Climate change will alter the capacity of carbon sequestration,and the risk assessment of carbon sequestration for terrestrial ecosystems will be helpful to the decision-making for climate change countermeasures and i...Climate change will alter the capacity of carbon sequestration,and the risk assessment of carbon sequestration for terrestrial ecosystems will be helpful to the decision-making for climate change countermeasures and international climate negotiations.Based on the net ecosystem productivity of terrestrial ecosystems simulated by Atmosphere Vegetation Integrated Model,each grid of the risk criterion was set by time series trend analysis.Then the risks of carbon sequestration of terrestrial ecosystems were investigated.The results show that,in the IPCCSRES-B2 climate scenario,climate change will bring risks of carbon sequestration,and the high-risk level will dominate terrestrial ecosystems.The risk would expand with the increase of warming degree.By the end of the long-term of this century,about 60% of the whole country will face the risk;Northwest China,mountainous areas in Northeast China,middle and lower reaches plain of Yangtze River areas,Southwest China and Southeast China tend to be extremely vulnerable.Risk levels in most regions are likely to grow with the increase of warming degree,and this increase will mainly occur during the near-term to mid-term.Northwest China will become an area of high risks,and deciduous coniferous forests,temperate mixed forests and desert grassland tend to be extremely vulnerable.展开更多
This article reviews recent advances over the past and their relationship to climate change in China. The was 0.19-0.26 Pg C yr-1 for the 1980s and 1990s. 4 years in the study of the carbon-nitrogen cycling net carbon...This article reviews recent advances over the past and their relationship to climate change in China. The was 0.19-0.26 Pg C yr-1 for the 1980s and 1990s. 4 years in the study of the carbon-nitrogen cycling net carbon sink in the Chinese terrestrial ecosystem Both natural wetlands and the rice-paddy regions emitted 1.76 Tg and 6.62 Tg of CH4 per year for the periods 1995 2004 and 2005 2009, respectively. China emitted -1.1 Tg N20-N yr-1 to the atmosphere in 2004. Land soil contained -8.3 Pg N. The excess nitrogen stored in farmland of the Yangtze River basin reached 1.51 Tg N and 2.67 Tg N in 1980 and 1990, respectively. The outer Yangtze Estuary served as a moderate or significant sink of atmospheric CO2 except in autumn. Phytoplankton could take up carbon at a rate of 6.4 ×1011 kg yr-1 in the China Sea. The global ocean absorbed anthropogenic CO2 at the rates of 1.64 and 1.73 Pg C yr-1 for two sinmlations in the 1990s. Land net ecosystem production in China would increase until the mid-21st century then would decrease gradually under future climate change scenarios. This research should be strengthened in the future, including collection of more observation data, measurement of the soil organic carbon (SOC) loss and sequestration, evaluation of changes in SOC in deep soil layers, and the impacts of grassland management, carbon-nitrogen coupled effects, and development and improvement of various component models and of the coupled carbon cycle-climate model.展开更多
In this paper, we use CEVSA, a process-based model, which has been validated on regional and global scales, to explore the temporal and spatial patterns of Net Primary Productivity (NPP) a...In this paper, we use CEVSA, a process-based model, which has been validated on regional and global scales, to explore the temporal and spatial patterns of Net Primary Productivity (NPP) and its responses to interannual climate fluctuations in China's terrestrial ecosystems over the period 1981-1998. The estimated results suggest that, in this study period, the averaged annual total NPP is about 3.09 Gt C/yr -1 and average NPP is about 342 g C/m 2 . The results also showed that the precipitation was the key factor determining the spatial distribution and temporal trends of NPP. Temporally, the total NPP exhibited a slowly increasing trend. In some ENSO years (e.g. 1982, 1986, 1997) NPP decreased clearly compared to the previous year, but the relationship between ENSO and NPP is complex due to the integrated effects of monsoons and regional differentiation. Spatially, the relatively high NPP occurred at the middle high latitudes, the low latitudes and the lower appeared at the middle latitudes. On national scale, precipitation is the key control factor on NPP variations and there exists a weak correlation between NPP and temperature, but regional responses are greatly different.展开更多
In the past,evaluations of ecosystem functions were mostly based on Costanza's model,whereas the spatial,quality and temporal characteristics of regional ecosystems were not considered in the model.Focusing on the...In the past,evaluations of ecosystem functions were mostly based on Costanza's model,whereas the spatial,quality and temporal characteristics of regional ecosystems were not considered in the model.Focusing on these issues,coefficients of regional difference,spatial heterogeneity and willingness-to-pay(WTP)were established to modify Costanza's model,and a new comprehensive valuation model of ecosystem functions is proposed.The analytical results indicate that the comprehensive model could evaluate regional ecosystem functions in China accurately and provide more helpful information for decision-making.The empirical study on Zhangbei County in Hebei Province shows that the intensive human activities could limit the provision of ecosystem functions while the planned ecological programs might promote the restoration of ecosystem functions.展开更多
