关键词: 气候变化, 巨柏, 环境因子, MaxEnt模型, 适生分析

Abstract: With the changing of global climate, the growth and survival patterns of species are affected. Predicting changes in the potential range of geographic distribution for a species under climate change is an important tool for assessing the response of species to climate change and helps to develop scientific management strategies. Cupressus gigantea is an endemic species of Tibet and one of the national key protected plant species, but its habitat is narrow and becoming more and more vulnerable under global climate change. In this study, we simulated the habitat suitability of C. gigantea under current and future climate change in Tibet by using MaxEnt model and ArcGIS spatial analysis based on the current actual geographical distribution information of C. gigantea which is obtained by field investigation, Tibetan topographic factor variables, and environmental factor data under current and future climatic conditions, respectively. The results of the study show that: (1) The potential geographical distribution of C. gigantea is narrow, and the suitable areas is concentrated in Gacha County to Gongbu Jiangda County, through which the Yarlung Zangbo River flows in Tibet, with scattered distribution in Lhuntse County, Gonggar County, and Shona County in eastern Tibet. (2) The most suitable climatic factors for growth of C. gigantea are Variation of temperature seasonlity, Precipitation of coldest quarte, Altitude and Mean temperature of coldest quarter, with suitable ranges of 565.75—603.44、3.89—5.48 mm、2893.37—3517.09 m and -1.24—2.11 ℃, respectively. (3) Under the two future climate change scenarios, the areas of total, low and medium suitable areas of C. gigantea showed different degrees of increase compared with the areas of different levels of potential geographic distribution of C. gigantea under the current climate conditions, but the area of high suitable areas showed a clear trend of shrinkage. (4) Compared to the current center of mass, the center of mass in the SSP1-2.6 future scenario would be shifted to the southeast by 19.897 km and the center of mass in the SSP5-8.5 future scenario would be shifted the east by 20.710 km. The results of the study are of great scientific significance and practical guidance for the investigation of key environmental factors for the growth of C. gigantea, the recovery and renewal of C. gigantea populations, and the improvement of the survival environment of C. gigantea.

Key words: climate change, C. gigantea, environment factor, MaxEnt model, suitable analysis