A comprehensive analysis on the change of the total grain production and the temporal and spatial change of three main crops production（including wheat,maize and rice）,as well as the transfer trace of the center gra...A comprehensive analysis on the change of the total grain production and the temporal and spatial change of three main crops production（including wheat,maize and rice）,as well as the transfer trace of the center gravity of grain production in China were analyzed to reveal the overall developing trend of the grain production,explore the reasons and finally propose the corresponding suggestions and strategies to cope with the situation.展开更多
The ecological systems services or multi-functionality of paddy rice cultivation are critical to the functioning of the Earth’s life-support system.We estimated the ecosystem services value(ESV)of paddy rice during 1...The ecological systems services or multi-functionality of paddy rice cultivation are critical to the functioning of the Earth’s life-support system.We estimated the ecosystem services value(ESV)of paddy rice during 1980-2014 across China.The results indicated that the ESV of the paddy field in China showed an upward trend during this period.The share of ESV on CO_(2)sequestration was the highest,followed by ESV on temperature cooling and greenhouse gas(GHG)emission.The yield-scaled ESVs of ZonesⅡ(southern rice-upland crops rotation regions)andⅢ(southern double rice production regions)were similar and significantly higher than the ESVs of ZonesⅠ(northeastern single rice production regions)and IV(Southwest rice-upland crops rotation regions).Between 1980 and 2014,the ESV of each region increased to varying degrees,except for the ESVs of Guangxi,Zhejiang,Fujian,and Guangdong.Such effects suggest the existence of a significant spatial-temporal variation in the total amount,structure,and density of ESV of paddy fields in China,which can further guide the development of future options for the adaptation of healthy rice production in China.展开更多
Precipitation is considered to be the primary resource limiting terrestrial biological activity in water-limited regions. Its overriding effect on the production of grassland is complex. In this paper, field data of 4...Precipitation is considered to be the primary resource limiting terrestrial biological activity in water-limited regions. Its overriding effect on the production of grassland is complex. In this paper, field data of 48 sites （including temperate meadow steppe, temperate steppe, temperate desert steppe and alpine meadow） were gathered from 31 published papers and monographs to analyze the relationship between above-ground net primary productivity （ANPP） and precipitation by the method of regression analysis. The results indicated that there was a great difference between spatial pattern and temporal pattern by which precipitation influenced grassland ANPP. Mean annual precipitation （MAP） was the main factor determining spatial distribution of grassland ANPP （r^2 = 0.61, P 〈 0.01）; while temporally, no significant relationship was found between the variance of AN PP and inter-annual precipitation for the four types of grassland. However, after dividing annual preeipitation into monthly value and taking time lag effect into account, the study found significant relationships between ANPP and precipitation. For the temperate meadow steppe, the key variable determining inter-annual change of ANPP was last August-May precipitation （r^2 = 0.47, P = 0.01）; for the temperate steppe, the key variable was July precipitation （r^2 = 0.36, P = 0.02）; for the temperate desert steppe, the key variable was April-June precipitation （r^2 = 0.51, P 〈 0.01）; for the alpine meadow, the key variable was last September-May precipitation （r^2 = 0.29, P 〈 0.05）. In comparison with analogous research, the study demonstrated that the key factor determining inter-annual changes of grassland ANPP was the cumulative precipitation in certain periods of that year or the previous year.展开更多
