Projecting the potential suitable distributions of Arenaria kansuensis in the Three-Rivers Headwaters region, Qinghai Province, under CMIP6 climate scenarios

The Three-Rivers Headwaters region of Qinghai Province, China, is a critical ecological zone. Climate change seriously affects the growth and distribution of vegetation in this region. A typical alpine plant in the Three-Rivers Headwaters region, Arenaria kansuensis, demonstrates changes that will have significance for the stability of the alpine ecosystem. Based on distribution data from the literature and climate environmental factors found in WorldClim, a jackknife test method and correlation analyses were applied to determine the dominant factors affecting distribution. The MaxEnt model was calibrated to the present climate conditions of the species. A suitable distribution area was projected in the mid-term (2041–2060) and long-term (2061–2080) under four climate scenarios in the Coupled Model Intercomparison Project Phase 6. Response to climate change was explored for spatial distribution. The results indicated that 1) conditions in the central region were more suitable for the species under present climate conditions. In the medium and far term, the suitable areas will expand under the climate scenarios of SSP370 (Regional Rivalry), whereas its area will decline under the other scenarios. The center of the suitable area will move toward the southeast region. 2) Most areas will become unsuitable under the SSP245 (Middle of the Road) climate scenario, particularly in the western regions, such as Zhiduo County, South of Golmud City, Qumalai County, and the eastern regions, such as Xinghai County and Gonghe County. 3) The dominant climatic factors affecting its spatial distribution will be annual precipitation and precipitation in the coldest quarter. The most suitable area for the species will be characterized as areas with annual precipitation of 500～750 mm and precipitation in the coldest quarter of > 15 mm. The results suggest a practical methodological approach for predicting the spatial distribution of indicator plant species and resulting ecosystem changes in alpine areas under future climate change scenarios. This can provide the theoretical foundations for future conservation policies for endangered plant species in Qinghai Province.