower ends of each being situated on a common lava flow or ash deposit. We used the reciprocal transplant technique to estimate decomposition rates of Metrosideros polymorpha leaf litter during a three-year period at warm...

  11. Impacts of emerald ash borer-induced tree mortality on leaf litter arthropods and exotic earthworms

    Science.gov (United States)

    Michael D. Ulyshen; Wendy S. Klooster; William T. Barrington; Daniel A. Herns

    2011-01-01

    Because leaf litter occurs at the interface between the soil and atmosphere, the invertebrates inhabiting it represent important linkages between above- and below-ground food webs. The responses of these organisms to forest disturbance brought about by invasive species should therefore have far-reaching ecological effects. The purpose of this study was to explore how...

  12. Litter mercury deposition in the Amazonian rainforest.

    Science.gov (United States)

    Fostier, Anne Hélène; Melendez-Perez, José Javier; Richter, Larissa

    2015-11-01

    The objective of this work was to assess the flux of atmospheric mercury transferred to the soil of the Amazonian rainforest by litterfall. Calculations were based on a large survey of published and unpublished data on litterfall and Hg concentrations in litterfall samples from the Amazonian region. Litterfall based on 65 sites located in the Amazon rainforest averaged 8.15 ± 2.25 Mg ha(-1) y(-1). Average Hg concentrations were calculated from nine datasets for fresh tree leaves and ten datasets for litter, and a median concentration of 60.5 ng Hg g(-1) was considered for Hg deposition in litterfall, which averaged 49 ± 14 μg m(-2) yr(-1). This value was used to estimate that in the Amazonian rainforest, litterfall would be responsible for the annual removing of 268 ± 77 Mg of Hg, approximately 8% of the total atmospheric Hg deposition to land. The impact of the Amazon deforestation on the Hg biogeochemical cycle is also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Collecting marine litter during regular fish surveys

    NARCIS (Netherlands)

    Sluis, van der M.T.; Hal, van R.

    2014-01-01

    This report presents the results of the marine litter monitoring on the IBTS survey of 2014 and the BTS survey of 2013. Since 2013 marine litter is collected during the International Bottom Trawl Survey (IBTS) and Dutch Beam Trawl Survey (BTS) following a protocol developed by ICES. The composition

  14. Lead and cadmium contamination and exposure risk assessment via consumption of vegetables grown in agricultural soils of five-selected regions of Pakistan

    Science.gov (United States)

    Rehman, Zahir Ur; Khan, Sardar; Brusseau, Mark L; Shah, Mohammad Tahir

    2017-01-01

    Rapid urbanization and industrialization result in serious contamination of soil with toxic metals such as lead (Pb) and cadmium (Cd), which can lead to deleterious health impacts in the exposed population. This study aimed to investigate Pb and Cd contamination in agricultural soils and vegetables in five different agricultural sites in Pakistan. The metal transfer from soil-to-plant, average daily intake of metals, and health risk index (HRI) were also characterized. The Pb concentrations for all soils were below the maximum allowable limits (MAL 350 mg kg−1) set by the State Environmental Protection Administration of China (SEPA), for soils in China. Conversely, Cd concentrations in the soils exceeded the MAL set by SEPA (0.6 mg kg−) and the European Union (1.5 mg kg−1) by 62-74% and 4-34%, respectively. The mean Pb concentration in edible parts of vegetables ranged from 1.8-11 mgkg−1. The Pb concentrations for leafy vegetables were higher than the fruiting and pulpy vegetables. The Pb concentrations exceeded the MAL (0.3 mg kg−1) for leafy vegetables and the MAL for fruity and rooty/tuber vegetables (0.1 mg kg−1) set by FAO/WHO-CODEX.. Likewise, all vegetables except Pisum sativum (0.12 mg kg−1) contained Cd concentrations that exceeded the MAL set by SEPA. The HRI values for Pb and Cd were vegetable species except Luffa acutangula, Solanum lycopersicum, Benincasa hispada, Momordi charantia, Aesculantus malvaceae, Cucumis sativus, Praecitrullus fistulosus, Brassica oleracea, and Colocasia esculanta for children. Based on these results, consumption of these Pb and Cd contaminated vegetables poses a potential health risk to the local consumers. PMID:27939659

  15. Spatiotemporal dynamics of phosphorus release, oxygen consumption and greenhouse gas emissions after localised soil amendment with organic fertilisers

    DEFF Research Database (Denmark)

    Christel, Wibke; Zhu, Kun; Hoefer, Christoph

    2016-01-01

    processes and fixation in the residue sphere, giving rise to distinct differences in nutrient availability, soil oxygen content and greenhouse gas (GHG) production. In this study we investigated the spatiotemporal dynamics of the reaction of manure solids and manure solids char with soil, focusing...... on their phosphorus (P) availability, as current emphasis on improving societal P efficiency through recycling waste or bio-based fertilisers necessitates a sound understanding of their behaviour. Soil layers amended at a constant P application rate with either pig manure solids or char made from pig manure solids...

  16. Spatiotemporal dynamics of phosphorus release, oxygen consumption and greenhouse gas emissions after localised soil amendment with organic fertilisers

    Energy Technology Data Exchange (ETDEWEB)

    Christel, Wibke [Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Department of Commerce, Industry and Agriculture, Danish Environmental Protection Agency, 1401 Copenhagen C (Denmark); Zhu, Kun [Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Hoefer, Christoph [Rhizosphere Ecology and Biogeochemistry Group, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Kreuzeder, Andreas [Rhizosphere Ecology and Biogeochemistry Group, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Land Salzburg, Natur- und Umweltschutz, Gewerbe (Abteilung 5), Michael-Pacher-Straße 36, 5020 Salzburg (Austria); Santner, Jakob [Rhizosphere Ecology and Biogeochemistry Group, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Division of Agronomy, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Bruun, Sander; Magid, Jakob [Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Jensen, Lars Stoumann, E-mail: lsj@plen.ku.dk [Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark)

    2016-06-01

    Organic fertilisation inevitably leads to heterogeneous distribution of organic matter and nutrients in soil, i.e. due to uneven surface spreading or inhomogeneous incorporation. The resulting localised hotspots of nutrient application will induce various biotic and abiotic nutrient turnover processes and fixation in the residuesphere, giving rise to distinct differences in nutrient availability, soil oxygen content and greenhouse gas (GHG) production. In this study we investigated the spatiotemporal dynamics of the reaction of manure solids and manure solids char with soil, focusing on their phosphorus (P) availability, as current emphasis on improving societal P efficiency through recycling waste or bio-based fertilisers necessitates a sound understanding of their behaviour. Soil layers amended at a constant P application rate with either pig manure solids or char made from pig manure solids were incubated for three weeks between layers of non-amended, P-depleted soil. Spatial and temporal changes in and around the amendment layers were simultaneously investigated in this study using a sandwich sensor consisting of a planar oxygen optode and multi-element diffusive gradients in thin films (DGT) gels, combined with GHG emission measurements. After three weeks of incubation, the soil containing a layer amended with manure solids had a lower overall O{sub 2} content and had emitted significantly more CO{sub 2} than the non-amended control or the char-amended soil. The P availability from manure solids was initially higher than that from the char, but decreased over time, whereas from the char-amended layer P availability increased in the same period. In both treatments, increases in P availability were confined to the amended soil layer and did not greatly affect P availability in the directly adjacent soil layers during the three-week incubation. These results highlight the importance of placing organic P fertilisers close to where the plant roots will grow in

  17. Spatiotemporal dynamics of phosphorus release, oxygen consumption and greenhouse gas emissions after localised soil amendment with organic fertilisers

    International Nuclear Information System (INIS)

    Christel, Wibke; Zhu, Kun; Hoefer, Christoph; Kreuzeder, Andreas; Santner, Jakob; Bruun, Sander; Magid, Jakob; Jensen, Lars Stoumann

