木论喀斯特林区翠柏群落学特征的初步研究

广西木论喀斯特林区，位于我国中亚热带南缘。据６００ｍ２翠柏群落样方调查结果：有维管束植物７６种，隶５１科６９属，其中单种的属占８９．９％。植物区系以热带分布区类型为主，占总属数（不含世界分布）的７１．０％，温带分布占２５．８％，但群落的种类组成是以亚热带成分占优势，按Ｒａｒｎｋｉａｅｒ生活型分类系统，高位芽植物占８２．９％，地面芽植物占１５．８％，一年生植物占１．３％，缺少地上芽和地下芽植物；从生理角度分析，叶级以小型叶（包括微型和鳞型叶）为主，占５９．２％；叶型以单叶占的比例最大，为８６．８％，群落结构可分为乔、灌、草三层，其中乔木层又可分出二个亚层。对该群落各乔木种群的大小结构分析，显示出翠柏群落是相对稳定性较大的群落。

PRELIMINARY STUDIES ON THE PHYTOCOENOLOGICAL FEATURES OF THE CALOCEDRUS MACROLEPIS COMMUNITY IN MULUN, HUANJIANG COUNTY, GUANGXI

This article deals with the community of Calocedrus macrolepis which is located in carst forest area of Mulun (107°540′01″～108°05′51″E, 25°07′01″～25°12′22″N) of Huanjiang , Guangxi, on the south boundary of the mid-subtropical region in China.According to the investigation in 6 plots of 600 m2 in total, the community of calocedrus macrolepis is consisted of 76 species of vascular plants, 51 families and 69 genera. Of the 69 genera 89.9% are single species genera. Analysis of floristic geographical elements showed that percentages of tropical elements are high, making up 71.0% of the total numbers of genera (no including Cosmopolitan), temperate elementsare 25.8%, but the species coposition of the community is mainly consisted of subtropical elements. According to Raunkiaer's classification system of life-form, the plant life form spectrum of Calocedrus macrolepis community shows that phanerophytes are rich, making up 82.9% of total species, hemicryptophytes and therophytes are 15.8% and 1.3% of total species respectively, chamaephytea and geophytes are missing on this plant life form spectrum. The leaf size class of community is mainly microphylla (59.2%), and 86.8% of the leaf pattern is simple leaf. The community can be structurally divided into arboreous layer, shrob layer and herbaceous layer. The arboreous layer can be subdivided into 2 layer too. Analysis of the age structure of the trees of community showed that it is a community of relative stability.