This paper presents the latest developments in the re search progress on mechanisms by which natural plants and crops respond to the doubled concentration of CO2 in the atmosphere, resultant climatic change and the mo...This paper presents the latest developments in the re search progress on mechanisms by which natural plants and crops respond to the doubled concentration of CO2 in the atmosphere, resultant climatic change and the modeling of vegetation and eco-systems in China. In addition, it points out that the future study on global change and terrestrial ecosystems should stress m(?)iti-disciplinary teamwork and inter-discipline penetration. Finally, the paper emphasizes 10 research realms in the field to be enhanced in the future.展开更多
The present study provides an overview of existing literature on changes in soil organic carbon(SOC) of various terrestrial ecosystems in China.Datasets from the literature suggest that SOC stocks in forest,grassland,...The present study provides an overview of existing literature on changes in soil organic carbon(SOC) of various terrestrial ecosystems in China.Datasets from the literature suggest that SOC stocks in forest,grassland,shrubland and cropland increased between the early 1980s and the early 2000s,amounting to(71±19) Tg·a-1.Conversion of marshland to cropland in the Sanjiang Plain of northeast China resulted in SOC loss of(6±2) Tg·a-1 during the same period.Nevertheless,large uncertainties exist in these estimates,especially for the SOC changes in the forest,shrubland and grassland.To reduce uncertainty,we suggest that future research should focus on:(i) identifying land use changes throughout China with high spatiotemporal resolution,and measuring the SOC loss and sequestration due to land use change;(ii) estimating the changes in SOC of shrubland and non-forest trees(i.e.,cash,shelter and landscape trees);(iii) quantifying the impacts of grassland management on the SOC pool;(iv) evaluating carbon changes in deep soil layers;(v) projecting SOC sequestration potential;and(vi) developing carbon budget models for better estimating the changes in SOC of terrestrial ecosystems in China.展开更多
Physical geography is the cornerstone of geography. In this article, the starting points of disciplines in physical geography in recent years in China are discussed. With the coupling of systems set as the research ob...Physical geography is the cornerstone of geography. In this article, the starting points of disciplines in physical geography in recent years in China are discussed. With the coupling of systems set as the research object, and sustainable development as the ultimate goal, the upgrade of physical geography can be deconstructed into three steps: deepen physical geography from the perspective of pattern-process coupling, improve the focus of physical geography from ecosystem processes to ecosystem services, and increase the understanding of the physical geography ‘pattern, process, service, sustainability' research cascade. The incorporation of human activities into physical geographic processes is essential to conduct integrated analysis on physical and human factors at different scales. The development of ecosystem service models that couple supply-demand and sustainable development are of great importance to bridge the role of ecosystem services between the natural environment and human well-being. Moreover, human-land systems and sustainable development have become the core areas and frontiers of integrated physical geography and even geography in general. China faces the great strategic demand of constructing an ecological civilization in a new era, and the development of the disciplines of physical geography should give full access to the advantages of intersecting and comprehensive disciplines, focus on the human-land system patterns,processes, and services in key research areas, and provide disciplinary support for regional, national, and global sustainable development.展开更多
Understanding the spatial variation in annual actual evapotranspiration (AET) and its influencing factors is crucial for a better understanding of hydrological processes and water resources management. By synthesizi...Understanding the spatial variation in annual actual evapotranspiration (AET) and its influencing factors is crucial for a better understanding of hydrological processes and water resources management. By synthesizing ecosystem-level observations of eddy-covariance flux sites in China (a total of 61 sites), we constructed the most complete AET dataset in China up to now. Based on this dataset, we quantified the statistic characteristics of AET and water budgets (defined as the ratio of AET to annual mean precipitation (MAP), AET/MAP) of terrestrial ecosystems in China. Results showed that AET differed significantly among both different vegetation types and climate types in China, with overall mean AET of 534.7+232.8 mm yr1. AET/MAP also differed significantly among different climate types, but there were no distinct differences in AET/MAP values across vegetation types, with mean AET/MAP of 0.82+0.28 for non-irrigated ecosystems. We further investigated how the main climatic factors and vegetation attributes control the spatial variation in AET. Our findings revealed that the