    2016-01-01

    Organic fertilisation inevitably leads to heterogeneous distribution of organic matter and nutrients in soil, i.e. due to uneven surface spreading or inhomogeneous incorporation. The resulting localised hotspots of nutrient application will induce various biotic and abiotic nutrient turnover processes and fixation in the residuesphere, giving rise to distinct differences in nutrient availability, soil oxygen content and greenhouse gas (GHG) production. In this study we investigated the spatiotemporal dynamics of the reaction of manure solids and manure solids char with soil, focusing on their phosphorus (P) availability, as current emphasis on improving societal P efficiency through recycling waste or bio-based fertilisers necessitates a sound understanding of their behaviour. Soil layers amended at a constant P application rate with either pig manure solids or char made from pig manure solids were incubated for three weeks between layers of non-amended, P-depleted soil. Spatial and temporal changes in and around the amendment layers were simultaneously investigated in this study using a sandwich sensor consisting of a planar oxygen optode and multi-element diffusive gradients in thin films (DGT) gels, combined with GHG emission measurements. After three weeks of incubation, the soil containing a layer amended with manure solids had a lower overall O_2 content and had emitted significantly more CO_2 than the non-amended control or the char-amended soil. The P availability from manure solids was initially higher than that from the char, but decreased over time, whereas from the char-amended layer P availability increased in the same period. In both treatments, increases in P availability were confined to the amended soil layer and did not greatly affect P availability in the directly adjacent soil layers during the three-week incubation. These results highlight the importance of placing organic P fertilisers close to where the plant roots will grow in order to

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

    Science.gov (United States)

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

    2017-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Zachary L Rinkes

    2013-09-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  1. Study on hydrological functions of litter layers in North China.

    Directory of Open Access Journals (Sweden)

    Xiang Li

    Full Text Available Canopy interception, throughfall, stemflow, and runoff have received considerable attention during the study of water balance and hydrological processes in forested ecosystems. Past research has either neglected or underestimated the role of hydrological functions of litter layers, although some studies have considered the impact of various characteristics of rainfall and litter on litter interception. Based on both simulated rainfall and litter conditions in North China, the effect of litter mass, rainfall intensity and litter type on the maximum water storage capacity of litter (S and litter interception storage capacity (C were investigated under five simulated rainfall intensities and four litter masses for two litter types. The results indicated: 1 the S values increased linearly with litter mass, and the S values of broadleaf litter were on average 2.65 times larger than the S values of needle leaf litter; 2 rainfall intensity rather than litter mass determined the maximum interception storage capacity (Cmax ; Cmax increased linearly with increasing rainfall intensity; by contrast, the minimum interception storage capacity (Cmin showed a linear relationship with litter mass, but a poor correlation with rainfall intensity; 3 litter type impacted Cmax and Cmin ; the values of Cmax and Cmin for broadleaf litter were larger than those of needle leaf litter, which indicated that broadleaf litter could intercepte and store more water than needle leaf litter; 4 a gap existed between Cmax and Cmin , indicating that litter played a significant role by allowing rainwater to infiltrate or to produce runoff rather than intercepting it and allowing it to evaporate after the rainfall event; 5 Cmin was always less than S at the same litter mass, which should be considered in future interception predictions. Vegetation and precipitation characteristics played important roles in hydrological characteristics.

  2. Type of litter determines the formation and properties of charred material during wildfires

    Science.gov (United States)

    Chavez, Bruno; Fonturbel, M. Teresa; Salgado, Josefa; García-Oliva, Felipe; Vega, Jose A.; Merino, Agustin

    2014-05-01

    Wildfire is one of the most important disturbances all over the World, affecting both the amount and composition of forest floor and mineral soils. In comparison with unburnt areas, wildfire-affected forest floor usually shows lower contents of labile C compounds and higher concentrations of recalcitrant aromatic forms. These changes in composition can have important impact on biogeochemical cycles and therefore ecosystem functions. Although burning of different types of litter can lead to different amount and types of pyrogenic compounds, this aspect has not been evaluated yet. The effect of wildfire on SOM composition and stability were evaluated in five major types of non-wood litter in Mediterranean ecosystems: Pinus nigra, E. arborea, P. pinaster, U. europaeus and Eucalyptus globulus. In each of these ecosystems, forest floor samples from different soil burn severities were sampled. Soil burnt severities were based on visual signs of changes in forest floor and deposition of ash. Pyrogenic carbon quality were analysed using elementary analysis, solid-state 13 C nuclear magnetic resonance spectroscopy, Reflectance Infrared Fourier Transform (FTIR) and thermal analysis (simultaneous DSC-TG). The study showed that the different types of litter influenced the formation and characteristics of charred material. They differed in the temperature at which they start to be formed, the amounts of charred compounds and in their chemical composition. The resulting charred materials from the different litter, showed an important variability in the degree of carbonitation/aromatization. Unlike the biochar obtained through pyrolysis of woody sources, which contains exclusively aromatic structures, in the charred material produced in some litter, lignin, cellulose and even cellulose persist even in the high soil burnt severity. Coinciding with increases in aromatic contents, important decreases in atomic H/C and O/C ratios were recorded. However, the values found in some

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

    Science.gov (United States)

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

    2009-07-01

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

  4. Lixiviação de cátions favorecida pela presença de ânions inorgânicos e ácidos orgânicos de baixa massa molecular em solos adubados com camas de aviário Cation leaching favored by inorganic anions and low molecular mass organic acids in soils fertilized with different poultry litters

    Directory of Open Access Journals (Sweden)

    Fabrício de Oliveira Gebrim

    2008-12-01

    textura média, Cl-e NO3-no solo de textura argilosa e, de maneira menos expressiva, pelo efeito acompanhante/complexante dos ácidos orgânicos de baixa massa molecular. No solo argiloso, a percolação de Ca esteve positivamente correlacionada com a concentração dos ácidos málico e oxálico. A concomitante elevada concentração de ácido acético nos percolados de solos tratados com todas as camas sugere que este pode estar favorecendo a lixiviação de bases no solo, provavelmente como ânion acompanhante.The exponential growth in poultry farming in Brazil has led to a parallel increase in the production of manure and poultry litter. The litter generated in this activity used to be largely employed as cattle feed. However, the enactment of a law that bans the use of poultry litter as animal feed intensified its use as organic fertilizer in agriculture. Despite its importance, there are gaps in our knowledge on an adequate use to obtain high plant yields without threatening the environment. One of these gaps is base-leaching in the soil profile as a result of the presence of accompanying anions such as chloride, nitrate and sulphate, and the complexing effect of low molecular mass organic acids. Samples of two Oxisols (a clayey and a sandy loam Red-Yellow Latosol were placed in PVC columns. Each column consisted of five PVC rings (5 cm diameter, 10 cm height fixed to each other with scotch tape. Five types of poultry litter (coffee husks, ground corn cob, rice husk, napier grass and wood shavings were homogenously applied to the soil in the top ring in a dose equivalent to 160 t ha-1 (dry weight basis. The treatments consisted of a 5 x 2 + 1 factorial combination, corresponding to five poultry litter types, two soils with distinct textures, and a control treatment with no poultry litter application, with five repetitions, arranged in a complete randomized block design. Deionized water was applied on top of the columns twice a week, in a total volume corresponding

  5. Experimental analysis of drainage and water storage of litter layers

    Science.gov (United States)

    Guevara-Escobar, A.; Gonzalez-Sosa, E.; Ramos-Salinas, M.; Hernandez-Delgado, G. D.

