假苍耳的地理分布及潜在适生区预测

Geographic distribution and prediction of potential suitable regions of Iva xanthifolia

外来入侵植物假苍耳在中国东北部地区快速蔓延,威胁自然生态系统的结构并对人们的健康产生危害。本研究通过野外调查获得假苍耳在东北地区的分布范围,采用Maxent模型软件对假苍耳在我国及世界的潜在适生区进行预测,运用ArcGIS软件中的自然间断点分级法进行适生等级分类,ROC曲线评价Maxent模型预测的准确性,并结合刀切法及环境变量反应曲线判断分析影响假苍耳分布的主要环境变量。结果表明,假苍耳的适生区较广,扩散范围可能继续增大。我国的华北地区、东北地区、华东地区、华中地区、西南地区、西北地区均存在适生区,高度适生区主要分布在我国的黑龙江省、吉林省、辽宁省、内蒙古自治区、山西省、陕西省、河南省、河北省、山东省、北京市、天津市、新疆维吾尔自治区。世界范围内除南极洲外均存在假苍耳的适生区,高度适生区主要在北美洲的加拿大和美国,非洲的摩洛哥,欧洲的西班牙、克罗地亚、匈牙利、斯洛伐克、波黑、塞尔维亚、马其顿、保加利亚、格鲁吉亚、亚美尼亚和阿塞拜疆,亚洲的土耳其、伊朗、哈萨克斯坦、吉尔吉斯斯坦、塔吉克斯坦、中国、朝鲜、韩国和日本。上述适生区预测显示出假苍耳适宜生长在年均温度较高,最冷月份最低温和最冷季度平均温度较低的中纬度地区。

Foreign invasion plant flase ragweed（Iva xanthifolia）is spreading rapidly in the Northeast of China,which threatens the natural ecosystem and does harm to people＇s health.By doing field work distribution of flase ragweed in Northeast China was detected.Maxent ecological niche models help to predict the potential suitable regions of flase ragweed both in China and the other parts of the world.And natural intermittent points classification method of ArcGIS helps to classify the risk regions.The receiver operating characteristic curve was applied to access the prediction accuracy.The main environmental variables were analyzed by Jackknife approach and response curve of environmental variables.The results showed that flase ragweed had a wildly suitable regions which continue to spread its areas.In China,the suitable distribution area mainly locates in the North,the Northeast,the East,the Central,the Southwest and the Northwest of China;most of the suitable regions were in Heilongjiang,Jilin,Liaoning,Shanxi,Shanxi,Henan,Hebei,Shandong,Beijing,Tianjin,Neimenggu and Xinjiang.In the world,risk regions existed worldwide except Antarctica;the risk regions mainly lie in North America（including Canada and America）,Africa（Morocoo）,Europe（Spain,Croatia,Hungary,Slovakia,Bosnia-herzegovina,Serbia,Macedonia,Bulgaria,Georgia,Armenia and Azerbaijan）,and Asia（Turkey,Iran,Kazakhstan,Tajikistan,China,North Korea,South Korea and Japan）.The above areas show that middle latitude regions with higher average annual temperature,the lowest in the coldest month or lower average temperature in coldest quarter are the most suitable for flase ragweed to grow.