Based on the results of seven corroded reinforced concrete(RC)shear walls with a high shear-span ratio under an artificial climatic environment(ACE)that were subjected to pseudo-static cyclic loading tests,the effects...Based on the results of seven corroded reinforced concrete(RC)shear walls with a high shear-span ratio under an artificial climatic environment(ACE)that were subjected to pseudo-static cyclic loading tests,the effects of corrosion degree,as well as the reinforcement ratio of horizontal distribution bars and boundary columns longitudinal bars on seismic performance of corroded RC shear walls were investigated.The experimental results show that the strength,stiffness,ductility and energy-dissipating capacity of the specimen lessened with the raising of corrosion degree.As the horizontal distribution reinforcement ratio improved,bearing capability was slightly enhanced,and the deformation and energy dissipation capacities of the specimens were markedly increased.With the rising boundary column longitudinal reinforcement ratio,the bearing capacity,stiffness degradation rate and cumulative energy consumption of the specimens intensified,and deformability was not significantly increased.After contemplating the correction of corroded materials and the buckling effect of corroded longitudinal bars,a finite element model of corroded RC shear walls was created on the basis of ShellMITC4 layered shell elements.Eventually,employing the constructed numerical model,the variation laws of other parameters on the seismic performance of the corroded RC shear wall were revealed.展开更多
Two decades have passed since China and Japan jointly launched hydrological ＆ climatological observations on the glaciers in Tanggula Pass, Tibetan Plateau. Although the research institutions involved have been eithe...Two decades have passed since China and Japan jointly launched hydrological ＆ climatological observations on the glaciers in Tanggula Pass, Tibetan Plateau. Although the research institutions involved have been either restructured or renamed, their work, between 1989 and 1993, was ground-breaking and remains significant even to this day. Some observation sites established at that time are still utilized for large-scaled projects sponsored by GAME/Tibet, NSFC （Natural Science Foundation of China） and the Major State Basic Research Development Program of China （973 Program）. Recently, a glacier monitoring system has been established on the cap of Dongkemadi Glacier, and is expected to make further contributions to research on the change of the cryospheric and climatic environment in the area.展开更多
Ultraviolet（UV） radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. O...Ultraviolet（UV） radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. One contains hourly observations of UV radiation measured at 40 Chinese Ecosystem Research Network stations from 2005 to 2015. CUV3 broadband radiometers were used to observe the UV radiation, with an accuracy of 5%, which meets the World Meteorology Organization＇s measurement standards. The extremum method was used to control the quality of the measured datasets. The other dataset contains daily cumulative UV radiation estimates that were calculated using an all-sky estimation model combined with a hybrid model. The reconstructed daily UV radiation data span from 1961 to 2014. The mean absolute bias error and root-mean-square error are smaller than 30% at most stations, and most of the mean bias error values are negative, which indicates underestimation of the UV radiation intensity. These datasets can improve our basic knowledge of the spatial and temporal variations in UV radiation. Additionally, these datasets can be used in studies of potential ozone formation and atmospheric oxidation, as well as simulations of ecological processes.展开更多
To improve seed yield of male sterile line,the relationship between outcrossing rate and climate factors was explored.Data of blooming period,outcrossing rate of male sterile line and climate during 2006–2016 growing...To improve seed yield of male sterile line,the relationship between outcrossing rate and climate factors was explored.Data of blooming period,outcrossing rate of male sterile line and climate during 2006–2016 growing seasons were investigated and analyzed.The shortest blooming period was 18.8 d with mean temperature of 24℃–25℃and 18.5 d with about 125 h natural illumination.More rainfall caused a longer blooming period,and a high outcrossing rate was found with about 100 mm rainfall and the mean temperature of 24℃–25℃.Increased natural illumination time by tapetum lucidum mulching improved outcrossing rate by 42.48%compared tocontrol.Overall,the selective combination of climate and environmental factors could be effective for increasing outcrossing rate and hybrid seed yield in the male sterile line of soybean.展开更多
