Study On The Influence Of Sloping Land Conversion Program On The Ecological Security Of Cultivated Land In Shanxi Province

As an ecological construction project with large investment,wide scope and high participation of farmers,the project aims to achieve ecological restoration and improve social welfare by encouraging and guiding farmers to change the type and structure of land use through ecological compensation.By 2019,the project has been implemented for 20 years,playing an important role in vegetation cover,soil conservation,income generation and poverty reduction.Cultivated land is an essential factor in food production,however,while adhering to the principle of basic farmland unwavering,but under the background of population growth and urban expansion,the implementation of returning farmland to forest project will cause a large area of cultivated land to forestland and grassland conversion,could exacerbate tensions in cultivated land resources,to a certain extent affect the farmland ecosystem.Therefore,whether the conversion of farmland will increase the pressure of farmland,what is the impact on the security of farmland,how to deal with the relationship between ecological protection and farmland protection,has been a problem that the conversion of farmland to forest project needs to pay attention to them.Therefore,to master the changes and spatial differences in the utilization of cultivated land and the ecological security of cultivated land during the conversion period,and to explore the influence of the conversion on the ecological security of cultivated land from the empirical level,is of guiding significance for the subsequent implementation of the conversion,and also helps to provide reference for the early warning of cultivated land ecology in the conversion area.This paper takes 114 districts and counties in Shanxi Province as research areas.Firstly,based on the improved ecological footprint model,the cultivated land ecological footprint,the cultivated land ecological carrying capacity and the index of cultivated land ecological pressure of each county in Shanxi Province from 2000 to 2015 were calculated,so as to evaluate the ecological security of cultivated land in Shanxi Province under the background of the project of returning cultivated land to forest.Secondly,the paper analyzes the temporal and spatial dynamic change of farmland utilization in Shanxi Province before and after farmland conversion,and compares the difference of farmland utilization between key and non-key counties in Shanxi Province before and after farmland conversion.Finally,based on the panel data of 114 districts and counties in Shanxi Province in 2000,2005,2010 and 2015,the panel data regression model was constructed to explore the impact mechanism of the project on the ecological security of cultivated land.The research conclusions are as follows:(1)The project of returning farmland to forest can promote the transfer of farmland to woodland and grassland,effectively increase the area of woodland and grassland in ecologically fragile areas,and the intensity of conversion of farmland in key counties is greater than that in non-key counties.a.From the perspective of the change in the utilization of cultivated land,the cultivated land area of both key and non-key counties decreased significantly after the conversion of cultivated land,but the extent of the reduction of cultivated land in key counties was significantly greater than that in non-key counties.b.In terms of the situation of farmland transfer,the farmland in the key counties after the conversion is mainly transferred to grassland and woodland,while the farmland in the non-key counties is mainly transferred to construction land.c.From the perspective of spatial distribution,the conversion of cultivated land to forest and grass land is more significant in the loess hilly and gully areas and the earthen and stone mountainous areas where soil erosion is relatively serious.(2)The overall performance of cultivated land ecological security in Shanxi Province is good.From the perspective of time,the cultivated land ecological security shows a trend of fluctuation and spatial distribution has obvious regional characteristics.a.From the perspective of time,the cultivated land ecological security is very safe and relatively safe as the main type,but from 2000 to 2015 the number of districts and counties with cultivated land ecological surplus decreased,the number of districts and counties with cultivated land deficit increased,and the cultivated land ecological security situation became worse.b.From the perspective of space,the overall situation of cultivated land ecological security is dominated by the ecological surplus areas,and the cultivated land ecological deficit areas are mainly distributed in the major grain-producing areas with a high degree of cultivated land use,as well as the economically developed and densely populated areas.(3)The project of returning farmland to forest can promote the ecological security of cultivated land.Within a certain range,the greater the intensity of returning farmland is,the more helpful it is to reduce the ecological pressure of cultivated land,so as to improve the ecological security of cultivated land.a.The accumulative converted cropland area has a significant negative impact on the ecological pressure of cultivated land.For every 1% increase of the accumulative converted cropland area,the ecological pressure of cultivated land decreases by 0.0664%.b.The accumulative area of cultivated land in both the key and non-key counties has a negative influence on the ecological pressure of cultivated land.c.There is a u-shaped relationship between the accumulative conversion area and the ecological pressure of cultivated land.In a certain range,with the increase of the accumulative conversion area,the ecological pressure of cultivated land decreases,which is helpful to improve the ecological security of cultivated land.