浙江古田山濒危植物长序榆的群落组成与结构特征

Community Composition and Structural Characteristics of Ulmus elongata,an Endangered Plant in Gutian Mountain,Zhejiang

长序榆(Ulmus elongata)是特产于我国的濒危物种,自然资源稀少,属国家Ⅱ级重点野生保护植物。为探明浙江古田山野生长序榆的群落特性、种群特点,分析长序榆种群的濒危机制,参照CTFS固定样地调查方法,对古田山长序榆野生群落的物种组成、垂直结构、物种多样性及长序榆种群结构进行调查。结果表明:古田山长序榆群落植物物种较丰富,科属组成分散。群落垂直结构可分为乔木层、灌木层和草本层,伴有一定数量层间植物。物种多样性大小依次为乔木层>灌木层>草本层。从径级结构看,古田山长序榆幼树和小树个体较多,中树和大树个体较少,属增长型种群。古田山长序榆群落距离自然村较近,植株总数较少,野生资源处于濒危状态,需进一步加强保护。

Ulmus elongata is a rare and endangered species and is discovered in China only. The specie belongs to wild plant under state protection （category Ⅱ）. The species composition, vertical structure, species diversity and population structure of wild U. elongata community in Gutian Mountain were investigated by using CTFS fixed sample plot method to explore community characteristics and population feature of wild U. elongata and analyze the endangered mechanism of U. elongata population. Result. The plant species in wild U. elongata community are abundance but the family and genus composition is dispersal in Gutian Mountain. The vertical structure in wild U. elongata community can be divided into tree layer, shrub layer and herb layer accompanied with a certain number of inter-layer plants. The species diversity in three layers is tree layer〉shrub layer〉herb layer. There are many U. elongata saplings and less middle and big U. elongata trees, which indicates that U. elongata population belongs to an expanding population. The wild U. elongata resources in a danger status should be further protected due to less U. elongata number and U. elongata community closer to natural villages.