基于MaxEnt模型的玉竹潜在适生区及关键生态因子分析

Analysis of Potential Suitable Areas and Key Ecological Factors of Polygonatum odoratum Based on MaxEnt Model

目的:分析玉竹在我国的潜在生态种植适生区、关键生态因子及其适宜范围,为玉竹的人工种植提供理论科学指导。方法:该研究基于玉竹在我国的454个地理分布记录及118项生态因子,运用最大熵模型(MaxEnt)对玉竹开展了生态位模拟预测,并通过刀切法、生态因子贡献率和响应曲线综合对其关键生态因子及其适宜范围进行了分析。结果:玉竹的适生区分布在我国西北、华北至东北部,其中,高适生区主要集中在陕西、山西和甘肃等地;11月太阳辐射值(Srad11)、7月降水量(Prec7)、常绿/落叶针叶林占比(Class1)、含泥量(2~50μm)质量分数(SLTPPT)及年均温(Bio1)为影响玉竹在全国适生分布的关键生态因子;太阳辐射因子累计贡献率(31.29%)>植被因子(25.61%)>土壤因子(19.52%)>降水因子(11.38%)>温度因子(8.57%)>地形因子(3.63%)。结论:建议在陕西(如宝鸡市、安康市、宁陕县、留坝县和华县等),甘肃(天水市、甘南藏族自治州、两当县和华亭县等)及山西(如阳泉市、太原市、汾阳市、晋中市和兴县等)对玉竹进行重点生态种植;种植过程中应优先考虑太阳辐射因子,其次分别是植被、土壤、降水、温度、地形因子;关键生态因子Srad11、Prec7、Class1、SLTPPT、Bio1的范围应分别控制在8 095.21~10 334.98(最适8 787.50)kJ·m^(-2)·d^(-1)、109.99~223.60(146.91)mm、1.00%~19.45%(6.76%~10.68%)、41.73%~50.35%(46.53%)、3.29~16.33(13.57)°C为宜。

Objective The potential suitable area for ecological planting,key ecological factors,and suitable range of Polygonatum odoratum in China were analyzed to provide theoretical and scientific guidance for the artificial planting of P.odoratum.Method A total of 454 geographical distribution records of P.odoratum in China and 118 ecological factors were used in this study.The maximum entropy model(MaxEnt)was adopted to predict the suitable areas of P.odoratum.The key ecological factors and their suitable ranges were analyzed by the jackknife method,contribution rates of ecological factors,and response curves.Result The suitable areas of P.odoratum were mainly located in the northwest,north,and northeast of China,the highly suitable areas of which were concentrated in Shaanxi,Shanxi,Gansu,etc.Solar radiation in November(Srad11),precipitation in July(Prec7),percentage of evergreen/deciduous needleleaf trees(Class1),silt content(2-50μm)mass fraction(SLTPPT),and annual average temperature(Bio1)were found to be the key ecological factors affecting the suitable distribution of P.odoratum in China.The cumulative contribution rate of solar radiation factors(31.29%)>vegetation factors(25.61%)>soil factors(19.52%)>precipitation factors(11.38%)>temperature factors(8.57%)>topography factors(3.63%).Conclusion It is suggested to carry out ecological planting of P.odoratum mainly in Shaanxi(such as Baoji and Ankang Cities and Ningshan,Liuba,and Hua Counties),Gansu(such as Tianshui City,Gannan Tibetan Autonomous Prefecture,and Liangdang and Huating Counties),and Shanxi(such as Yangquan,Taiyuan,Fenyang,and Jinzhong Cities,as well as Xingxian County)of China.Solar radiation factors should be given priority in the planting process,followed by vegetation,soil,precipitation,temperature,and topography factors.The range of key ecological factors,namely Srad11,Prec7,Class1,SLTPPT,and Bio1 should be controlled within 8095.21-10334.98(optimum 8787.50)kJ·m^(-2)·d^(-1),109.99-223.60(146.91)mm,1.00%-9.45%(6.76%-10.68%),41.73%-50.35%(46.53%),and 3.29-16.33(13.57)°C,respectively.