“双碳”目标下中国耕地利用生态效率的区域差异、动态演进及收敛性

Regional Differences Dynamic Evolution and Convergence of Ecological Efficiency of Cultivated Land Use in China Under the Dual Carbon Target

科学测度和分析“双碳”目标下中国耕地利用生态效率对实现耕地可持续利用、农业农村高质量发展具有重要参考价值。从耕地利用生态效率内涵出发,基于碳汇、碳排放和面源污染视角构建中国耕地利用生态效率评价指标体系,运用包含非期望产出的混合超效率SBM-DEA模型、Dagum基尼系数、Kernel密度估计、空间收敛模型等方法分析2001—2020年中国耕地利用生态效率的时空分异、区域差异、动态演进及收敛性。结果表明:①中国省级耕地利用生态效率整体较高,但呈现下降趋势,三大粮食功能区耕地利用生态效率整体呈现“粮食主销区>粮食产销平衡区>粮食主产区”的区域分布格局。②区域间差异和区域内差异是中国耕地利用生态效率的区域差异主要来源,粮食主产区和粮食产销平衡区耕地利用生态效率区域内基尼系数超过全国总体基尼系数。③除粮食主产区外,全国及其他粮食功能区耕地利用生态效率均存在一定程度的两极或多级分化现象。④除粮食主产区存在发散特征外,全国、粮食主销区和粮食产销平衡区均存在不同程度的σ收敛、绝对β收敛和条件β收敛。此外,经济发展水平、科技进步状况、城镇化率等对不同粮食功能区耕地利用生态效率的影响具有显著异质性。

Scientific measurement and analysis of the ecological efficiency of cultivated land use in China under the“dual carbon”target have important reference value for achieving the sustainable use of cultivated land,and the high-quality development of agriculture and rural areas.Taking the connotation of ecological efficiency of cultivated land use as the starting point,this paper constructs an evaluation index system for ecological efficiency of cultivated land use in China from the perspectives of carbon sequestration,carbon emissions,and non-point source pollution.In addition,this paper analyzes the temporal-spatial differentiation,regional differences,dynamic evolution,and convergence of ecological efficiency of cultivated land use in China from 2001 to 2020 using methods such as the mixed super efficiency SBM-DEA model,Dagum Gini coefficient,Kernel density estimation,and spatial convergence model,which include unexpected outputs.The results are as follows:①The ecological efficiency of cultivated land utilization at the provincial level in China was relatively high,but showed a downward trend.The ecological efficiency of cultivated land utilization in the three major grain functional areas showed a regional distribution pattern in which the efficiency inmain grain sales area is higher than that of the grain production and marketing balance area which in turn is higher than that of main grain production area.②Inter-regional differences and intra-regional differences are the main sources of regional differences in the ecological efficiency of cultivated land use in China.The Gini coefficient in the main grain producing areas and grain production and marketing balance areas is higher than the overall Gini coefficient in the country.③Except for the main grain producing areas,there is a certain degree of polarization or multi-level differentiation in the ecological efficiency of cultivated land use in the whole country and other grain functional areas.④In addition to the divergence characteristics in the main grain production areas,there are different degrees ofσconvergence,absoluteβconvergence and conditionalβconvergence in the whole country,even in the main grain sales areas and the grain production and marketing balance areas.In addition,the level of economic development,scientific and technological progress and urbanization rate and other factors have significant heterogeneity in their impact on the ecological efficiency of cultivated land use in different grain functional areas.