To provide a genetic basis for japonica rice breeding, the genetic similarity and cluster of 139 accessions of improved japonica rice varieties from 12 provinces and cities of China were analyzed using 34 SSR markers....To provide a genetic basis for japonica rice breeding, the genetic similarity and cluster of 139 accessions of improved japonica rice varieties from 12 provinces and cities of China were analyzed using 34 SSR markers. Totally 198 alleles were detected among these improved japonica rice varieties with the average number of alleles per pair of primers was 5.3235. RM320, RM531, RM1, RM286, and RM336 showed more alleles, which were 15, 12, 11, 9, and 9, respectively. RM320, RM336, RM286 and RM531 showed higher genetic diversity indexes; which were 2.3324, 2.0292, 1.8996, and 1.7820, respectively. The range of genetic similar index among improved japonica rice varieties from different provinces was from 0.321 to 0.914, with the average of 0.686. There was a high genetic similarity among improved japonica rice varieties from Heilongjiang, Jilin, Liaoning, Ningxia, and Yunnan, which were located in similar latitude or similar ecological environment, while there was a low genetic similarity between improved japonica rice varieties from Guizhou and Jiangsu, and other provinces which were located in more different latitudes and ecological environments. The markers of RM320, RM531, RM1, RM286, and RM336 fit to be used in analysis of genetic diversity for improved japonica rice variety. The genetic similarity among improved japonica rice varieties from different provinces was closely associated with genetic basis of parents, and was also correlated with latitude and ecological environment where the varieties were bred.展开更多
As one of the methods of urban environmental assessment,sensitivity assessment of urban climatic environment can accurately reflect the problem areas of current urban climate and built environment through visual means...As one of the methods of urban environmental assessment,sensitivity assessment of urban climatic environment can accurately reflect the problem areas of current urban climate and built environment through visual means,and help cities to carry out sustainable transformation and renewal in the stock era to optimize the living environment.Taking the central urban area of Beijing as the research object,the sensitivity of climatic environment was evaluated by meteorological data and built environment element data.The results showed that the distribution of sensitive units showed a centrifugal radiation pattern of"high in the center and low in the periphery".Block units with high climate sensitivity were mostly concentrated in Xicheng District and Dongcheng District,accounting for 93%of the total number of units.Further research showed that complex built environment and lack of elements to regulate climatic environment were the main reasons for the poor local climatic environment in the region with high climate sensitivity.Finally,a comprehensive evaluation of the remolding capacity,renewal potential and future development intensity of different grades of climate sensitive units was given.The results will provide scientific reference for urban renewal and reconstruction under climatic and environmental changes,so as to promote urban sustainable development and improvement of living environment.展开更多
During the 2006/07 Antarctic summer,the species population,distribution and reproductive behavior of penguins in areas near the Great Wall Station were investigated.Five species of penguin were recorded：gentoo pengui...During the 2006/07 Antarctic summer,the species population,distribution and reproductive behavior of penguins in areas near the Great Wall Station were investigated.Five species of penguin were recorded：gentoo penguin（Pygoscelis papua）,adelie penguin（P.adeliae）,chinstrap penguin（P.antarctica）, King penguin（Aptenodytes patagonicus） and Emperor penguin（A.forsteri）. The first three species bred locally,while the other two species were observed occasionally.Ardley Island is one of the most important breeding areas for penguins.After the breeding season of 2006/07,there were a total of about 17 234 penguins and the breeding success rate was 0.40—1.41.Comparing with historical data,changes in penguin species populations and distribution were analyzed, and their relationships with the environment,climate change and human activity were investigated.展开更多
Canopy photosynthetic productivity is crucial for the formation of crop yields.Identifying limiting factors and adjustment targets for canopy photosynthesis in specific climates is important for yield increase.However...Canopy photosynthetic productivity is crucial for the formation of crop yields.Identifying limiting factors and adjustment targets for canopy photosynthesis in specific climates is important for yield increase.However,conducting relevant quantitative research remains challenging.In this study,two typical regions with distinct climatic characteristics were selected for a two-year trial of greenhouse tomatoes grown in different seasons.A three-dimensional canopy photosynthesis model was developed to quantify the factor contributions to the regional differences in accumulated canopy photosynthesis throughout the entire growing season(ACP),and to predict gains in ACP through three scenarios:leaf photosynthetic modifications(S1),plant layout adjustments(S2),and greenhouse film haze increase(S3).The results indicated that differences in ACP were mainly influ-enced by light environment(LE),leaf photosynthetic physiology(PP),and LE-PP interaction in spring,and canopy structure(CS),PP,LE,and LE-PP interaction in autumn.The predicted ACP enhancement showed as S1>S2>S3,with S3 showing a more limited effect.The light quantum efficiency under limiting light(κ_(2LL))and maximum electron transport rate(J_(max))were identified as key biochemical phenotypes for tomato high photo-synthetic efficiency breeding in different environments.Additionally,adjusting row spacing under current planting density could further improve ACP.Our conclusions could assist researchers in deepening their un-derstanding of canopy photosynthesis limitations under real production conditions,and provide a theoretical foundation for optimizing greenhouse tomato yield in the context of climate change.展开更多
