气候变化情景下大沙鼠潜在地理分布

大沙鼠（Rhombomys opimus）是中亚地区典型的荒漠啮齿动物，其采食和掘洞行为造成了荒漠林和荒漠草原退化加剧，生态环境恶化。基于大沙鼠分布数据、气候、土壤和地形因子数据，采用MaxEnt模型预测大沙鼠在当前气候和温室气体低、中、高3种浓度排放情景下2050年和2070年的潜在适生区，分析亚洲大陆未来气候条件下大沙鼠适生面积和分布格局的变化趋势，探讨影响大沙鼠分布的主要环境因子。结果表明：模型AUC（Area Under Curve）值达到0.9以上，预测的准确性达到"极好"。经刀切法分析（Jackknife）表明，影响大沙鼠在适生区分布最主要的环境变量为温度季节性变化的标准差、土壤基本饱和度、最干季度降水量、最暖季度降水量和土壤可交换钠盐。Rcp2.6、Rcp4.5和Rcp8.5三种气候场景下2050年高适生区面积较当前分别增长15.78%、15.10%和13.44%；Rcp2.6、Rcp4.5和Rcp8.5三种气候场景下2070年高适生区面积较当前增长8.32%、13.18%和18.18%。中国大沙鼠适生区范围内，新疆所分布的大沙鼠适生区分布范围变化较大，3种情景模式下大沙鼠的适生区位置向新疆北部扩张；甘肃适生区位置向西北部扩张；内蒙西北部和阿拉善地区大沙鼠的适生区位置向四周扩张。研究揭示了未来气候下大沙鼠高适生区范围和空间变化，并得到影响其分布的主要环境变量，对其防控具有重要意义。

Potential geographical distribution of Rhombomys opimus under climate change scenarios

The Rhombomys opimus is a typical desert rodent in Central Asia. Its feeding and burrowing behaviors have caused the deterioration of desert forests and desert grasslands and the deterioration of the ecological environment. Based on the distribution data of gerbils, climate, soil and topographic factor data, the MaxEnt model was used to predict the potential suitable areas of Rhombomys opimus in 2050 and 2070 under the current climate and the low, medium and high concentration emission scenarios of greenhouse gases. we analyze the changing trend of suitable area and distribution pattern of Rhombomys opimus in the Asian continent in the future, and discuss the main environmental factors that affect the distribution of gerbils. The results showed that the model''s Area Under Curve value was above 0.9, and the accuracy of prediction reached excellent. Jackknife analysis showed that the most important environmental variables affecting the distribution of Rhombomys opimus in suitable areas were the standard deviation of seasonal changes in temperature, basic soil saturation, precipitation of the driest quarter, precipitation of the warmest quarter, and the soil exchangeable sodium salt. Under three climate scenarios of Rcp2.6, Rcp4.5 and Rcp8.5, the area of high growth zone in 2050 will increase by 15.78%, 15.10% and 13.44% compared with the current climate model. Under the three climate scenarios, the area of high growth zone in 2070 will increase by 8.32%, 13.18% and 18.18% compared with the current climate model. Within the range of suitable areas for Rhombomys opimus in China, the distribution range of suitable areas for gerbils in Xinjiang varies greatly. Under the three scenarios, suitable areas for Rhombomys opimus will expand to the north of Xinjiang; the suitable areas for Gansu will expand to the northwest. The suitable areas of Rhombomys opimus in northwest Inner Mongolia and Alxa area will expand to the surrounding area. The study revealed the range and spatial changes of highly suitable habitat of gerbils in the future climate, and the main environmental variables that affect its distribution, which was of great significance to the prevention and control of Rhombomys opimus.