[Objectives]Integrated land productivity can reflect the comprehensive utilization of land and the overall output level,which is the most basic and commonly used indicator in assessing land use efficiency.This thesis ...[Objectives]Integrated land productivity can reflect the comprehensive utilization of land and the overall output level,which is the most basic and commonly used indicator in assessing land use efficiency.This thesis aims to analyze the spatial and temporal changes of integrated land productivity in Chongqing from 1997 to 2023 in order to assess its land use efficiency.[Methods]This study measured the integrated land productivity of Chongqing Municipality,the only municipality directly under the central government in the western part of China,over the past 26 years(1997-2023)through relevant surveys and statistical data,and analyzed in depth the integrated land productivity of the 38 districts and counties under the jurisdiction of Chongqing,as well as the functional sub-districts of the"one district and two clusters"and the"one district and two clusters"in Chongqing.It also analyzes the characteristics of spatial and temporal differences in land productivity in 38 districts and counties under the jurisdiction of Chongqing and"one district and two clusters".[Results]The results of the study show that over the past 26 years,the integrated land productivity of Chongqing has shown an annual growth trend,and the integrated land productivity of the 38 districts and counties and the functional subregions of"one district and two clusters"has also increased significantly,but the average annual growth rate of the integrated land productivity varies among different regions.From the perspective of spatial differences,there are significant differences in land productivity among the 38 districts and counties of Chongqing and the functional subregions of"one district and two clusters",which are mainly due to the different natural conditions,economic development levels and functional positioning of each region.[Conclusions]Based on the results of the study and the actual situation of Chongqing,this paper puts forward the leading measures to improve the integrated land productivity,with a view to providing a reference basis for Chongqing to improve the efficiency of land use and promote the sustainable use of land resources.展开更多
This study develops geospatial analysis of terrestrial carbon exchange for the conterminous United State and estimates large-scale NEP （net ecosystem production） dynamic from 2008 to 2013. We apply land-use and land...This study develops geospatial analysis of terrestrial carbon exchange for the conterminous United State and estimates large-scale NEP （net ecosystem production） dynamic from 2008 to 2013. We apply land-use and land-cover data in order to coherently include cropland, forest, wetland and other ecologically active landscapes in the mapping. Our results show a distribution of high harvest carbon release in the Corn Belt states, in addition to hot spots around the US in areas like Southern California and Arizona. Harvest carbon is low in areas in the southern United States, and central/southern Appalachian Mountains. We identify NEP changes for coupled agricultural, forest and other high-carbon-uptake ecosystems systems, conversions to and from crop, and land in frequent conversion among forest, wetland, pasture and rangeland. Findings from this study will provide important information to support and promote the co-production of science and decision-making.展开更多
Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-sour...Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-source data, an effective model named the Spatial Production Allocation Model （SPAM） which integrates arable land distribution, administrative unit statistics of crop data, agricultural irrigation data and crop suitability data, was used to get a series of spatial distributions of rice area and production with 10-km pixels at a national scale -it was applied from the early 1980s onwards and used to analyze the pattern of spatial and temporal changes. The results show that significant changes occurred in rice in China during 1980-2010. Overall, more than 50% of the rice area decreased, while nearly 70% of rice production increased in the change region during 1980-2010. Spatially, most of the increased area and production were in Northeast China, especially, in Jilin and Heilongjiang; most of the decreased area and production were located in Southeast China, especially, in regions of rapidly urbanization in Guangdong, Fujian and Zhejiang. Thus, the centroid of rice area was moved northeast approximately 230 km since 1980, and rice production about 320 km, which means rice production moved northeastward faster than rice area because of the significant rice yield increase in Northeast China. The results also show that rice area change had a decisive impact on rice production change. About 54.5% of the increase in rice pro- duction is due to the expansion of sown area, while around 83.2% of the decrease in rice production is due to contraction of rice area. This implies that rice production increase may be due to area expansion and other non-area factors, but reduced rice production could largely be attributed to rice area decrease.展开更多
