Construction and optimization of ecological security patterns in Chinese black soil areas considering ecological importance and vulnerability

As important guarantees of national food security, black soil regions have faced many ecological problems in recent years, such as soil erosion and salinization, which threaten the sustainable development of agriculture and ecological security. This study explores the dynamic changes in the ecological security pattern of China's black soil region in a time series and proposes corresponding optimization suggestions on the basis of the characteristics of these changes. Taking 2002, 2012 and 2022 as the time nodes, we identified ecological source areas through analyses of ecosystem service value and ecological sensitivity and then constructed ecological corridors by combining the minimum cumulative resistance (MCR) model and circuit theory. The findings are as follows: (1) Ecosystem service functions exhibit a spatial pattern of higher values in the east and lower values in the west, with ecological sensitivity decreasing annually. Although the number of ecological source areas has decreased, their total area has increased. (2) The number of ecological corridors has decreased, but their length has fluctuated, and the number of stepping stones has significantly increased. (3) On the basis of the results of this study, a "point-line-polygon-network" optimization strategy is proposed, which includes constructing ecological belts, strengthening ecological barriers, and restoring the connectivity of ecological nodes and corridors to improve regional ecosystem stability and sustainability, providing policymakers with scientific guidance.