Long-Term Spatiotemporal Evolution Characteristics and Driving Force Analysis of Landscape Stability in the Forest–Grassland Ecotone of the Greater Khingan Mountains, Inner Mongolia, China

Forest–grassland ecotones refer to the transitional area between forest and grassland ecosystems. Previous studies mainly focus on environmentally sensitive features and landscape risk pressures caused by edge effects, ignoring the landscape restoration and stability changes brought about by high species diversity. In this study, we calculated the landscape stability in the forest–grassland ecotone of the Greater Khingan Mountains in Inner Mongolia, China from 1990 to 2020, analyzed the changing trends and spatial migration dynamics of the landscape stability, and revealed the potential driving factors and spatial heterogeneity of dominant driving factors for the changes in landscape stability. The results indicated that the dominant landscapes in the study area changed from forests and grasslands in 1990 to forest-dominated landscapes in 2020, and the landscape stability gradually improved from a lower level to a higher level. The stability gradually expanded from the center to the northeast and southwest edges, exhibiting a ribbon sprawl pattern, and the stable center gradually moved to the northeast from 1990 to 2020. Climate factors were the main driving forces affecting the changes in landscape stability in the study area. Different dominant driving factors showed various spatial heterogeneity over time. In the northern part of the forest–grassland ecotone, precipitation, and NDVI had positive correlations with landscape stability, while the opposite was true in the south. In addition, the area of landscape stability in the south that was positively correlated with temperature and NDVI gradually expanded over time. This study analyzed the unique ecological advantages of the forest–grassland ecotones from the perspective of landscape stability changes, which will be facilitated in the ecological assessments and restoration of the forest–grassland ecotones.