spatial variation of AET in China was closely correlated with the geographical patterns of climate and vegetation, in which the effects of total annual net radiation (Ro), MAP and mean annual air temperature (MAT) were dominant. Thus, we proposed an empirical equation to describe the spatial patterns of AET in China, which could explain about 84% of the spatial variation in AET of terrestrial ecosystems in China. Based on the constructed dataset, we also evaluated the uncertainties of five published global evapotranspiration products in simulating site-specific AET in China. Results showed that large biases in site-specific AET values existed for all five global evapotranspiration products, which indicated that it is necessary to involve more observation data of China in their parameterization or validation, while our AET dataset would provide a data source for it.展开更多
Atotal of 13.86 million rural poor were raised out of poverty, and 2.8 million people living in remote areas, areas frequently hit by natural disasters, or areas with fragile ecosystems were relocated and are living w...Atotal of 13.86 million rural poor were raised out of poverty, and 2.8 million people living in remote areas, areas frequently hit by natural disasters, or areas with fragile ecosystems were relocated and are living well-off lives in 2018, said Premier Li Keqiang in the Report on the Work of the Government he delivered on March 5.展开更多
The projected changes in carbon exchange between China terrestrial ecosystem and the atmosphere and vegetation and soil carbon storage during the 21st century were investigated using an atmos-phere-vegetation interact...The projected changes in carbon exchange between China terrestrial ecosystem and the atmosphere and vegetation and soil carbon storage during the 21st century were investigated using an atmos-phere-vegetation interaction model (AVIM2). The results show that in the coming 100 a, for SRES B2 scenario and constant atmospheric CO2 concentration, the net primary productivity (NPP) of terrestrial ecosystem in China will be decreased slowly, and vegetation and soil carbon storage as well as net ecosystem productivity (NEP) will also be decreased. The carbon sink for China terrestrial ecosystem in the beginning of the 20th century will become totally a carbon source by the year of 2020, while for B2 scenario and changing atmospheric CO2 concentration, NPP for China will increase continuously from 2.94 GtC·a?1 by the end of the 20th century to 3.99 GtC·a?1 by the end of the 21st century, and vegetation and soil carbon storage will increase to 110.3 GtC. NEP in China will keep rising during the first and middle periods of the 21st century, and reach the peak around 2050s, then will decrease gradually and approach to zero by the end of the 21st century.展开更多
As the third largest country in the world, China has highly variable environmental condition and eco- logical pattern in both space and time. Quantification of the spatial-temporal pattern and dynamic of terrestrial e...As the third largest country in the world, China has highly variable environmental condition and eco- logical pattern in both space and time. Quantification of the spatial-temporal pattern and dynamic of terrestrial ecosystem carbon cycle in China is of great significance to regional and global carbon budget. In this study, we used a high-resolution climate database and an improved ecosystem process-based model to quantify spatio-temporal pattern and dynamic of net ecosystem productivity (NEP) in China and its responses to climate change during 1981 to 2000. The results showed that NEP increased from north to south and from northeast to southwest. Positive NEP (carbon sinks) occurred in the west of Southwest China, southeastern Tibet, Sanjiang Plain, Da Hinggan Mountains and the mid-west of North China. Negative NEP (carbon sources) were mainly found in Central China, the south of Southwest China, the north of Xinjiang, west and north of Inner Mongolia, and parts of North China. From the 1980s to 1990s, the increasing trend of NEP occurred in the middle of Northeast China Plain and the Loess Plateau and decreasing trends mainly occurred in a greater part of Central China. In the study period, natural forests had minimal carbon uptake, while grassland and shrublands accounted for nearly three fourths of the total carbon terrestrial uptakes in China during 1981―2000.展开更多
China announced its national goal to reach the peak of carbon emission by 2030 and achieve carbon neutrality by 2060,during the General Assembly of the United Nations in September 2020.In this context,the potential of...China announced its national goal to reach the peak of carbon emission by 2030 and achieve carbon neutrality by 2060,during the General Assembly of the United Nations in September 2020.In this context,the potential of the carbon sink in China’s terrestrial ecosystems to mitigate anthropogenic carbon emissions has attracted unprecedented attention from scientific communities,policy makers and the public.Here,we reviewed the assessments on China’s terrestrial ecosystem carbon sink,with focus on the principles,frameworks and methods of terrestrial ecosystem carbon sink estimates,as well as the recent progress and existing problems.Looking forward,we identified critical issues for improving the accuracy and precision of China’s terrestrial ecosystem carbon sink,in order to serve the more realistic policy making in pathways to achieve carbon neutrality for China.展开更多