High-speed railway aerodynamics is the key basic science for solving the bottleneck problem of high-speed railway development.This paper systematically summarizes the aerodynamic research relating to China’s high-spe...High-speed railway aerodynamics is the key basic science for solving the bottleneck problem of high-speed railway development.This paper systematically summarizes the aerodynamic research relating to China’s high-speed railway network.Seven key research advances are comprehensively discussed,including train aerodynamic drag-reduction technology,train aerodynamic noise-reduction technology,train ventilation technology,train crossing aerodynamics,train/tunnel aerodynamics,train/climate environment aerodynamics,and train/human body aerodynamics.Seven types of railway aerodynamic test platform built by Central South University are introduced.Five major systems for a high-speed railway network—the aerodynamics theoretical system,the aerodynamic shape(train,tunnel,and so on)design system,the aerodynamics evaluation system,the 3D protection system for operational safety of the high-speed railway network,and the high-speed railway aerodynamic test/computation/analysis platform system—are also introduced.Finally,eight future development directions for the field of railway aerodynamics are proposed.For over 30 years,railway aerodynamics has been an important supporting element in the development of China’s high-speed railway network,which has also promoted the development of high-speed railway aerodynamics throughout the world.展开更多
Although sudden nocturnal warming events near the earth＇s surface in Australia and the United States have been examined in previous studies, similar events observed occasionally over the Loess Plateau of Northwest Ch...Although sudden nocturnal warming events near the earth＇s surface in Australia and the United States have been examined in previous studies, similar events observed occasionally over the Loess Plateau of Northwest China have not yet been investigated. The factors that lead to these warming events in such areas with their unique topography and climate remain not clear. To understand the formation mechanisms and associated thermal and dynamical features, a nocturnal warming event recorded in Gansu Province （northwest of the Loess Plateau） in June 2007 was investigated by using observations and model simulations with the Weather Research and Forecasting （WRF） model. Observations showed that this near-surface warming event lasted for 4 h and the temperature increased by 2.5℃. During this event, a decrease in humidity occurred simultaneously with the increase of temperature. The model simulation showed that the nocturnal warming was caused mainly by the transport of warmer and drier air aloft downward to the surface through enhanced vertical mixing. Wind shear played an important role in inducing the elevated vertical mixing, and it was enhanced by the continuous development of the atmospheric baroclinicity, which converted more potential energy to kinetic energy.展开更多
Rangeland systems play an important role in ecological stabilization and the terrestrial carbon cycle in arid and semiarid regions. However, little is known about the vegetative carbon dynamics and climatic and topog-...Rangeland systems play an important role in ecological stabilization and the terrestrial carbon cycle in arid and semiarid regions. However, little is known about the vegetative carbon dynamics and climatic and topog- raphical factors that affect vegetative carbon stock in these rangelands. Our goal was to assess vegetative carbon stock by examining meteorological data in conjunction with NDVI （normalized difference vegetation index） time se- ries datasets from 2001-2012. An improved CASA （Carnegie Ames Stanford Approach） model was then applied to simulate the spatiotemporal dynamic variation of vegetative carbon stock, and analyze its response to climatic and topographical factors. We estimated the vegetative carbon stock of rangeland in Gansu province, China to be 4.4×10^14 gC, increasing linearly at an annual rate of 9.8×10^11 gC. The mean vegetative carbon density of the whole rangeland was 136.5 gC m-2. Vegetative carbon density and total carbon varied temporally and spatially and were highly associated with temperature, precipitation and solar radiation. Vegetative carbon density reached the maximal value on elevation at 2500-3500 m, a slope of 〉30°and easterly aspect. The effect of precipitation, tem- perature and solar radiation on the vegetative carbon density of five rangeland types （desert and salinized meadow, steppe, alpine meadow, shrub and tussock, and marginal grassland in the forest） depends on the acquired quantity of water and heat for rangeland plants at all spatial scales. The results of this study provide new evidence for ex- plaining spatiotemporal heterogeneity in vegetative carbon dynamics and responses to global change for rangeland vegetative carbon stock, and offer a theoretical and practical basis for grassland agriculture management in arid and semiarid regions.展开更多
