春飞蓬是源自北美的外来入侵杂草,已入侵我国的上海、江苏、安徽等地,并对当地生态系统造成了危害,表现出巨大的入侵潜力.本文将最大熵生态位元(MaxEnt)模型与地理信息系统相结合,综合分析了影响春飞蓬分布的环境因素,直观和定量地预测了春飞蓬在我国的潜在分布区,并采用接受者操作特性曲线(ROC)分析法对预测结果进行验证.结果表明:春飞蓬在我国有广泛的潜在分布区,主要适生区包括上海、江苏、浙江、安徽、河南、湖北、湖南、江西等地.其目前的实际分布远未达到最大潜在分布范围,仍有可能继续扩散.ROC曲线检验结果表明,MaxEnt模型对春飞蓬在中国潜在分布区的预测精度较高,结果可信.春飞蓬潜在入侵区分布可能主要受温度和降水的影响.应高度重视春飞蓬的危害性,采取灭除已经发生的种群、严格监控向最适分布区入侵等措施阻止春飞蓬的扩散蔓延.
Erigeron philadelphicus,an alien weed originated from North America,has already invaded in Shanghai,Jiangsu,Anhui,and some other places in China,caused harm on local ecosystem and demonstrated huge potential invasiveness.By using MaxEnt model and geographic information system(GIS),this paper analyzed the environmental variables affecting the distribution of E.philadelphicus,and intuitively and quantitatively predicted its potential distribution regions in China.The prediction was verified by the ROC curve,and the results showed that E.philadelphicus had a wide potential distribution range,with the main suitable distribution area in Shanghai,Jiangsu,Zhejiang,Anhui,Henan,Hubei,Hunan and Jiangxi.At present,the actual invasive range of E.philadelphicus was far narrower than its potential maximum invasive range,and likely to be continued to spread.The ROC curve test indicated that the prediction with MaxEnt model had a higher precision,and was credible.Air temperature and precipitation could be the main environmental variables affecting the potential distribution of E.philadelphicus.More attentions should be addressed to the harmfulness of the weed.To eradicate the existing E.philadelphicus populations and to strictly monitor the invasion of E.philadelphicus to its most suitable distribution area could be the effective measures to prevent and control the further invasion of the alien weed.