Stable carbon isotopes of C3 and C4 plants have completely distinct δ13C values respectively. Carbonate in tooth enamel of herbivorous mammals is significantly and regularly enriched in 13C compared to source carbon....Stable carbon isotopes of C3 and C4 plants have completely distinct δ13C values respectively. Carbonate in tooth enamel of herbivorous mammals is significantly and regularly enriched in 13C compared to source carbon. As a result, we can reconstruct distributions of C3 and C4 plants in geological history based on carbon isotopes of mammalian tooth enamel. Carbon isotopes of 70 mammalian tooth enamel samples from 11 Quaternary localities in northern China are analyzed. This analysis indicates that C3 plants were dominant in the terrestrial ecosystem of northern China during the Quaternary, which is completely different from Pakistan with relatively close latitudes where C4 plants were absolutely dominant. The great difference was caused by the uplift of the Tibetan Plateau. A simulation implied that a marked temperature decrease would happen in the north side of the Tibetan Plateau, but a temperature increase in the south side. The warming condition caused the transition from C3 to C4 plants in Pakistan展开更多
Using China's ground observations,e.g.,forest inventory,grassland resource,agricultural statistics,climate,and satellite data,we estimate terrestrial vegetation carbon sinks for China's major biomes between 19...Using China's ground observations,e.g.,forest inventory,grassland resource,agricultural statistics,climate,and satellite data,we estimate terrestrial vegetation carbon sinks for China's major biomes between 1981 and 2000.The main results are in the following:(1)Forest area and forest biomass car-bon(C)stock increased from 116.5×10^(6) ha and 4.3 Pg C(1 Pg C=10^(15) g C)in the early 1980s to 142.8×10^(6) ha and 5.9 Pg C in the early 2000s,respectively.Forest biomass carbon density increased form 36.9 Mg C/ha(1 Mg C=10^(6) g C)to 41.0 Mg C/ha,with an annual carbon sequestration rate of 0.075 Pg C/a.Grassland,shrub,and crop biomass sequestrate carbon at annual rates of 0.007 Pg C/a,0.014―0.024 Pg C/a,and 0.0125―0.0143 Pg C/a,respectively.(2)The total terrestrial vegetation C sink in China is in a range of 0.096―0.106 Pg C/a between 1981 and 2000,accounting for 14.6%―16.1%of carbon dioxide(CO_(2))emitted by China's industry in the same period.In addition,soil carbon sink is estimated at 0.04―0.07 Pg C/a.Accordingly,carbon sequestration by China's terrestrial ecosystems(vegetation and soil)offsets 20.8%―26.8%of its industrial CO_(2) emission for the study period.(3)Considerable uncertainties exist in the present study,especially in the estimation of soil carbon sinks,and need further intensive investigation in the future.展开更多
Since Westman(1977) and Ehrlich(1982) put forward the concepts of "the service of nature" and "ecosystem service functions",respectively,methods for conducting value accounting for them,and their p...Since Westman(1977) and Ehrlich(1982) put forward the concepts of "the service of nature" and "ecosystem service functions",respectively,methods for conducting value accounting for them,and their practical application have become the subjects of intense study.Based on an overview of available research findings,we discuss three scientific hypotheses.First,the terrestrial ecosystem offers both positive and negative service functions.Second,changes in terrestrial ecosystem service functions lie not only in the number of ecosystem types and the coverage area of each type,but also in their quality.Third,the value of terrestrial ecosystem service functions should be assessed both in terms of the value stocked and the value added.We collected land use data from China during the period 1999-2008,and Normalized Difference Vegetation Index data based on remote sensing images from the Global Inventory Modeling and Mapping Studies for the same period.We then calculated and analyzed spatial and temporal changes in China's terrestrial ecosystem service values over the 10-year period.Considering temporal change,the total value(stocked) of China's terrestrial ecosystem service functions decreased from 6.82 trillion Yuan RMB in 1999 to 6.57 trillion Yuan RMB in 2008.During that period,the positive value decreased by 240.17 billion Yuan RMB and the negative value increased by 8.85 billion Yuan RMB.The decrease in total value lies mainly in the humidity control,soil formation,and waste recycling functions.The total value(added) of China's terrestrial ecosystem service functions increased by 4.31 billion Yuan RMB in 2000,but decreased by 0.13 billion Yuan RMB in 2008(based on the constant price of China in 1999).The value(added) was a negative figure.From the perspective of spatial change,we can see that the supply of China's terrestrial ecosystem service functions fell slightly over the past 10 years,mainly in Northeast and Southern China.As a result of human activities on ecosystems,the loss of ecosystem service functions' value was relatively prominent in Shanxi and Gansu provinces,compared with an increase in value in Shaanxi Province.Terrestrial ecosystem service functions' value per unit area was relatively high in mid-and East China,showing a prominent spatial change over the 10-year period,but low in Western China.Some conclusions are drawn after an in-depth analysis of the factors causing the spatial and temporal changes in China's terrestrial ecosystem service functions,in the hope that our suggestions will be helpful for the management of China's terrestrial ecosystems.展开更多
