Insights into climatic adaptability of Acer truncatum and Quercus mongolica in typical sandy lands of China using the Maximum Entropy (MaxEnt) model

A B S T R A C T Climate change poses an escalating threat to forest sustainability in transitional zones between semi-arid and semi-humid regions, primarily by intensifying tree mortality and hindering ecological recovery. In northern China, Acer truncatum Bunge and Quercus mongolica Fisch. ex Ledeb., two native cold- and drought-tolerant temperate tree species, are widely used for afforestation. However, their future climatic suitability under continuous warming remains unclear. Using the Maximum Entropy model, we assessed the current and projected suitable habitats of these two species across China under three climate scenarios, including Shared Socioeconomic Pathway (SSP)126, SSP245, and SSP585, with a particular focus on the four major sandy lands in northern China: Hulun Buir Sandy Land, Hunshandak Sandy Land, Horqin Sandy Land, and Mu Us Sandy Land. Occurrence records and environmental variables were integrated to quantify habitat suitability for the two species and their spatial distribution dynamics under ongoing climate change. Model outputs were used to identify shifts in suitable habitat areas, expansion–contraction patterns, and changes in habitat stability across scenarios. The results show that the distribution of A. truncatum is primarily shaped by precipitation of wettest month (bio13), elevation, and temperature seasonality, whereas Q. mongolica is mainly influenced by bio13, annual mean temperature, and precipitation of driest month. At present, the suitable habitat area is 9.30×10 5 km 2 for A. truncatum and 9.90×10 5 km 2 for Q. mongolica , accounting for 9.69% and 10.31% of China’s land area, respectively. Future projections indicate that both species will retain stable core distributions, with potential expansion toward northeastern, southern, and southwestern China. The suitable range for A. truncatum is expected to expand, with newly suitable areas accounting for 2.59%–4.69% of China’s land area, whereas Q. mongolica may see new suitable areas accounting for 2.25%–4.50% of the total land area, despite projected contractions along its southern margins. Within the four major sandy lands, both species were predicted to shift from peripheral areas to interior zones. Notably, potential suitable habitats for Q. mongolica may expand to the Hulun Buir Sandy Land under SSP245 and SSP585 scenarios by 2090. These findings highlight the climatic resilience and ecological potential of both species and provide scientific support for climate-informed afforestation and restoration strategies in water-limited areas.