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Kristiina Karhu - One of the best experts on this subject based on the ideXlab platform.
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temperature sensitivity of soil respiration rates enhanced by Microbial Community response
Nature, 2014Co-Authors: Marc D Auffret, Jensarne Subke, Jennifer A J Dungait, Kristiina Karhu, Philip A Wookey, James I. Prosser, Brajesh K. Singh, D W Hopkins, Göran I. ÅgrenAbstract:Microbial Community responses in soils from the Arctic to the Amazon often enhance the longer-term temperature sensitivity of respiration, particularly in soils with high carbon-to-nitrogen ratios and in soils from cold regions, suggesting that carbon stored in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted. Much of the large amount of carbon stored in soils is released into the atmosphere as carbon dioxide through soil Microbial respiration. It is thought that a warming induced stimulation of soil Microbial respiration rates could increase soil carbon dioxide emissions and hence induce a positive climate feedback effect, but the response of soil Microbial communities to changing temperatures remains uncertain. This paper investigates the role of Microbial Community level responses in controlling the temperature sensitivity of respiration in soils from the Arctic to the Amazon. The authors find that the Microbial Community level response enhances the longer-term temperature sensitivity of respiration more often than it reduces it. The strongest enhancing responses are observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions, suggesting that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted. Soils store about four times as much carbon as plant biomass1, and soil Microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide2. Short-term experiments have shown that soil Microbial respiration increases exponentially with temperature3. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change4. The magnitude of this feedback remains uncertain, however, not least because the response of soil Microbial communities to changing temperatures has the potential to either decrease5,6,7 or increase8,9 warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how Microbial Community-level responses control the temperature sensitivity of soil respiration. We find that the Microbial Community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, Microbial Community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted.
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temperature sensitivity of soil respiration rates enhanced by Microbial Community response
Nature, 2014Co-Authors: Kristiina Karhu, Marc D Auffret, Jensarne Subke, Jennifer A J Dungait, Philip A Wookey, Göran I. Ågren, James I. Prosser, Brajesh K. Singh, D W Hopkins, Mariateresa SebastiaAbstract:Soils store about four times as much carbon as plant biomass, and soil Microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide. Short-term experiments have shown that soil Microbial respiration increases exponentially with temperature. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change. The magnitude of this feedback remains uncertain, however, not least because the response of soil Microbial communities to changing temperatures has the potential to either decrease or increase warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how Microbial Community-level responses control the temperature sensitivity of soil respiration. We find that the Microbial Community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, Microbial Community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted.
Jizhong Zhou - One of the best experts on this subject based on the ideXlab platform.
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analyses of soil Microbial Community compositions and functional genes reveal potential consequences of natural forest succession
Scientific Reports, 2015Co-Authors: Jing Cong, Huaqun Yin, Xueduan Liu, Jizhong Zhou, Yunfeng Yang, Xiao Liu, Junjun Ding, Yuguang ZhangAbstract:The succession of Microbial Community structure and function is a central ecological topic, as microbes drive the Earth’s biogeochemical cycles. To elucidate the response and mechanistic underpinnings of soil Microbial Community structure and metabolic potential relevant to natural forest succession, we compared soil Microbial communities from three adjacent natural forests: a coniferous forest (CF), a mixed broadleaf forest (MBF) and a deciduous broadleaf forest (DBF) on Shennongjia Mountain in central China. In contrary to plant communities, the Microbial taxonomic diversity of the DBF was significantly (P < 0.05) higher than those of CF and MBF, rendering their Microbial Community compositions markedly different. Consistently, Microbial functional diversity was also highest in the DBF. Furthermore, a network analysis of Microbial carbon and nitrogen cycling genes showed the network for the DBF samples was relatively large and tight, revealing strong couplings between microbes. Soil temperature, reflective of climate regimes, was important in shaping Microbial communities at both taxonomic and functional gene levels. As a first glimpse of both the taxonomic and functional compositions of soil Microbial communities, our results suggest that Microbial Community structure and function potentials will be altered by future environmental changes, which have implications for forest succession.
