基于MaxEnt模型预测砂生槐在西藏的潜在分布区

Prediction of Tibet's Potential Suitable Areas for Sophora moorcroftiana Based on MaxEnt Model

砂生槐具有极强的抗旱、耐瘠薄、防风固沙等生态适应性和水土保持功能,是雅江流域干旱、半干旱河谷的主要建群灌丛植物,也是防沙治沙与生态建设的先锋树种。使用MaxEnt生态位模型软件和ArcGIS软件预测砂生槐在西藏的潜在分布范围,用ROC曲线检测预测精度,用刀切法筛选主要环境变量,通过主要环境变量的响应曲线分析适宜砂生槐的生态环境条件,并在此基础上划分适宜栽培区。结果表明:采用MaxEnt模型预测砂生槐潜在适宜分布区准确度极高,预测模型的训练数据集和测试数据集的AUC值分别是0.980和0.977;采用MaxEnt模型预测的砂生槐适宜分布区涵盖西藏辖区内的那曲、拉萨、日喀则、山南、林芝5个地市,高度适宜区集中分布在西藏雅鲁藏布江中游的山坡、河谷、沙滩,主要涉及拉孜县、城关区、贡嘎县、扎囊县、乃东区、桑日县、朗县、隆子县8个县(区)的中部,桑珠孜区、白朗县和江孜县3个县(区)的北部,林周县的南部、达孜区的西北部等区域,预测结果与现地调查结果高度契合;降水因子和气温因子对砂生槐分布的影响很大。

Sophora moorcroftiana has strong ecological adaptability and soil and water conservation functions such as drought resistance,barren tolerance,wind and sand fixation.It is the main group-building shrub plant in arid and semi-arid valleys of the Yajiang River Basin,and also a pioneer tree species for sand prevention and ecological construction.In this study,MaxEnt niche model software and ArcGIS software were used to predict the potential distribution range of Sophora moorcroftiana in Tibet.ROC curve was used to test the prediction accuracy,the main environmental variables were screened by knife cutting method,and the ecological and environmental conditions suitable for Sophora moorcroftiana were analyzed by the response curve of the main environmental variables.Then the suitable cultivation regions were divided based on it.The results show that it has an extremely degree of accuracy to use MaxEnt to predict the potential suitable distribution range of Sophora moorcroftiana,the AUC values of training data set and test data set of the established prediction model are 0.980 and 0.977 respectively;the suitable distribution areas of Sophora psammophila in Tibet obtained form this prediction include Naqu,Lhasa,Shigatse,Shannan and Linzhi within the jurisdiction of Tibet,and the highly suitable areas are mainly concentrated in the middle of the the Yarlung Zangbo River,in the Lazi County,Chengguan District,Gongga,Zhayang,Naidong,Sangri,Lang County and Longzi County,in the north of Sangzhuzi District,Bailang County and Gyantse County,and the slopes,valleys,and beaches in the south of Linzhou County and in the northwest and other areas of Dazi County,and the predicted results are highly consistent with the current survey results;the distribution of Sophora moorcroftiana is affected greatly by factors such as precipitation and temperature.