Mineralisable soil organic carbon(SOC)pools vary with ecosystem type in response to changes in climate,vegetation and soil properties.Understanding the effect of climate and soil factors on SOC pools is critical for p...Mineralisable soil organic carbon(SOC)pools vary with ecosystem type in response to changes in climate,vegetation and soil properties.Understanding the effect of climate and soil factors on SOC pools is critical for predicting change over time.Surface soil samples from six ecoregions of the United States were analyzed for permanganate oxidizable C(KMnO4-C)and mineralizable C pools.Variations of SOC ranged from 7.9 mg g^-1(Florida site)to 325 mg g^-1(Hawaii site).Mineralisable C pools and KMnO4-C were highest in soils from the Hawaii site.Mean annual precipitation explains SOC and resistant C pool variations.Clay content was related to mineralisable active C pools and bacterial abundance.Mean annual precipitation and clay content are potential variables for predicting changes in SOC pools at large spatial scales.展开更多
Biochar is a carbon-rich(】60%)organic material derived from incomplete combustion of fossil fuels and biomass.It consists of a continuum ranging from slightly charred material through char and charcoal to soot,and is...Biochar is a carbon-rich(】60%)organic material derived from incomplete combustion of fossil fuels and biomass.It consists of a continuum ranging from slightly charred material through char and charcoal to soot,and is ubiquitous in the atmosphere,marine sediment,soil and water.Moreover,】80%of biochar produced ends up in soils,where it resides for hundreds to thousands of years.Because of its resistance to biological and chemical breakdown, biochar can serve as a pool of C with long residence time in the soil.As a result,there has been increasing attention given to the potential of biochar to sequestrate carbon and counteract展开更多
It is of important referential values for the further understanding of the effects of fertilization on greenhouse gas emissions and the effects of winter green manure on soil carbon pool to study the effects of fertil...It is of important referential values for the further understanding of the effects of fertilization on greenhouse gas emissions and the effects of winter green manure on soil carbon pool to study the effects of fertilization on the greenhouse gas emissions and soil carbon pool during the growing season of winter Chinese milk vetch in the process of rice cultivation.This study investigated the effects of nitrogen application in late rice season on the yield of the succeeding Chinese milk vetch and greenhouse gas emissions as well as the soil carbon pool characteristics after the winter planting of Chinese milk vetch with the winter idling of no nitrogen application as the control.The results showed that the yield of Chinese milk vetch was the highest under the nitrogen application of 225 kg/hm^2 in the late rice season,reaching up to 18 388.97 kg/hm^2,which was significantly different from other treatments( P <0.05).Nitrogen application in late rice season increased the emissions of N_2 O,CH_4,CO_2 and global warming potential( GWP) in the growing season of Chinese milk vetch.Compared with the winter idling treatment,winter planting of Chinese milk vetch significantly increased the soil organic carbon and soil carbon pool management index.The yield of Chinese milk vetch was significantly positively correlated with N_2O and CH_4 emissions( P < 0.05),while it presented extremely significant positive correlations with CO_2 emissions,GWP,active organic carbon,and carbon pool management index( P < 0.01).Nitrogen application in the late rice season increased the emissions of N_2 O,CH_4,CO_2,and enhanced the greenhouse gas emission potential during the growing season of Chinese milk vetch.Therefore,without reducing the yield of rice,reducing the amount of nitrogen fertilizer in rice could reduce the greenhouse gas emissions in the growing season of succeeding Chinese milk vetch.展开更多