基金National Natural Science Foundation of China under Grant No.52278530National Key R&D Program of China under Grant No.2019YFC1509302Key R&D Project of Shaanxi Province under Grant No.2021ZDLSF06-10。
文摘Based on the results of seven corroded reinforced concrete(RC)shear walls with a high shear-span ratio under an artificial climatic environment(ACE)that were subjected to pseudo-static cyclic loading tests,the effects of corrosion degree,as well as the reinforcement ratio of horizontal distribution bars and boundary columns longitudinal bars on seismic performance of corroded RC shear walls were investigated.The experimental results show that the strength,stiffness,ductility and energy-dissipating capacity of the specimen lessened with the raising of corrosion degree.As the horizontal distribution reinforcement ratio improved,bearing capability was slightly enhanced,and the deformation and energy dissipation capacities of the specimens were markedly increased.With the rising boundary column longitudinal reinforcement ratio,the bearing capacity,stiffness degradation rate and cumulative energy consumption of the specimens intensified,and deformability was not significantly increased.After contemplating the correction of corroded materials and the buckling effect of corroded longitudinal bars,a finite element model of corroded RC shear walls was created on the basis of ShellMITC4 layered shell elements.Eventually,employing the constructed numerical model,the variation laws of other parameters on the seismic performance of the corroded RC shear wall were revealed.
基金funded by the Major State Basic Research Development Program of China (973 Program) under Grant No.2010CB951701the Natural ScienceFoundation of China (No.41071042)supported by the Innovation Project of Chinese Academy of Sciences(KZCX2-YW-BR-22)
文摘Two decades have passed since China and Japan jointly launched hydrological ＆ climatological observations on the glaciers in Tanggula Pass, Tibetan Plateau. Although the research institutions involved have been either restructured or renamed, their work, between 1989 and 1993, was ground-breaking and remains significant even to this day. Some observation sites established at that time are still utilized for large-scaled projects sponsored by GAME/Tibet, NSFC （Natural Science Foundation of China） and the Major State Basic Research Development Program of China （973 Program）. Recently, a glacier monitoring system has been established on the cap of Dongkemadi Glacier, and is expected to make further contributions to research on the change of the cryospheric and climatic environment in the area.
文摘Ultraviolet（UV） radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. One contains hourly observations of UV radiation measured at 40 Chinese Ecosystem Research Network stations from 2005 to 2015. CUV3 broadband radiometers were used to observe the UV radiation, with an accuracy of 5%, which meets the World Meteorology Organization＇s measurement standards. The extremum method was used to control the quality of the measured datasets. The other dataset contains daily cumulative UV radiation estimates that were calculated using an all-sky estimation model combined with a hybrid model. The reconstructed daily UV radiation data span from 1961 to 2014. The mean absolute bias error and root-mean-square error are smaller than 30% at most stations, and most of the mean bias error values are negative, which indicates underestimation of the UV radiation intensity. These datasets can improve our basic knowledge of the spatial and temporal variations in UV radiation. Additionally, these datasets can be used in studies of potential ozone formation and atmospheric oxidation, as well as simulations of ecological processes.
基金supported by the Earmarked Fund for China Agricultural Research System(CARS-04)。
文摘To improve seed yield of male sterile line,the relationship between outcrossing rate and climate factors was explored.Data of blooming period,outcrossing rate of male sterile line and climate during 2006–2016 growing seasons were investigated and analyzed.The shortest blooming period was 18.8 d with mean temperature of 24℃–25℃and 18.5 d with about 125 h natural illumination.More rainfall caused a longer blooming period,and a high outcrossing rate was found with about 100 mm rainfall and the mean temperature of 24℃–25℃.Increased natural illumination time by tapetum lucidum mulching improved outcrossing rate by 42.48%compared tocontrol.Overall,the selective combination of climate and environmental factors could be effective for increasing outcrossing rate and hybrid seed yield in the male sterile line of soybean.