    2007-06-01

    Leaf litter overlying forested floors are important for erosion control and slope stability, but also reduces pasture growth in silvopastoral systems. Little information exists regarding the value of percolation and storage capacity parameters for litter layers. These estimates are needed for modelling better management practices for leaf litter. Therefore, this work measured the effect of four rainfall intensities: 9.8, 30.2, 40.4 and 70.9 mm h-1 on the hydrological response of layers of three materials: recently senesced poplar leaves, fresh grass and woodchips. Maximum storage (Cmax), defined as the detention of water immediately before rainfall cessation, increased with rainfall intensity. The magnitude of the increment was 0.2 mm between the lowest and highest rainfall intensities. Mean values of Cmax were: 1.27, 1.51, 1.67 and 1.65 mm for poplar leaves; 0.63 0.77, 0.73 and 0.76 for fresh grass and; 1.64, 2.23, 2.21 and 2.16 for woodchips. Drainage parameters were: 9.9, 8.8 and 2.2 mm-1 for poplar, grass and woodchips layers. An underlying soil matrix influenced the drainage flow from poplar leaf layers producing pseudo-Hortonian overland flow, but this occurred only when the rainfall intensity was 40.4 and 70.9 mm h-1 and accounted for 0.4 and 0.8‰ of total drainage. On the other hand, the presence of a poplar leaf layer had a damping effect on the drainage rate from the underlying soil matrix, particularly at intermediate rainfall intensities: 30.2 or 40.4 mm h-1.

  6. Interactions between soil consumption and archaeological heritage: spatial analysis for hydrogeological risk evaluation and urban sprawl in the Tavoliere di Puglia (southern Italy)

    Science.gov (United States)

    Danese, Maria; Gioia, Dario; Masini, Nicola

    2015-04-01

    The soil consumption is a complex phenomenon because it is due to different causes and it also produces many consequences on landscape and related human activities. In low-relief areas of the Mediterranean regions such as the foredeep of the southern Italian chain, alluvional processes and flooding can play an important role on the amount of available soil, especially if one consider the recent climate changes and the recurrence of extreme events. Moreover the uncontrolled growth of the cities is a cause of soil consumption too. Consequently occurrence of flood events in low-relief areas, erosion processes and urban sprawl have a strong impact on agricultural activities and real estate market, but also in research activities about archaeological heritage, with the risk to loose signs of the past. To consider this phenomenon from a spatial point of view is essential to determine protection policies, but it is nowadays still a problem. In this contribution, we performed a detailed study of the geological and geomorphological features of the drainage network of the Tavoliere di Puglia plain in order to investigate erosional and depositional processes. GIS-supported statistical analysis of the drainage network features allow us to compile a map of the hydrogeological hazard [1]. The map has been used as a basic tool useful to consider areal distribution in soil consumption coming from alluvional processes, erosional phenomena and the urban sprawl of the Tavoliere di Puglia plain (Southern Italy). Moreover, we investigated the relationships between sectors of the Tavoliere di Puglia plain featured by higher hydrogeological risk and archaeological sensibility areas, such as places with existing or with not yet discovered archaeological sites or areas characterized by crop marks [2]. [1] Danese M., Gioia D., Biscione M., Masini N. 2014. Spatial Methods for Archaeological Flood Risk: The Case Study of the Neolithic Sites in the Apulia Region (Southern Italy). Computational

  7. Can the trees save the soil? Biomass fuel consumption and dung use as manure in highland Ethiopia

    Energy Technology Data Exchange (ETDEWEB)

    Mekonnen Getnet, Alemu (Addis Ababa Univ., Addis Ababa (Ethiopia)); Koehlin, Gunnar (Goeteborg Univ., Goeteborg (Sweden))

    2008-07-01

    Dung use as manure is limited partly because of dung consumption as fuel. Plantations are assumed to substitute fuelwood for dung as fuel. This study examines the determinants of: (1) decision to use dung as fuel and as manure and (2) woody biomass and dung consumption as fuel. The results suggest roles of credit, factor and product market imperfections and indicate wood and dung are complements as fuel. Implications include the need to focus on the asset poor and use of appropriate stove/energy types in attempts to address issues of limited manure use and significant dung use as fuel

  8. SPATIAL AND VERTICAL DISTRIBUTION OF LITTER AND BELOWGROUND CARBON IN A BRAZILIAN CERRADO VEGETATION

    Directory of Open Access Journals (Sweden)

    Vinícius Augusto Morais

    2017-03-01

    Full Text Available Forest ecosystems contribute significantly to store greenhouse gases. This paper aimed to investigate the spatial and vertical distribution of litter, roots, and soil carbon. We obtained biomass and carbon of compartments (litter, roots, and soil in a vegetation from Cerrado biome, state of Minas Gerais, Brazil. The materials were collected in 7 0.5 m² sub-plots randomly allocated in the vegetation. Root and soil samples were taken from five soil layers across the 0-100 cm depth. Roots were classified into three diameter classes: fine (10 mm roots. The carbon stock was mapped through geostatistical analysis. The results indicated averages of soil carbon stock of 208.5 Mg.ha-1 (94.6% of the total carbon, root carbon of 6.8 Mg.ha-1 (3.1%, and litter of 5 Mg.ha-1 (2.3%. The root carbon was majority stored in coarse roots (83%, followed by fine (10%, and medium roots (7%. The largest portion of fine roots concentrated in the 0-10 cm soil depth, whereas medium and coarse roots were majority in the 10-20 cm depth. The largest portion of soil (53% and root (85% carbon were stored in superficial soil layers (above 40 cm. As conclusion, the carbon spatial distribution follows a reasonable trend among the compartments. There is a vertical relation of which the deeper the soil layer, the lower the soil and root carbon stock. Excepting the shallowest layer, coarse roots held the largest portion of carbon across the evaluated soil layers.

  9. Skin interface pressure on the NATO litter.

    Science.gov (United States)

    Bridges, Elizabeth J; Schmelz, Joseph O; Mazer, Stephen

    2003-04-01

    The NATO litter serves as a transport device and hospital bed during all types of operations. Little is known about the skin interface pressure on this litter. The purpose of this study was to determine whether various types of padding on the litter and body position affect the peak skin interface pressure and the total body area exposed to interface pressures above 30 mm Hg at different body areas. Thirty-two subjects participated. A repeated measures design was used. The surface effect was statistically significant for all peak pressure and surface area analyses (repeated-measures analysis of variance, p patients if feasible. Preventive measures (turning, elevating the heels) are still required.

  10. An Approach to Litter Generation and Littering Practices in a Mexico City Neighborhood

    Directory of Open Access Journals (Sweden)

    Cecilia E. Muñoz-Cadena

    2012-08-01

    Full Text Available Urban litter is generated by human societies everywhere. Some litter is recyclable waste. In this study, the acronym RMSW is used to refer to recyclable municipal solid waste generated in streets. Public attitude towards RMSW generation, generators’ perceptions, and quantification of RMSW in streets were examined in a Mexico City neighborhood, where litter presence causes major environmental problems affecting the population year after year. Interviews with neighborhood residents and item counts were carried out from 2010 to 2011. In all, 58% of interviewees reported generating RMSW at variable frequencies while 42% said they did not generate this kind of waste. Laziness, lack of vigilance by municipal authorities, no litter bins in streets, and imitation were the main causes identified by interviewees as reasons for littering. Potential litter generators may be of any age, educational level or income. Interviewees’ perception of RMSW generation was compared with item counts in the neighborhood studied.

