中国特有植物雪落樱桃潜在分布及其生态特征

为明确中国特有植物雪落樱桃(Cerasus xueluoensis)的潜在分布与居群生态特征,利用DIVA-GIS软件及其耦合的BIOCLIM模型,首次绘制了雪落樱桃适生区分布模拟图,并对影响其分布的主导气候因子进行了定性定量分析。结果表明,雪落樱桃当前潜在适生区主要分布在亚热带长江流域1 200 m以上高海拔山区,其中渝-鄂-湘三省交界的大巴山-巫山山脉可视为现代核心分布区,湘黔交界及湘南的南岭山脉可视为雪落樱桃潜在分布的南界,陕-豫-鄂交界山区的秦岭南麓可能是其潜在分布的北界。主成分分析(PCA)筛选的主导气候因子及其贡献率依次为:年降水量(bio12)最冷季降水量(bio19)最暖季降水量(bio18)最湿季降水量(bio16),累计频率曲线进一步确定其适宜范围分别为:993.00～1 870.22、500.00～680.00、430.00～669.16和500.00～680.00mm,表明降水是影响雪落樱桃当下分布格局的主导气候限制因子。Pearson相关性分析表明,雪落樱桃分布格局在区域尺度上受海拔、经、纬度影响;最小树分析和聚类分析表明,雪落樱桃7个野生居群可划分为中西部与东部两大分支;受试者工作特征曲线(ROC) AUC值达到0.751,满足模型预测精度的基本要求。这些有助于为雪落樱桃制定科学合理的资源保护与科学引种规划。

Potential Distribution and Ecological Characteristic of Chinese Endemic Species Cerasus xueluoensis

To clarify the potential distribution and habitat ecological characteristics of Chinese endemic species Cerasus xueluoensis, the simulated diagram of suitable distribution of C. xueluoensis was drawn for the first time by using DIVA-GIS software coupled with the ecological niche model (BIOCLIM). Meanwhile, the qualitative and quantitative analysis of main climate factors influencing their distribution was also carried out. The results showed that the current suitable region of C. xueluoensis was mainly distributed in subtropical Yangtze River basin of China at high altitude mountainous above 1 200 m. Among them, the junctions of Chongqing-Hubei-Hunan belonging to the Daba-Wushan Mountain ranges were considered as the modern core distribution area, and boundary areas between Hunan and Guizhou Provinces belonging to the Nanling Mountains should be regarded as the southern distributional border. What''s more, the southern foothill of the Qinling Mountain from the junction of Shanxi-Henan-Hubei provinces should be the northern border of suitable distribution. Principal component analysis (PCA) showed that the dominant climate factor and its contribution rates was in the order of annual precipitation (bio12) > precipitation of the coldest quarter (bio19) > precipitation of the warmest quarter (bio18) > precipitation of the wettest quarter (bio16). The cumulative frequency curve further confirmed their optimal ranges were 993.00-1 870.22, 500.00-680.00, 430.00-669.16 and 500.00-680.00 mm, respectively, indicating the precipitation is the dominant climate limiting factor affecting the current distribution pattern of C. xueluoensis. Pearson correlation analysis indicated that the distribution pattern of C. xueluoensis was affected by altitude, longitude and latitude at a regional scale. The seven wild populations of C. xueluoensis could be divided into two major branches, such as central & western China and eastern China, according to minimum tree analysis and cluster analysis. The receiver operating characteristic curve (ROC) was reached to 0.751, which met the basic requirements of model prediction accuracy. So, these would be help to formulate scientific plans for resource protection and reasonable introduction of C. xueluoensis.