近几十年来新疆气候变化显著,“暖湿化”转型与“湿干转折”先后出现,势必对地区植被生产力、大气干旱状况以及二者间的响应关系产生影响。以植被总初级生产力(GPP)和大气水分亏缺(VPD)作为评价指标,分析了1982—2018年新疆地区植被GPP...近几十年来新疆气候变化显著,“暖湿化”转型与“湿干转折”先后出现,势必对地区植被生产力、大气干旱状况以及二者间的响应关系产生影响。以植被总初级生产力(GPP)和大气水分亏缺(VPD)作为评价指标,分析了1982—2018年新疆地区植被GPP、VPD的时空分布与演变规律,并揭示了大气水分胁迫对植被GPP的影响。结果表明:(1)新疆植被GPP整体具有北高南低的分布特征,年均值为256.6 g C·m^(-2)·a^(-1),呈显著上升趋势。GPP增加趋势占植被总面积的82.00%,其中增加显著区约占42.81%,多分布于南疆绿洲和北疆山前农业区;GPP下降趋势占比较小且分布零散。(2)新疆地区VPD具有“山区低、平原/盆地高”的鲜明格局,年均值为0.66 kPa,呈不显著波动上升趋势。全疆大部地区表现出VPD显著性上升,下降趋势零星出现在昆仑山脉高海拔山区。(3)新疆植被GPP对VPD的响应“正负共存”,并具有明显空间异质性。GPP与VPD的负相关占植被区总面积的54.52%,主要出现在山前草地地带;正相关则主要分布在塔里木盆地边缘和天山北坡及其东段,以栽培作物和灌木类型为主。VPD对GPP的影响在不同植被类型间差异鲜明,而在同一植被类型内正、负响应共存。分析认为,虽然大气水分胁迫尚未成为地区植被生产力变化的主导驱动力,但在新疆干旱化急剧增加背景下,仍需加强对GPP与VPD响应关系的跟踪。展开更多
The relics of ancient rice have been regarded as the most important objective evidence of the origina- tion and spread of rice cultivation.Based on the records of 280 rice relics sites and the rice cropping regionaliz...The relics of ancient rice have been regarded as the most important objective evidence of the origina- tion and spread of rice cultivation.Based on the records of 280 rice relics sites and the rice cropping regionalization as well as the distribution map of paddy soils,the current study compiled the temporal and spatial distribution map of ancient rice distribution in China.The map shows that the distribution of ancient rice is spatially extensive and meantime comparatively concentrated,temporarily covering a long and relatively continuous time-span.The rice relics in the Central China double and single rice cropping regions are among the earliest and the most abundant ones,possessing continuity in time sequence.Combined with the discovery of ancient rice and paddy filed relics,soil micromorphology, pollen combination and element geochemistry,it is suggested that Central China was the origin center of rice cultivation in China.Rice had been spread to the rest part of China in three major waves,also to the East Asian part like Korea and Japan.The temporal and spatial distribution of ancient rice reflects the past environmental change,which is also meaningful to the current rice regionalization and plan- ning as well as food security in China.展开更多
基金Supported by National Scientific and Technological Supporting Project(2006BAD20B05)~~
文摘A comprehensive analysis on the change of the total grain production and the temporal and spatial change of three main crops production（including wheat,maize and rice）,as well as the transfer trace of the center gravity of grain production in China were analyzed to reveal the overall developing trend of the grain production,explore the reasons and finally propose the corresponding suggestions and strategies to cope with the situation.
基金supported by the Natural Science Foundation of Zhejiang,China(Q21C130007)the National Key Research and Development Program of China(2016YFD0300210)。
文摘The ecological systems services or multi-functionality of paddy rice cultivation are critical to the functioning of the Earth’s life-support system.We estimated the ecosystem services value(ESV)of paddy rice during 1980-2014 across China.The results indicated that the ESV of the paddy field in China showed an upward trend during this period.The share of ESV on CO_(2)sequestration was the highest,followed by ESV on temperature cooling and greenhouse gas(GHG)emission.The yield-scaled ESVs of ZonesⅡ(southern rice-upland crops rotation regions)andⅢ(southern double rice production regions)were similar and significantly higher than the ESVs of ZonesⅠ(northeastern single rice production regions)and IV(Southwest rice-upland crops rotation regions).Between 1980 and 2014,the ESV of each region increased to varying degrees,except for the ESVs of Guangxi,Zhejiang,Fujian,and Guangdong.Such effects suggest the existence of a significant spatial-temporal variation in the total amount,structure,and density of ESV of paddy fields in China,which can further guide the development of future options for the adaptation of healthy rice production in China.
