天目山皆伐毛竹林自然更新群落类型与多样性分析

  目的  毛竹Phyllostachys edulis林是中国亚热带区域近30 a来不断扩展的森林群落类型之一，物种多样性单一、生态功能不强。近年来，毛竹林蔓延和入侵越来越严重，已威胁到竹林周边植被，势必要进行更新改造。本研究旨在探讨毛竹纯林皆伐后自然更新形成群落类型、生物多样性特点和影响因素。  方法  基于天目山毛竹林皆伐自然更新后形成的次生群落的监测数据，利用TWINSPAN分析方法对自然更新群落进行了分类，比较了不同群落之间α多样性之间的差异性，用冗余分析法分析环境因素的影响。  结果  毛竹林皆伐后自然更新群落物种和类型多样，可分成11个不同的群落，不同群落之间α多样性存在显著差异。冗余分析发现:在海拔、坡向、坡度3个地形因子中海拔是决定自然更新群落木本层以及草本层α多样性大小的主要因子，且与其呈显著负相关关系(P＜0.05)。  结论  揭示了毛竹林皆伐后演替初期群落与环境因子的分布格局，为天目山自然保护区内植被恢复提供理论依据。图3表3参38

Types and diversity of natural regeneration community after clear cutting of Phyllostachys edulis forests in Mount Tianmu,China

  Objective  Phyllostachys edulis(Moso bamboo) forest is one of the forest community types that have been expanding in the subtropical region of China in recent 30 years. The spread and invasion of Ph. edulis forests are becoming more and more serious, threatening the vegetation around the Moso bamboo forest. It has become an important problem of forestry ecological construction at present and in the future. The study aim is to know the type and species diversity of natural regeneration community, and their influencing factors after clear cutting of Moso bamboo forest.  Method  This paper is based on the monitoring data of secondary communities formed by natural regeneration after clear cutting of Moso bamboo forest in Mount Tianmu, TWINSPAN analysis was used to classify the natural regeneration communities, The differences of α diversity among different communities were compared, the influence of environmental factors was analyzed by redundancy analysis.  Result  (1)Species and types of natural regeneration community are varied after clear-cutting of Moso bamboo forest, can be divided into 11 different communities. There were significant differences in alpha diversity among different communities. (2) Through redundancy analysis, it was found that among the three topographic factors of elevation, slope direction and slope, elevation was the main factor that determined the alpha diversity of woody layer and herbaceous layer of natural regeneration community and was significant negatively correlated with it(P＜0.05).  Conclusion  This paper reveals the distribution pattern of community and environmental factors in the early stage of succession and provides theoretical basis for vegetation restoration in the protected area. Ch, 3 fig. 3 tab. 38 ref.]