物种丰富度的垂直分布格局及其形成机制

Elevational patterns of species richness and their underlying mechanism

物种丰富度海拔梯度格局及其形成机制一直是宏观生态学研究的重要议题。物种丰富度沿海拔梯度呈4种分布格局,其中单峰分布格局最为普遍。人们提出各种假设从不同角度解释物种丰富度的海拔梯度格局,这些假设主要以气候、空间效应、物种间相互作用及其进化历史为出发点,提出的假设主要有水分-能量动态假设、生物多样性代谢理论、生产力假设、种-面积关系、中域效应、栖息地异质性假设及静态进化模型。本文系统介绍了物种丰富度的海拔格局及影响其格局的生态过程。目前,物种丰富度的海拔格局主要集中在现代气候对物种丰富度海拔格局的形成过程的作用,但这些现代气候的参数之间具有显著共线性,难以分辨具体的某种环境因子对其的绝对贡献。结合现代气候和物种的谱系进化过程,系统比较不同海拔区域物种的系统发育特征有助于进一步理解物种丰富度的海拔分布格局及其成因机制,同时有助于理解现代环境的波动对植被群落的影响。

Elevational patterns of species richness and their underlying mechanism have long been one of significant issues in macroecology. Species richness along the elevation gradients shows four patterns, the common pattern of which is unimodel with midelevation peak. Multiple hypotheses were proposed to explain the patterns, including four aspects： climate, spatial effect, interaction among species, and evolutional history. These hypotheses were used to explain the species richness elevational patterns from different aspects. This article reviewed the history of research on elevational pattern of species richness, the methodology and the potential mechanisms for elevation patterns. These hypotheses mainly included waterenergy dynamic hypothesis, metabolic theory of biodiversity, productivity hypothesis, relationship between species and area, middomain effect, habitat heterogeneity and static evolutionary models. The review introduced the distributional pattern of species richness along elevation gradient and the ecological evolution process affecting the pattern. At present, most of studies focused on the role of modern climate, but the parameters used as modern climate were so strongly collinear with each other that it was difficult to distinguish the absolute contribution of certain climate factor. Combined modern climate with phylogenetic analysis, the phylogenetic characters of species in different elevational bands were compared to help to further understand the elevation patterns of species richness, their underlying mechanisms and effect of modern climate fluctuation on vegetation community.