基于Maxent模型的青藏高原大花红景天生态适宜性分析

濒危物种大花红景天Rhodiola crenulata的野生抚育和人工栽培是保护其野生资源的重要方式,是目前研究的热点问题。研究通过查询标本馆及实地采样调查,收集大花红景天野外分布点经纬度信息,综合气候、土壤、高程等相关生态因子,利用Maxent模型对大花红景天进行适生性分析,研究其在我国青藏高原地区的潜在分布区域以及主要生态特征。Maxent模型预测结果表明,大花红景天生长的潜在分布区域在西藏东部、四川西部、青海南部,以及甘肃甘南藏族自治州、云南迪庆藏族自治州的部分区域;对大花红景天生长贡献率大的主要生态因子为海拔(61.8%)、最暖季度降水量(19%)、降水量变异系数(4.7%)、温度季节性变化标准差(4%)和最干季度平均温度(2.5%)。测试集和训练集ROC曲线下的AUC均大于0.9,表明所建立的大花红景天Maxent预测模型准确度高。应用Maxent模型,对大花红景天进行生态适宜性区划研究准确度高,可为大花红景天野生抚育与人工栽培选址提供科学依据。

Potential distribution of Rhodiola crenulata in Tibetan Plateau based on Maxent model

Wildlife tending and artificial cultivation is an important way to protect the wild resources of Rhodiola crenulata. It is a study hotspot at present. The distribution information of R. crenulata was collected by query data and field survey, the ecological suitability regionalization was conducted based on maximum entropy model combine with ecological factors, including climate, soil and altitude. To provide the reference for production layout, suitable planting area and the selection of artificial planting base by studying the ecological suitability regionalization of R. crenulata. The potential distribution areas mainly concentrated in the easen Tibet, western Sichuan, southern Qinghai, and Gansu Gannan Tibetan Autonomous Prefecture, Yunnan Diqing Tibetan Autonomous Prefecture. There were 5 major environmental factors to have obvious influence on ecology suitability distributions of R. crenulata, including altitude(contribution rate of 61.8%), precipitation of warmest quarter(contribution rate of 19%), the coefficient of variation of precipitation seasonality(contribution rate of 4.7%), the SD of temperature seasonality(contribution rate of 4%), mean temperature of driest quarter(contribution rate of 2.5%). The AUCs of ROC curve were both above 0.9, indicating that the predictive results with the Maxent model were highly precise. The study of the ecological suitability regionalization of R. crenulata based on Maxent can provide a scientific basis for the selection of artificial planting base.