The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Noah Fierer - One of the best experts on this subject based on the ideXlab platform.
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cross biome patterns in soil Microbial Respiration predictable from evolutionary theory on thermal adaptation
Nature Ecology and Evolution, 2019Co-Authors: Mark A Bradford, Thomas W Crowther, Rebecca L Mcculley, Emily E Oldfield, Stephen A Wood, Noah FiererAbstract:Climate warming may stimulate Microbial metabolism of soil carbon, causing a carbon-cycle–climate feedback whereby carbon is redistributed from the soil to atmospheric CO2. The magnitude of this feedback is uncertain, in part because warming-induced shifts in Microbial physiology and/or community composition could retard or accelerate soil carbon losses. Here, we measure Microbial Respiration rates for soils collected from 22 sites in each of 3 years, at locations spanning boreal to tropical climates. Respiration was measured in the laboratory with standard temperatures, moisture and excess carbon substrate, to allow physiological and community effects to be detected independent of the influence of these abiotic controls. Patterns in Respiration for soils collected across the climate gradient are consistent with evolutionary theory on physiological responses that compensate for positive effects of temperature on metabolism. Respiration rates per unit Microbial biomass were as much as 2.6 times higher for soils sampled from sites with a mean annual temperature of −2.0 versus 21.7 °C. Subsequent 100-d incubations suggested differences in the plasticity of the thermal response among Microbial communities, with communities sampled from sites with higher mean annual temperature having a more plastic response. Our findings are consistent with adaptive metabolic responses to contrasting thermal regimes that are also observed in plants and animals. These results may help build confidence in soil-carbon–climate feedback projections by improving understanding of Microbial processes represented in biogeochemical models.
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cross biome patterns in soil Microbial Respiration predictable from evolutionary theory on thermal adaptation
Nature Ecology and Evolution, 2019Co-Authors: Mark A Bradford, Thomas W Crowther, Rebecca L Mcculley, Emily E Oldfield, Stephen A Wood, Noah FiererAbstract:Climate warming may stimulate Microbial metabolism of soil carbon, causing a carbon-cycle–climate feedback whereby carbon is redistributed from the soil to atmospheric CO2. The magnitude of this feedback is uncertain, in part because warming-induced shifts in Microbial physiology and/or community composition could retard or accelerate soil carbon losses. Here, we measure Microbial Respiration rates for soils collected from 22 sites in each of 3 years, at locations spanning boreal to tropical climates. Respiration was measured in the laboratory with standard temperatures, moisture and excess carbon substrate, to allow physiological and community effects to be detected independent of the influence of these abiotic controls. Patterns in Respiration for soils collected across the climate gradient are consistent with evolutionary theory on physiological responses that compensate for positive effects of temperature on metabolism. Respiration rates per unit Microbial biomass were as much as 2.6 times higher for soils sampled from sites with a mean annual temperature of −2.0 versus 21.7 °C. Subsequent 100-d incubations suggested differences in the plasticity of the thermal response among Microbial communities, with communities sampled from sites with higher mean annual temperature having a more plastic response. Our findings are consistent with adaptive metabolic responses to contrasting thermal regimes that are also observed in plants and animals. These results may help build confidence in soil-carbon–climate feedback projections by improving understanding of Microbial processes represented in biogeochemical models. Measuring Microbial Respiration in soils collected for three years along a latitudinal gradient, the authors find lower Respiration rates and greater plasticity in responses at sites with higher mean annual temperatures, consistent with adaptation to thermal regimes.
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nitrogen fertilization inhibits soil Microbial Respiration regardless of the form of nitrogen applied
Soil Biology & Biochemistry, 2010Co-Authors: Kelly S Ramirez, Noah Fierer, Joseph M CraineAbstract:Abstract We tested how amendments of different forms of nitrogen (N) affect Microbial Respiration rates by adding six different forms of N (NH 4 NO 3 , (NH 2 ) 2 CO (urea), KNO 3 , NH 4 Cl, (NH 4 ) 2 SO 4 , Ca(NO 3 ) 2 ) to three distinct soils. All inorganic N forms led to a net reduction in Microbial Respiration, and the magnitude of the observed response (up to 60 % reduction) was consistent across all soils and negatively correlated with N concentration. Urea also reduced Respiration rates in nearly all cases, but the effect was attenuated by the associated input of labile organic carbon. We observed decreases in Respiration regardless of soil type, the specific N counter ion, N added as NH 4 + or NO 3 − , or the effects of N form on soil pH, suggesting that decreases in Respiration rates were mainly a direct result of the increase in soil N availability, rather than indirect effects caused by the form of N added.
