Projected Expansion and Northwestern Shift of Wikstroemia indica Suitable Habitats in China Under Multiple Climate Change Scenarios: An Optimized MaxEnt Approach

This study assesses the impact of climate change on the potential distribution of the traditional Chinese medicinal plant Wikstroemia indica, employing an optimized maximum entropy (MaxEnt) model for the first time for this species under multiple climate scenarios. Our analysis, based on 902 occurrence records and key environmental variables, provides clear evidence that climate change will significantly alter its distribution pattern. The results demonstrated that annual mean temperature (69.4% contribution) and mean diurnal temperature range (12.6% contribution) were the principal climatic factors affecting the distribution of W. indica. Under current climatic conditions, the total potential suitable habitat area for W. indica in China was calculated to be 153.31 × 104 km2, accounting for 15.97% of China's land area. Projections indicate significant habitat expansion under future climate scenarios: under the SSP1-2.6 scenario, the total suitable habitat area would increase by 32.0% to 202.42 × 104 km2 by the 2090s; under the SSP5-8.5 scenario, suitable habitat was anticipated to expand by 49.6% to 229.39 × 104 km2. Furthermore, the distribution centroid of W. indica was predicted to shift 76.68–119.91 km northwestward by the 2050s. The key message is that W. indica demonstrates considerable resilience to climate change, with its suitable habitat expected to expand and shift northwestward. This quantitative prediction, based on robust modeling evidence, provides critical insights for future conservation planning, sustainable management, and utilization strategies for this important medicinal resource in the context of global environmental change.