文摘Climate change will alter the capacity of carbon sequestration,and the risk assessment of carbon sequestration for terrestrial ecosystems will be helpful to the decision-making for climate change countermeasures and international climate negotiations.Based on the net ecosystem productivity of terrestrial ecosystems simulated by Atmosphere Vegetation Integrated Model,each grid of the risk criterion was set by time series trend analysis.Then the risks of carbon sequestration of terrestrial ecosystems were investigated.The results show that,in the IPCCSRES-B2 climate scenario,climate change will bring risks of carbon sequestration,and the high-risk level will dominate terrestrial ecosystems.The risk would expand with the increase of warming degree.By the end of the long-term of this century,about 60% of the whole country will face the risk;Northwest China,mountainous areas in Northeast China,middle and lower reaches plain of Yangtze River areas,Southwest China and Southeast China tend to be extremely vulnerable.Risk levels in most regions are likely to grow with the increase of warming degree,and this increase will mainly occur during the near-term to mid-term.Northwest China will become an area of high risks,and deciduous coniferous forests,temperate mixed forests and desert grassland tend to be extremely vulnerable.
基金supported by the National Key Basic Research Development Program of China (Grant Nos. 2010CB950604 and 2010CB951802)the National Natural Science Foundation of China (Grant No. 40730106, 41075091)
文摘This article reviews recent advances over the past and their relationship to climate change in China. The was 0.19-0.26 Pg C yr-1 for the 1980s and 1990s. 4 years in the study of the carbon-nitrogen cycling net carbon sink in the Chinese terrestrial ecosystem Both natural wetlands and the rice-paddy regions emitted 1.76 Tg and 6.62 Tg of CH4 per year for the periods 1995 2004 and 2005 2009, respectively. China emitted -1.1 Tg N20-N yr-1 to the atmosphere in 2004. Land soil contained -8.3 Pg N. The excess nitrogen stored in farmland of the Yangtze River basin reached 1.51 Tg N and 2.67 Tg N in 1980 and 1990, respectively. The outer Yangtze Estuary served as a moderate or significant sink of atmospheric CO2 except in autumn. Phytoplankton could take up carbon at a rate of 6.4 ×1011 kg yr-1 in the China Sea. The global ocean absorbed anthropogenic CO2 at the rates of 1.64 and 1.73 Pg C yr-1 for two sinmlations in the 1990s. Land net ecosystem production in China would increase until the mid-21st century then would decrease gradually under future climate change scenarios. This research should be strengthened in the future, including collection of more observation data, measurement of the soil organic carbon (SOC) loss and sequestration, evaluation of changes in SOC in deep soil layers, and the impacts of grassland management, carbon-nitrogen coupled effects, and development and improvement of various component models and of the coupled carbon cycle-climate model.
基金Knowledge Innovation Project of IGSNRR CAS No.CXIOG-E01-02-04
文摘In this paper, we use CEVSA, a process-based model, which has been validated on regional and global scales, to explore the temporal and spatial patterns of Net Primary Productivity (NPP) and its responses to interannual climate fluctuations in China's terrestrial ecosystems over the period 1981-1998. The estimated results suggest that, in this study period, the averaged annual total NPP is about 3.09 Gt C/yr -1 and average NPP is about 342 g C/m 2 . The results also showed that the precipitation was the key factor determining the spatial distribution and temporal trends of NPP. Temporally, the total NPP exhibited a slowly increasing trend. In some ENSO years (e.g. 1982, 1986, 1997) NPP decreased clearly compared to the previous year, but the relationship between ENSO and NPP is complex due to the integrated effects of monsoons and regional differentiation. Spatially, the relatively high NPP occurred at the middle high latitudes, the low latitudes and the lower appeared at the middle latitudes. On national scale, precipitation is the key control factor on NPP variations and there exists a weak correlation between NPP and temperature, but regional responses are greatly different.
基金supported by National Natural Science Foundation of China(Grant No.40171001)National Science and Technology Support Program(Grant No.2006BAB15B02-04)+1 种基金Key Fundamental Item of Hebei Province(Grant No.08966712D)Key Discipline Construction Item of Physical Geography of Hebei Province
文摘In the past,evaluations of ecosystem functions were mostly based on Costanza's model,whereas the spatial,quality and temporal characteristics of regional ecosystems were not considered in the model.Focusing on these issues,coefficients of regional difference,spatial heterogeneity and willingness-to-pay(WTP)were established to modify Costanza's model,and a new comprehensive valuation model of ecosystem functions is proposed.The analytical results indicate that the comprehensive model could evaluate regional ecosystem functions in China accurately and provide more helpful information for decision-making.The empirical study on Zhangbei County in Hebei Province shows that the intensive human activities could limit the provision of ecosystem functions while the planned ecological programs might promote the restoration of ecosystem functions.