基金supported by the National Key Technology R&D Program of China(2006BAD13B01)the Protective Program of Crop Germpalsm of China[NB07-2130135(25-30-01)]
文摘To provide a genetic basis for japonica rice breeding, the genetic similarity and cluster of 139 accessions of improved japonica rice varieties from 12 provinces and cities of China were analyzed using 34 SSR markers. Totally 198 alleles were detected among these improved japonica rice varieties with the average number of alleles per pair of primers was 5.3235. RM320, RM531, RM1, RM286, and RM336 showed more alleles, which were 15, 12, 11, 9, and 9, respectively. RM320, RM336, RM286 and RM531 showed higher genetic diversity indexes; which were 2.3324, 2.0292, 1.8996, and 1.7820, respectively. The range of genetic similar index among improved japonica rice varieties from different provinces was from 0.321 to 0.914, with the average of 0.686. There was a high genetic similarity among improved japonica rice varieties from Heilongjiang, Jilin, Liaoning, Ningxia, and Yunnan, which were located in similar latitude or similar ecological environment, while there was a low genetic similarity between improved japonica rice varieties from Guizhou and Jiangsu, and other provinces which were located in more different latitudes and ecological environments. The markers of RM320, RM531, RM1, RM286, and RM336 fit to be used in analysis of genetic diversity for improved japonica rice variety. The genetic similarity among improved japonica rice varieties from different provinces was closely associated with genetic basis of parents, and was also correlated with latitude and ecological environment where the varieties were bred.
基金Sponsored by General Project of Natural Science Foundation of Beijing City(8202017)Youth Talent Support Program of 2018 Beijing Municipal University Academic Human Resources Development(PXM2018_014212_000043)。
文摘As one of the methods of urban environmental assessment,sensitivity assessment of urban climatic environment can accurately reflect the problem areas of current urban climate and built environment through visual means,and help cities to carry out sustainable transformation and renewal in the stock era to optimize the living environment.Taking the central urban area of Beijing as the research object,the sensitivity of climatic environment was evaluated by meteorological data and built environment element data.The results showed that the distribution of sensitive units showed a centrifugal radiation pattern of"high in the center and low in the periphery".Block units with high climate sensitivity were mostly concentrated in Xicheng District and Dongcheng District,accounting for 93%of the total number of units.Further research showed that complex built environment and lack of elements to regulate climatic environment were the main reasons for the poor local climatic environment in the region with high climate sensitivity.Finally,a comprehensive evaluation of the remolding capacity,renewal potential and future development intensity of different grades of climate sensitive units was given.The results will provide scientific reference for urban renewal and reconstruction under climatic and environmental changes,so as to promote urban sustainable development and improvement of living environment.
基金supported by the National Natural Science Foundation of China(Grants No.40876104D0611)
文摘During the 2006/07 Antarctic summer,the species population,distribution and reproductive behavior of penguins in areas near the Great Wall Station were investigated.Five species of penguin were recorded：gentoo penguin（Pygoscelis papua）,adelie penguin（P.adeliae）,chinstrap penguin（P.antarctica）, King penguin（Aptenodytes patagonicus） and Emperor penguin（A.forsteri）. The first three species bred locally,while the other two species were observed occasionally.Ardley Island is one of the most important breeding areas for penguins.After the breeding season of 2006/07,there were a total of about 17 234 penguins and the breeding success rate was 0.40—1.41.Comparing with historical data,changes in penguin species populations and distribution were analyzed, and their relationships with the environment,climate change and human activity were investigated.
基金This work was funded by China Agriculture Research System(CARS-23-C-05)National Natural Science Foundation of China(32472816).
文摘Canopy photosynthetic productivity is crucial for the formation of crop yields.Identifying limiting factors and adjustment targets for canopy photosynthesis in specific climates is important for yield increase.However,conducting relevant quantitative research remains challenging.In this study,two typical regions with distinct climatic characteristics were selected for a two-year trial of greenhouse tomatoes grown in different seasons.A three-dimensional canopy photosynthesis model was developed to quantify the factor contributions to the regional differences in accumulated canopy photosynthesis throughout the entire growing season(ACP),and to predict gains in ACP through three scenarios:leaf photosynthetic modifications(S1),plant layout adjustments(S2),and greenhouse film haze increase(S3).The results indicated that differences in ACP were mainly influ-enced by light environment(LE),leaf photosynthetic physiology(PP),and LE-PP interaction in spring,and canopy structure(CS),PP,LE,and LE-PP interaction in autumn.The predicted ACP enhancement showed as S1>S2>S3,with S3 showing a more limited effect.The light quantum efficiency under limiting light(κ_(2LL))and maximum electron transport rate(J_(max))were identified as key biochemical phenotypes for tomato high photo-synthetic efficiency breeding in different environments.Additionally,adjusting row spacing under current planting density could further improve ACP.Our conclusions could assist researchers in deepening their un-derstanding of canopy photosynthesis limitations under real production conditions,and provide a theoretical foundation for optimizing greenhouse tomato yield in the context of climate change.
