Impact of climate change on the geographical distribution and niche dynamics of .

BACKGROUND

is widely used in China as a valuable herbal medicine. Owing to its high medicinal and nutrient value, wild resources of have been overexploited and its native areas have been severely damaged. Understanding the impacts of climate change on the distribution of this endangered species is important for the conservation and sustainable use of .

METHODS

We used the optimized maximum entropy model to simulate the potential distribution of under contemporary and future time periods (1970-2000, 2050s, 2070s, and 2090s) and different climate change scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5). Under these conditions, we investigated the key environmental factors influencing the distribution of as well as the spatial and temporal characteristics of its niche dynamics.

RESULTS

With high Maxent model accuracy (AUCmean = 0.947 ± 0.012, and the Kappa value is 0.817), our analysis revealed that annual precipitation, altitude, and mean temperature of driest quarter are the most important environmental factors influencing the distribution of . Under current bioclimatic conditions, the potentially suitable area for in China is 71.98 × 10 km, while the highly suitable region for growth is 7.28 × 10 km. Our models for three future periods under four climate change scenarios indicate that can maintain stable distributions in southern Shaanxi, southwestern Hubei, and around the Sichuan basin, as these areas are highly suitable for its growth. However, the center of the highly suitable areas of shift depending on different climatic scenarios. The values of niche overlap for show a decreasing trend over the forecasted periods, of which the niche overlap under the SSP3-7.0 scenario shows the greatest decrease.

DISCUSSIONS

Under the condition of global climate change in the future, our study provides basic reference data for the conservation and sustainable utilization of the valuable and endangered medicinal plant . It is important to carefully choose the protection area of wild resources according the suitable area conditions modeled. Moreover, these findings will be valuable for providing insights into the breeding and artificial cultivation of this plant, including the selection of suitable areas for planting.