Prediction of the potential distribution of two endemic tree species in Xinjiang of western China under future climate scenarios

  Objective  Sabina centrasiatica and Populus xjrtyschensis are two endemic tree species in Xinjiang of western China. Sabina centrasiatica is an endangered wild plant under Xinjiang Class I and National Class II key protection, Populus xjrtyschensis is drought resistant, barren, cold resistant and has a certain tolerance to saline alkali and barren soil. It is a valuable material for breeding improved varieties and an important plant for soil and water conservation. In the context of climate change, the study of the climate factors affecting the distribution of the two species and their response models to climate change plays an important role in the conservation of precious species in Xinjiang.

  Method  In this paper, three of the four shared socioeconomic pathways (SSP245, SSP370 and SSP585) proposed by the researchers were used in the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The maximum entropy method was used to predict the potential suitable areas of Sabina centrasiatica and Populus xjrtyschensis in the present (1970−2000) and future (2041−2060, 2061−2080) with 10 selected environmental variables, and to compare the changing trend of habitat areas of the two species and their response models to climate change in different periods in the future under the three greenhouse gas concentration paths.

  Result  The temperature, precipitation and altitude were the main environmental factors affecting the distribution of Sabina centrasiatica and Populus xjrtyschensis. The Sabina centrasiatica is mainly distributed in the northern part of West Kunlun Mountain, Shache and Yecheng. In the future, the suitable area of Aksu area will be greatly reduced; the Populus xjrtyschensis is mainly distributed in the Erqis River and its tributaries, there will be a trend of moving from south to north in the future. The current total suitable areas of the two species are 673 909.49 and 976 827.81 km², respectively. Under different climate scenarios in the future, the suitable areas of the two species will show a downward trend. The comparison of the response patterns of the two species to climate change indicated that the large temperature difference had reduced the suitable area of Sabina centrasiatica; and the decrease of suitable area of Populus xjrtyschensis was caused by the increase of annual average temperature.

  Conclusion  Rising temperatures in the future will reduce the range of species distribution, so the research results can help the government optimize management, protect endangered wild plants and provide a theoretical basis for the protection of China’s natural population diversity.