基金The National Basic Research Project (973) of China (No. 2002CB412500) and the Pilot Project of Knowledge and InnovationProgram of the Chinese Academy of Sciences (No. KZCX1-01-17)
文摘Precipitation is considered to be the primary resource limiting terrestrial biological activity in water-limited regions. Its overriding effect on the production of grassland is complex. In this paper, field data of 48 sites （including temperate meadow steppe, temperate steppe, temperate desert steppe and alpine meadow） were gathered from 31 published papers and monographs to analyze the relationship between above-ground net primary productivity （ANPP） and precipitation by the method of regression analysis. The results indicated that there was a great difference between spatial pattern and temporal pattern by which precipitation influenced grassland ANPP. Mean annual precipitation （MAP） was the main factor determining spatial distribution of grassland ANPP （r^2 = 0.61, P 〈 0.01）; while temporally, no significant relationship was found between the variance of AN PP and inter-annual precipitation for the four types of grassland. However, after dividing annual preeipitation into monthly value and taking time lag effect into account, the study found significant relationships between ANPP and precipitation. For the temperate meadow steppe, the key variable determining inter-annual change of ANPP was last August-May precipitation （r^2 = 0.47, P = 0.01）; for the temperate steppe, the key variable was July precipitation （r^2 = 0.36, P = 0.02）; for the temperate desert steppe, the key variable was April-June precipitation （r^2 = 0.51, P 〈 0.01）; for the alpine meadow, the key variable was last September-May precipitation （r^2 = 0.29, P 〈 0.05）. In comparison with analogous research, the study demonstrated that the key factor determining inter-annual changes of grassland ANPP was the cumulative precipitation in certain periods of that year or the previous year.
文摘[Objectives]Integrated land productivity can reflect the comprehensive utilization of land and the overall output level,which is the most basic and commonly used indicator in assessing land use efficiency.This thesis aims to analyze the spatial and temporal changes of integrated land productivity in Chongqing from 1997 to 2023 in order to assess its land use efficiency.[Methods]This study measured the integrated land productivity of Chongqing Municipality,the only municipality directly under the central government in the western part of China,over the past 26 years(1997-2023)through relevant surveys and statistical data,and analyzed in depth the integrated land productivity of the 38 districts and counties under the jurisdiction of Chongqing,as well as the functional sub-districts of the"one district and two clusters"and the"one district and two clusters"in Chongqing.It also analyzes the characteristics of spatial and temporal differences in land productivity in 38 districts and counties under the jurisdiction of Chongqing and"one district and two clusters".[Results]The results of the study show that over the past 26 years,the integrated land productivity of Chongqing has shown an annual growth trend,and the integrated land productivity of the 38 districts and counties and the functional subregions of"one district and two clusters"has also increased significantly,but the average annual growth rate of the integrated land productivity varies among different regions.From the perspective of spatial differences,there are significant differences in land productivity among the 38 districts and counties of Chongqing and the functional subregions of"one district and two clusters",which are mainly due to the different natural conditions,economic development levels and functional positioning of each region.[Conclusions]Based on the results of the study and the actual situation of Chongqing,this paper puts forward the leading measures to improve the integrated land productivity,with a view to providing a reference basis for Chongqing to improve the efficiency of land use and promote the sustainable use of land resources.
文摘This study develops geospatial analysis of terrestrial carbon exchange for the conterminous United State and estimates large-scale NEP （net ecosystem production） dynamic from 2008 to 2013. We apply land-use and land-cover data in order to coherently include cropland, forest, wetland and other ecologically active landscapes in the mapping. Our results show a distribution of high harvest carbon release in the Corn Belt states, in addition to hot spots around the US in areas like Southern California and Arizona. Harvest carbon is low in areas in the southern United States, and central/southern Appalachian Mountains. We identify NEP changes for coupled agricultural, forest and other high-carbon-uptake ecosystems systems, conversions to and from crop, and land in frequent conversion among forest, wetland, pasture and rangeland. Findings from this study will provide important information to support and promote the co-production of science and decision-making.
