【作者】 赵谷风；

【导师】 傅承新； 于明坚；

【作者基本信息】 浙江大学 ， 植物学， 2010， 博士

【摘要】 植物群落在组成、结构、动态和功能方面所表现出的异同是群落生态学及保护生物学领域研究的重要内容。群落Beta多样性是评估群落中物种的替代程度以及群落多样性和环境异质性关联的重要指标和研究方法。本研究针对我国东部古田山24公顷常绿阔叶林动态样地,采用了多尺度的评估手段进行了群落Beta多样性格局及其与地形环境间关联性的评估。同时,以巴拿马Barro Colorado岛(BCI)50公顷热带低地森林动态样地作为对照,探讨了在地形陡峭多变和地形起伏不大的森林中Beta多样性格局及其与地形环境的相互作用的差异。研究发现在古田山样地中,距离梯度对于物种相似性的下降具有明显效应,但在研究的几个尺度内物种相似性没有表现出尺度敏感性。在地形环境复杂和简单的森林中,群落在100米范围受扩散限制效应均较为明显,且空间距离能够独立影响群落的Beta多样性分布。地形(并主要是海拔和凹凸度)异质性在陡峭多变的森林中对群落格局的形成起到更关键的作用,虽然扩散限制也可能在同时影响着群落分布格局。功能多样性由于其可以被用以从物种功能特征的角度探讨群落空间格局及其与环境间的关联性,从而切入到物种共存机制学说的探讨中而成为近年来群落生态研究的热点。本研究针对我国东部古田山24公顷常绿阔叶林样地,对群落功能多样性及功能群的分布格局,及其与地形异质性的关联性进行了分析。研究同时考虑了群落各垂直层的差异,以及多个空间尺度。研究发现群落中功能多样性的地形因素关联度要显著高于不考虑物种功能特征差别的群落物种多样性的地形因素关联度,从而证实了功能特征和功能多样性在常绿阔叶林群落多样性与环境互作过程中起到的关键角色。同时,常绿阔叶林群落的功能多样性在对于群落组成的表达上能够在成年树的水平更好的被体现,且功能群中功能特征相近的物种其彼此的竞争激烈程度要大于功能特征距离较远的物种。功能群的空间分布格局并没有提供支持生态位理论观点的证据。更多还原

【Abstract】 The forming and maintenance of species diversity in space, which has been a crucial question in community ecology, has motivated much research. Beta diversity, as a fundamental macroecological pattern, is useful for understanding community assembly. This study evaluated the pattern of Beta diversity derived from species abundance and its environmental association in a 24 ha rugged subtropical evergreen broad-leaved forest plot (GTS plot) in East China. The 50 ha plot in Barro Colorado Island (BCI) was chosen as a comparison of different habitat topographies, and multi-scale approach was also adopted to detect scale sensitivity.The results showed that in GTS plot, species similarity had monotonic decline along the distance gradient, and was not sensitive to scales within the analyzed distance range. Both species similarities in plots with rougher and plainer topographies had the steepest decrease occurring in the first 100 m, and distance had independant effect on Beta diversity. Habitat heterogeneity, especially elevation and convexity differences, tend to be the key factors that influence Beta diverisity, and dispersal limitation also have have significant contribution in community assembly in GTS with rougher topography.Functional diversity, the extent of functional differences among the species in a community, has been widely emphasized in community and ecological researches, because of its exceptional angle which can engage in species coexistence, especially in evaluation of species-environment associations. The patterns of functional diversity, functional groups and their topographic association were evaluated in 24 ha GTS plot in this study. Vertical layers and multi-scale angles were also considered in the evaluation.The results showed that topographic explanations of functional diversity in the multi-scales were significantly greater than that of species diversity, which provided an evidence of that composition which based on phylogenetic classification has better association with ecosystem processes in the evergreen broad-leaved forest. This study also found that species in tree layer had better topographic association with their functional diversity, and functional traits tend to play different roles in species’interaction with habitat in different vertical layers in GTS plot. Species clustered with closer functional traits attributes tended to have tighter competition exclusions. The pattern of functional groups displayed strong aggregative distribution and seemed not provide support of the niche theory.更多还原