The three-pool and first-order model separates the mineralizable organic carbon into active,slow,and passive carbon pools.This paper used the model and decomposition curves of the soil organic carbon to fit the active...The three-pool and first-order model separates the mineralizable organic carbon into active,slow,and passive carbon pools.This paper used the model and decomposition curves of the soil organic carbon to fit the active pool and its decomposition rate,slow pool and its decomposition rate.The results showed that the size of the active pool from different profiles accounted for 2.09%-3.08% of the total soil organic carbon and the mean residue time was 3.57-17.21 days.And the size of the slow pool accounted for 3.19%-43.55% and the mean residue time was 1.12-4.94 years.Acid hydrolysis(6M HCl) was used to fractionate the passive organic carbon,which accounted for 50.83%-94.44% of the total soil organic carbon.展开更多
Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the d...Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the dynamics of SOC mineralization and its correlations with other soil properties in a young forest and mid-aged forest at soil depths of 0–10,>10–20,>20–40 and>40–60 cm.The results showed that compared with a mid-aged forest,the SOC stock in the young forest was 32%higher.Potentially mineralizable soil carbon(C0)in the young forest was 1.1–2.5 g kg^-1,accounting for 5.5–8.1%of total SOC during the 105 days incubation period and 0.3–1.5 g kg^-1 in the mid-aged forest at different soil depths,occupying 2.8–3.4%of total SOC.There was a significant difference in C0 among the soil depths.The dynamics of the SOC mineralization was a good fit to a three-pool(labile,intermediate and stable)carbon decomposition kinetic model.The SOC decomposition rate for different stand ages and different soil depths reached high levels for the first 15 days.Correlation analysis revealed that the C0 was significantly positively related with SOC content,soil total N(TN)and readily available K(AK)concentration.The labile soil carbon pool was significantly related to SOC and TN concentration,and significantly negatively correlated with soil bulk density.The intermediate carbon pool was positively associated with TN and AK.The stable carbon pool had negative correlations with SOC,TN and AK.展开更多
Global and local climate changes could disturb carbon sequestration and carbon stocks in forest soils. Thus, it is important to characterize the stability of soil organic matter and the dynamics of soil organic carbon...Global and local climate changes could disturb carbon sequestration and carbon stocks in forest soils. Thus, it is important to characterize the stability of soil organic matter and the dynamics of soil organic carbon(SOC) fractions in forest ecosystems. This study had two aims:(1) to evaluate the effects of altitude and vegetation on the content of labile and stabile forms of organic carbon in the mountain soils; and(2) to assess the impact of the properties of soil organic matter on the SOC pools under changing environmental conditions. The studies were conducted in the Karkonosze Mountains(SW Poland, Central Europe). The content of the most labile fraction of carbon(dissolved organic carbon,DOC) decreases with altitude, but the content of fulvic acids(FA), clearly increases in the zone above 1000 m asl, while the stabile fraction(humins, nonhydrolyzing carbon) significantly decreases. A higher contribution of stabile forms was found in soils under coniferous forests(Norway spruce), while a smaller-under deciduous forests(European beech) and on grasslands. The expected climate change and the ongoing land use transformations in the zone above1000 m asl may lead to a substantial increase in the stable humus fraction(mainly of a non-hydrolyzing carbon) and an increase in the SOC pools, even if humus acids are characterized by a lower maturity and greater mobility favorable to soil podzolization.In the lower zone(below 1000 m asl), a decrease in the most stable humus forms can be expected,accompanied by an increase of DOC contribution,which will result in a reduction in SOC pools. Overall,the expected prevailing(spatial) effect is a decreasing contribution of the most stable humus fractions,which will be associated with a reduction in the SOC pools in medium-high mountains of temperate zone of Central Europe.展开更多
