永德大雪山中山湿性常绿阔叶林植物区系的初步研究

A Preliminary Floristic Study on the Mid-Montane Humid Evergreen Broad-Leaved Forest in Yongde Snow Mountain, SW Yunnan, China

中山湿性常绿阔叶林是永德大雪山亚热带山地植被垂直带上最具特征性的植被类型,也是该地区面积最大、保存最为完整、最有保护价值的植被类型。从该类型植被中219种常见和优势植物的种类结构分析看,只有热带亚洲成分、中国-喜马拉雅成分及中国特有成分能够贯穿于乔木Ⅰ、Ⅱ、Ⅲ层,灌木层,草本层和层外植物各层次之中;其区系成分以中国-喜马拉雅和中国特有成分占优势,同时热带亚洲成分也占有相当的比例,说明其区系具有亚热带向温带过渡的性质;而中国特有种的进一步分析亦表明其区系的过渡性质。这表明永德大雪山处于中国-喜马拉雅森林植物区系和热带亚洲植物区系的分界面上,其植物区系的过渡特征非常明显。通过永德大雪山中山湿性常绿阔叶林与邻近地区同类型植被的优势种和主要伴生种的比较,我们初步认为该地此类森林植被环境更“温湿”。

The mid-montane humid evergreen broad-leaved forest is the most typical vegetation type. of the subtropical-montane vegetation type in Yongde Snow Mountain （YSM）. It is also the vegetation type occupied the largest area, most integrated and valuable of YSM. Analysis of the disposition in vertical structure of 219 dominant and frequent species in the forest, it can be shown that only Tropical Asian, Sino-Himalayan and China-endemic elements occurred in all synusiae including the A, B, C tree layers, the shrub layer, and the herb layer. Among 219 dominant and frequent species, the Sino-Himalayan and China-endemic elements take a large portion, and the Tropical Asian elements play an important role as well, It is suggested that YSM is floristically intervenient between subtropical and temperate elements. Further analysis of China-endemic species shows that YSM is floristically transitional. All evidence indicats that YSM is on the border between Sino-Himalayan floristic subkingdom and Malesian floristic subkingdom, and its transitional floristic characteristics are rather distinct. Comparison of dominant and main companion species between Yongde Snow Mountain and those of its neighbouring regions shows that the forestry environment of Yongde Snow Mountain is humider and warmer than that of other regions.