永定桫椤群落的结构特征

在相邻格子抽样调查的基础上，分析了福建省永定桫椤Alsophila spinulosa(Wall.ex Hook.)Tryon]群落的种类组成、重要值、种内与种间的竞争指数、水平结构和垂直结构特征。该群落共有植物186种，隶属于75个科132属，植物种类丰富。该群落乔木种群的重要值，以及桫椤与其他优势种群种内和种间的竞争指数表明，该群落由多个种群共建而成，初步认定有5个共建种群或优势种群。在水平空间上，5个可能的共建种群均服从聚集分布，在垂直空间上层次分化明显。通过分析表明永定桫椤群落是保存完好、结构典型、物种丰富多样的珍贵群落，应很好加以保护。

Structure features of Alsophila spinulosa community in Yongding, Fujian Province

Based on the data collected with sampling method by continuous quadrate grid, the species composition, the importance values of main tree populations, the competition index of intraspecific and interspecific competition, and spatial structure of Alsophila spinulosa (Wall. ex Hook.) Tryon community in Yongding, Fujian Province, were analysed and calculated. The community is composed of 186 species belonging to 75 families and 132 genera. The importance values and the competition index showed that the community of richer plant species may be constructed by 5 dominance populations. The level spatial pattern of 5 dominance populations conform to aggregated distribution. The tree layer can be divided into multiple layers in terms of height. The analysis showed that the Alsophila spinulosa community is a precious community with well\|preserved and typical structures and various species, and this community should be well protected.