Agricultural soils can sequester and release large amounts of carbon. Accessibility of soil carbon to microbial attacks depends on biological, chemical, and physical protection mechanisms such as organic matter compos...Agricultural soils can sequester and release large amounts of carbon. Accessibility of soil carbon to microbial attacks depends on biological, chemical, and physical protection mechanisms such as organic matter composition and particle size, soil aggregation, and chemical protection through the silt-clayorganic matter complex. While soil and organic matter are fractal objects controlling exposure of reactive surfaces to the environment, soil aggregation and biomass production and quality are regulated by agricultural practices. Organic matter decomposition in soil is generally described by the classical first-order kinetics equations fitted to define distinct carbon pools. By comparison, fractal kinetics assigns a coefficient to adjust time-dependent decomposition rate of total soil carbon to protection mechanisms. Our objective was to relate fractal parameters of organic matter decomposition to soil management systems. Retrieving published data, the decomposition of organic matter was modeled in a silt loam soil maintained under pasture, annual cropping or bare fallow during 11 years. The classical first-order kinetics model returned quadratic relationships indicating that reactive carbon decreased with time. Fractal kinetics rectified the relationships successfully. Initial decomposition rate (k 1 at t = 1) was 7 × 10-4 for pasture, 1 × 10-4 for annual cropping, and 0.5 × 10-4 for bare-soil fallow. Fractal coefficients h were 0.71, 0.45, and 0.25 for pasture, annual cropping and fallow, respectively. Due to aggregation, physical protection against microbial attacks was highest under pasture management, leading to higher carbon sequestration despite higher biomass production and “priming” effects. Parameters k 1 and h proved to be useful indicators for soil quality classification integrating the opposite effects of labile carbon decomposition and carbon protection mechanisms that regulate the decomposition rate of organic matter with time as driven by soil management practices.展开更多
灌丛化会改变草本植物的分布格局,影响生态系统结构和功能。为了解“灌丛化”相关领域的发展现状、研究热点及前沿趋势,理清该领域研究的知识结构。本研究依托中国知网数据库(CNKI)及Web of Science(WOS)核心合集数据库,以1982~2023年...灌丛化会改变草本植物的分布格局,影响生态系统结构和功能。为了解“灌丛化”相关领域的发展现状、研究热点及前沿趋势,理清该领域研究的知识结构。本研究依托中国知网数据库(CNKI)及Web of Science(WOS)核心合集数据库,以1982~2023年“灌丛化”相关领域已发表的4114篇文献为数据源,利用VOSviewer和CiteSpace可视化软件对“灌丛化”相关研究领域发文情况(数量、趋势、被引频次)、合作关系(团队、机构、国家)和关键词等进行可视化分析。结果显示:(1)国内国际相关研究总体呈稳步增长趋势,外文研究的热度大于中文研究,且高被引论文均发表在国内外影响力较高的期刊上,表明“灌丛化”相关研究成果在该领域认可度较高,具有较高学术价值;(2)“灌丛化”相关研究国际合作关系(团队、机构、国家)较国内更为密切,且美国、中国、南非、澳大利亚及德国是“灌丛化”相关领域研究的中坚力量。(3)目前“灌丛化”相关领域的研究内容主要包括灌丛化形成机制及生物多样性对灌丛化的响应,草、灌木之间的竞争关系和土壤性质对灌丛化的响应等。研究指出:我国“灌丛化”相关研究尚处于起步阶段,且前人对灌丛化的研究多针对具体研究区域,相对分散,且合作较少;同时在全球尺度上的研究及大数据整合分析相对较少,仍需进一步研究。随着“灌丛化”研究的深入发展,灌丛化对微生物群落组成的影响、灌丛化对干旱胁迫等环境因子的响应及控制灌丛化有效措施等相关研究将在未来一段时间持续热门。展开更多
基金This project was supported by the North Dakota Agricultural Experiment Station,North Dakota State University(FARG007858).
文摘Mineralisable soil organic carbon(SOC)pools vary with ecosystem type in response to changes in climate,vegetation and soil properties.Understanding the effect of climate and soil factors on SOC pools is critical for predicting change over time.Surface soil samples from six ecoregions of the United States were analyzed for permanganate oxidizable C(KMnO4-C)and mineralizable C pools.Variations of SOC ranged from 7.9 mg g^-1(Florida site)to 325 mg g^-1(Hawaii site).Mineralisable C pools and KMnO4-C were highest in soils from the Hawaii site.Mean annual precipitation explains SOC and resistant C pool variations.Clay content was related to mineralisable active C pools and bacterial abundance.Mean annual precipitation and clay content are potential variables for predicting changes in SOC pools at large spatial scales.
