Scenario-based simulation and analysis of future terrestrial ecosystem changes in Inner Mongolia under different ecological-economic development pathways

The Inner Mongolia autonomous region is the largest ecological functional area and a key ecological barrier in northern China. The condition of its macro-ecosystem affects not only human survival and livelihood but also the ecological security of northern, northeastern, and northwestern China, and even the entire country. In this study, a dataset was constructed firstly based on the patterns and impacting factors in the Inner Mongolia macro-ecosystem in 1990, 2000, and 2015. Then, the regional socio-economic and ecosystem development plans were introduced as reference to set up three scenarios: business as usual scenario（baseline, continuing the historical development trend）, coordinated ecological-economic development scenario（prioritizing ecology）, and ecological-economic trade-off scenario（prioritizing economics）. A land-use equilibrium analysis model was applied to simulate the changes in the structure and spatial pattern of six types of terrestrial ecosystem in Inner Mongolia in 2025 and 2035 under three scenarios. The quantitative results showed that under the baseline and trade-off scenarios, grassland and farmland ecosystems would be unable to recover to 2000 levels by 2035, and planning targets for the macro-ecosystem structure would not be met. Under the coordinated development scenario, with an emphasis on ecological conservation, the area of grassland, forest, and wetland ecosystems would increase significantly. This would be in line with the goal of strategically developing Inner Mongolia as an ecological barrier in Northern China. From a spatial perspective, future shrinkage of farmland ecosystems will be concentrated mainly in farmland–grassland ecotones; these "grain-to-green" regions will also constitute the main areas of grassland ecosystem growth. Grassland ecosystem expansion will also be distributed in the region of previously degraded grassland in recent ten years. This is consistent with the trend that the previously degraded grassland ecosystem in Inner Mongolia is gradually recovering after the implementation of ecological projects such as "Control of Sources of Sandstorms in Beijing and Tianjin" and "Grassland Reward and Subsidy Policy" in recent decades. Forest ecosystem growth will be concentrated in a few regions such as the Greater Hinggan Mountains. Urban ecosystem sprawl will be concentrated in the surrounding regions of existing urban settlements, especially the towns close to the mining fields, industrial lands, and traffi