基于MaxEnt模型的毛红椿适生区预测

目的]了解环境因子对毛红椿适生区分布的影响,为其资源保护、引种及其人工林的发展提供参考。方法]基于MaxEnt模型能利用现存不完整、小样本、离散型分布数据构建物种适生区预测模型,用受试者工作曲线线下面积(AUC)检验预测模型的精度,面积越大精度越高等优点,本研究应用毛红椿在云南的分布数据及1个地型因子和6个气候因子,来构建其适生区分布模型。结果]毛红椿适生区分布MaxEnt模型平均训练AUC和平均测试AUC分别为0.891、0.885,说明对毛红椿适生区的预测是可靠的;降水量变异系数和最干季度降水量是决定毛红椿适生区分布的主要因子,年均气温变化范围、最冷季度平均气温、最湿季度降水量、最冷季度降水量是次要因子。在当代和未来(2050S、2070S)气候变暖条件下(RCP2.6情景),云南省和全国适生区面积计算结果直观、定量的反应了全球变暖对毛红椿适生区变迁的影响。结论]预测云南省及全国的毛红椿适生区随全球变暖而小幅萎缩。

Distributional Change in Suitable Areas for T.ciliata var. pubescens Based on MaxEnt

Objective] To understand the relation between environmental variables and suitable region of T.ciliata var. pubescens, which can provides reference to resource conservation, introduction and plantation for this plant.Method] An MaxEnt model, because of the advantages of using presence-only data and performing well with small sample sizes, incomplete data and gaps, was employed to simulate the habitat suitability distribution. And the area under the receive operating characteristic curve(AUC)were used to examine the model''s accuracy, the AUC is larger and predictions is more accuracy. So, based on the location in Yunnan province of T.ciliata var. pubescens, the MaxEnt was used to set up it''s distributional model of potential habitat, one topographic variable and the six main bioclimatic variables influencing species distribution. Result] The results show that the Mean training AUC and Mean test AUC were 0.891,0.885, respectively, it illustrated that the prediction of T.ciliata var. pubescens''s suitable habitats are reliable. CV of precipitation and Precipitation of the coldest quarter are significant factors, Range of annual temperature, Mean temperature of the coldest quarter, Precipitation of the wettest quarter, Precipitation of the driest quarter are secondary factors to determining T.ciliata var. pubescens''s suitable habitat. Habitat suitability for current and future climate warming(2050S,2070S) under scenarios RCP2.6 in Yunnan province and China were calculated. The result predictions the T.ciliata var. pubescens'' suitable habitats change under different climate in intuitive and quantitative. Conclusion] The habitat suitability of T.ciliata var. pubescensin Yunnan Province and China are predicted to deteriorate in slight with globalwarming.