Prediction of Potential Distribution Area of Two Parapatric Species in Triosteum under Climate Change

Abstract

Climate change has a profound impact on global biodiversity and species geographical distribution, especially in alpine regions. The prediction of species’ habitat could help the understanding of species’ responses to potential climate threats. Triosteum L. (1753) is a typical mountain plant with medicinal and ecological value. There are three species of this genus in East Asia. Triosteum Pinnatifidum Maxim. 1888 and Triosteum himalayanum Wall. 1829 are mainly distributed in the Qinghai–Tibet Plateau and its surroundings, and they are sensitive to climate changes. In this study, a MaxEnt model was used to predict the potential distribution of T. Pinnatifidum and T. himalayanum in the present time and at four different time periods in the future under two different Shared Socioeconomic Pathways (SSPs). Topographic factors were taken into account in the prediction. In the present study, the accuracy of the model’s prediction was verified (the AUC values are 0.975 and 0.974), and the results indicate that temperature is the key factor that affects the distribution of these two species. Compared with current distribution, the potential suitable area of T. Pinnatifidum will increase in the future under two types of SSPs (an average increase is 31%), but the potential suitable area of T. himalayanum will decrease significantly (the average area is 93% of what it was before). In addition, the overlap of potential suitable areas of these two species will also expand, potentially affecting their hybridization and interspecific competition. The centroids of T. Pinnatifidum will migrate to the east, but the trajectory of centroids of T. himalayanum is complex. This study could provide basic data for the resource utilization and biogeography research of Triosteum. It will also be helpful for conservation and sustainable use of mountain herbaceous plants under climate change.