Spatiotemporal evolution and convergence characteristics of land green use efficiency in shrinking counties of China

[Objective] The purpose of this study was to evaluate the land green use efficiency of shrinking regions at the county level in China, and to investigate the dynamic leap and stochastic convergence characteristics of county land green use efficiency, so as to provide a reference for shrinking counties to achieve high-quality development in the new period. [Methods] Based on the economic-social-environmental analysis framework, we constructed a non-radial, non-angle super-efficiency slacks-based measure-data envelopment analysis (SBM-DEA) model with non-expected outputs under global reference to measure the land green use efficiency of the shrinking counties in China from 2011 to 2020; used the exploratory spatiotemporal data analysis method to examine the spatiotemporal dependent characteristics and dynamic leap characteristics of county land green use efficiency; and based on the panel unit root test method to test the global and club stochastic convergence of county land green use efficiency, in order to identify the possible convergent subsets. [Results] During the study period, more than half of the county-level administrative unit samples were in the population shrinkage state and showed the trend of continuous development, and the land green use efficiency of contraction-type counties was in the low-value range and generally showed a decreasing trend. The land green use efficiency of counties showed a typical spatial agglomeration phenomenon, and although there are good conditions for spatial integration in future evolution, the probability of shifting to the “low-low” quadrant is higher in the short term. Regions with a higher degree of shrinkage showed more obvious path dependence and low-value lock-in behaviors. No global or club stochastic convergence trends were found at the national and sub-regional levels, and a large number of convergent subsets existed at the sub-provincial level. [Conclusion] The potential for enhancing the land green use efficiency of shrinking regions at the county level in China is substantial，indicating that the region should pay attention to the influence of spatial interaction， promote small-scale and refined communication and cooperation, and contribute to the realization of coordinated development of human-land relationship in counties with population losses.