Hailong Zhang, Jianjun Guo, Yihe Zhang, Z Wang, Zhao Liu
Quercus baronii Skan (Q. baronii) is an ecologically important tree species in arid and soil erosion-prone areas of northern China, and also holds significant potential as a bioenergy tree species, providing substantial ecological benefits. Global climate change has profoundly influenced the suitable habitats and habitat fragmentation of Quercus baronii forests. This study employed the Maximum Entropy (MaxEnt) model to project the current and future suitable habitats of Q. baronii forests, along with their trends of contraction and expansion. Concurrently, composite landscape indices were used to assess the fragmentation of these suitable habitats. The results indicate that the suitable habitats for Q. baronii forests are primarily located in the eastern part of Northwest China, the northern part of Central China, and the southern part of North China. Minimum temperature of the coldest month (bio6), annual precipitation (bio12), and temperature seasonality (bio4) emerged as the primary determinants of habitat suitability. Under three future climate scenarios, the centroid of suitable habitats for Q. baronii forests is projected to shift towards higher latitudes in the northwest, with the elevation of suitable habitats also gradually rising in tandem with increased carbon emissions. Under low carbon emission scenarios, the extent of suitable habitat for Q. baronii forests is expected to expand; under medium and high carbon emission scenarios, it is expected to first increase and then decline. Although over two-thirds of the suitable habitat for Q. baronii forests is projected to remain relatively intact, future suitable habitats are expected to be more fragmented compared to the present. This fragmentation is projected to intensify with increasing carbon emissions, primarily occurring at the edges of the suitable areas. The results of this study lay the groundwork for both the preservation of forest biodiversity and the ecological conservation and sustainable management of temperate broad-leaved forest ecosystems.