暖温带森林功能发育过程中的物种扩散和生态位分化  

Species diffusion and niche differentiation of the warm temperate deciduous broad-leaved forest in its functional development process

作　　者：刘海丰[1] 薛达元[2] 桑卫国[1] 

机构地区：[1]中国科学院植物研究所、植被与环境变化国家重点实验室,北京100093 [2]中央民族大学生命与环境科学学院,北京100081

出　　处：《科学通报》2014年第24期2359-2366,共8页Chinese Science Bulletin

基　　金：中国科学院战略性先导科技专项(XDA05050203-02);教育部和国家外国专家局“111计划”(2008-B08044)资助

摘　　要：群落构建的驱动力(随机过程与确定性过程)对群落构建的作用受森林功能发育过程的影响,但鲜有研究探讨两者随群落功能发育过程发生的特点.次生林功能发育阶段多样,具有检测发育过程中群落构建驱动力变化的优势.本研究利用20 hm2暖温带次生林样地基础调查数据检测了局域尺度上暖温带森林功能发育过程中群落物种扩散与生态位过程的发生特点,区分了2类过程对群落多样性构建的相对贡献.结果显示,局域尺度上功能发育过程显著影响物种扩散与生态位过程,对生态位分化过程的影响速率要快于物种扩散.在森林功能发育过程中,生态位分化表现为稳定下降,而物种扩散则为前期不变,后期稳定下降.群落功能发育尺度上的物种扩散伴随了冠层稳定的骨架结构及分离的垂直结构,提高了垂直分布上群落物种组成的匀质性,有利于物种共存.局域尺度上,物种扩散与生态位分化过程的交互效应是群落构建的主要动力,物种扩散作用要强于生态位分化过程.本研究暗示除了空间因子等的被动调节,中性与生态位过程对群落构建的相对贡献也受群落功能发育阶段的影响,群落构建驱动力受群落自身功能的调节.Random and deterministic processes have strong effects on the functional development in forest ecosystems. However, few studies have explored these effects because appropriate methods for this type of study are lacking and such studies require large amounts of forest spatial monitoring data. A 20-hm2 forest plot in a secondary warm temperate deciduous broad-leaved forest of Beijing, China, was established in 2010 using the standard Barro Colorado Island plot survey method. Data from this plot were used to test the effects of species dispersal and niche differentiation on changes in tree species richness, and to gain an understanding of the patterns of change in species dispersal and niche differentiation during long-term community functional development. The results showed the effects of species dispersal and niche differentiation on community functional development processes changed significantly over time and those of niche differentiation changed faster than the effects of species dispersal. In the process of forest functional development, niche differentiation steadily declined while the species dispersal index, which compares the canopy and understory layers of forests, stabilized in the early stage and then declined. The species dispersal index remained stable, as did the canopy profile structure in the early stage; the variation in the vertical structure of the forest during community functional development increased the vertical distribution and dissimilation of species making it easier for forest species to coexist. We also found the interaction between species dispersal and niche differentiation was the main driving force for changes in species diversity, and species dispersal had stronger effects on community assembly than did niche differentiation. The results of this study suggest that, in addition to changes in the spatial factors related to community assembly, the relative contributions of neutral and niche processes on community assembly are different during various stages of community functional

关 键 词：群落构建 群落结构 物种丰富度 中性过程 确定性过程 相对贡献 

分 类 号：Q948[生物学—植物学]