Ecotones have received great attention due to its critical function in energy flux, species harbor, global carbon sequestration, and land-atmosphere interaction. This study investigated land use pattern and spatial he...Ecotones have received great attention due to its critical function in energy flux, species harbor, global carbon sequestration, and land-atmosphere interaction. This study investigated land use pattern and spatial heterogeneity of the ecotones among agricultural land, forest land, and grassland of the southeastern Da Hinggan Mountains in the northeastern China. The change of these delineated ecotones under different slopes and aridity conditions was analyzed by two landscape indices, edge density(ED) and core area percentage of landscape(CPL), to explore the inter-linkage between spatial structure of ecotones and socioeconomic development and land management. Specifically, the ecotones such as agriculture-forest(AF) ecotone, forest-grassland(FG) ecotone, and agriculture-forestgrassland(AFG) ecotone moved from the arid southeast to the humid northwest. The flat area with small slope is more edge-fragmented than the steep area since the ED decreases as the slope increases. The AF ecotone mostly found in the humid region is moving to more humid areas while the agriculture-grassland(AG) ecotone mostly found in the dry region is moving towards the drier region.展开更多
This paper, concerning uneven development in China, empirically analyzes the core-periphery gradient of manufacturing industries across provinces （autonomous regions, municipalities）, and assesses the extent to whic...This paper, concerning uneven development in China, empirically analyzes the core-periphery gradient of manufacturing industries across provinces （autonomous regions, municipalities）, and assesses the extent to which these provinces have changed in recent years. Since China＇s reform and opening-up, the spatial structure of the economy has pre- sented a significant core-periphery pattern, the core evidently skewing towards east-coastal areas. With the deepening of market reforms and expansion of globalization, industrial loca- tion is gradually in line with the development advantages of provinces. The core provinces specialize in those industries characterized by strong forward and backward linkages, as well as a high consumption ratio, a high degree of increasing returns to scale, and labor or hu- man-capital intensity. However, it is the opposite with regard to peripheral provinces, in addi- tion, energy intensive industries are gradually concentrating in these areas. To a certain de- gree, the comparative advantage theory and new economic geography identify the underlying forces that determine the spatial distribution of manufacturing industries in China. This paper indicates that the industrialization of regions along different gradients becomes unsynchro- nized will be a long-term trend. Within a certain period, regions are bound to develop indus- trial sectors in line with their respective characteristics and development stage. A core-periphery pattern of industries also indicates that industrial development differentials across regions arise because of not only the uneven distribution of industries but also the inconsistent evolving trends of industrial structure for each province.展开更多
As a special branch of global trade,the trade of agricultural products has an important impact on food security and the environment.In this paper,we studied international trade network of agricultural products from 20...As a special branch of global trade,the trade of agricultural products has an important impact on food security and the environment.In this paper,we studied international trade network of agricultural products from 2000 to 2016 as a whole and in part.We explored the overall characteristics of the network,analyzed the evolution of communities and identified core countries of the communities.The results show that the structure of the trade network became increasingly complex and the trade relations became closer over time.There were four major communities in the network,whose primary core countries were Germany,the United States,Brazil,and China.Since 2007,the community represented by China has disappeared,and the community pattern of the network has been in a three-pillar state and basically stable.We discuss the actual roles of certain trading countries,the formation of communities and the impact of economic events on agricultural products trade.This paper reveals the underlying patterns of the agricultural products trade and provides a way to track its evolution over time.展开更多
基金Under the auspices of'Strategic Priority Research Program-Climate Change:Carbon Budget and Relevant Issues'of Chinese Academy of Sciences(No.XDA05090310)
文摘Ecotones have received great attention due to its critical function in energy flux, species harbor, global carbon sequestration, and land-atmosphere interaction. This study investigated land use pattern and spatial heterogeneity of the ecotones among agricultural land, forest land, and grassland of the southeastern Da Hinggan Mountains in the northeastern China. The change of these delineated ecotones under different slopes and aridity conditions was analyzed by two landscape indices, edge density(ED) and core area percentage of landscape(CPL), to explore the inter-linkage between spatial structure of ecotones and socioeconomic development and land management. Specifically, the ecotones such as agriculture-forest(AF) ecotone, forest-grassland(FG) ecotone, and agriculture-forestgrassland(AFG) ecotone moved from the arid southeast to the humid northwest. The flat area with small slope is more edge-fragmented than the steep area since the ED decreases as the slope increases. The AF ecotone mostly found in the humid region is moving to more humid areas while the agriculture-grassland(AG) ecotone mostly found in the dry region is moving towards the drier region.
基金National Science and Technology Infrastructure Program of China,No.2007FY110300
文摘This paper, concerning uneven development in China, empirically analyzes the core-periphery gradient of manufacturing industries across provinces （autonomous regions, municipalities）, and assesses the extent to which these provinces have changed in recent years. Since China＇s reform and opening-up, the spatial structure of the economy has pre- sented a significant core-periphery pattern, the core evidently skewing towards east-coastal areas. With the deepening of market reforms and expansion of globalization, industrial loca- tion is gradually in line with the development advantages of provinces. The core provinces specialize in those industries characterized by strong forward and backward linkages, as well as a high consumption ratio, a high degree of increasing returns to scale, and labor or hu- man-capital intensity. However, it is the opposite with regard to peripheral provinces, in addi- tion, energy intensive industries are gradually concentrating in these areas. To a certain de- gree, the comparative advantage theory and new economic geography identify the underlying forces that determine the spatial distribution of manufacturing industries in China. This paper indicates that the industrialization of regions along different gradients becomes unsynchro- nized will be a long-term trend. Within a certain period, regions are bound to develop indus- trial sectors in line with their respective characteristics and development stage. A core-periphery pattern of industries also indicates that industrial development differentials across regions arise because of not only the uneven distribution of industries but also the inconsistent evolving trends of industrial structure for each province.
基金supported by the National Key Research and Development Program of China[grant number 2016YFC0803106]the National Natural Science Foundation of China[grant number 41571438].
文摘As a special branch of global trade,the trade of agricultural products has an important impact on food security and the environment.In this paper,we studied international trade network of agricultural products from 2000 to 2016 as a whole and in part.We explored the overall characteristics of the network,analyzed the evolution of communities and identified core countries of the communities.The results show that the structure of the trade network became increasingly complex and the trade relations became closer over time.There were four major communities in the network,whose primary core countries were Germany,the United States,Brazil,and China.Since 2007,the community represented by China has disappeared,and the community pattern of the network has been in a three-pillar state and basically stable.We discuss the actual roles of certain trading countries,the formation of communities and the impact of economic events on agricultural products trade.This paper reveals the underlying patterns of the agricultural products trade and provides a way to track its evolution over time.
