Trade-offs and synergies of ecosystem services in the hohhot-baotou-ordos-yulin resource-based urban agglomeration, China

Resource-based cities are the key carriers of China’s energy security and the goal of “dual carbon”, and they are also sensitive areas of the evolution of human-land relationship. It is of great significance to clarify the mutual feedback mechanism between land use and ecosystem services (ESs) to break the high-carbon lock and realize the synergy of ecological development. Based on the land use data from 2003 to 2023, this study takes Hohhot-Baotou-Ordos-Yulin urban agglomeration as the research object, coupled with PLUS-InVEST model, analyzes the temporal and spatial evolution characteristics of carbon stock, habitat quality, water yield and soil conservation, and weighs the synergistic relationship. Further set four scenarios of natural development, economic priority, green low-carbon and high-quality development to simulate the land use pattern and ESs response in 2033. On this basis, the driving factors of ESs are identified by using the geographical detector model based on the optimal parameters. The results show that: (1) The area of construction land increased sharply from 2003 to 2023, and the transfer effect between grassland, cultivated land and unused land was significant; (2) ESs is differentiated in stages, with carbon stock, habitat quality and soil conservation evolving in an inverted“U”shape, and the water yield continues to decline. The high-value areas are concentrated in ecological restoration areas, and the low-value areas are highly overlapped with industrial, mining and urban construction areas; (3) In the historical period, ESs was dominated by synergy, and soil conservation was significantly coordinated with carbon stock and habitat quality, while the negative balance between habitat quality and water yield was a typical feature of the study area, and it only showed a weak mitigation trend with the promotion of ecological restoration; (4) Scenario simulation shows that high-quality development scenarios can achieve ESs collaborative promotion, which is the best way to give consideration to ecological protection and double carbon targets; (5) Natural factors (precipitation, slope, evapotranspiration) determine the basic pattern of ESs spatial differentiation, and human factors such as GDP and population strengthen the trade-off/synergy effect between services through land development and urban expansion. This study reveals the high sensitivity of ESs in resource-based cities to land use change, which can provide scientific basis for land space optimization and ecological restoration policy formulation under the goal of “dual carbon” in similar areas.