物种多样性与生态系统功能时间变异性的关系研究进展

Effect of species diversity on temporal variability of ecosystem function

近年来物种多样性的急剧丧失使得物种多样性与生态系统功能的时间变异性的关系及其机制问题的研究成为了生态学研究的一个热点。综述了物种多样性与群落集合性质变异性以及种群性质变异性的关系及其机制的最新研究成果:1.理论上探讨造成物种多样性与群落集合性质变异性负相关关系的机制包括:抽样效应、资源利用分化假说、统计平均效应、保险假说、种群变异性的均匀度效应等;但实验研究对理论预期的支持并不是普遍的;2.多样性与种群变异性之间的关系主要依赖于均值-方差尺度系数Z;理论上大部分自然群落中种群变异性应该随着多样性的增加而增加;但有研究表明:在变动环境中多样性对单个组分物种的种群水平有稳定性作用;而经验研究并不能得出多样性对种群变异性效应的清晰模式。讨论了目前的理论和实验研究中存在的和今后研究中需要认真思考的问题。

The effect of species diversity on temporal variability of ecosystem function has recently emerged as a topic of considerable ecological interests due to the increadsing species extinction in recent decades. In this paper, the theoretical and empirical studies on the relationships and underlying mechanisms between species diversity and temporal variability in community structure were reviewed. First, Theoretical studies predict that community variability should decline with increasing species diversity, and the underlying mechanisms include: sampling effect, resource-use segregation effect, statistical averaging effect, insurance effect, evenness effect in population variability. Many, but not all, empirical studies support these expectations. However, there are no clear interpretations to the differences of conclusions about diversity-variability relationship drawn from each experiment. Second, studies that test the effect of species diversity on temporal variability in population property were also summarized. Theoretical studies suggest that the relationship between species diversity and population variability depends primarily on the mean-variance rescaling coefficient Z; in most natural communities, population variability should theoretically increase with species diversity;However, some studies show that species diversity has stable effect on population level of individual component species in varied environment. But empirical studies still cannot show a clear pattern of the effect species diversity on population variability. Last, we discussed several aspects of the disadvantages that exist in current theoretical and empirical studies and hope that this paper could be a synthetically consultation to further researches.