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predicting the temperature dependence of Microbial Respiration in soil a continental scale analysis
Global Biogeochemical Cycles, 2006Co-Authors: Noah Fierer, Benjamin P Colman, Joshua P Schimel, Robert B JacksonAbstract:[1] The production of CO2 by soil microorganisms is an important component of the global carbon cycle, and its temperature sensitivity is poorly constrained in global models. To improve our understanding of the factors controlling the temperature dependence of soil Microbial Respiration, we analyzed the temperature sensitivity of labile soil organic carbon decomposition for 77 soils collected from a wide array of ecosystem types. Across all of the soils, the average Q10 value (the factor by which decomposition rates increase for a 10C increase in temperature) was 3.0, but the range in Q10 values was substantial (2.2 to 4.6). A large percentage (45%) of the variation in Q10 values could be explained by the relative rate of Microbial Respiration per unit organic C, an analog for C quality. This result provides support for the ‘‘carbon quality-temperature’’ hypothesis that directly links the temperature dependence of Microbial decomposition and the biochemical recalcitrance of soil organic carbon. A smaller percentage (17%) of the variability in Q10 values could be explained by the mean monthly temperature at the time of sampling, suggesting that Microbial communities may adapt to the antecedent temperature regime. By showing that the Q10 of Microbial Respiration in soil is largely predictable under standardized incubation conditions, this work increases our understanding of the temperature sensitivity of labile soil organic carbon stores.
Mark A Bradford - One of the best experts on this subject based on the ideXlab platform.
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cross biome patterns in soil Microbial Respiration predictable from evolutionary theory on thermal adaptation
Nature Ecology and Evolution, 2019Co-Authors: Mark A Bradford, Thomas W Crowther, Rebecca L Mcculley, Emily E Oldfield, Stephen A Wood, Noah FiererAbstract:Climate warming may stimulate Microbial metabolism of soil carbon, causing a carbon-cycle–climate feedback whereby carbon is redistributed from the soil to atmospheric CO2. The magnitude of this feedback is uncertain, in part because warming-induced shifts in Microbial physiology and/or community composition could retard or accelerate soil carbon losses. Here, we measure Microbial Respiration rates for soils collected from 22 sites in each of 3 years, at locations spanning boreal to tropical climates. Respiration was measured in the laboratory with standard temperatures, moisture and excess carbon substrate, to allow physiological and community effects to be detected independent of the influence of these abiotic controls. Patterns in Respiration for soils collected across the climate gradient are consistent with evolutionary theory on physiological responses that compensate for positive effects of temperature on metabolism. Respiration rates per unit Microbial biomass were as much as 2.6 times higher for soils sampled from sites with a mean annual temperature of −2.0 versus 21.7 °C. Subsequent 100-d incubations suggested differences in the plasticity of the thermal response among Microbial communities, with communities sampled from sites with higher mean annual temperature having a more plastic response. Our findings are consistent with adaptive metabolic responses to contrasting thermal regimes that are also observed in plants and animals. These results may help build confidence in soil-carbon–climate feedback projections by improving understanding of Microbial processes represented in biogeochemical models.
