Research On The Spatial Correlation Characteristics And Mechanism Of Cultivated Land Fragmentation And Cultivated Land Ecological Security In Different Landform Areas Of Liaoning Province

Cultivated land,as the basic means of production for agricultural production,is the most precious resource for human survival,and plays an important supporting role in ensuring food security,ecological security and sustainable development.Cultivated land fragmentation is a land use pattern relative to the large-scale management of cultivated land.In recent years,the cultivated land in my country has been affected by natural and human factors,showing a state of dispersion,fragmentation and disorder.The landscape structure of cultivated land has undergone profound and significant changes,and the problem of cultivated land fragmentation has become increasingly prominent.The reduction in the effective area of cultivated land,the decline in the quality of cultivated land,and the vulnerability of cultivated land ecosystems brought about by the fragmentation of cultivated land have gradually become apparent.The relationship between the fragmentation of cultivated land and the ecological security of cultivated land in different landforms needs to be studied,especially in the perspective of fragmentation.Strengthening the protection of cultivated land ecological security is of great significance to the protection of cultivated land resources,the protection and the sustainable utilization of cultivated land ecosystems.This study takes different landform types in Liaoning Province as the research object,takes the township as the evaluation unit,constructs the evaluation system of cultivated land fragmentation from the perspective of landscape pattern,constructs the evaluation index system of cultivated land ecological security based on the pressure-state-response model,and uses the Geoda spatial autocorrelation tool.Carry out research on the spatial correlation characteristics of cultivated land fragmentation and cultivated land ecological security in different landforms in the western hilly area,central plain area,and eastern mountain area of Liaoning Province.Finally,the econometric model is used to analyze the mechanism of cultivated land fragmentation on cultivated land ecological security.The research conclusions are as follows:(1)There are significant differences in the degree of cultivated land fragmentation in different landform areas,and the regional differences in the characteristics of cultivated land fragmentation are obvious.From the mean value of cultivated land fragmentation index,the eastern mountain area(0.1759)> the western hilly area(0.1273)> the central plain area(0.0950),indicating that the degree of cultivated land fragmentation in the western hilly area and the eastern mountain area is higher than that in the central plain area.From the mean values of cultivated land area fragmentation(AFI),shape fragmentation(SFI)and distribution fragmentation(DFI),the western hilly area: SFI(0.2715)> AFI(0.1987)> DFI(0.0493);the central plain area: AFI(0.1193)> SFI(0.1136)> DFI(0.0737);the eastern mountain area: SFI(0.2715)> AFI(0.1987)> DFI(0.0493).The main feature of cultivated land fragmentation in the western hilly area and the eastern mountain area is the complex irregularity in shape,while the central plain area is characterized by the fragmentation of the number of cultivated land patches.(2)There are significant differences in the ecological security level of cultivated land in different landform areas,and the pressure,state and response of cultivated land in different landform areas are different.From the mean value of the cultivated land ecological security index,the central plain area(0.3812)> the eastern mountain area(0.3184)> the western hilly area(0.2644),and the overall cultivated land ecological security level in the central plain area is relatively high.From the perspective of each subsystem of cultivated land ecological security,the ecological security index of the cultivated land pressure subsystem is the largest in the eastern mountain area(0.6210),the ecological security index of the cultivated land state subsystem in the central plain area(0.6138)is the largest,and the cultivated land response subsystem in the western hilly area(0.5001)is the largest.The ecological safety index is the largest.The cultivated land in the eastern mountain area is under the least pressure,the cultivated land in the central plain area is in the best state,and the western hilly area has a relatively good response effect.(3)The spatial autocorrelation and correlation characteristics of cultivated land fragmentation and cultivated land ecological security in different landform regions are quite different.According to the results of univariate spatial autocorrelation analysis,the global Moran’s I value of cultivated land fragmentation index(CLF): the central plain area(0.4665)>the eastern mountain area(0.4116)> the western hilly area(0.2202);the global cultivated land ecological security index(CLES)Moran’s I value: eastern mountain area(0.7369)> central plain area(0.6559)> western hilly area(0.3562),indicating that both the cultivated land fragmentation index(CLF)and the cultivated land ecological security index(CLES)have a strong positive spatial correlation.From the results of bivariate spatial autocorrelation analysis,the absolute value of the global Moran’s I value of the two-variable cultivated land fragmentation index(CLF)and cultivated land ecological security index(CLES)in different landform areas is as follows: the western hilly area(0.2445)> the eastern mountain area(0.2141)> the central plain area(0.0726),both have a certain spatial correlation in space,and the western hilly area has the strongest spatial correlation.(4)At the scale of the township evaluation unit,the effect of cultivated land fragmentation on the ecological security of cultivated land varies significantly across regions.The regression results at the level of cultivated land fragmentation type show that: the western hilly area and the eastern mountain area are dominated by cultivated land distribution fragmentation(DFI)and cultivated land shape fragmentation(SFI),respectively,while the central plain area is only negatively affected by cultivated land distribution fragmentation(DFI).effect.The cultivated land distribution fragmentation index(DFI)in the western hilly area and the central plain area decreased by 1,and the cultivated land ecological security index increased by 0.0489 and0.1218,respectively;the cultivated land shape fragmentation index(SFI)in the eastern mountain area decreased by 1,and the cultivated land ecological security index increased by0.0633.The regression results of cultivated land fragmentation index level show that: when the number of cultivated land patches(NP)and area-weighted shape index(AWMSI)in the western hilly area are 1783 and 2.13,respectively,and the patch aggregation index(AI)in the central plain area is 94,the cultivated land ecological The safety level reached the optimal level;when the patch aggregation index(AI)in the eastern mountain area was greater than 92,the ecological safety level of cultivated land increased accordingly.Therefore,it is suggested to continuously improve the ecological security level of cultivated land in different landform areas by zoning the types and index characteristics of cultivated land in different landform areas to adapt to local conditions.