文摘Biochar is a carbon-rich(】60%)organic material derived from incomplete combustion of fossil fuels and biomass.It consists of a continuum ranging from slightly charred material through char and charcoal to soot,and is ubiquitous in the atmosphere,marine sediment,soil and water.Moreover,】80%of biochar produced ends up in soils,where it resides for hundreds to thousands of years.Because of its resistance to biological and chemical breakdown, biochar can serve as a pool of C with long residence time in the soil.As a result,there has been increasing attention given to the potential of biochar to sequestrate carbon and counteract
基金Supported by the National Key Research and Development Program(No.2016YFD0300208)the National Natural Science Foundation of China(No.41661070)
文摘It is of important referential values for the further understanding of the effects of fertilization on greenhouse gas emissions and the effects of winter green manure on soil carbon pool to study the effects of fertilization on the greenhouse gas emissions and soil carbon pool during the growing season of winter Chinese milk vetch in the process of rice cultivation.This study investigated the effects of nitrogen application in late rice season on the yield of the succeeding Chinese milk vetch and greenhouse gas emissions as well as the soil carbon pool characteristics after the winter planting of Chinese milk vetch with the winter idling of no nitrogen application as the control.The results showed that the yield of Chinese milk vetch was the highest under the nitrogen application of 225 kg/hm^2 in the late rice season,reaching up to 18 388.97 kg/hm^2,which was significantly different from other treatments( P <0.05).Nitrogen application in late rice season increased the emissions of N_2 O,CH_4,CO_2 and global warming potential( GWP) in the growing season of Chinese milk vetch.Compared with the winter idling treatment,winter planting of Chinese milk vetch significantly increased the soil organic carbon and soil carbon pool management index.The yield of Chinese milk vetch was significantly positively correlated with N_2O and CH_4 emissions( P < 0.05),while it presented extremely significant positive correlations with CO_2 emissions,GWP,active organic carbon,and carbon pool management index( P < 0.01).Nitrogen application in the late rice season increased the emissions of N_2 O,CH_4,CO_2,and enhanced the greenhouse gas emission potential during the growing season of Chinese milk vetch.Therefore,without reducing the yield of rice,reducing the amount of nitrogen fertilizer in rice could reduce the greenhouse gas emissions in the growing season of succeeding Chinese milk vetch.
基金Supported by the Work Project of China Geological Survey (1212010911062)Guangxi Zhuang Autonomous Region Innovation Project (0842008)National Natural Science Foundation (40872213)
文摘The three-pool and first-order model separates the mineralizable organic carbon into active,slow,and passive carbon pools.This paper used the model and decomposition curves of the soil organic carbon to fit the active pool and its decomposition rate,slow pool and its decomposition rate.The results showed that the size of the active pool from different profiles accounted for 2.09%-3.08% of the total soil organic carbon and the mean residue time was 3.57-17.21 days.And the size of the slow pool accounted for 3.19%-43.55% and the mean residue time was 1.12-4.94 years.Acid hydrolysis(6M HCl) was used to fractionate the passive organic carbon,which accounted for 50.83%-94.44% of the total soil organic carbon.
基金jointly supported by National Key R&D Program of China(Grant No.2017YFC0504002)Natural Science Foundation of China(No.31270679)
文摘Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the dynamics of SOC mineralization and its correlations with other soil properties in a young forest and mid-aged forest at soil depths of 0–10,>10–20,>20–40 and>40–60 cm.The results showed that compared with a mid-aged forest,the SOC stock in the young forest was 32%higher.Potentially mineralizable soil carbon(C0)in the young forest was 1.1–2.5 g kg^-1,accounting for 5.5–8.1%of total SOC during the 105 days incubation period and 0.3–1.5 g kg^-1 in the mid-aged forest at different soil depths,occupying 2.8–3.4%of total SOC.There was a significant difference in C0 among the soil depths.The dynamics of the SOC mineralization was a good fit to a three-pool(labile,intermediate and stable)carbon decomposition kinetic model.The SOC decomposition rate for different stand ages and different soil depths reached high levels for the first 15 days.Correlation analysis revealed that the C0 was significantly positively related with SOC content,soil total N(TN)and readily available K(AK)concentration.The labile soil carbon pool was significantly related to SOC and TN concentration,and significantly negatively correlated with soil bulk density.The intermediate carbon pool was positively associated with TN and AK.The stable carbon pool had negative correlations with SOC,TN and AK.
