孑遗濒危植物四合木(Tetraena mongolica)的地理分布与潜在适生区预测

Geographical distribution and prediction of potentially suitable regions of endangered relict plant Tetraena mongolica

以孑遗濒危植物四合木( Tetraena mongolica Maxim.)为对象,利用MaxEnt模型和Bioclim模型预测其在我国的潜在适生区,结合刀切法及环境变量响应曲线评估影响四合木分布的主导环境因素,运用ArcGIS软件自然间断法对其适生等级进行划分。结果显示:四合木主要分布于我国新疆、西藏、甘肃、宁夏、内蒙古、青海、陕西、山西、河北、辽宁、吉林和黑龙江等省区;在中国的适生区面积为1. 49 × 10 6 km 2 ,高适生区集中在乌海市毛乌素沙地、阿拉善左旗腾格里沙漠、阴山南部和贺兰山低山地区;2050年四合木潜在分布区将向内蒙古地区北部和东北地区西部方向缩减;两个模型的受试者工作特征曲线下的面积(AUC值)平均值均达到0. 8以上,预测结果较准确;环境因子评估结果显示,影响四合木分布的主要环境因子是最冷季度的平均降水量和年温的变化范围,其次是降水量变异系数和温度季节性变化的标准差。

The endangered relict plant Tetraena mongolica Maxim was studied, with the MaxEnt and Bioclim models used to predict potentially suitable regions. We used the knife-cutting method and environmental variable response curves to evaluate the dominant environmental factors affecting the distribution of T. mongolica. Furthermore, we used the ArcGIS natural discontinuity method to divide fitness levels. Results showed that T. mongolica was mainly distributed in the Xinjiang Uygur Autonomous Region, Tibet Region, Ningxia Hui Autonomous Region, Inner Mongolia, and the Gansu, Qinghai, Shaanxi, Shanxi, Hebei, Liaoning, Jilin, and Heilongjiang provinces in China, with a total area of 1. 49 × 10 6 km 2 . Highly suitable zones were found in the Maowusu Sandy Land of Wuhai city, the Tengger Desert in the Alxa Left Banner, the southeastern part of Yinshan Mountain, and mountains in the Helan range. The potential distribution area of T. mongolica will be reduced to north of Inner Mongolia and western Northeast China by 2050. The Area Under Curve (AUC) average values of the two models were all above 0. 8, justifying their application for predicting potential areas of T. mongolica . Among the 19 environmental variables, the main factors affecting the potential distribution of T. mongolica were average precipitation of the coldest quarter and temperature annual range, followed by the coefficient of variation of precipitation seasonality and standard deviation (SD) of temperature seasonality.