  11. Effect of biotic lignin decomposition on the fate of radiocesium-contaminated plant litter

    Energy Technology Data Exchange (ETDEWEB)

    Hashida, Shin-nosuke; Yoshihara, Toshihiro [Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Abiko 1646, Abiko-shi, Chiba (Japan)

    2014-07-01

    Fungi are the most important components in the fate of radionuclides deposited in forests following the Fukushima nuclear accident. Pruned woody parts and litter contain a considerable amount of radiocesium. Studies that focused on the migration of radiocesium have demonstrated that its ecological half-life is lower in the humus layer than in the deeper soil zone, suggesting a substantial contribution of litter decomposition on the mobilization of radiocesium. Furthermore, white-rot fungi appear to play a key role in the mobilization of radiocesium because they are the primary source of enzymes necessary to degrade the litter organic matter. Cell walls are the primary component of plant litter; they are composed of cellulose, hemi-cellulose, and lignin. Although cellulose is the most abundant organic compound in litter, the strength of the cell wall is limited by rigid hemi-cellulose complexes that protect the surrounding cellulose microfibrils. In the cell wall, lignin fills the spaces between cellulose and hemi-cellulose; thus, the biotic degradation of lignin could be considered a primary step in litter decomposition. The contribution of the amount of lignin on the fate of radiocesium has not been identified, which limits the possibility of predicting the effect of the bacterial community structure that determines the biodegradation activity of lignin on the vertical migration of radiocesium. Here, we directly addressed the role of lignin as controller of the distribution of radiocesium in soil-ecosystems. Radiocesium-contaminated litter samples were collected with traps set under the target stands, i.e., Japanese flowering cherry trees (Prunus x yedoensis cv. Somei-Yoshino) and Japanese cedars (Cryptomeria japonica) at Abiko (Laboratory of Environmental Science, CRIEPI) located approximately 200 km SSW from the Fukushima Daiichi Nuclear Power Plant in 2011. The litter samples were inoculated with white-rot fungi having ligno-celluloses-degrading activity, i

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

    Science.gov (United States)

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

    2016-03-01

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

  13. Preliminary economic analysis of poultry litter gasification option with a simple transportation model.

    Science.gov (United States)

    Sheth, Atul C; English, Jennifer

    2005-04-01

    Several environmental issues are related to the disposal of poultry litter. In an effort to provide a more environmentally friendly alternative than landfill disposal or spreading as a soil amendment, work has been carried out previously at the University of Tennessee Space Institute (UTSI). This past UTSI work was concentrated on developing a catalytic steam gasification concept to produce energy from poultry litter. In the past UTSI studies, preliminary design and economics for a stationary, centralized gasification plant capable of processing approximately 100 ton/day of poultry litter were developed. However, in this preliminary design the economic impact of transporting litter to a centralized gasification plant location was not addressed. To determine the preliminary impact of transporting the poultry litter on the overall economics of this energy conversion plant design, a simple transportation model was developed. This model was used in conjunction with the earlier plant design prepared at UTSI to determine the economic feasibility of a centralized, stationary poultry litter gasification plant. To do so, major variables such as traveling distance, plant feed rate (or capacity), fluctuations in the sales price of the product gas (that means value of the energy), population density of poultry farms, impact of tipping fees, and cost of litter were varied. The study showed that for plant with a capacity of 1000 ton/day to be able to withstand several changes in economic conditions and sustain itself, the poultry farm density would need to be approximately 0.3 houses/mi2. Smaller plants would need either a higher energy price or some kind of subsidy to be economically feasible.

  14. Soil

    International Nuclear Information System (INIS)

    Freudenschuss, A.; Huber, S.; Riss, A.; Schwarz, S.; Tulipan, M.

    2002-01-01

    Environmental soil surveys in each province of Austria have been performed, soils of about 5,000 sites were described and analyzed for nutrients and pollutants, the majority of these data are recorded in the soil information system of Austria (BORIS) soil database, http://www.ubavie.gv.at/umweltsituation/boden/boris), which also contains a soil map of Austria, data from 30 specific investigations mainly in areas with industry and results from the Austria - wide cesium investigation. With respect to the environmental state of soils a short discussion is given, including two geographical charts, one showing which sites have soil data (2001) and the other the cadmium distribution in top soils according land use (forest, grassland, arable land, others). Information related to the soil erosion, Corine land cover (Europe-wide land cover database), evaluation of pollutants in soils (reference values of As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Se, Pb, Tl, Va, Zn, AOX, PAH, PCB, PCDD/pcdf, dioxin), and relevant Austrian and European standards and regulations is provided. Figs. 2, Tables 4. (nevyjel)

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

    Science.gov (United States)

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

    2012-01-01

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

  16. Pengaruh Berbagai Jenis Bahan Litter terhadap Kualitas Litter Broiler Fase Finisher di Closed House

    OpenAIRE

    Tiwi Metasari; Dian Septinova; Veronica Wanniatie

    2014-01-01

    The aim of this research was to 1) determine the effect of the use of rice husk, wood shavings,rice straw as litter material on litter quality for broiler during the finisher phase in closed house, 2)determine the best type of litter material on litter quality for broiler during the finisher phase in closedhouse. The duration of the research was 26 days. The research was started from 15 April to 10 May2014 in the closed house owned by PT. Rama Jaya Lampung Krawang Sari Village, the District o...

  17. Performance, carcass yield and litter quality of broilers raised on litters treated with micro-organisms

    OpenAIRE

    Cruz,Dayane Prado da; Otutumi,Luciana Kazue; Piau Júnior,Ranulfo; Cervantes,Rodrigo Panucci; Mezalira,Taniara Suelen; Gerônimo,Edson

    2013-01-01

    The present paper aimed at evaluating the effect of adding beneficial micro-organisms to the litters on litter quality, performance and carcass yield for broilers. A total of 240 one-day chicks were used, and randomly distributed in blocks with four treatments and four replications. The following treatments were carried out in the housing: Treatment 1 – Control with weekly spraying of water on the litters; Treatment 2 – Litter treated with a mixture of inoculated and fermented meal by micro-o...

  18. Arst on patsiendi poolel / Galina Litter

    Index Scriptorium Estoniae

    Litter, Galina, 1956-

    2006-01-01

    Naistearst Galina Litter seadusest, mis lubab alaealistel ilma vanema nõusolekuta aborti teha. Vastus artiklile : Varro Vooglaid. Vanemate vastutus - kas reaalne või paljasõnaline? // Õpetajate Leht (2006) 13. okt., lk. 1, 7

  19. Litter quality and its response to water level drawdown in boreal peatlands at plant species and community level

    Science.gov (United States)

    Straková, Petra; Anttila, Jani; Spetz, Peter; Kitunen, Veikko; Tapanila, Tarja; Laiho, Raija

    2010-05-01

    drawdown, compared to respective values of 394-658, 5.6-9.3, 0.22-24.4, 161-293 and 44-81 for the pristine conditions. The direct effects of WL drawdown on litter quality were overruled by the indirect effects via changes in vegetation composition. The short-term (reflecting transient conditions) and long-term (reflecting longer-lasting situation of already adapted ecosystem) effects were very different. Our results imply that the long-term effects will strongly affect the soil properties and C cycle of peatlands.

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

    Science.gov (United States)

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

    2016-12-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  2. The role of organic matter as a source of nitrogen in Douglas-fir forest soils.

    Science.gov (United States)

    Robert F. Tarrant

    1948-01-01

    The organic material supplied the forest soil by deposits of needles, deadwood and roots, and soil insect remains, decomposes to form humus, defined as the plant and animal residues of the soil, fresh surface litter excluded, which are undergoing evident decomposition (2). This decomposition is necessary before the nutrient elements contained in the organic litter can...

