Spatiotemporal Characteristics And Driving Mechanism Of Cultivated Land Use Transition In The Main Grain-producing Areas In The Middle And Lower Reaches Of The Yangtze River

Food production in major grain producing areas is an important foundation for ensuring food security.China is currently at an important stage of comprehensively promoting the construction of new urbanization and industrialization,as well as a crucial period for the transformation of social and economic patterns.The changes in social and economic patterns are particularly significant,and the patterns of cultivated land use have also undergone significant changes.However,due to the competitive impact of excessive losses caused by food production,land finance,and urban and rural construction in China,the transition of cultivated land use and socio-economic transition have been misaligned,resulting in social and resource environmental issues such as cultivated land marginalization,non grain,and ecosystem degradation.Therefore,how to distinguish the characteristics of cultivated land use transition under specific socio-economic conditions and analyze the driving mechanism of cultivated land use transition has become an urgent need to achieve coordination between cultivated land resources and social,economic,and ecological environment.This study selects the main grain producing areas in the middle and lower reaches of the Yangtze River as a research case.Based on the construction of a "spatial-functional" transition analysis framework for cultivated land use,it measures the evolution characteristics of the cultivated land use transition index from 2000 to 2020,and analyzes the spatial autocorrelation and the spatial evolution characteristics of the center of gravity migration in the process of cultivated land use transition based on exploratory spatial data analysis and standard deviation ellipse method,using spatial econometric models to identify the driving factors of cultivated land use transition and propose regulatory paths.The main conclusions are as follows:(1)The comprehensive transition index of cultivated land use in the main grain producing areas in the middle and lower reaches of the Yangtze River increased from 0.191 in2000 to 0.283 in 2020.Among them,the spatial transition index of cultivated land use increased from 0.097 in 2000 to 0.119 in 2020,and the change rate of the transition index decreased from 12.332% to 1.556%.In the morphological subsystem,the quantitative pattern index increased slightly,the structural pattern index showed a fluctuating and increasing trend,and the landscape pattern index showed a downward trend.The transition index of cultivated land use function increased from 0.093 in 2000 to 0.163 in 2020,with the change rate of the transition index increasing from 7.781% to 45.721%,and then decreasing to 13.426%,which is higher than the change rate of the spatial transition index as a whole.In the functional subsystems,the food security function and economic contribution function showed an upward trend,the living security function showed an inverted "V" upward trend,and the ecological maintenance function changed slightly.(2)The comprehensive,spatial,and functional transition of cultivated land use in the main grain producing areas in the middle and lower reaches of the Yangtze River have significant positive spatial agglomeration effects.In the comprehensive transition,the local spatial agglomeration is characterized by high in the northeast-southwest and low in the middle,the spatial transition is characterized by high in the northeast and low in the middle,and the functional transition is characterized by high in the southwest and low in the middle.The development space of cultivated land use transition focus is significantly unbalanced.The focus of comprehensive and spatial transition shifts from southwest to northeast,and the focus of functional transition shifts from northeast to southwest.The focus of comprehensive,spatial and functional transition of cultivated land use shifted 30.475 km,59.393 km and42.802 km respectively,and the migration speed slowed down.(3)The spatial and functional transition of cultivated land use in the main grain producing areas in the middle and lower reaches of the Yangtze River is jointly driven by the internal conditions of the natural environment and the external conditions of the social economy.DEM,annual average temperature,precipitation,per capita GDP,per capita fixed assets investment,the proportion of secondary and tertiary industries,highway mileage,the proportion of urban population,population density,farmers’ income level,the total power of agricultural machinery and the proportion of financial support for agriculture and other factors have different degrees of impact on the transition of cultivated land use space and function.(4)The optimal regulation and control of cultivated land use transition in the middle and lower reaches of the Yangtze River should take the sustainable use of cultivated land resources as the primary goal,start from the regulation and control ideas of guiding regulation,comprehensive management,benefit coordination and efficient use,strengthen the management of cultivated land resources and environment,promote the adjustment and transition of industrial structure,optimize the pattern of cultivated land use,and other measures to achieve the optimal regulation and control of cultivated land use transition.