东北黑土区典型地域耕地生态退化时空分异——以富锦市为例

耕地生态退化严重威胁黑土区耕地的可持续利用,明确其时空分异规律是提高黑土耕地产能实现农业可持续发展的重要科学命题。以东北黑土区典型地域富锦市为研究区,立足于耕地外部扰动变化所引发的环境胁迫与生态恢复,利用遥感驱动的多源环境胁迫监测模型、改进的CRITIC模型、优化的InVEST模型,明确二者间的作用结果,揭示研究区2000—2020年耕地生态退化的时空分异规律。研究结果表明：（1）研究区耕地外源环境胁迫强度整体偏低,呈现出以东部、西部、北部高,中部、南部低为主基调的时空分异格局;（2）研究区耕地內源生态恢复强度高于胁迫强度,表现出以西部—东部—中部梯度衰减的时空分异格局;（3）研究区共有968.12 km²耕地发生生态退化,展现出以团块状集中分布在研究区东部和中部,零星分布在其他区域的空间分异格局。研究明晰了多源环境胁迫/多源生态恢复之间的交互效应,实现了各耕地图斑对多种环境胁迫力和生态恢复力的动态敏感度测算,进一步刻画出了生态退化过程,测度结果与现实耕地利用强度吻合,为准确诊断黑土区耕地生态退化提供了理论参考和技术支撑。

Spatio-temporal differentiation of cultivated land ecological degradation in typical black soil regions of Northeast China: A case study of Fujin city

The ecological degradation of cultivated land poses a serious threat to the sustainable development of black soil regions. Clarifying the law of the spatial and temporal differentiation is an important scientific proposition to improve the productivity of black soil cultivated land and achieve sustainable agricultural development. Taking Fujin, a typical city of black soil in Northeast China as the research area, based on the environmental stress and ecological restoration caused by external disturbance changes in cultivated land, the remote sensing-driven multi-source environmental stress monitoring model, the improved CRITIC model, and the optimized InVEST model are used to clarify the results of the interaction between the environmental stress and ecological restoration, revealing the spatio-temporal differentiation of the ecological degradation of cultivated land in the study area from 2000 to 2020. Results showed that: (1) The exogenous environmental stress intensity of cultivated land is overall low, showing a spatial and temporal differentiation pattern with the intensity being high in the east, west, and north, while low in the middle and south. (2) The endogenous ecological restoration intensity of the cultivated land is higher than the stress intensity, showing a spatial and temporal differentiation pattern with a west-east-central gradient attenuation. (3) A total of 968.12 km² of cultivated land has experienced ecological degradation, which is concentrated in the eastern and central parts of the study area and sporadically distributed in other parts. The study clarified the interaction effect between multi-source environmental stress and multi-source ecological restoration, realized the dynamic sensitivity measurement of each cultivated land plot to various environmental stresses and ecological resilience, and further characterized the ecological degradation process and the measurement results, which is consistent with the actual cultivated land use intensity. The results provide theoretical reference and technical support for the accurate diagnosis of ecologically degraded cultivated land in black soil regions.