基于Maxent生态位模型的水葫芦在中国的适生区预测

Prediction of potential distribution for water hyacinth in China by using Maxant Ecologic Niche Model

水葫芦(Eichhornia crassipes),原产南美洲,是目前世界上危害最严重的多年生水生杂草之一。利用Maxent模型进行水葫芦的适生区预测,并运用ROC(Receiver operating characteristic)曲线进行结果分析,同时,使用刀切法检测环境变量对该物种分布的重要性。结果显示,训练集和测试集的AUC值分别为0.949和0.878,表明该模型的预测效果良好。预测结果显示水葫芦在我国的适生区为贵州、广西、广东、湖南、福建、江西、重庆、四川、云南、浙江、上海、湖北、海南、台湾、西藏、安徽及江苏等省市局部地区,而西藏、安徽和台湾目前还没有记录却也进入适生区,属于易受入侵区域。且逐渐向周边可生长区蔓延。同时,bio1(年平均温度)、bio6(最冷月份最低温度)、bio9(最干燥季节平均温度)和bio11(最冷季节平均温度)这4个环境变量对水葫芦分布的影响比较大。加强其适生区和可生长区的防控和监测,对防治水葫芦的传播有重要意义。

Water hyacinth（Eichhornia crassipes）,native to South America,is one of the most serious perennial aquatic weeds in the world.In this paper,the potential geographic distribution of Eichhornia crassipes in China was predicted by Maxent models,and its result was evaluated by the receiver operating characteristic curve（ROC curve）.Meanwhile,environmental variables were analyzed with jackknife method to judge the influence on Eichhornia crassipes.The results showed that the areas under ROC curves were 0.949 and 0.878 respectively.It meant that Maxent model was good in predicting its potential geographic distribution.According to the prediction of Maxent,the distribution areas of Eichhornia crassipes were in local area of Guizhou,Guangxi,Guangdong,Hunan,Fujian,Jiangxi,Chongqing,Sichuan,Yunnan,Zhejiang,Shanghai,Hubei,Hainan,Taiwan,Tibet,Anhui and Jiangsu,while Tibet,Anhui and Taiwan were vulnerable to invasion because they also entered a suitable habitat without records currently and this grass was spreading gradually to the growth zone around optimum growth area.Bioclimatic variable including Annual Mean Temperature,Min Temperature of Coldest Month,Mean Temperature of Driest Quarter and Mean Temperature of Coldest Quarter had greater influence on the distribution of Water hyacinth.It is of great significance to control the spread of water hyacinth by strengthening the control and monitoring of its suitable growing areas and growing areas.