Predicting the potential suitable habitats of Alsophila spinulosa and their changes.

Alsophila spinulosa is a rare and endangered relict fern species. With the Maxent model, we predicted the global potential suitable habitat and its future changes for A. spinulosa. We evaluated the accuracy of our prediction based on the receiver operating characteristic curve (ROC), in order to provide reference for the protection, detection and cultivation of its resources. The results showed that most potential suitable habitat for A. spinulosa would be in Asia and few in North Ame-rica, Central America, Madagascar, La Reunion, Mauritius, Seychelles, New Zealand, New Caledonia and Fiji. The global potential suitable habitat for A. spinulosa under current climate conditions encompassed 357.1×104 km2, with Asia accounting for 88.4% and China for 49.5% of the total. The highly suitable habitat for A. spinulosa in China would be mainly in Yunnan-Guizhou Plateau, Sichuan Basin, south of the Nanling Mountains and Taiwan Island. The critical factors driving the distribution of A. spinulosa would be the precipitation of warmest quarter, July average precipita-tion, temperature seasonality and mean diurnal range. Under the SSP1_2.6 climate scenario, the global potential suitable habitat for A. spinulosa would decrease by 7.8% from 2041 to 2060, and increase by 3.2% from 2081 to 2100. Under the SSP2_4.5 climate scenario, it would increase by 2.9% from 2041 to 2060 and by 7.2% from 2081 to 2100. Under the SSP5_8.5 climate scenario, it would increase by 3.3% from 2041 to 2060 and by 5.3% from 2081 to 2100.