群落生态学中的中性模型默认所有物种的所有生物个体在生态学上是相同的，群落结构将由随机性的物种灭绝、迁入或物种形成等过程来决定。中性模型在预测物种多度分布曲线和物种数-面 积关系等方面取得了巨大成功，但是仍然存在诸多不足之处，比如，它不能预测哪个物种是常见种，哪个是稀有种。地表过程与资源生态国家重点实验室张大勇等 人，提出了一个近中性模型，允许不同物种在竞争能力上存在微小差异。该模型中物种尽管存在适合度差异，仍然可以共存相当长的时间；共存时间比严格的中性模 型所预测的要短很多；近中性模型得到的物种多度分布曲线不同于中性模型，同时预测竞争能力更强的物种多度更高。

近中性模型为整合物种共存理论与生物多样性-生态系统功能关系提供了一个理论框架。

 

 

 

A nearly neutral model of biodiversity

 

Shu-Rong Zhou and Da-Yong Zhang

 

 

S. P. Hubbell’s unified neutral theory of biodiversity has stimulated much new thinking about biodiversity. However, empirical support for the neutral theory is limited, and several observations are inconsistent with the predictions of the theory, including positive correlations between traits associated with competitive ability and species abundance and correlations between species diversity and ecosystem functioning. The neutral theory can be extended to explain these observations by allowing species to differ slightly in their competitive ability (fitness). Here, we show that even slight differences in fecundity can greatly reduce the time to extinction of competitors even when the community size is large and dispersal is spatially limited. In this case, species richness is dramatically reduced, and a markedly different species abundance distribution is predicted than under pure neutrality. In the nearly neutral model, species co-occur in the same community not because of, but in spite of, ecological differences. The more competitive species with higher fecundity tend to have higher abundance both in the metacommunity and in local communities. The nearly neutral perspective provides a theoretical framework that unites the sampling model of the neutral theory with theory of biodiversity affecting ecosystem function.

 

 

Ecology, 89(1), 248-258, 2008

http://www.esajournals.org/doi/abs/10.1890/06-1817.1