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responses of the functional structure of soil Microbial Community to livestock grazing in the tibetan alpine grassland
Global Change Biology, 2013Co-Authors: Yunfeng Yang, Joy D. Van Nostrand, Jizhong Zhou, Qiaoyan Lin, Mengting Yuan, Jichuang Duan, Kai Xue, Shiping WangAbstract:Microbes play key roles in various biogeochemical processes, including carbon (C) and nitrogen (N) cycling. However, changes of Microbial Community at the functional gene level by livestock grazing, which is a global land-use activity, remain unclear. Here we use a functional gene array, GeoChip 4.0, to examine the effects of free livestock grazing on the Microbial Community at an experimental site of Tibet, a region known to be very sensitive to anthropogenic perturbation and global warming. Our results showed that grazing changed Microbial Community functional structure, in addition to aboveground vegetation and soil geochemical properties. Further statistical tests showed that Microbial Community functional structures were closely correlated with environmental variables, and variations in Microbial Community functional structures were mainly controlled by aboveground vegetation, soil C/N ratio, and NH4+-N. In-depth examination of N cycling genes showed that abundances of N mineralization and nitrification genes were increased at grazed sites, but denitrification and N-reduction genes were decreased, suggesting that functional potentials of relevant bioprocesses were changed. Meanwhile, abundances of genes involved in methane cycling, C fixation, and degradation were decreased, which might be caused by vegetation removal and hence decrease in litter accumulation at grazed sites. In contrast, abundances of virulence, stress, and antibiotics resistance genes were increased because of the presence of livestock. In conclusion, these results indicated that soil Microbial Community functional structure was very sensitive to the impact of livestock grazing and revealed Microbial functional potentials in regulating soil N and C cycling, supporting the necessity to include Microbial components in evaluating the consequence of land-use and/or climate changes.
Mary K Firestone - One of the best experts on this subject based on the ideXlab platform.
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seasonal dynamics of Microbial Community composition and function in oak canopy and open grassland soils
Microbial Ecology, 2006Co-Authors: M P Waldrop, Mary K FirestoneAbstract:Soil Microbial communities are closely associated with aboveground plant communities, with multiple potential drivers of this relationship. Plants can affect available soil carbon, temperature, and water content, which each have the potential to affect Microbial Community composition and function. These same variables change seasonally, and thus plant control on Microbial Community composition may be modulated or overshadowed by annual climatic patterns. We examined Microbial Community composition, C cycling processes, and environmental data in California annual grassland soils from beneath oak canopies and in open grassland areas to distinguish factors controlling Microbial Community composition and function seasonally and in association with the two plant overstory communities. Every 3 months for up to 2 years, we monitored Microbial Community composition using phospholipid fatty acid (PLFA) analysis, Microbial biomass, respiration rates, Microbial enzyme activities, and the activity of Microbial groups using isotope labeling of PLFA biomarkers (13C-PLFA). Distinct Microbial communities were associated with oak canopy soils and open grassland soils and Microbial communities displayed seasonal patterns from year to year. The effects of plant species and seasonal climate on Microbial Community composition were similar in magnitude. In this Mediterranean ecosystem, plant control of Microbial Community composition was primarily due to effects on soil water content, whereas the changes in Microbial Community composition seasonally appeared to be due, in large part, to soil temperature. Available soil carbon was not a significant control on Microbial Community composition. Microbial Community composition (PLFA) and 13C-PLFA ordination values were strongly related to intra-annual variability in soil enzyme activities and soil respiration, but Microbial biomass was not. In this Mediterranean climate, soil microclimate appeared to be the master variable controlling Microbial Community composition and function.
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linking Microbial Community composition and soil processes in a california annual grassland and mixed conifer forest
Biogeochemistry, 2005Co-Authors: Teri C Balser, Mary K FirestoneAbstract:To investigate the potential role of Microbial Community composition in soil carbon and nitrogen cycling, we transplanted soil cores between a grassland and a conifer ecosystem in the Sierra Nevada California and measured soil process rates (N-mineralization, nitrous oxide and carbondioxide flux, nitrification potential), soil water and temperature, and Microbial Community parameters (PLFA and substrate utilization profiles) over a 2 year period. Our goal was to assess whether Microbial Community composition could be related to soil process rates independent of soil temperature and water content. We performed multiple regression analyses using Microbial Community parameters and soil water and temperature as X-variables and soil process rates and inorganic N concentrations as Y-variables. We found that field soil temperature had the strongest relationship with CO2 production and soil NH4+ concentration, while Microbial Community characteristics correlated with N2O production, nitrification potential, gross N-mineralization, and soil NO3− concentration, independent of environmentalcontrollers. We observed a relationship between specific components of the Microbial Community (as determined by PLFA) and soil processes,particularly processes tightly linked to Microbial phylogeny (e.g. nitrification). The most apparent change in Microbial Community composition in response to the 2 year transplant was a change in relative abundance of fungi (there was only one significant change in PLFA biomarkers for bacteria during 2 years). The relationship between Microbial Community composition and soil processes suggests that prediction of ecosystem response to environmental change may be improved by recognizing and accounting for changes in Microbial Community composition and physiological ecology.