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soil Microbial Respiration adapts to ambient temperature in global drylands
Nature Ecology and Evolution, 2019Co-Authors: Marina Dacal, Mark A Bradford, Cesar Plaza, Fernando T Maestre, Pablo GarciapalaciosAbstract:Heterotrophic soil Microbial Respiration-one of the main processes of carbon loss from the soil to the atmosphere-is sensitive to temperature in the short term. However, how this sensitivity is affected by long-term thermal regimes is uncertain. There is an expectation that soil Microbial Respiration rates adapt to the ambient thermal regime, but whether this adaptation magnifies or reduces Respiration sensitivities to temperature fluctuations remains unresolved. This gap in understanding is particularly pronounced for drylands because most studies conducted so far have focused on mesic systems. Here, we conduct an incubation study using soil samples from 110 global drylands encompassing a wide gradient in mean annual temperature. We test how mean annual temperature affects soil Respiration rates at three assay temperatures while controlling for substrate depletion and Microbial biomass. Estimated soil Respiration rates at the mean Microbial biomass were lower in sites with higher mean annual temperatures across the three assayed temperatures. The patterns observed are consistent with expected evolutionary trade-offs in the structure and function of enzymes under different thermal regimes. Therefore, our results suggest that soil Microbial Respiration adapts to the ambient thermal regime in global drylands.
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cross biome patterns in soil Microbial Respiration predictable from evolutionary theory on thermal adaptation
Nature Ecology and Evolution, 2019Co-Authors: Mark A Bradford, Thomas W Crowther, Rebecca L Mcculley, Emily E Oldfield, Stephen A Wood, Noah FiererAbstract:Climate warming may stimulate Microbial metabolism of soil carbon, causing a carbon-cycle–climate feedback whereby carbon is redistributed from the soil to atmospheric CO2. The magnitude of this feedback is uncertain, in part because warming-induced shifts in Microbial physiology and/or community composition could retard or accelerate soil carbon losses. Here, we measure Microbial Respiration rates for soils collected from 22 sites in each of 3 years, at locations spanning boreal to tropical climates. Respiration was measured in the laboratory with standard temperatures, moisture and excess carbon substrate, to allow physiological and community effects to be detected independent of the influence of these abiotic controls. Patterns in Respiration for soils collected across the climate gradient are consistent with evolutionary theory on physiological responses that compensate for positive effects of temperature on metabolism. Respiration rates per unit Microbial biomass were as much as 2.6 times higher for soils sampled from sites with a mean annual temperature of −2.0 versus 21.7 °C. Subsequent 100-d incubations suggested differences in the plasticity of the thermal response among Microbial communities, with communities sampled from sites with higher mean annual temperature having a more plastic response. Our findings are consistent with adaptive metabolic responses to contrasting thermal regimes that are also observed in plants and animals. These results may help build confidence in soil-carbon–climate feedback projections by improving understanding of Microbial processes represented in biogeochemical models. Measuring Microbial Respiration in soils collected for three years along a latitudinal gradient, the authors find lower Respiration rates and greater plasticity in responses at sites with higher mean annual temperatures, consistent with adaptation to thermal regimes.
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thermal adaptation of soil Microbial Respiration to elevated temperature
Ecology Letters, 2008Co-Authors: Mark A Bradford, Christian A Davies, Serita D Frey, Tom Maddox, Jerry M Melillo, Jacqueline E Mohan, James F Reynolds, Kathleen K Treseder, Matthew D WallensteinAbstract:In the short-term heterotrophic soil Respiration is strongly and positively related to temperature. In the long-term, its response to temperature is uncertain. One reason for this is because in field experiments increases in Respiration due to warming are relatively short-lived. The explanations proposed for this ephemeral response include depletion of fast-cycling, soil carbon pools and thermal adaptation of Microbial Respiration. Using a > 15 year soil warming experiment in a mid-latitude forest, we show that the apparent 'acclimation' of soil Respiration at the ecosystem scale results from combined effects of reductions in soil carbon pools and Microbial biomass, and thermal adaptation of Microbial Respiration. Mass-specific Respiration rates were lower when seasonal temperatures were higher, suggesting that rate reductions under experimental warming likely occurred through temperature-induced changes in the Microbial community. Our results imply that stimulatory effects of global temperature rise on soil Respiration rates may be lower than currently predicted.
Saori Fujii - One of the best experts on this subject based on the ideXlab platform.
