Global Warming Drives Expansion of Endangered Spruce Forest on the Tibetan Plateau

Abstract

Global warming is critical to the distribution pattern of endangered plants; therefore, understanding the future changes in the adaptive areas of endangered spruce and driving factors on the Tibetan Plateau is of great research significance for spruce species conservation and sustainability. In this study, variations in the distribution pattern of four endangered spruce species (Picea. Balfouriana, Picea. Linzhiensis, Picea. Complanata, and Picea. Aurantiaca) on the Tibetan Plateau were predicted by the MaxEnt model, and the important environmental variables affecting its geographic distribution were analyzed. We found that under the current climate conditions, the four endangered spruce species were mainly situated in the southern and southeastern Tibetan Plateau. The mean temperature of the coldest quarter was a key environmental variable affecting the geographic distribution of four endangered spruce species, with suitable growth ranges of −9–8 °C for P. balfouriana and −6–5 °C for P. linzhiensis, P. complanata, and P. aurantiaca. Under different future climate pathways, the highly suitable habitat of four endangered spruce was mainly situated in the east, south, and southeast districts of the Tibetan Plateau. With the suitable growth range of key variables continuing to expand on the Tibetan Plateau, the area of suitable habitat for each of the four endangered spruce species increases to varying degrees. Compared with the current climate, four endangered spruce species will expand to the northwest of the Tibetan Plateau under different future climate scenarios, and the degree of expansion will increase with the increase in temperature. This study not only reveals the response of suitable habitats of four endangered spruce species to global warming, but also provides scientific insights for spruce population conservation and sustainable development.