基金National Natural Science Foundation, No.41171382 National Basic Program of China （973 Program）, No.2010CB951502
文摘Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-source data, an effective model named the Spatial Production Allocation Model （SPAM） which integrates arable land distribution, administrative unit statistics of crop data, agricultural irrigation data and crop suitability data, was used to get a series of spatial distributions of rice area and production with 10-km pixels at a national scale -it was applied from the early 1980s onwards and used to analyze the pattern of spatial and temporal changes. The results show that significant changes occurred in rice in China during 1980-2010. Overall, more than 50% of the rice area decreased, while nearly 70% of rice production increased in the change region during 1980-2010. Spatially, most of the increased area and production were in Northeast China, especially, in Jilin and Heilongjiang; most of the decreased area and production were located in Southeast China, especially, in regions of rapidly urbanization in Guangdong, Fujian and Zhejiang. Thus, the centroid of rice area was moved northeast approximately 230 km since 1980, and rice production about 320 km, which means rice production moved northeastward faster than rice area because of the significant rice yield increase in Northeast China. The results also show that rice area change had a decisive impact on rice production change. About 54.5% of the increase in rice pro- duction is due to the expansion of sown area, while around 83.2% of the decrease in rice production is due to contraction of rice area. This implies that rice production increase may be due to area expansion and other non-area factors, but reduced rice production could largely be attributed to rice area decrease.
文摘近几十年来新疆气候变化显著,“暖湿化”转型与“湿干转折”先后出现,势必对地区植被生产力、大气干旱状况以及二者间的响应关系产生影响。以植被总初级生产力(GPP)和大气水分亏缺(VPD)作为评价指标,分析了1982—2018年新疆地区植被GPP、VPD的时空分布与演变规律,并揭示了大气水分胁迫对植被GPP的影响。结果表明:(1)新疆植被GPP整体具有北高南低的分布特征,年均值为256.6 g C·m^(-2)·a^(-1),呈显著上升趋势。GPP增加趋势占植被总面积的82.00%,其中增加显著区约占42.81%,多分布于南疆绿洲和北疆山前农业区;GPP下降趋势占比较小且分布零散。(2)新疆地区VPD具有“山区低、平原/盆地高”的鲜明格局,年均值为0.66 kPa,呈不显著波动上升趋势。全疆大部地区表现出VPD显著性上升,下降趋势零星出现在昆仑山脉高海拔山区。(3)新疆植被GPP对VPD的响应“正负共存”,并具有明显空间异质性。GPP与VPD的负相关占植被区总面积的54.52%,主要出现在山前草地地带;正相关则主要分布在塔里木盆地边缘和天山北坡及其东段,以栽培作物和灌木类型为主。VPD对GPP的影响在不同植被类型间差异鲜明,而在同一植被类型内正、负响应共存。分析认为,虽然大气水分胁迫尚未成为地区植被生产力变化的主导驱动力,但在新疆干旱化急剧增加背景下,仍需加强对GPP与VPD响应关系的跟踪。
基金Supported by the National Natural Science Foundation of China(Grant Nos.40625001 and 40235054)
文摘The relics of ancient rice have been regarded as the most important objective evidence of the origina- tion and spread of rice cultivation.Based on the records of 280 rice relics sites and the rice cropping regionalization as well as the distribution map of paddy soils,the current study compiled the temporal and spatial distribution map of ancient rice distribution in China.The map shows that the distribution of ancient rice is spatially extensive and meantime comparatively concentrated,temporarily covering a long and relatively continuous time-span.The rice relics in the Central China double and single rice cropping regions are among the earliest and the most abundant ones,possessing continuity in time sequence.Combined with the discovery of ancient rice and paddy filed relics,soil micromorphology, pollen combination and element geochemistry,it is suggested that Central China was the origin center of rice cultivation in China.Rice had been spread to the rest part of China in three major waves,also to the East Asian part like Korea and Japan.The temporal and spatial distribution of ancient rice reflects the past environmental change,which is also meaningful to the current rice regionalization and plan- ning as well as food security in China.
