广西大石围天坑群不同植物群落的特征

Characteristics of different plant communities in the Dashiwei Tiankeng group, Guangxi, China

大石围天坑群孕育了极为丰富的植物多样性资源。为进一步了解大石围天坑群植物群落特征,该文在天坑不同位置(坑口、坑腰、坑底)以及坑外共布设25个样地,采用样方法进行调查,共鉴定出269种维管植物,隶属于89科176属,群落物种组成数量较多的科主要有樟科、蔷薇科、荨麻科等。群落成层现象明显,各层优势种分布较为均匀,其中乔木层优势种主要有香木莲(Manglietia aromatica)、南酸枣(Choerospondias axillaris)、掌叶木(Handeliodendron bodinieri)等,灌木层优势种有异叶梁王茶(Metapanax davidii)、滇鼠刺(Itea yunnanensis)等,草本层以楼梯草属(Elatostema)占优势。群落季相明显,以常绿、落叶阔叶混交林为主,底部有常绿阔叶林分布,坑口边缘小面积分布有落叶阔叶林;群落生活型谱:高位芽植物为55.76%,地上芽植物为29.74%,地面芽植物为6.69%,隐芽植物为5.21%,一年生植物为2.60%。该文分析了天坑植物群落类型、组成、结构等特征。

Dashiwei Tiankeng group is rich in plant diversity resources. In order to further understand the plant community characteristics of the Dashiwei Tiankeng group, a total of 25 sample plots were set up in different positions(mouth pit, waist pit, bottom pit) and outside the pit in the Dashiwei Tiankeng group. 269 species of vascular plants belonging to 176 genera and 89 families were investigated by the sampling method, and Lauraceae, Rosaceae, Urticaceae and so on are the most abundant families in the community. The stratification is obvious and the distribution of dominant species was more uniform in each layer of the community. Among them, Manglietia aromatica, Choerospondias axillaris, Handeliodendron bodinieri were dominant species in the tree layer;Metapanax davidii, Itea yunnanensi were dominant species in the shrub layer, and the dominant herb layer is Elatostema. The seasonal phase is obvious of the community. It is mainly evergreen and deciduous broad-leaved mixed forest, with the evergreen broad-leaved forest at the bottom pit and the deciduous broad-leaved forest at the edge of mouth pit. The life form spectrum of the community is 55.76% for phanerophytes, 29.74% for aboveground plants, 6.69% for aboveground plants, 5.21% for cryptophytes and 2.60% for annual plants. The characteristics of the community types, composition and structure of Tiankeng were analyzed in this paper, which provided basic information for studies of plant communities in Dashiwei.