  3. Tea polyphenols dominate the short-term tea (Camellia sinensis) leaf litter decomposition*

    Science.gov (United States)

    Fan, Dong-mei; Fan, Kai; Yu, Cui-ping; Lu, Ya-ting; Wang, Xiao-chang

    2017-01-01

    Polyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months. The release patterns of nitrogen, potassium, calcium, and magnesium were also determined. The decomposition pattern of tea leaf litter could be described by a two-phase decomposition model, and the polyphenol/N ratio effectively regulated the degradation process. Most of the catechins decreased dramatically within two months; gallic acid (GA), catechin gallate (CG), and gallocatechin (GC) were faintly detected, while others were outside the detection limits by the end of the experiment. These results demonstrated that tea polyphenols transformed quickly and catechins had an effect on the individual conversion rate. The nutrient release pattern was different from other plants which might be due to the existence of tea polyphenols. PMID:28124839

  4. Microbial functional diversity associated with plant litter decomposition along a climatic gradient.

    Science.gov (United States)

    Sherman, Chen; Steinberger, Yosef

    2012-08-01

    Predicted changes in climate associated with increased greenhouse gas emissions can cause increases in global mean temperature and changes in precipitation regimes. These changes may affect key soil processes, e.g., microbial CO(2) evolution and biomass, mineralization rates, primary productivity, biodiversity, and litter decomposition, which play an important role in carbon and nutrient cycling in terrestrial ecosystems. Our study examined the changes in litter microbial communities and decomposition along a climatic gradient, ranging from arid desert to humid Mediterranean regions in Israel. Wheat straw litter bags were placed in arid, semi-arid, Mediterranean, and humid Mediterranean sites. Samples were collected seasonally over a 2-year period in order to evaluate mass loss, litter moisture, C/N ratio, bacterial colony-forming units (CFUs), microbial CO(2) evolution and biomass, microbial functional diversity, and catabolic profile. Decomposition rate was the highest during the first year of the study at the Mediterranean and arid sites. Community-level physiological profile and microbial biomass were the highest in summer, while bacterial CFUs were the highest in winter. Microbial functional diversity was found to be highest at the humid Mediterranean site, whereas substrate utilization increased at the arid site. Our results support the assumption that climatic factors control litter degradation and regulate microbial activity.

  5. Tea polyphenols dominate the short-term tea (Camellia sinensis) leaf litter decomposition.

    Science.gov (United States)

    Fan, Dong-Mei; Fan, Kai; Yu, Cui-Ping; Lu, Ya-Ting; Wang, Xiao-Chang

    Polyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months. The release patterns of nitrogen, potassium, calcium, and magnesium were also determined. The decomposition pattern of tea leaf litter could be described by a two-phase decomposition model, and the polyphenol/N ratio effectively regulated the degradation process. Most of the catechins decreased dramatically within two months; gallic acid (GA), catechin gallate (CG), and gallocatechin (GC) were faintly detected, while others were outside the detection limits by the end of the experiment. These results demonstrated that tea polyphenols transformed quickly and catechins had an effect on the individual conversion rate. The nutrient release pattern was different from other plants which might be due to the existence of tea polyphenols.

  6. Soils

    International Nuclear Information System (INIS)

    Freudenschuss, A.; Huber, S.; Riss, A.; Schwarz, S.; Tulipan, M.

    2001-01-01

    For Austria there exists a comprehensive soil data collection, integrated in a GIS (geographical information system). The content values of pollutants (cadmium, mercury, lead, copper, mercury, radio-cesium) are given in geographical charts and in tables by regions and by type of soil (forests, agriculture, greenland, others) for the whole area of Austria. Erosion effects are studied for the Austrian region. Legal regulations and measures for an effective soil protection, reduction of soil degradation and sustainable development in Austria and the European Union are discussed. (a.n.)

  7. Fuel consumption of tractor for different soil types in semi-arid regions; Consumo de combustivel de um trator agricola para diferentes tipos de solo em regioes semi-aridas

    Energy Technology Data Exchange (ETDEWEB)

    Montanha, Gustavo K. [Universidade Estadual Paulista (FAC/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Engenharia Rural], E-mail: gmontanha@fca.unesp.br; Guerra, Saulo P.S. [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Dept. de Gestao e Tecnologia Agroindustrial; Andrade-Sanchez, Pedro; Heun, John [The University of Arizona, Maricopa, AZ (United States); Monteiro, Leonardo A. [The University of Arizona (MAC/UA), Maricopa, AZ (United States). Maricopa Agricultural Center

    2010-07-01

    The appropriate use of agricultural machinery enables greater operational efficiency and higher productivity for the farmer. Some factors such as soil type can influence the fuel consumption, one of the biggest costs. This study aimed to compare the fuel consumption of a tractor operating in two different conditions of soil in semi-arid regions. The area used for testing is located in the city of Maricopa, in Arizona, belonging to 'The University of Arizona'. The area 1 is classified as sandy clay loam soil (52% sand, 35% clay, 13% silt). The area 2 is classified as a sandy loam soil (71% sand, 12% clay and 17% silt). The tractor 4 x 2 TDA, with 88 kw (120 hp) engine power equipped with auto pilot system and an implement for tillage were used in the experiment. A data acquisition system was installed in the tractor to collect the data generated by the GPS and fuel consumption sensor. The results showed significant statistical difference in fuel consumption between soil textures. (author)

  8. Living roots effect on 14C-labelled root litter decomposition

    International Nuclear Information System (INIS)

    Billes, G.; Bottner, P.

    1981-01-01

    Wheat was 14 C-labelled by cultivation on soil in pots, from seedling to maturity, in a chamber with constant CO 2 and 14 CO 2 levels. The 14 C-distribution was constant amongst the aerial parts, the roots and the soil in the whole pots. After cutting the plant tops, the pots were dried without disturbing the soil and root system. The pots were then incubated under controlled humidity and temperature conditions for 62 days. In the same time a second wheat cultivation was grown on one half of the pots in normal atmosphere without plant cultivation. The purpose of the work is to study the effect of living roots on decomposition of the former 14 C labelled roots litter. The CO 2 and the 14 CO 2 released from the soil were continuously measured. On incubation days 0, 18, 33 and 62, the remaining litter was separated from soil, and the organic matter was fractionated by repeated hydrolysis and NaOH extraction. Root litter disappeared faster when living roots were present than in bare soil. The accumulation and mineralization rates of humified components in soil followed two stages. While the roots of second wheat cultivation grew actively (until earing), the strong acid hydrolysable components accumulated in larger amount than in the case of bare soil. After earing, while roots activity was depressed, these components were partly mineralized and the 14 CO 2 release was then higher with plants than with bare soil. The humification and mineralization rate were related with living plant phenology stages. (orig.)

  9. Effects of flooding-induced N2O production, consumption and emission dynamics on the annual N2O emission budget in wetland soil

    DEFF Research Database (Denmark)

    Jørgensen, Christian Juncher; Elberling, Bo

    2012-01-01

    during mid-summer when the WL was at its seasonally lowest counterbalancing ~6.4% of the total annual net N2O emission budget. Main surface emission periods of N2O were observed when the water level and associated peaks in subsurface N2O concentrations were gradually decreasing to soil depths down to 40...... production and consumption capacities where >500 nmol N2O cm-3 were sequentially produced and consumed in less than 24 hrs. It is concluded that a higher future frequency of flooding induced N2O emissions will have a very limited effect on the net annual N2O emission budget as long as NO3- availability...

  10. Year-round poultry litter decomposition and N, P, K and Ca release

    Directory of Open Access Journals (Sweden)

    Christiano Santos Rocha Pitta

    2012-06-01

    Full Text Available Poultry litter is an important nutrient source in agriculture, although little information is available regarding its decomposition rate and nutrient release. To evaluate these processes, poultry litter (PL was applied to the soil to supply 100, 200 and 300 kg ha-1 N contained in 4,953, 9,907 and 14,860 kg ha-1 PL, respectively. The litter bag technique was used to monitor the process of decomposition and nutrient release from the litter. These bags were left on the soil surface and collected periodically (after 15, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, and 365 days. The dry matter (DM loss was highest (35 % after the first 30 days of field incubation. The highest nutrient release occurred in the first 60 days on the field, when 40, 34, 91, and 39 %, respectively, of N, P, K, and Ca of the initial PL dry matter (4,860 kg ha-1 was already released to the soil. In absolute terms, these percentages represent 40, 23, 134, and 69 kg ha-1 of N, P, K, and Ca and these values doubled and tripled as the PL fertilization rates increased to 9,907 and 14,860 kg ha-1, respectively. After one year of field incubation, the residual contents in the litter were 27, 15, 18 and 30 % of the initial DM , and N, P and Ca, respectively. The release rate of K was the fastest and 91 % of the K had been released from the PL after 30 days of field incubation.

