森林害虫雅氏落叶松尺蠖在蒙古国的适生区分布预测

摘要

对雅氏落叶松尺蠖(Erannis jacobsoni Djak)在蒙古国的适生区分布进行预测,旨在为有效防控该虫扩散提供科学依据.利用Maxent生态位模型和GIS空间分析方法预测雅氏落叶松尺蠖在蒙古国的适生区并对其进行等级划分,然后用受试者工作特征曲线(ROC曲线)对预测结果进行精度评定,最后采用刀切法(Jackknife)分析环境变量对害虫适生的重要性.结果表明,雅氏落叶松尺蠖适生区面积达13988265.42 hm2,主要分布在蒙古国北部10省(后杭爱、布尔干、前杭爱、库苏古尔、鄂尔浑、中央、乌兰巴托、色楞格、肯特和扎布汗)和东部1省(东方),其中极高适生区主要分布在布尔干、后杭爱和中央等,高适生区主要分布在布尔干、库苏古尔和中央等;中适生区主要分布在库苏古尔、肯特和色楞格等;低适生区主要分布在后杭爱、布尔干和肯特等.森林种类、最暖季度平均温度、年降水量、最热月份最高温度和最冷月份最低温度等环境变量对预测的贡献率达77.91℅.可见,雅氏落叶松尺蠖在蒙古国的适生区分布广,一旦暴发后果不堪设想.蒙古国东部的害虫适生区分布,将威胁中国大兴安岭林区生态系统安全.森林种类、最暖季度平均温度、年降水量、最热月份最高温度及最冷月份最低温度是主要影响害虫适生的环境变量.%The suitable area distribution of Jas's larch inchworm in Mongolia was predicted to provide scientific basis for ef-fectively preventing and controlling the pest diffusion. The suitable area distribution of Jas's larch inchworm in Mongolia was predicted and graded by maxent ecological niche model and GIS spatial analysis method, then accuracy of prediction result was evaluated by receiver operating characteristic curve, finally importance of environmental variables to the pest was analyzed by jackknife method. The result showed that the adaptable area of Jas's larch inchworm had an area of 13988265.42 hectares and mostly distributed in ten provinces including Arkhangai, Bulgan, ?v?rhangay, Hovsgol, Orhon, Central, Ulan Bator, Selenge, Kent and Zavkhan in northern Mongolia and one province (Dornod) in eastern Mongolia. In which extremely high adaptable areas were chiefly distributed in Bulgan, Arkhangai and Central Aymag etc. High adaptable areas were mainly distributed in Bulgan, Hovsgol and Central Aymag etc. Middle adaptable areas were largely distributed in Hovsgol, Kent and Selenge Aymag etc. Low adaptable areas were prevailingly distributed in Arkhangai, Bulgan and Kent Aymag etc. The contri-bution rates of some environmental variables such as forest species, mean temperature of the warmest quarter, annual precip-itation, max temperature of the warmest month and min temperature of the coldest month reached 77.91℅. Accordingly, the suitable area distribution of Jas's larch inchworm were wide in Mongolia, and consequences would be unimaginable once the pests outbreak. The adaptable area distribution of Jas's larch inchworm in eastern Mongolia would threaten security of the for-est ecological system of Greater Khingan Mountains. Environmental variables like forest species, mean temperature of the warmest quarter, annual precipitation, max temperature of the warmest month and min temperature of the coldest month had great influence on suitable area distribution of the pest.