Sophora alopecuroides L., a perennial herb in the arid and semi-arid regions of northwest China, has the ecological functions of windbreaking and sand fixation and high medicinal value. In recent years, global warming and human activities have led to changes in suitable habitats for S. alopecuroides, which may affect the accumulation of natural products. In this study, MaxEnt 3.4 and ArcGIS 10.4 software were used to predict the distribution of potentially suitable habitats for S. alopecuroides in China under climate change. Furthermore, the geographical distribution of S. alopecuroides as affected by human activities, the differences in the content of natural products of S. alopecuroides between different suitable habitats, and the correlation between natural products and environmental factors were analyzed. The results showed that suitable habitats for S. alopecuroides were projected to expand in the future, and the major environmental factors were temperature (Bio1), rainfall (Bio18), and soil pH (pH). When Bio1, Bio18, and pH were 8.4283 °C, 7.1968 mm, and 9.9331, respectively, the distribution probability (P) of S. alopecuroides was the highest. After adding a human activity factor, the accuracy of the model prediction results was improved, and the area of suitable habitats was greatly reduced, showing a fragmented pattern. Meanwhile, habitat suitability had a specific effect on the content of natural products in S. alopecuroides. Specifically, the content of natural products in S. alopecuroides in wild habitats was higher than that in artificial cultivation, and highly suitable habitats showed higher contents than those in non-highly suitable habitats. The contents of total alkaloids and total flavonoids were positively correlated with human activities and negatively correlated with land use types. Among them, total alkaloids were negatively correlated with aspect, and total flavonoids were positively correlated with aspect. In addition, it is suggested that Xinjiang should be the priority planting area for S. alopecuroides in China, and priority should be given to protection measures in the Alashan area. Overall, this study provides an important foundation for the determination of priority planting areas and resource protection for S. alopecuroides.

The aim of our study is to achieve a comprehensive understanding of the global distribution of suitable habitats for Sophora alopecuroides L., as well as how these habitats might change in response to climate change. We employed the MaxEnt niche model to integrate distribution data from the Global Biodiversity Information Platform, incorporating 19 bioclimatic factors. This approach enabled us to predict the potential geographic distribution of S. alopecuroides L. worldwide under both current climatic conditions and future greenhouse gas emission scenarios. The results were visualized via ArcGIS 10.8 software. The findings indicate that currently, the suitable habitat for S. alopecuroides L. spans 12,897,100 km², with the majority situated in the arid regions of Central and Eastern Asia. The key environmental variables influencing its distribution are annual mean temperature, maximum temperature of the warmest month, precipitation of the warmest season, and mean temperature of the coldest season. For future climate projections, suitable habitats generally exhibit a shrinking trend. The most pronounced decrease is anticipated under the moderate greenhouse gas emission scenario (SSP245). However, under the high greenhouse gas emission scenario (SSP585), the suitable habitat area is projected to increase marginally by 2060. This dynamic change warning suggests that it is necessary to optimize climate adaptation strategies, strengthen ecological protection and restoration in suitable areas, so as to maintain the ecological service functions of S. alopecuroides L. in arid and semi-arid ecosystems, such as sand fixation and soil conservation, and maintain biodiversity, and provide basic guarantee for the sustainable development and utilization of its medicinal and forage resources. This study reveals the dynamic impact of climate change on the distribution of S. alopecuroides L. suitable areas, which not only provides a scientific basis for ecological restoration and S. alopecuroides L. resource protection in arid and semi-arid areas, but also has important practical significance for promoting the regional practice of the concept of sustainable development of “harmonious coexistence between man and nature.”