Habitat suitability distribution and fragmentation of Camellia oleifera in China under current and future climate scenarios based on MaxEnt and Fragstats

Applying the MaxEnt model to simulate vegetation distribution and its response to climate change has garnered significant scientific attention. However, existing studies lack in-depth exploration of habitat fragmentation, a research gap that can be effectively addressed by adopting landscape indices. This study integrates the MaxEnt model with bioclimatic, topographic, edaphic factors, and landscape indices to assess spatiotemporal changes in habitat suitability and fragmentation patterns of Camellia oleifera — subtropical woody oleaginous plants—from 1970 to 2100. The results are as follows: (1) Key factors and their ranges affecting the habitat suitability of Camellia oleifera include precipitation of the driest quarter exceeding 50 mm, annual precipitation exceeding 1000 mm, mean temperature of the coldest quarter exceeding 4 °C, and root depth exceeding 13 cm, with a combined contribution rate of over 90%. (2) The optimal habitat regions for Camellia oleifera are primarily distributed in southern China, specifically south of the Yangtze River and east of the Yunnan-Guizhou Plateau. The largest areas of the optimal and suitable habitat regions occurred in the 2030s85 and 2070s45. The habitat suitability changes of Camellia oleifera exhibited drastic fluctuations over time. (3) The fragmentation degree of Camellia oleifera habitat suitability, as indicated by landscape indices, is relatively high in southern China, particularly in the transitional zones between different habitat suitability levels. The degree of fragmentation shows a fluctuating upward trend over time. (4) Regions with high planting potential are the hilly regions of southern China, while future developable regions include the hilly regions of southwestern and northern China. Developing hilly areas is conducive to the rational utilization of regional resources in accordance with local conditions, thereby promoting economic development and improving residents’ living conditions. This study enhances to understanding of changes in habitat suitability and fragmentation of subtropical woody oleiferous plants under climate change. Additionally, it provides insights into the rational use of regional resources to boost the economy and improve living conditions in hilly regions based on local circumstances.