文摘This paper presents the latest developments in the re search progress on mechanisms by which natural plants and crops respond to the doubled concentration of CO2 in the atmosphere, resultant climatic change and the modeling of vegetation and eco-systems in China. In addition, it points out that the future study on global change and terrestrial ecosystems should stress m(?)iti-disciplinary teamwork and inter-discipline penetration. Finally, the paper emphasizes 10 research realms in the field to be enhanced in the future.
基金supported by the A3 Foresight Program (Grant No. 30721140306),National Science Foundation of China, the Knowledge Innovation Program (Grant No. KZCX2-YW-Q1-15)Chinese Academy of Sciences, and the National High-Tech Research and Development Program of China (Grant No. 2009AA12Z1462)
文摘The present study provides an overview of existing literature on changes in soil organic carbon(SOC) of various terrestrial ecosystems in China.Datasets from the literature suggest that SOC stocks in forest,grassland,shrubland and cropland increased between the early 1980s and the early 2000s,amounting to(71±19) Tg·a-1.Conversion of marshland to cropland in the Sanjiang Plain of northeast China resulted in SOC loss of(6±2) Tg·a-1 during the same period.Nevertheless,large uncertainties exist in these estimates,especially for the SOC changes in the forest,shrubland and grassland.To reduce uncertainty,we suggest that future research should focus on:(i) identifying land use changes throughout China with high spatiotemporal resolution,and measuring the SOC loss and sequestration due to land use change;(ii) estimating the changes in SOC of shrubland and non-forest trees(i.e.,cash,shelter and landscape trees);(iii) quantifying the impacts of grassland management on the SOC pool;(iv) evaluating carbon changes in deep soil layers;(v) projecting SOC sequestration potential;and(vi) developing carbon budget models for better estimating the changes in SOC of terrestrial ecosystems in China.
基金Under the auspices of Key Research Program of Frontier Sciences of Chinese Academy of Sciences(No.QYZDY-SSW-DQC025)National Key Research and Development Program of China(No.2017YFA0604701)
文摘Physical geography is the cornerstone of geography. In this article, the starting points of disciplines in physical geography in recent years in China are discussed. With the coupling of systems set as the research object, and sustainable development as the ultimate goal, the upgrade of physical geography can be deconstructed into three steps: deepen physical geography from the perspective of pattern-process coupling, improve the focus of physical geography from ecosystem processes to ecosystem services, and increase the understanding of the physical geography ‘pattern, process, service, sustainability' research cascade. The incorporation of human activities into physical geographic processes is essential to conduct integrated analysis on physical and human factors at different scales. The development of ecosystem service models that couple supply-demand and sustainable development are of great importance to bridge the role of ecosystem services between the natural environment and human well-being. Moreover, human-land systems and sustainable development have become the core areas and frontiers of integrated physical geography and even geography in general. China faces the great strategic demand of constructing an ecological civilization in a new era, and the development of the disciplines of physical geography should give full access to the advantages of intersecting and comprehensive disciplines, focus on the human-land system patterns,processes, and services in key research areas, and provide disciplinary support for regional, national, and global sustainable development.
基金National Natural Science Foundation of China,No.31290221,No.31420103917
文摘Understanding the spatial variation in annual actual evapotranspiration (AET) and its influencing factors is crucial for a better understanding of hydrological processes and water resources management. By synthesizing ecosystem-level observations of eddy-covariance flux sites in China (a total of 61 sites), we constructed the most complete AET dataset in China up to now. Based on this dataset, we quantified the statistic characteristics of AET and water budgets (defined as the ratio of AET to annual mean precipitation (MAP), AET/MAP) of terrestrial ecosystems in China. Results showed that AET differed significantly among both different vegetation types and climate types in China, with overall mean AET of 534.7+232.8 mm yr1. AET/MAP also differed significantly among different climate types, but there were no distinct differences in AET/MAP values across vegetation types, with mean AET/MAP of 0.82+0.28 for non-irrigated ecosystems. We further investigated how the main climatic factors and vegetation attributes control the spatial variation in AET. Our findings revealed that the spatial variation of AET in China was closely correlated with the geographical patterns of climate and vegetation, in which the effects of total annual net radiation (Ro), MAP and mean annual air temperature (MAT) were dominant. Thus, we proposed an empirical equation to describe the spatial patterns of AET in China, which could explain about 84% of the spatial variation in AET of terrestrial ecosystems in China. Based on the constructed dataset, we also evaluated the uncertainties of five published global evapotranspiration products in simulating site-specific AET in China. Results showed that large biases in site-specific AET values existed for all five global evapotranspiration products, which indicated that it is necessary to involve more observation data of China in their parameterization or validation, while our AET dataset would provide a data source for it.