基金financially supported by the National Science Centre as research grant No2013/11/N/ST10/01528
文摘Global and local climate changes could disturb carbon sequestration and carbon stocks in forest soils. Thus, it is important to characterize the stability of soil organic matter and the dynamics of soil organic carbon(SOC) fractions in forest ecosystems. This study had two aims:(1) to evaluate the effects of altitude and vegetation on the content of labile and stabile forms of organic carbon in the mountain soils; and(2) to assess the impact of the properties of soil organic matter on the SOC pools under changing environmental conditions. The studies were conducted in the Karkonosze Mountains(SW Poland, Central Europe). The content of the most labile fraction of carbon(dissolved organic carbon,DOC) decreases with altitude, but the content of fulvic acids(FA), clearly increases in the zone above 1000 m asl, while the stabile fraction(humins, nonhydrolyzing carbon) significantly decreases. A higher contribution of stabile forms was found in soils under coniferous forests(Norway spruce), while a smaller-under deciduous forests(European beech) and on grasslands. The expected climate change and the ongoing land use transformations in the zone above1000 m asl may lead to a substantial increase in the stable humus fraction(mainly of a non-hydrolyzing carbon) and an increase in the SOC pools, even if humus acids are characterized by a lower maturity and greater mobility favorable to soil podzolization.In the lower zone(below 1000 m asl), a decrease in the most stable humus forms can be expected,accompanied by an increase of DOC contribution,which will result in a reduction in SOC pools. Overall,the expected prevailing(spatial) effect is a decreasing contribution of the most stable humus fractions,which will be associated with a reduction in the SOC pools in medium-high mountains of temperate zone of Central Europe.
文摘Agricultural soils can sequester and release large amounts of carbon. Accessibility of soil carbon to microbial attacks depends on biological, chemical, and physical protection mechanisms such as organic matter composition and particle size, soil aggregation, and chemical protection through the silt-clayorganic matter complex. While soil and organic matter are fractal objects controlling exposure of reactive surfaces to the environment, soil aggregation and biomass production and quality are regulated by agricultural practices. Organic matter decomposition in soil is generally described by the classical first-order kinetics equations fitted to define distinct carbon pools. By comparison, fractal kinetics assigns a coefficient to adjust time-dependent decomposition rate of total soil carbon to protection mechanisms. Our objective was to relate fractal parameters of organic matter decomposition to soil management systems. Retrieving published data, the decomposition of organic matter was modeled in a silt loam soil maintained under pasture, annual cropping or bare fallow during 11 years. The classical first-order kinetics model returned quadratic relationships indicating that reactive carbon decreased with time. Fractal kinetics rectified the relationships successfully. Initial decomposition rate (k 1 at t = 1) was 7 × 10-4 for pasture, 1 × 10-4 for annual cropping, and 0.5 × 10-4 for bare-soil fallow. Fractal coefficients h were 0.71, 0.45, and 0.25 for pasture, annual cropping and fallow, respectively. Due to aggregation, physical protection against microbial attacks was highest under pasture management, leading to higher carbon sequestration despite higher biomass production and “priming” effects. Parameters k 1 and h proved to be useful indicators for soil quality classification integrating the opposite effects of labile carbon decomposition and carbon protection mechanisms that regulate the decomposition rate of organic matter with time as driven by soil management practices.
文摘灌丛化会改变草本植物的分布格局,影响生态系统结构和功能。为了解“灌丛化”相关领域的发展现状、研究热点及前沿趋势,理清该领域研究的知识结构。本研究依托中国知网数据库(CNKI)及Web of Science(WOS)核心合集数据库,以1982~2023年“灌丛化”相关领域已发表的4114篇文献为数据源,利用VOSviewer和CiteSpace可视化软件对“灌丛化”相关研究领域发文情况(数量、趋势、被引频次)、合作关系(团队、机构、国家)和关键词等进行可视化分析。结果显示:(1)国内国际相关研究总体呈稳步增长趋势,外文研究的热度大于中文研究,且高被引论文均发表在国内外影响力较高的期刊上,表明“灌丛化”相关研究成果在该领域认可度较高,具有较高学术价值;(2)“灌丛化”相关研究国际合作关系(团队、机构、国家)较国内更为密切,且美国、中国、南非、澳大利亚及德国是“灌丛化”相关领域研究的中坚力量。(3)目前“灌丛化”相关领域的研究内容主要包括灌丛化形成机制及生物多样性对灌丛化的响应,草、灌木之间的竞争关系和土壤性质对灌丛化的响应等。研究指出:我国“灌丛化”相关研究尚处于起步阶段,且前人对灌丛化的研究多针对具体研究区域,相对分散,且合作较少;同时在全球尺度上的研究及大数据整合分析相对较少,仍需进一步研究。随着“灌丛化”研究的深入发展,灌丛化对微生物群落组成的影响、灌丛化对干旱胁迫等环境因子的响应及控制灌丛化有效措施等相关研究将在未来一段时间持续热门。