  11. Leaf litter arthropod responses to tropical forest restoration.

    Science.gov (United States)

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

    2016-08-01

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

  12. Dissipation of 17β-estradiol in composted poultry litter.

    Science.gov (United States)

    Hakk, Heldur; Sikora, Lawrence

    2011-01-01

    The excreted estrogen rate of all livestock in the United States is estimated at 134 kg d. The influence of manure treatment on the fate of estrogens is critical in deciding the recycling of over 300 million dry tons of livestock produced annually. The effects of two common manure management practices, heated composting and ambient temperature decomposition, on the fate of 17β-estradiol in poultry litter were determined. A mixture of poultry litter, wood chips, and straw was amended with [C]17β-estradiol and allowed to undergo decomposition with a laboratory-scale heated composter (HC) or room temperature incubation (RTI) for 24 d. Radiolabel in the finished products was fractionated into water-extractable, acetone-extractable, nonextractable, and mineralized fractions. Total 17β-estradiol radioactive residues in the HC and RTI ( = 2) treatments were not different ( > 0.05), except that statistically less 17β-estradiol was mineralized to CO during HC than RTI (1.1 vs. 10.0% for HC and RTI, respectively). Estrone was the major degradation product in extracts of HC and RTI treatments as determined by liquid chromatography/mass spectrometry analyses. The nonextractable residues indicated no quantitative differences among the humins between the treatments. An estimated 3% of the fortified estrogenicity remained after HC treatment, and 15% of the fortified estrogenicity remained after RTI treatment. If reduction of water-removable, biologically active 17β-estradiol is the treatment goal, then HC treatment would be slightly preferred over ambient temperature degradation. However, unmanaged, ambient temperature litter piles are less costly and time consuming for food animal producers and result in greater mineralization and similar immobilization of estradiol. by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  13. The Effect of Litter Position on Ultraviolet Photodegradation of Standing Dead Litter

    Science.gov (United States)

    Lin, Y.; King, J. Y.

    2012-12-01

    In dryland ecosystems, models incorporating only biotic mechanisms usually underestimate the decay rate of plant litter. Photodegradation, an abiotic process through which solar radiation breaks down organic matter, has recently been proposed as an important pathway of litter decomposition in dryland ecosystems, accounting for as much as 25 to 60% of mass loss. However, it remains unclear what factors control the relative importance of photodegradation and biotic decomposition. It is hypothesized that this balance is affected by the location of litter within the litter layer (or thatch): in upper layers of thatch, photodegradation is significant because litter is exposed to sunlight; in lower layers where litter is strongly shaded, photodegradation is negligible compared to biotic decomposition. In August 2011, a field experiment was initiated at the University of California's Sedgwick Reserve, Santa Ynez, CA, in order to understand how ultraviolet (UV) radiation and litter position within the thatch affect litter decomposition. Two levels of UV radiation (280-400 nm) are achieved by screens: "UV-Pass" (transmitting > 81% of UV radiation) and "UV-Block" (transmitting plant litter was 19% higher in UV-Pass than in UV-Block treatments, but there was no difference at the top of the thatch. Because lignin is recalcitrant to biotic decomposition, a greater proportion of lignin could remain in litter where biotic decomposition was faster. Therefore, the pattern of lignin concentration supports the interpretation that greater biotic decomposition occurred under the UV-Pass treatment. Regardless of UV manipulation, litter mass loss was 25% faster at the top of the thatch than at the bottom. Litter at the top of the thatch also had 6% higher cellulose concentration and 13% lower lignin concentration than at the bottom of the thatch after 9 months of field exposure. Photodegradation (by UV and visible light) likely contributed more to decomposition at the top of the thatch

  14. Earthworms and litter management contributions to ecosystem services in a tropical agroforestry system.

    Science.gov (United States)

    Fonte, Steven J; Six, Johan

    2010-06-01

    The development of sustainable agricultural systems depends in part upon improved management of non-crop species to enhance the overall functioning and provision of services by agroecosystems. To address this need, our research examined the role of earthworms and litter management on nutrient dynamics, soil organic matter (SOM) stabilization, and crop growth in the Quesungual agroforestry system of western Honduras. Field mesocosms were established with two earthworm treatments (0 vs. 8 Pontoscolex corethrurus individuals per mesocosm) and four litter quality treatments: (1) low-quality Zea mays, (2) high-quality Diphysa robinioides, (3) a mixture of low- and high-quality litters, and (4) a control with no organic residues applied. Mesocosms included a single Z. mays plant and additions of 15N-labeled inorganic nitrogen. At maize harvest, surface soils (0-15 cm) in the mesocosms were sampled to determine total and available P as well as the distribution of C, N, and 15N among different aggregate-associated SOM pools. Maize plants were divided into grain and non-grain components and analyzed for total P, N, and 15N. Earthworm additions improved soil structure as demonstrated by a 10% increase in mean weight diameter and higher C and N storage within large macro-aggregates (>2000 microm). A corresponding 17% increase in C contained in micro-aggregates within the macro-aggregates indicates that earthworms enhance the stabilization of SOM in these soils; however, this effect only occurred when organic residues were applied. Earthworms also decreased available P and total soil P, indicating that earthworms may facilitate the loss of labile P added to this system. Earthworms decreased the recovery of fertilizer-derived N in the soil but increased the uptake of 15N by maize by 7%. Litter treatments yielded minimal effects on soil properties and plant growth. Our results indicate that the application of litter inputs and proper management of earthworm populations can have

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

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    Špoljar Andrija

    2014-08-01

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

  16. ECONOMIC RETURNS FROM REDUCING POULTRY LITTER PHOSPHORUS WITH MICROBIAL PHYTASE

    OpenAIRE

    Bosch, Darrell J.; Zhu, Minkang; Kornegay, Ervin T.

    1997-01-01

    Requiring that crop applications of manure be based on phosphorus content (P-standard) could increase poultry litter disposal costs. Microbial phytase reduces litter P content and could reduce litter disposal costs under a P-standard. For a representative Virginia turkey farm, phytase costs $2,500 and could increase value of litter used for fertilizer on the turkey farm by $390 and reduce supplemental P feed costs by $1,431. Based on assumed litter demand and supply, estimated litter export p...

