乌饭树的地理分布及潜在分布区分析

Geographic distribution and potential distribution of Vaccinium bracteatum

利用Bioclim模型,结合354个乌饭树地理分布点以及19个气候因子,对乌饭树在我国的潜在分布区和适宜等级进行了预测。结果表明:潜在分布区的预测结果与实际分布点吻合较好,其适生区(适宜度≥5%)主要为广西、广东、福建、浙江、江西东南部、湖南西部及贵州东部等地区;湖南、江西南部与广东、广西北部交界处的南岭地区及福建中部山地等地区为乌饭树的最适生区(≥20%)。ROC曲线的AUC值为0.819,表明预测结果很准确。极端低温、最干季降雨量、极端高温、温差是影响乌饭树分布的主要水热因子,最适宜区气候参数为:年平均温为14.7—23℃,适宜越冬的年极端低温为-3.1—13.4℃,年降雨量为948.8—1988.4mm,最干季降雨量为54.6—201mm,分布的最适宜海拔范围为3—806m之间。气候变暖将使得乌饭树潜在最适分布区面积显著缩小,现有最适生境位置发生改变。

Based on Bioclim model,354 occurrence records and 19 climatic variables were used to predict the potential distribution and habitat suitability of Vaccinium bracteatum.The results showed that the potential distribution of the species matched its actual distribution.The potential distribution(suitability index≥5%)mainly located in Guangxi,Guangdong,Fujian,Zhejiang,southeastern Jiangxi,western Hunan,and eastern Guizhou,with the highly potential distribution(suitability index≥20%)mainly in the Nanling mountains and the middle part of Fujian Province.Areas under the receiver operating characteristic curve(AUC values)of Boiclim model was 0.819.Environmental factors,such as minimum temperature,precipitation of the driest quarter,maximum temperature and temperature range,greatly influenced the distribution of V.bracteatum.Either condition as 14.7-23℃mean annual temperature,-3.1-13.4℃mean temperature of coldest quarter,948.8-1 988.4 mm annual precipitation,54.6-201 mm precipitation of the driest quarter,was suitable for V.bracteatum,which distributed in the low altitude mountain,from 3-806 m.In addition,the highly potential distribution of V.bracteatum would be shrinking and have been moving under future climate warming.