Potential distribution study of Caragana microphylla in China based on MaxEnt modeling

Climate, soil factors, and topography play a decisive role in the spatial distribution of species. Predicting the potential distribution of Caragana microphylla Lam. over time is of great significance for maintaining ecological balance, soil and water conservation, and evaluating ecological services in northwestern China. In this study, we used the Global Biodiversity Information Service (GBIF) and SDM Toolbox v2.5 to remove spatial autocorrelation from 103 occurrence records of C. microphylla. We then employed the Maximum Entropy model and ArcGIS software with correlation analysis to select 6 climatic factors, 23 soil factors, and 3 topographic factors for analyzing the potential suitable habitats of C. microphylla, and predicted its distribution changes under three SSP scenarios (2030, 2050, 2070).The results show: (1) Current suitable habitat covers 3.329 million km² (34.7% of China), mainly in northern regions; (2) Annual precipitation (bio-12, 350-400 mm), slope (89-90°), Precipitation of Coldest Quarter (bio-19, 0-10 mm), Topsoil Calcium Carbonate (t_CaCO₃, 3-5%), and temperature seasonality (bio-4, 1060-1080) were dominant factors (cumulative contribution: 67.6%); (3) Higher CO₂ scenarios (SSP37.0) increased suitable areas compared to SSP12.6; (4) Future distribution centers will migrate westward, with maximal displacement (448.51 km) under 2050-SSP24.5. It is recommended that priority be given to the protection of existing populations in Inner Mongolia and Xinjiang. while assisted migration programs could target western expansion zones under high-emission scenarios. In vulnerable areas like the Qinling Mountains, soil amendments should be applied to mitigate waterlogging risks from extreme precipitation events (> 50 mm). Furthermore, a long-term monitoring network should be established across the species' distribution range to dynamically assess population changes of C. microphylla and inform adaptive management strategies.