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Microbial Community utilization of recalcitrant and simple carbon compounds impact of oak woodland plant communities
Oecologia, 2004Co-Authors: Mark P Waldrop, Mary K FirestoneAbstract:Little is known about how the structure of Microbial communities impacts carbon cycling or how soil Microbial Community composition mediates plant effects on C-decomposition processes. We examined the degradation of four 13C-labeled compounds (starch, xylose, vanillin, and pine litter), quantified rates of associated enzyme activities, and identified Microbial groups utilizing the 13C-labeled substrates in soils under oaks and in adjacent open grasslands. By quantifying increases in non-13C-labeled carbon in Microbial biomarkers, we were also able to identify functional groups responsible for the metabolism of indigenous soil organic matter. Although Microbial Community composition differed between oak and grassland soils, the Microbial groups responsible for starch, xylose, and vanillin degradation, as defined by 13C-PLFA, did not differ significantly between oak and grassland soils. Microbial groups responsible for pine litter and SOM-C degradation did differ between the two soils. Enhanced degradation of SOM resulting from substrate addition (priming) was greater in grassland soils, particularly in response to pine litter addition; under these conditions, fungal and Gram + biomarkers showed more incorporation of SOM-C than did Gram – biomarkers. In contrast, the oak soil Microbial Community primarily incorporated C from the added substrates. More 13C (from both simple and recalcitrant sources) was incorporated into the Gram – biomarkers than Gram + biomarkers despite the fact that the Gram + group generally comprised a greater portion of the bacterial biomass than did markers for the Gram – group. These experiments begin to identify components of the soil Microbial Community responsible for decomposition of different types of C-substrates. The results demonstrate that the presence of distinctly different plant communities did not alter the Microbial Community profile responsible for decomposition of relatively labile C-substrates but did alter the profiles of Microbial communities responsible for decomposition of the more recalcitrant substrates, pine litter and indigenous soil organic matter.
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linking Microbial Community composition to function in a tropical soil
Soil Biology & Biochemistry, 2000Co-Authors: Mark P Waldrop, Teri C Balser, Mary K FirestoneAbstract:Abstract If changes in the composition of the soil Microbial Community alter the physiological capacity of the Community then such changes may have ecosystem consequences. We examined the relationships among Community composition (PLFA), Microbial biomass (CFDE), substrate utilization profiles (BIOLOG), lignocellulose degrading enzyme activities (β-glucosidase, cellobiohydrolase, β-xylosidase, phenol oxidase, peroxidase), and nutrient releasing enzyme activities (phosphatase, sulphatase) in a Tropeptic Haplustol soil. The soils supported a tropical forest and pineapple plantations of varying ages that were at different stages within the management cycle. Conversion from forest to agriculture significantly decreased %C and %N of the soil by 50–55%, Microbial biomass by 75%, β-glucosidase by 54%, sulphatase activity by 85%, decreased Ca, Mg, and Mn availability, and produced compositionally and functionally distinct Microbial communities. Total enzyme activities were generally correlated with %C, %N, Microbial biomass and, occasionally with Community composition. We calculated the specific activities of the enzymes assayed (enzyme activity per unit Microbial biomass C) in order to normalize activity to the size of the Microbial Community. Values for enzyme specific activities were more highly correlated with Community composition than were total enzyme activities. In addition, BIOLOG was not correlated with Community composition or enzyme activities. Enzyme activities and specific activities may provide a useful linkage between Microbial Community composition and carbon processing.
Göran I. Ågren - One of the best experts on this subject based on the ideXlab platform.