文摘Atotal of 13.86 million rural poor were raised out of poverty, and 2.8 million people living in remote areas, areas frequently hit by natural disasters, or areas with fragile ecosystems were relocated and are living well-off lives in 2018, said Premier Li Keqiang in the Report on the Work of the Government he delivered on March 5.
基金the Basic Research Program of China (Grant No. 2002CB412500)the National Natural Science Foundation of China (Grant No. 30590384)
文摘The projected changes in carbon exchange between China terrestrial ecosystem and the atmosphere and vegetation and soil carbon storage during the 21st century were investigated using an atmos-phere-vegetation interaction model (AVIM2). The results show that in the coming 100 a, for SRES B2 scenario and constant atmospheric CO2 concentration, the net primary productivity (NPP) of terrestrial ecosystem in China will be decreased slowly, and vegetation and soil carbon storage as well as net ecosystem productivity (NEP) will also be decreased. The carbon sink for China terrestrial ecosystem in the beginning of the 20th century will become totally a carbon source by the year of 2020, while for B2 scenario and changing atmospheric CO2 concentration, NPP for China will increase continuously from 2.94 GtC·a?1 by the end of the 20th century to 3.99 GtC·a?1 by the end of the 21st century, and vegetation and soil carbon storage will increase to 110.3 GtC. NEP in China will keep rising during the first and middle periods of the 21st century, and reach the peak around 2050s, then will decrease gradually and approach to zero by the end of the 21st century.
基金Supported by the Ministry of Science and Technology of China (G2002CB412507)the Major Program of the National Natural Science Foundation of China (Grant No.30590384)the "Hundred Talent" Program of the Chinese Academy of Sciences, and K C WONE Education Foundation
文摘As the third largest country in the world, China has highly variable environmental condition and eco- logical pattern in both space and time. Quantification of the spatial-temporal pattern and dynamic of terrestrial ecosystem carbon cycle in China is of great significance to regional and global carbon budget. In this study, we used a high-resolution climate database and an improved ecosystem process-based model to quantify spatio-temporal pattern and dynamic of net ecosystem productivity (NEP) in China and its responses to climate change during 1981 to 2000. The results showed that NEP increased from north to south and from northeast to southwest. Positive NEP (carbon sinks) occurred in the west of Southwest China, southeastern Tibet, Sanjiang Plain, Da Hinggan Mountains and the mid-west of North China. Negative NEP (carbon sources) were mainly found in Central China, the south of Southwest China, the north of Xinjiang, west and north of Inner Mongolia, and parts of North China. From the 1980s to 1990s, the increasing trend of NEP occurred in the middle of Northeast China Plain and the Loess Plateau and decreasing trends mainly occurred in a greater part of Central China. In the study period, natural forests had minimal carbon uptake, while grassland and shrublands accounted for nearly three fourths of the total carbon terrestrial uptakes in China during 1981―2000.
基金supported by the National Natural Science Foundation of China(Grant No.41988101)National Key R&D Program of China(Grant No.2019YFA0607304)。
文摘China announced its national goal to reach the peak of carbon emission by 2030 and achieve carbon neutrality by 2060,during the General Assembly of the United Nations in September 2020.In this context,the potential of the carbon sink in China’s terrestrial ecosystems to mitigate anthropogenic carbon emissions has attracted unprecedented attention from scientific communities,policy makers and the public.Here,we reviewed the assessments on China’s terrestrial ecosystem carbon sink,with focus on the principles,frameworks and methods of terrestrial ecosystem carbon sink estimates,as well as the recent progress and existing problems.Looking forward,we identified critical issues for improving the accuracy and precision of China’s terrestrial ecosystem carbon sink,in order to serve the more realistic policy making in pathways to achieve carbon neutrality for China.
基金This work was supported by the Chinese Academy of Sciences (Grant No. KZCX 2-103) President Fellowship (NIGP LPS 003118) the Special Funds for the Major State Basic Research Project of China (Grant No. G2000077700).
