中国耕地低碳利用效率时空演变及其驱动因素

探究耕地低碳利用效率演变规律及其驱动因素对实现耕地利用高效低碳、助力农业绿色发展具有重要意义。该研究构建耕地低碳利用效率评价体系,采用超效率SBM模型测度1998-2018年中国30个省级行政区耕地低碳利用效率,分别采用核密度估计、可视化制图和总体分异测度指数刻画耕地低碳利用效率时序特征、空间格局和区域差异,进而采用地理探测器模型识别耕地低碳利用效率演变驱动因素并剖析各因素驱动机制。研究结果表明：1）研究期内中国耕地低碳利用效率逐步提高并呈现"西高东低、北高南低"的空间格局,空间分布由分散转向集中。2）中国耕地低碳利用效率区域差异水平较低且逐步缩小,耕地低碳利用效率总体分异测度指数由0.185 4下降至0.141 8。不同地区耕地低碳利用效率区域差异程度为中部>东部>西部。其中,东部地区、中部地区和西部地区区域差异分别呈现"W"形波动式下降、"U"形先降后升和持续下降趋势,总体分异测度指数分别由0.159 8、0.261 1和0.131 6降至0.154 1、0.198 3和0.075 0。3）耕地低碳利用效率受自然环境条件、耕地资源禀赋、经济发展水平和农业生产条件共同影响。其中,复种指数、农村居民人均纯收入和灌溉指数驱动力分别由0.367 2、0.374 5和0.469 8降至0.339 4、0.129 1和0.397 7,人均耕地面积驱动力由0.302 4升至0.403 1。各因素交互作用类型均为双因子增强或非线性增强,交互作用正向强化了单因素对耕地低碳利用效率演变的驱动力。研究结果对于深化耕地利用效率研究具有指导意义,也可为推动耕地可持续利用和农业绿色发展提供决策支撑。

Spatial-temporal evolution and driving factors of low-carbon use efficiency of cultivated land in China

Abstract: Low-carbon utilization efficiency of cultivated land can offer significant insights for the decision-making on the cultivated land utilization in ecological agriculture. In this study, an evaluation system was established for the low-carbon utilization efficiency of cultivated land, further exploring the spatial-temporal evolution and driving factors. A super-efficiency Slacks-Based Measure (SBM) model was adopted to evaluate the efficiency using the data of 30 provinces in China from 1998 to 2018. Furthermore, a systematic investigation was made to reveal the spatial-temporal evolution and regional differences in the low-carbon utilization efficiency of cultivated land with kernel density estimation, visualization mapping, and Global Differentiation Index (GDI). Finally, a geographical detector was used to explore the driving factors and mechanism for the low-carbon utilization efficiency evolution of cultivated land. The results showed that: 1) The low-carbon utilization efficiency of cultivated land was gradually improved from the perspective of temporal evolution. The average level of cultivated land low-carbon use efficiency in western and eastern China was higher than that in the whole country, whereas, the average level in central China was higher than the national average level. There was a spatial pattern of "high in the west and low in the east, while, high in the north and low in the south", indicating that the spatial distribution was changed from the scattered to the concentrated pattern. Specifically, the high-efficiency areas lay in the western and northeastern regions, whereas, the low-efficiency areas were in the lower Yangtze Region. 2) There was a relatively low and gradually narrow regional difference in cultivated land low-carbon utilization efficiency in China, where the GDI of cultivated land low-carbon utilization efficiency dropped from 0.185 4 to 0.141 8. The regional differences in the cultivated land low-carbon utilization efficiency were ranked in descending order to central, eastern, and western China. Specifically, the GDI of cultivated land low-carbon utilization efficiency in eastern China showed a "W" shaped fluctuation trend, and the GDI dropped from 0.159 8 to 0.154 1. There was a "U" shaped fluctuation trend of the GDI in the central China, where the GDI dropped from 0.261 1 to 0.198 3. A continuous decrease trend was found in western China, where the GDI dropped from 0.131 6 to 0.075 0. 3) The cultivated land''s low-carbon utilization efficiency depended mainly on the natural environment condition, cultivated land endowment, economic development level, and agricultural production conditions. In addition, the driving force of multiple cropping index, per capita net income of farmers, and irrigation index dropped from 0.367 2 to 0.339 4, 0.374 5 to 0.129 1, and 0.469 8 to 0.397 7, respectively, whereas, the driving force of per capita cultivated land increased from 0.302 4 to 0.403 1. Moreover, the interaction of factors positively strengthened the single-factor driving force, indicating the outstanding divergence in the driving force of various factors. The interaction type of two driving factors was double or nonlinear enhancement. In conclusion, the findings can provide a promising guideline for the study on cultivated land utilization efficiency and the decision making on the sustainable cultivated land utilization and green agriculture development.