青藏高原高寒草甸南坡-北坡梯度上植物群落构建机理研究

Over the past century, a central theme in ecology is the underling mechanisms of formation and maintenance of species diversity in community, i.e., community assembly rules. Although located only a tens of meters apart and sharing the same macroclimatic zone, the microclimatic conditions on different slopes vary dramatically affecting species composition, biodiversity and productivity. Until now, the studies on this topic are descriptive, as we know no of them do this research from the assembly mechanism of plant community. In this project, we studied the turnover of species in community along aspect of slope and ecological mechanism of community type conversion by combining niche and neutral theory, and field experimental observations and modeling. We did the field experiments at Qinghai-Tibetan plateau and our object was alpine meadow communities. From niche theory, we should confirm how species interaction affects α-diversity of local community through analyzing plant functional traits and how the environmental filter promotes β-diversity along the community gradient. From neutral theory, we examined the effects of stochastic birth, death and migration between communities on α-diversity and of environmental heterogeneity and dispersal limitation on β-diversity, respectively. Hence, we incorporated the study of plant functional traits into the frame of niche-neutral continuum hypothesis, and explained the plant community assembly mechanism from a new perspective.

群落中物种多样性的形成及维持机制，是一个世纪以来生态学的核心论题。在南坡-北坡梯度上，由于地形学的缘故，在数十米的距离可能会造成环境因素极大的变化，植物群落组成等随之也发生很大的改变。目前对此问题的研究主要是描述性的，而未从植物群落构建机理的角度进行探讨。本项目基于前期研究积累，以青藏高原高寒草甸植被为对象，结合生态位与中性理论，以野外实验及建模相结合的方法，探究坡向梯度上群落组分种周转（turnover）、群落类型转换的生态学机制。从生态位理论的角度，基于植物功能性状分析，确认种间相互作用如何影响局域群落的α多样性以及环境筛选如何促成群落梯度上的β多样性。从中性理论的角度，明确随机出生、死亡过程和群落间的迁移过程在维持群落α多样性中的作用，辨析扩散限制和生境异质性各自对β多样性的贡献。由此，将植物功能性状的研究纳入生态位-中性理论连续统的框架，从一个新的视角阐释多物种植物群落构建机理。

群落中物种多样性的形成及维持机制，是一个世纪以来生态学的核心论题。在南坡-北坡梯度上，由于地形学的缘故，在数十米的距离可能会造成环境因素极大的变化，植物群落组成等随之也发生很大的改变。目前对此问题的研究主要是描述性的，而未从植物群落构建机理的角度进行探讨。本项目基于前期研究积累，以青藏高原高寒草甸植被为对象，结合生态位与中性理论，以野外实验及建模相结合的方法，探究坡向梯度上群落组分种周转（turnover）、群落类型转换的生态学机制。从生态位理论的角度，基于植物功能性状分析，确认种间相互作用如何影响局域群落的α多样性以及环境筛选如何促成群落梯度上的β多样性。从中性理论的角度，明确随机出生、死亡过程和群落间的迁移过程在维持群落α多样性中的作用，辨析扩散限制和生境异质性各自对β多样性的贡献。由此，将植物功能性状的研究纳入生态位-中性理论连续统的框架，从一个新的视角阐释多物种植物群落构建机理。