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temperature sensitivity of soil respiration rates enhanced by Microbial Community response
Nature, 2014Co-Authors: Marc D Auffret, Jensarne Subke, Jennifer A J Dungait, Kristiina Karhu, Philip A Wookey, James I. Prosser, Brajesh K. Singh, D W Hopkins, Göran I. ÅgrenAbstract:Microbial Community responses in soils from the Arctic to the Amazon often enhance the longer-term temperature sensitivity of respiration, particularly in soils with high carbon-to-nitrogen ratios and in soils from cold regions, suggesting that carbon stored in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted. Much of the large amount of carbon stored in soils is released into the atmosphere as carbon dioxide through soil Microbial respiration. It is thought that a warming induced stimulation of soil Microbial respiration rates could increase soil carbon dioxide emissions and hence induce a positive climate feedback effect, but the response of soil Microbial communities to changing temperatures remains uncertain. This paper investigates the role of Microbial Community level responses in controlling the temperature sensitivity of respiration in soils from the Arctic to the Amazon. The authors find that the Microbial Community level response enhances the longer-term temperature sensitivity of respiration more often than it reduces it. The strongest enhancing responses are observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions, suggesting that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted. Soils store about four times as much carbon as plant biomass1, and soil Microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide2. Short-term experiments have shown that soil Microbial respiration increases exponentially with temperature3. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change4. The magnitude of this feedback remains uncertain, however, not least because the response of soil Microbial communities to changing temperatures has the potential to either decrease5,6,7 or increase8,9 warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how Microbial Community-level responses control the temperature sensitivity of soil respiration. We find that the Microbial Community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, Microbial Community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted.
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temperature sensitivity of soil respiration rates enhanced by Microbial Community response
Nature, 2014Co-Authors: Kristiina Karhu, Marc D Auffret, Jensarne Subke, Jennifer A J Dungait, Philip A Wookey, Göran I. Ågren, James I. Prosser, Brajesh K. Singh, D W Hopkins, Mariateresa SebastiaAbstract:Soils store about four times as much carbon as plant biomass, and soil Microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide. Short-term experiments have shown that soil Microbial respiration increases exponentially with temperature. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change. The magnitude of this feedback remains uncertain, however, not least because the response of soil Microbial communities to changing temperatures has the potential to either decrease or increase warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how Microbial Community-level responses control the temperature sensitivity of soil respiration. We find that the Microbial Community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, Microbial Community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted.
Yakov Kuzyakov - One of the best experts on this subject based on the ideXlab platform.
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response of soil Microbial Community to afforestation with pure and mixed species
Plant and Soil, 2017Co-Authors: Anna Gunina, Andrew R Smith, Douglas L Godbold, Davey L Jones, Yakov KuzyakovAbstract:Objectives Afforestation changes soil chemical properties over several decades. In contrast, Microbial Community structure can be shifted within the first decade and so, the direct effects of tree species can be revealed. The aim of this study was to determine the alteration of soil Microbial Community composition 10 years after afforestation by trees with contrasting functional traits.
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biochar affects soil organic matter cycling and Microbial functions but does not alter Microbial Community structure in a paddy soil
Science of The Total Environment, 2016Co-Authors: Jing Tian, Jingyuan Wang, Michaela A Dippold, Yang Gao, Evgenia Blagodatskaya, Yakov KuzyakovAbstract:The application of biochar (BC) in conjunction with mineral fertilizers is one of the most promising management practices recommended to improve soil quality. However, the interactive mechanisms of BC and mineral fertilizer addition affecting Microbial communities and functions associated with soil organic matter (SOM) cycling are poorly understood. We investigated the SOM in physical and chemical fractions, Microbial Community structure (using phospholipid fatty acid analysis, PLFA) and functions (by analyzing enzymes involved in C and N cycling and Biolog) in a 6-year field experiment with BC and NPK amendment. BC application increased total soil C and particulate organic C for 47.4-50.4% and 63.7-74.6%, respectively. The effects of BC on the Microbial Community and C-cycling enzymes were dependent on fertilization. Addition of BC alone did not change the Microbial Community compared with the control, but altered the Microbial Community structure in conjunction with NPK fertilization. SOM fractions accounted for 55% of the variance in the PLFA-related Microbial Community structure. The particulate organic N explained the largest variation in the Microbial Community structure. Microbial metabolic activity strongly increased after BC addition, particularly the utilization of amino acids and amines due to an increase in the activity of proteolytic (l-leucine aminopeptidase) enzymes. These results indicate that microorganisms start to mine N from the SOM to compensate for high C:N ratios after BC application, which consequently accelerate cycling of stable N. Concluding, BC in combination with NPK fertilizer application strongly affected Microbial Community composition and functions, which consequently influenced SOM cycling.