文摘Stable carbon isotopes of C3 and C4 plants have completely distinct δ13C values respectively. Carbonate in tooth enamel of herbivorous mammals is significantly and regularly enriched in 13C compared to source carbon. As a result, we can reconstruct distributions of C3 and C4 plants in geological history based on carbon isotopes of mammalian tooth enamel. Carbon isotopes of 70 mammalian tooth enamel samples from 11 Quaternary localities in northern China are analyzed. This analysis indicates that C3 plants were dominant in the terrestrial ecosystem of northern China during the Quaternary, which is completely different from Pakistan with relatively close latitudes where C4 plants were absolutely dominant. The great difference was caused by the uplift of the Tibetan Plateau. A simulation implied that a marked temperature decrease would happen in the north side of the Tibetan Plateau, but a temperature increase in the south side. The warming condition caused the transition from C3 to C4 plants in Pakistan
基金Supported by the National Natural Science Foundation of China(Grant Nos.90211016,40638039,40228001,and 40021101)the Key MOE Research Project(Grant No.306019)
文摘Using China's ground observations,e.g.,forest inventory,grassland resource,agricultural statistics,climate,and satellite data,we estimate terrestrial vegetation carbon sinks for China's major biomes between 1981 and 2000.The main results are in the following:(1)Forest area and forest biomass car-bon(C)stock increased from 116.5×10^(6) ha and 4.3 Pg C(1 Pg C=10^(15) g C)in the early 1980s to 142.8×10^(6) ha and 5.9 Pg C in the early 2000s,respectively.Forest biomass carbon density increased form 36.9 Mg C/ha(1 Mg C=10^(6) g C)to 41.0 Mg C/ha,with an annual carbon sequestration rate of 0.075 Pg C/a.Grassland,shrub,and crop biomass sequestrate carbon at annual rates of 0.007 Pg C/a,0.014―0.024 Pg C/a,and 0.0125―0.0143 Pg C/a,respectively.(2)The total terrestrial vegetation C sink in China is in a range of 0.096―0.106 Pg C/a between 1981 and 2000,accounting for 14.6%―16.1%of carbon dioxide(CO_(2))emitted by China's industry in the same period.In addition,soil carbon sink is estimated at 0.04―0.07 Pg C/a.Accordingly,carbon sequestration by China's terrestrial ecosystems(vegetation and soil)offsets 20.8%―26.8%of its industrial CO_(2) emission for the study period.(3)Considerable uncertainties exist in the present study,especially in the estimation of soil carbon sinks,and need further intensive investigation in the future.
基金supported by the Key Project of National Natural Science Foundation of China (71033005)
文摘Since Westman(1977) and Ehrlich(1982) put forward the concepts of "the service of nature" and "ecosystem service functions",respectively,methods for conducting value accounting for them,and their practical application have become the subjects of intense study.Based on an overview of available research findings,we discuss three scientific hypotheses.First,the terrestrial ecosystem offers both positive and negative service functions.Second,changes in terrestrial ecosystem service functions lie not only in the number of ecosystem types and the coverage area of each type,but also in their quality.Third,the value of terrestrial ecosystem service functions should be assessed both in terms of the value stocked and the value added.We collected land use data from China during the period 1999-2008,and Normalized Difference Vegetation Index data based on remote sensing images from the Global Inventory Modeling and Mapping Studies for the same period.We then calculated and analyzed spatial and temporal changes in China's terrestrial ecosystem service values over the 10-year period.Considering temporal change,the total value(stocked) of China's terrestrial ecosystem service functions decreased from 6.82 trillion Yuan RMB in 1999 to 6.57 trillion Yuan RMB in 2008.During that period,the positive value decreased by 240.17 billion Yuan RMB and the negative value increased by 8.85 billion Yuan RMB.The decrease in total value lies mainly in the humidity control,soil formation,and waste recycling functions.The total value(added) of China's terrestrial ecosystem service functions increased by 4.31 billion Yuan RMB in 2000,but decreased by 0.13 billion Yuan RMB in 2008(based on the constant price of China in 1999).The value(added) was a negative figure.From the perspective of spatial change,we can see that the supply of China's terrestrial ecosystem service functions fell slightly over the past 10 years,mainly in Northeast and Southern China.As a result of human activities on ecosystems,the loss of ecosystem service functions' value was relatively prominent in Shanxi and Gansu provinces,compared with an increase in value in Shaanxi Province.Terrestrial ecosystem service functions' value per unit area was relatively high in mid-and East China,showing a prominent spatial change over the 10-year period,but low in Western China.Some conclusions are drawn after an in-depth analysis of the factors causing the spatial and temporal changes in China's terrestrial ecosystem service functions,in the hope that our suggestions will be helpful for the management of China's terrestrial ecosystems.