Abstract: Caryopteris mongolica,a rare and endangered small shrub with high ecological values,is distributed in the arid and semi-arid areas of northwest China. Its distribution areas have rapidly shrunken in recent years,because of the historical fluctuations in climate and human disturbances. In order to explore the formation and changes of the geographical distribution pattern of C. mongolica,this study took the climatic factor data of 49 distribution points of C. mongolica as variables,to simulate the potential geographical distribution of C. mongolica in the current and future through the Maximum Entropy (MaxEnt) model. Meanwhile,the main climatic factors affecting the geographical distribution of C. mongolica has been identified. The main results are as follows:the main ecological factors influencing the distribution of C. mongolica were Precipitation Seasonality (Coefficient of Variation),Mean Temperature of Driest Quarter,Annual Mean Temperature and Precipitation of Coldest Quarter. And the optimum range for each were 87.57~115.05%,-15.31℃~-5.02℃,2.26℃~8.90℃,1.42~9.97 mm. The area of a potential distribution of C. mongolica increased as global warming intensified,and the higher the concentration of greenhouse gases,the larger the potential distribution area. At the same time,due to the temperature limit,distribution area of C. mongolica could not expand to the Qinghai-Tibet Plateau with higher altitude and colder climate during its movement,but could only move to the eastern Part of Inner Mongolia Plateau with a small difference in temperature conditions. The core distributional area of C. mongolica is affected by annual precipitation and temperature,under the RCP 4.5 scenario,the core distributional area would shift in the direction of northeast from the current to 2050 s,then would move to northwest from 2050 s to 2070 s. However,under the RCP 8.5 scenario,that core distributional area would shift to northeast from current to 2050 s,then to southwest from 2050 s to 2070 s.

Key words: Caryopteris mongolica, MaxEnt model, Climatic factors, Species distribution, Core distributional area

摘要： 蒙古莸(Caryopteris mongolica)是干旱半干旱区具有较高经济价值和生态价值的小灌木，其地理分布范围日渐缩小，成为濒危植物。为了探究蒙古莸地理分布格局形成演化过程，以蒙古莸49个分布点的环境因子数据为变量，通过建立MaxEnt生态位模型，探明影响蒙古莸地理分布的主要环境因子，模拟蒙古莸在当代和未来的潜在地理分布，结果表明：最冷季度降水量、最冷季度平均温、年平均气温、季节性降水量变异系数是影响蒙古莸分布的主要生态因子；适宜蒙古莸存活的年平均气温为2.26℃~8.90℃，最干季度平均温为-15.31℃~-5.02℃，最冷季度降水量为1.42~9.97 mm；未来气候变化条件下，蒙古莸潜在分布区面积呈增加趋势；蒙古莸分布核心区域的变化受到年均降水量和温度影响，在RCP 4.5气候变化情景下向北迁移。RCP 8.5气候变化情景下先向东北方向迁移之后沿原途径返回。

关键词: 蒙古莸, MaxEnt模型, 生态因子, 物种分布, 迁移路线