  17. Effect of Quail Litter Biochar on Productivity of Four New Physic Nut Varieties Planted in Cadmium-Contaminated Soil Efecto del Biocarbón de Cama de Codorniz en la Productividad de Cuatro Variedades Nuevas de Jatrofa Plantadas en Suelo Contaminado con Cadmio

    Directory of Open Access Journals (Sweden)

    Tawadchai Suppadit

    2012-03-01

    Full Text Available Biochar can improve soil structure and water retention, enhance nutrient availability and retention, ameliorate acidity, and reduce heavy metal toxicity to plant roots. In this study, a basin experiment was conducted to investigate the effects of quail litter biochar (QLB on the availability of Cd to physic nut (Jatropha curcas L. plants. QLB was applied to the soil in which four new physic nut varieties (Takfa, Doi Saket, Lao, and Rayong in factorial combinations at four levels (0, 5, 10, and 15 g kg-1 soil to soil that contained 60.8 mg Cd kg-1. After transplanting plant height and canopy radius were measured every 2-mo and the number of leaves and branches at 6-mo, while yield components and Cd residues were measured at 8-mo intervals. The contaminated soil was analyzed for chemical characteristics, nutrients, and Cd residue after the plant harvest. The addition of QLB to soil caused a significant increase in the soil's growth potential and physic nut yield components (P Se ha visto que el biocarbón mejora la estructura del suelo y la retención de agua, mejora la disponibilidad y la retención de nutrientes, controla la acidez y reduce la toxicidad de metales pesados en las raíces de las plantas. En este trabajo se investiga el uso de biocarbón de cama de codorniz (QLB en la disponibilidad de Cd para la planta de jatrofa (Jatropha curcas L. en un estudio de laboratorio. Se realiza una combinación factorial con cuatro variedades nuevas de jatrofa (Takfa, Doi Saket, Lao y Rayong sobre cuatro proporciones de QLB a 0, 5, 10, y 15 g kg-1 añadidos por separado a suelo contaminado con 60,8 mg Cd kg-1. Tras el trasplante se midió la altura de la planta y la cubierta vegetal cada 2 meses, el número de hojas y ramas a los 6 meses y los parámetros de rendimiento así como el residuo de Cd a los 8 meses. A continuación, tras la cosecha de la planta, se analizaron las características químicas, nutrientes y residuo de Cd en el suelo contaminado

  18. Carbon dynamics in peatlands under changing hydrology. Effects of water level drawdown on litter quality, microbial enzyme activities and litter decomposition rates

    Energy Technology Data Exchange (ETDEWEB)

    Strakova, P.

    2010-07-01

    Pristine peatlands are carbon (C) accumulating wetland ecosystems sustained by a high water level (WL) and consequent anoxia that slows down decomposition. Persistent WL drawdown as a response to climate and/or land-use change directly affects decomposition: increased oxygenation stimulates decomposition of the 'old C' (peat) sequestered under prior anoxic conditions. Responses of the 'new C' (plant litter) in terms of quality, production and decomposability, and the consequences for the whole C cycle of peatlands are not fully understood. WL drawdown induces changes in plant community resulting in shift in dominance from Sphagnum and graminoids to shrubs and trees. There is increasing evidence that the indirect effects of WL drawdown via the changes in plant communities will have more impact on the ecosystem C cycling than any direct effects. The aim of this study is to disentangle the direct and indirect effects of WL drawdown on the 'new C' by measuring the relative importance of (1) environmental parameters (WL depth, temperature, soil chemistry) and (2) plant community composition on litter production, microbial activity, litter decomposition rates and, consequently, on the C accumulation. This information is crucial for modelling C cycle under changing climate and/or land-use. The effects of WL drawdown were tested in a large-scale experiment with manipulated WL at two time scales and three nutrient regimes. Furthermore, the effect of climate on litter decomposability was tested along a north-south gradient. Additionally, a novel method for estimating litter chemical quality and decomposability was explored by combining Near infrared spectroscopy with multivariate modelling. WL drawdown had direct effects on litter quality, microbial community composition and activity and litter decomposition rates. However, the direct effects of WL drawdown were overruled by the indirect effects via changes in litter type composition and

  19. Natural zeolites in diet or litter of broilers.

    Science.gov (United States)

    Schneider, A F; Almeida, D S De; Yuri, F M; Zimmermann, O F; Gerber, M W; Gewehr, C E

    2016-04-01

    This study aims to analyse the influence of adding natural zeolites (clinoptilolite) to the diet or litter of broilers and their effects on growth performance, carcass yield and litter quality. Three consecutive flocks of broilers were raised on the same sawdust litter, from d 1 to d 42 of age, and distributed in three treatments (control with no added zeolites, addition of 5 g/kg zeolite to diet and addition of 100 g/kg zeolites to litter). The addition of zeolites to the diet or litter did not affect growth performance or carcass yield. The addition of zeolites to the diet did not influence moisture content of the litter, ammonia volatilisation was reduced only in the first flock and pH of litter was reduced in the second and third flock. However, the addition of zeolites to the litter reduced moisture content, litter pH and ammonia volatilisation in all flocks analysed. The addition of 5 g/kg zeolite to the diet in three consecutive flocks was not effective in maintaining litter quality, whereas the addition of 100 g/kg natural zeolites to sawdust litter reduced litter moisture and ammonia volatilisation in three consecutive flocks raised on the same litter.

  20. Dual role of lignin in plant litter decomposition in terrestrial ecosystems.

    Science.gov (United States)

    Austin, Amy T; Ballaré, Carlos L

    2010-03-09

    Plant litter decomposition is a critical step in the formation of soil organic matter, the mineralization of organic nutrients, and the carbon balance in terrestrial ecosystems. Biotic decomposition in mesic ecosystems is generally negatively correlated with the concentration of lignin, a group of complex aromatic polymers present in plant cell walls that is recalcitrant to enzymatic degradation and serves as a structural barrier impeding microbial access to labile carbon compounds. Although photochemical mineralization of carbon has recently been shown to be important in semiarid ecosystems, litter chemistry controls on photodegradative losses are not understood. We evaluated the importance of litter chemistry on photodegradation of grass litter and cellulose substrates with varying levels of lignin [cellulose-lignin (CL) substrates] under field conditions. Using wavelength-specific light attenuation filters, we found that light-driven mass loss was promoted by both UV and visible radiation. The spectral dependence of photodegradation correlated with the absorption spectrum of lignin but not of cellulose. Field incubations demonstrated that increasing lignin concentration reduced biotic decomposition, as expected, but linearly increased photodegradation. In addition, lignin content in CL substrates consistently decreased in photodegradative incubations. We conclude that lignin has a dual role affecting litter decomposition, depending on the dominant driver (biotic or abiotic) controlling carbon turnover. Under photodegradative conditions, lignin is preferentially degraded because it acts as an effective light-absorbing compound over a wide range of wavelengths. This mechanistic understanding of the role of lignin in plant litter decomposition will allow for more accurate predictions of carbon dynamics in terrestrial ecosystems.

  1. Control of climate and litter quality on leaf litter decomposition in different climatic zones.

    Science.gov (United States)

    Zhang, Xinyue; Wang, Wei

    2015-09-01

    Climate and initial litter quality are the major factors influencing decomposition rates on large scales. We established a comprehensive database of terrestrial leaf litter decomposition, including 785 datasets, to examine the relationship between climate and litter quality and evaluate the factors controlling decomposition on a global scale, the arid and semi-arid (AS) zone, the humid middle and humid low (HL) latitude zones. Initial litter nitrogen (N) and phosphorus (P) concentration only increased with mean annual temperature (MAT) in the AS zone and decreased with mean annual precipitation (MAP) in the HL zone. Compared with nutrient content, MAT imposed less effect on initial litter lignin content than MAP. MAT were the most important decomposition driving factors on a global scale as well as in different climatic zones. MAP only significantly affected decomposition constants in AS zone. Although litter quality parameters also showed significant influence on decomposition, their importance was less than the climatic factors. Besides, different litter quality parameters exerted significant influence on decomposition in different climatic zones. Our results emphasized that climate consistently exerted important effects on decomposition constants across different climatic zones.

