Prediction of the potential distribution of Tirpitzia sinensis in China based on MaxEnt modelling

Tirpitzia sinensis, a traditional medicinal plant, is known for its ability to promote blood circulation, reduce swelling, alleviate pain, and assist in bone healing through its stems and leaves. This study utilized 174 reliable distribution records of T. sinensis in China, along with 10 environmental variables, to predict its current and future distribution patterns. Using the MaxEnt model and ArcGIS software, the study also identified the climatic factors limiting its distribution. The results are as follows: (1) The MaxEnt model demonstrated extremely high predictive accuracy, with an Area Under the Curve (AUC) value of 0.985. Currently, the total suitable area for T. sinensis covers 1,869,438 km², accounting for 19.47% of China's land area. This area is mainly concentrated in western Guangxi Province, southeastern Yunnan Province, southern Guizhou Province, southeastern Sichuan Province, and southwestern Chongqing Municipality. (2) The primary environmental factors influencing the potential distribution of T. sinensis include precipitation during the warmest quarter (bio18), minimum temperature of the coldest month (bio06), temperature seasonality (bio04), and mean temperature of the driest quarter (bio09). (3) Under future climate change scenarios, the potential distribution area of T. sinensis is expected to expand compared to the current distribution, with an overall trend of northward migration. Specifically, under the SSP126 climate scenario, the distribution center is projected to shift from Guizhou Province to Hunan Province. Under the SSP585 climate scenario, this shift extends further towards Hunan and Hubei Provinces.