The effect of Sloping Land Conversion Program on regional carbon sinks—Empirical analysis based on PSM-DID

Abstract

The terrestrial ecosystem carbon sink serves as a crucial metric in gauging the carbon sequestration capabilities of ecosystems, forming an intricate bond with the dynamics of land use change.The Sloping Land Conversion Program (SLCP) has caused significant changes in regional land use patterns and has significantly impacted terrestrial ecosystem carbon sinks. By analysing the impacts of the SLCP on the carbon sink effect in Shaanxi Province and revealing the spatial and temporal heterogeneity of the regional carbon sink effect, it is of great significance to consolidate the results of SLCP and to clarify the target areas for quality enhancement and sink enhancement of the SLCP. In this paper, based on the panel data of Shaanxi Province from 1992 to 2020, we used the PSM-DID model to analyze the influence of the carbon sink effect of the SLCP and analyze the heterogeneity of the carbon sink effect of the SLCP in Shaanxi Province. We found that the carbon sink effect of the SLCP was significantly positive without excluding other factors, increasing the vegetation carbon sink by 20.20% and the vegetation cover by 46.21%, respectively; after excluding the influence of other factors, the effect of the SLCP on the vegetation carbon sink and the vegetation cover was significantly enhanced, increasing the vegetation carbon sink by 21.42% and the vegetation cover by 53.51%, respectively. Meanwhile, the results of spatial heterogeneity showed that the effect of the SLCP on carbon sinks was most evident in Northern Shaanxi, followed by Southern Shaanxi and Central Shaanxi; the results of temporal heterogeneity showed that the effect of the SLCP on carbon sinks at each stage was significantly positive, and then the positive effect decreased with the change of time, but it was still statistically significant.