Projected Non-Monotonic Changes in the Potential Suitable Range of Phyllanthus emblica in China Under Future Climate Scenarios

The economically important species Phyllanthus emblica L. has received increasing attention, yet its climate-driven distributional shifts across China remain unexplored. Using 446 occurrence records and a parameter-optimized MaxEnt model (RM = 0.1, FC = LQ), we forecasted habitat changes under three SSP scenarios (126, 370, 585) across the 2050s, 2070s, and 2090s. Three temperature variables, namely temperature seasonality (Bio4), temperature annual range (Bio7), and mean temperature of the driest quarter (Bio9), collectively contributed 90.2% to the model, confirming that thermal conditions, particularly during dry seasons, dominate habitat suitability. Current suitable habitat covers 86.43 × 104 km2, largely confined to South China’s tropical and southern subtropical belts. Future projections indicate non-linear range responses, with a general northwestward centroid shift, although intermediate periods exhibit oscillatory northeastward and southwestward fluctuations. Under the high-emission SSP585 scenario, modest expansion occurs in high-elevation areas of southeastern Tibet, while contraction affects less than 1% of current suitable low-elevation zones. Based on these findings, we recommend designating long-term core conservation areas (southern Yunnan, southern Guangxi, and Hainan), conducting adaptive introduction trials in expansion zones (e.g., Panzhihua, Sichuan), and implementing planting controls in contraction zones (e.g., northern Guizhou). These insights provide a scientific basis for climate-adaptive management of P. emblica in China.