基于MaxEnt模型的可可潜在适宜分布研究

根据野外采样和文献查阅,系统整理了可可的地理分布记录,并利用MaxEnt生态位模型和ArcGIS软件对可可的潜在适宜分布范围进行预测。结果表明:北美洲南部、中南美洲北部、非洲西部、亚洲东南部以及太平洋美拉尼西亚群岛地区均是可可的潜在适宜分布区域。其中,中国海南、台湾南部、云南西双版纳、广东雷州半岛也属于可可的适生范围。经ROC(Receiver operating characteristic)曲线分析法验证,MaxEnt模型的AUC(Area under curve)值为0.977,表明预测结果具有较高的可信度。各环境变量重要性的Jacknife检验表明,极端最低温度、年降雨量、年温度变化范围、最暖季降雨量对可可的潜在分布影响最大。

Potential Distribution of Theobroma cacao L.Using Maximum Entropy

Theobroma cacao L, the chocolate tree, is an important tropical crop. In order to understand the possible distribution areas of T. cacao L., a prediction of potential geographical distribution of T. cacao L. was conducted by the maximum entropy(MaxEnt)species distribution model combined with geographic information system(ArcGIS). The results showed that the potential distribution of T. cacao L. mainly concentrated in Southern North America, Northern South America, Western Africa, South-Eastern Asia, and Melanesian Islands in the South Pacific. The suitable areas for T. cacao L. cover only some areas in Hainan, Southern Taiwan, Xishuan Banna in Yunnan, Leizhou Peninsula in Guangdong in China. The checked result of receiver operating characteristic(ROC)curve analysis showed that the area under curve(AUC)value of MaxEnt model reached 0.977, indicating that the predicted results was fairly satisfactory. A Jackknife test in MaxEnt showed that minimum temperature of coldest month, annual precipitation, temperature annual range, and precipitation of warmest quarter were the most important environmental variable affecting the distribution of the cocoa species.