  2. Influence of temperature and organic matter content on soil respiration in a deciduous oak forest

    Directory of Open Access Journals (Sweden)

    Zsolt Kotroczó

    2014-12-01

    Full Text Available The increasing temperature enhances soil respiration differently depend on different conditions (soil moisture, soil organic matter, the activity of soil microbes. It is an essential factor to predicting the effect of climate change on soil respiration. In a temperate deciduous forest (North-Hungary we added or removal aboveground and belowground litter to determine total soil respiration. We investigated the relationship between total soil CO2 efflux, soil moisture and soil temperature. Soil CO2 efflux was measured at each plot using chamber based soil respiration measurements. We determined the temperature sensitivity of soil respiration. The effect of doubled litter was less than the effect of removal. We found that temperature was more influential in the control of soil respiration than soil moisture in litter removal treatments, particularly in the wetter root exclusion treatments (NR and NI (R2: 0.49-0.61. Soil moisture (R2: 0.18-0.24 and temperature (R2: 0.18-0.20 influenced soil respiration similarly in treatments, where soil was drier (Control, Double Litter, Double Wood. A significantly greater increase in temperature induced higher soil respiration were significantly higher (2-2.5-fold in root exclusion treatments, where soil was wetter throughout the year, than in control and litter addition treatments. The highest bacterial and fungal count was at the DL treatment but the differences is not significant compared to the Control. The bacterial number at the No Litter, No Root, No Input treatment was significantly lower at the Control. Similar phenomenon can be observed at the fungal too, but the differences are not significant. The results of soil respiration suggest that the soil aridity can reduce soil respiration increases with the temperature increase. Soil bacterial and fungal count results show the higher organic matter content and soil surface cover litter favors the activity.

  3. Enriquecimento artificial da diversidade de espécies em reflorestamentos: análise preliminar de dois métodos, transferência de serapilheira e semeadura direta - DOI: 10.4025/actascibiolsci.v30i2.3629 Artificial enrichment of species diversity in restoration areas: preliminary test of two techniques, soil and litter transference and direct seeding - DOI: 10.4025/actascibiolsci.v30i3.3629

    Directory of Open Access Journals (Sweden)

    Alba Lúcia Cavalheiro

    2008-05-01

    Full Text Available Em paisagens fragmentadas, a colonização por novas espécies em reflorestamentos e capoeiras é dificultada pelas grandes distâncias das fontes de propágulos e a alta degradação do solo. Neste contexto, o enriquecimento artificial de reflorestamentos com espécies nativas de níveis sucessionais mais avançados torna-se imprescindível para garantir a sustentabilidade do ecossistema. Métodos como a transferência de serapilheira e solo de florestas maduras e a semeadura direta podem ser alternativas. Amostras de serapilheira e solo foram distribuídas em duas áreas de reflorestamento e uma área-controle, e nove espécies nativas não-pioneiras foram semeadas diretamente nas mesmas áreas e em dois controles. Da serapilheira, germinaram 14 espécies no controle: sete arbóreas, três herbáceas, duas lianescentes e duas arbustivas. As árvores são na maioria pioneiras e, portanto, de interesse limitado para o enriquecimento. Entretanto, as espécies não-arbóreas, importantes na diversidade de ecossistemas florestais, representaram metade dos indivíduos catalogados. Na semeadura direta, a espécie mais interessante foi Diospyros brasiliensis, com taxas de germinação de 50%. Achatocarpus pubescens e Cordia ecalyculata apresentaram resultados expressivos, apesar de heterogêneos. Os resultados mostram que são necessários estudos sobre a época de coleta da serapilheira e a influência do clima na germinação das sementes e emergência de plântulas.In fragmented landscapes, large distances from seed sources and strong soil degradation raises difficulties for colonization of new species in reforested areas and in early secondary forests. In this context, the artificial enrichment of reforestation areas with advanced successional level species is vital for the ecosystem sustainability. Methods like transference of soil and litter from mature forests and direct seeding may be alternatives. In this work, samples of surface soil and

  4. Transformações do nitrogênio no solo após adição de dejeto líquido e cama sobreposta de suínos Nitrogen transformations in soil after the addition of pig slurry and pig deep‑litter

    Directory of Open Access Journals (Sweden)

    Sandro José Giacomini

    2013-02-01

    Full Text Available O objetivo deste trabalho foi avaliar as transformações do N no solo após a aplicação de dejeto líquido (DLS e cama sobreposta (CSS de suínos, com e sem palha de aveia, e com e sem incorporação ao solo. Os tratamentos avaliados foram: solo (S, S + palha incorporada (S + Pi, S + palha em superfície (S + Ps, S + CSS incorporada (S + CSSi, S + CSS em superfície (S + CSSs, S + DLS incorporado (S + DLSi, S + DLS em superfície (S + DLSs, S + Pi + DLSi e S + Ps + DLSs. Avaliaram-se a volatilização de amônia, a nitrificação e a mineralização do N do DLS e da CSS. A incorporação do DLS reduziu a volatilização de amônia em 93%, em comparação à aplicação na superfície do solo. O N amoniacal da CSS foi nitrificado nos cinco primeiros dias. A taxa de nitrificação líquida foi duas vezes maior com a incorporação do DLS ao solo do que na superfície. A mineralização do N orgânico não diferiu com o modo de aplicação do DLS e da CSS no solo. Na CSS, 14,6% do N foi mineralizado, contra 34,9% no DLS. A aplicação do DLS com a palha de aveia na superfície do solo favorece a imobilização microbiana de N, mas não reduz as perdas de N por volatilização de amônia.The objective of this work was to evaluate soil N transformations after the application of pig slurry (PS and pig deep‑litter (PDL, with and without oat straw, and with and without incorporation into the soil. The evaluated treatments were: soil (S, S + incorporated straw (S + Sti, S + straw on surface (S + Sts, S + incorporated PDL (S + PDLi, S + PDL on surface (S + PDLs, S + incorporated PS (S + PSi, S + PS on surface (S + PSs, S + Sti + Psi, and S + Sts + PSs. The following were evaluated: ammonia volatilization, nitrification and N mineralization of PS and PDL. Incorporation of PS reduced ammonia volatilization in 93% when compared to surface application. The ammoniacal N in PDL was nitrified within the first five days. The net nitrification rate was two

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

    Science.gov (United States)

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

    2016-08-15

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

  6. Direct and indirect effects of ammonia, ammonium and nitrate on phosphatase activity and carbon fluxes from decomposing litter in peatland

    International Nuclear Information System (INIS)

    Johnson, David; Moore, Lucy; Green, Samuel; Leith, Ian D.; Sheppard, Lucy J.

    2010-01-01

    Here we investigate the response of soils and litter to 5 years of experimental additions of ammonium (NH 4 ), nitrate (NO 3 ), and ammonia (NH 3 ) to an ombrotrophic peatland. We test the importance of direct (via soil) and indirect (via litter) effects on phosphatase activity and efflux of CO 2 . We also determined how species representing different functional types responded to the nitrogen treatments. Our results demonstrate that additions of NO 3 , NH 4 and NH 3 all stimulated phosphatase activity but the effects were dependent on species of litter and mechanism (direct or indirect). Deposition of NH 3 had no effect on efflux of CO 2 from Calluna vulgaris litter, despite it showing signs of stress in the field, whereas both NO 3 and NH 4 reduced CO 2 fluxes. Our results show that the collective impacts on peatlands of the three principal forms of nitrogen in atmospheric deposition are a result of differential effects and mechanisms on individual components. - We found that nitrogen deposition affects microbial activity associated with litter through both indirect and direct mechanisms, but these effects were dependent on the chemical form of inorganic nitrogen compounds.

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

    Science.gov (United States)

    Nordhaus, Inga; Wolff, Matthias; Diele, Karen

    2006-03-01

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

  8. Long-term litter input manipulation effects on production and properties of dissolved organic matter in the forest floor of a Norway spruce stand.

    NARCIS (Netherlands)

    Klotzbücher, T.; Kaiser, K.; Stepper, C.; van Loon, E.; Gerstberger, P.; Kalbitz, K.

    2012-01-01

    Background and aims Environmental factors such as climate and atmospheric CO2 control inputs of plant-derived matter into soils, which then determines properties and decomposition of soil organic matter. We studied how dissolved organic matter (DOM) in forest floors responded to six years of litter

  9. Sorptive fractionation of organic matter and formation of organo-hydroxy-aluminum complexes during litter biodegradation in the presence of gibbsite

    Science.gov (United States)