Spatiotemporal Evolution of Ecological Patterns and Ecological-Security Risk Assessment with Identification of Potential Influencing Factors in the Agro-Pastoral Ecotone of Inner Mongolia

As an important ecologically sensitive zone and ecological security barrier in northern China, the agro-pastoral ecotone of Inner Mongolia has an ecological pattern and security status that are closely related to regional sustainable development. Based on satellite remote sensing, land-cover, and meteorological observation data from 2000 to 2023, this study applied an ecological pattern transition matrix, vegetation models, and the PSR framework to quantitatively analyze regional ecosystem transitions, ecological function evolution, and ecological security risks. The results showed that from 1990 to 2023, forest and grassland areas increased, desert, water body, and wetland areas decreased, and settlements exhibited a sharp expansion trend. From 2000 to 2023, the region exhibited an apparent warming tendency and a statistically significant wetting trend. NPP and NDVI displayed an increasing spatial distribution from northwest to southeast. For the independently observed NDVI, correlation with precipitation (r = 0.823) was markedly higher than with temperature (r = 0.141). Correlation coefficients for model-simulated NPP against climate variables should be interpreted with caution because precipitation and temperature are explicit inputs within the NPP empirical-statistical model. The ecological security index of the study area generally increased, while the response subsystem continued to decline after 2005. The security levels showed spatial differentiation characterized by security in the northeast, insecurity in the southwest, and critical status in the central region, and the areas showing improvement gradually expanded from 2000 to 2023. In addition, feasible and constructive ecological restoration and regulation strategies were proposed for different regions. This study reveals the evolutionary characteristics and potential influencing mechanisms of regional ecological patterns and security, providing support for the construction of the ecological security barrier in northern China.