文摘High-speed railway aerodynamics is the key basic science for solving the bottleneck problem of high-speed railway development.This paper systematically summarizes the aerodynamic research relating to China’s high-speed railway network.Seven key research advances are comprehensively discussed,including train aerodynamic drag-reduction technology,train aerodynamic noise-reduction technology,train ventilation technology,train crossing aerodynamics,train/tunnel aerodynamics,train/climate environment aerodynamics,and train/human body aerodynamics.Seven types of railway aerodynamic test platform built by Central South University are introduced.Five major systems for a high-speed railway network—the aerodynamics theoretical system,the aerodynamic shape(train,tunnel,and so on)design system,the aerodynamics evaluation system,the 3D protection system for operational safety of the high-speed railway network,and the high-speed railway aerodynamic test/computation/analysis platform system—are also introduced.Finally,eight future development directions for the field of railway aerodynamics are proposed.For over 30 years,railway aerodynamics has been an important supporting element in the development of China’s high-speed railway network,which has also promoted the development of high-speed railway aerodynamics throughout the world.
基金Supported by the National Natural Science Foundation of China(41375109)National(Key)Basic Research and Development(973)Program of China(2014CB441406)Key Laboratory of Meteorological Disaster of Ministry of Education,Nanjing University of Information Science&Technology(KLME1412)
文摘Although sudden nocturnal warming events near the earth＇s surface in Australia and the United States have been examined in previous studies, similar events observed occasionally over the Loess Plateau of Northwest China have not yet been investigated. The factors that lead to these warming events in such areas with their unique topography and climate remain not clear. To understand the formation mechanisms and associated thermal and dynamical features, a nocturnal warming event recorded in Gansu Province （northwest of the Loess Plateau） in June 2007 was investigated by using observations and model simulations with the Weather Research and Forecasting （WRF） model. Observations showed that this near-surface warming event lasted for 4 h and the temperature increased by 2.5℃. During this event, a decrease in humidity occurred simultaneously with the increase of temperature. The model simulation showed that the nocturnal warming was caused mainly by the transport of warmer and drier air aloft downward to the surface through enhanced vertical mixing. Wind shear played an important role in inducing the elevated vertical mixing, and it was enhanced by the continuous development of the atmospheric baroclinicity, which converted more potential energy to kinetic energy.
基金National Natural Science Foundation of China(30960264 and 31160475)Science and technology program of Gansu province(1107RJYA058)+1 种基金open project of Key Laboratory of Grassland Ecosystem(Gansu Agricultural University),Ministry of Education(CYZS–2011014)Fund of technology innovation commemorated Sheng Tongsheng in Gansu Agricultural University(GSAU-STS-1304 and GSAU-STS-1505)
文摘Rangeland systems play an important role in ecological stabilization and the terrestrial carbon cycle in arid and semiarid regions. However, little is known about the vegetative carbon dynamics and climatic and topog- raphical factors that affect vegetative carbon stock in these rangelands. Our goal was to assess vegetative carbon stock by examining meteorological data in conjunction with NDVI （normalized difference vegetation index） time se- ries datasets from 2001-2012. An improved CASA （Carnegie Ames Stanford Approach） model was then applied to simulate the spatiotemporal dynamic variation of vegetative carbon stock, and analyze its response to climatic and topographical factors. We estimated the vegetative carbon stock of rangeland in Gansu province, China to be 4.4×10^14 gC, increasing linearly at an annual rate of 9.8×10^11 gC. The mean vegetative carbon density of the whole rangeland was 136.5 gC m-2. Vegetative carbon density and total carbon varied temporally and spatially and were highly associated with temperature, precipitation and solar radiation. Vegetative carbon density reached the maximal value on elevation at 2500-3500 m, a slope of 〉30°and easterly aspect. The effect of precipitation, tem- perature and solar radiation on the vegetative carbon density of five rangeland types （desert and salinized meadow, steppe, alpine meadow, shrub and tussock, and marginal grassland in the forest） depends on the acquired quantity of water and heat for rangeland plants at all spatial scales. The results of this study provide new evidence for ex- plaining spatiotemporal heterogeneity in vegetative carbon dynamics and responses to global change for rangeland vegetative carbon stock, and offer a theoretical and practical basis for grassland agriculture management in arid and semiarid regions.
