关键词: 荆条, MaxEnt模型, 潜在适生区, 气候变化

Abstract: Aims Vitex negundo var. heterophylla is an important shrub species for soil and water conservation and ecological restoration in northern China. Our objective was to identifying its potential suitable habitats under current and future climate scenarios, and to determine the dominant environmental factors controlling its distribution. Methods Based on 180 distribution records and 14 environmental factors, we applied an optimized MaxEnt model (feature combination FC = LQH, regularization multiplier RM = 2) to predict the potential suitable range of Vitex negundo var. Heterophylla in China under current (1970–2000) and future (2021–2040, 2041–2060, 2061–2080) climate scenarios (SSP2-4.5 and SSP5-8.5, abbreviated as SSP245 and SSP585). Model parameter optimization was performed using the ENMeval package in R software. Spatial pattern dynamics were analyzed using ArcGIS 10.8. Important findings Seasonal variation in precipitation, precipitation of the wettest month, and mean temperature of the coldest quarter were the dominant environmental factors, with a cumulative contribution exceeding 80%. Under current climate conditions, the total suitable area is approximately 568,100 km², accounting for 5.92% of China's land area, and is concentrated in Liaoning, North China, Shaanxi, southeastern Gansu, northern Henan, Shandong, and parts of Sichuan.Under SSP245, the total suitable area first increases then decreases, while under SSP585 it continuously increases. Under both scenarios, the suitable area expands significantly northward and northwestward, with contraction occurring in Sichuan, the Shaanxi–Gansu border area, northern Henan, and southern Shandong. The expansion is more pronounced under SSP585. This study provides a theoretical basis for the scientific utilization of this species in ecological restoration, soil and water conservation, and carbon sequestration.

Key words: Vitex negundo var. heterophylla, MaxEnt model, potential suitable habitat, climate change