鼎湖山针阔混交林演替过程中群落组成和结构短期动态研究

分析了鼎湖山针阔混交林永久样地在4a演变过程中群落的物种组成结构、空间结构、物种多样性以及生物量的动态变化。结果表明：群落乔、灌、草3层的物种个体数量有很大变化，但其物种组成结构变幅很小；针叶树种马尾松(Pinus massoniana)的优势地位逐步丧失，而阔叶树种荷木(Schima superba)和锥栗(Castanopsis chinensis)等优势地位日益巩固，同时中生性树种的罗伞(Ardisia quinquegona)和九节(Psychotria rubra)等地位也在加强，整个群落向常绿阔叶林演变：群落乔木层的生物量增加而灌木层的生物量逐步减少，但群落总生物量仍在增加：群落各层次物种多样性的变化及其相互关系较为复杂，但各层次的物种多样性指数只表现微小的起伏，说明针阔混交林群落的演替是一种缓慢的、较为稳定的过程。同时，在群落的演替过程中，偶见种及珍稀植物的保护值得关注。

Short-term Dynamics of Community Composition and Structure during Succession of Coniferous and Broad-leaved Mixed Forest in Dinghushan

The dynamics of species composition, spatial structures and species diversity as well as biomass were analyzed in a four-year successional process of coniferous and broad-leaved mixed forest in Dinghushan Nature Reserve in Guangdong. No obvious changes were observed in species composition in tree, shrub and herb layers in community, but the number of individuals changed greatly. The dominant conifer Pinus massoniana declinedgradually, whereas broad-leaved species, such as Schima superba and Castanopsis chinensis, and mesophytes(Ardisia quinquegona and Psychotria rubra) increased. The whole community was changing into evergreen broad-leaved forest. Biomass in tree layer increased and that in shrub layer decreased. The species richness, diversityindex, evenness index and ecological dominance in each layer had only a slight change, which indicated that the succession of coniferous and broad-leaved mixed forest in Dinghushan was a slow and relatively stable process. With the succession process, some rare species such as Glochidion eriocarpum and Mallotus apelta disappeared, furthermore, the endangered species Aquilaria sinensis decreased from 25 to 12 individuals within four years, to which attention should be paid.