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tree species effects on Microbial Respiration from decomposing leaf and fine root litter
Soil Biology & Biochemistry, 2015Co-Authors: Naoki Makita, Saori FujiiAbstract:Abstract Tree species have an impact on decomposition processes of woody litter, but the effects of different tree species on Microbial heterotrophic Respiration derived from decomposing litter are still unclear. Here we used leaf and fine root litter of six tree species differing in chemical and morphological traits in a temperate forest and elucidated the effects of tree species on the relationships between litter-derived Microbial Respiration rates and decomposition rates and morphological traits, including specific leaf area (cm 2 g −1 ) and specific root length (m g −1 ) of litter at the same site. Litterbags set in forest soil were sequentially collected five times over the course of 18 months. During litter decomposition, Microbial Respiration from leaf and fine root litter differed among the six tree species. Temporal changes in the remaining mass and morphology (specific leaf area and specific root length) were observed, and the magnitude of these changes differed among species. Positive correlations were observed between Respiration and mass loss or morphology across species. These results revealed that litter mass loss and morphological dynamics during decomposition jointly enhanced Microbial Respiration, and these carbon-based litter traits explained species differences in decomposition of leaves and fine roots. In conclusion, tree species influenced the magnitude and direction of Microbial Respiration during leaf/fine root litter decomposition. Tree species also affected the relationship between Microbial Respiration and litter decomposition through direct effects of litter traits and indirect effects mediated by regulation of heterotroph requirements.
Naoki Makita - One of the best experts on this subject based on the ideXlab platform.
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tree species effects on Microbial Respiration from decomposing leaf and fine root litter
Soil Biology & Biochemistry, 2015Co-Authors: Naoki Makita, Saori FujiiAbstract:Abstract Tree species have an impact on decomposition processes of woody litter, but the effects of different tree species on Microbial heterotrophic Respiration derived from decomposing litter are still unclear. Here we used leaf and fine root litter of six tree species differing in chemical and morphological traits in a temperate forest and elucidated the effects of tree species on the relationships between litter-derived Microbial Respiration rates and decomposition rates and morphological traits, including specific leaf area (cm 2 g −1 ) and specific root length (m g −1 ) of litter at the same site. Litterbags set in forest soil were sequentially collected five times over the course of 18 months. During litter decomposition, Microbial Respiration from leaf and fine root litter differed among the six tree species. Temporal changes in the remaining mass and morphology (specific leaf area and specific root length) were observed, and the magnitude of these changes differed among species. Positive correlations were observed between Respiration and mass loss or morphology across species. These results revealed that litter mass loss and morphological dynamics during decomposition jointly enhanced Microbial Respiration, and these carbon-based litter traits explained species differences in decomposition of leaves and fine roots. In conclusion, tree species influenced the magnitude and direction of Microbial Respiration during leaf/fine root litter decomposition. Tree species also affected the relationship between Microbial Respiration and litter decomposition through direct effects of litter traits and indirect effects mediated by regulation of heterotroph requirements.
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temperature sensitivity of Microbial Respiration of fine root litter in a temperate broad leaved forest
PLOS ONE, 2015Co-Authors: Naoki Makita, Ayumi KawamuraAbstract:The Microbial decomposition Respiration of plant litter generates a major CO2 efflux from terrestrial ecosystems that plays a critical role in the regulation of carbon cycling on regional and global scales. However, the Respiration from root litter decomposition and its sensitivity to temperature changes are unclear in current models of carbon turnover in forest soils. Thus, we examined seasonal changes in the temperature sensitivity and decomposition rates of fine root litter of two diameter classes (0–0.5 and 0.5–2.0 mm) of Quercus serrata and Ilex pedunculosa in a deciduous broad-leaved forest. During the study period, fine root litter of both diameter classes and species decreased approximately exponentially over time. The Q10 values of Microbial Respiration rates of root litter for the two classes were 1.59–3.31 and 1.28–6.27 for Q. serrata and 1.36–6.31 and 1.65–5.86 for I. pedunculosa. A significant difference in Q10 was observed between the diameter classes, indicating that root diameter represents the initial substrate quality, which may determine the magnitude of Q10 value of Microbial Respiration. Changes in these Q10 values were related to seasonal soil temperature patterns; the values were higher in winter than in summer. Moreover, seasonal variations in Q10 were larger during the 2-year decomposition period than the 1-year period. These results showed that the Q10 values of fine root litter of 0–0.5 and 0.5–2.0 mm have been shown to increase with lower temperatures and with the higher recalcitrance pool of the decomposed substrate during 2 years of decomposition. Thus, the temperature sensitivity of Microbial Respiration in root litter showed distinct patterns according to the decay period and season because of the temperature acclimation and adaptation of the Microbial decomposer communities in root litter.
Stephen A Wood - One of the best experts on this subject based on the ideXlab platform.
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cross biome patterns in soil Microbial Respiration predictable from evolutionary theory on thermal adaptation
Nature Ecology and Evolution, 2019Co-Authors: Mark A Bradford, Thomas W Crowther, Rebecca L Mcculley, Emily E Oldfield, Stephen A Wood, Noah FiererAbstract:Climate warming may stimulate Microbial metabolism of soil carbon, causing a carbon-cycle–climate feedback whereby carbon is redistributed from the soil to atmospheric CO2. The magnitude of this feedback is uncertain, in part because warming-induced shifts in Microbial physiology and/or community composition could retard or accelerate soil carbon losses. Here, we measure Microbial Respiration rates for soils collected from 22 sites in each of 3 years, at locations spanning boreal to tropical climates. Respiration was measured in the laboratory with standard temperatures, moisture and excess carbon substrate, to allow physiological and community effects to be detected independent of the influence of these abiotic controls. Patterns in Respiration for soils collected across the climate gradient are consistent with evolutionary theory on physiological responses that compensate for positive effects of temperature on metabolism. Respiration rates per unit Microbial biomass were as much as 2.6 times higher for soils sampled from sites with a mean annual temperature of −2.0 versus 21.7 °C. Subsequent 100-d incubations suggested differences in the plasticity of the thermal response among Microbial communities, with communities sampled from sites with higher mean annual temperature having a more plastic response. Our findings are consistent with adaptive metabolic responses to contrasting thermal regimes that are also observed in plants and animals. These results may help build confidence in soil-carbon–climate feedback projections by improving understanding of Microbial processes represented in biogeochemical models.
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cross biome patterns in soil Microbial Respiration predictable from evolutionary theory on thermal adaptation
Nature Ecology and Evolution, 2019Co-Authors: Mark A Bradford, Thomas W Crowther, Rebecca L Mcculley, Emily E Oldfield, Stephen A Wood, Noah FiererAbstract:Climate warming may stimulate Microbial metabolism of soil carbon, causing a carbon-cycle–climate feedback whereby carbon is redistributed from the soil to atmospheric CO2. The magnitude of this feedback is uncertain, in part because warming-induced shifts in Microbial physiology and/or community composition could retard or accelerate soil carbon losses. Here, we measure Microbial Respiration rates for soils collected from 22 sites in each of 3 years, at locations spanning boreal to tropical climates. Respiration was measured in the laboratory with standard temperatures, moisture and excess carbon substrate, to allow physiological and community effects to be detected independent of the influence of these abiotic controls. Patterns in Respiration for soils collected across the climate gradient are consistent with evolutionary theory on physiological responses that compensate for positive effects of temperature on metabolism. Respiration rates per unit Microbial biomass were as much as 2.6 times higher for soils sampled from sites with a mean annual temperature of −2.0 versus 21.7 °C. Subsequent 100-d incubations suggested differences in the plasticity of the thermal response among Microbial communities, with communities sampled from sites with higher mean annual temperature having a more plastic response. Our findings are consistent with adaptive metabolic responses to contrasting thermal regimes that are also observed in plants and animals. These results may help build confidence in soil-carbon–climate feedback projections by improving understanding of Microbial processes represented in biogeochemical models. Measuring Microbial Respiration in soils collected for three years along a latitudinal gradient, the authors find lower Respiration rates and greater plasticity in responses at sites with higher mean annual temperatures, consistent with adaptation to thermal regimes.