MONOTONIC OR UNIMODAL DIVERSITY PRODUCTIVITY GRADIENTS - WHAT DOES COMPETITION THEORY PREDICT
MONOTONIC OR UNIMODAL DIVERSITY PRODUCTIVITY GRADIENTS - WHAT DOES COMPETITION THEORY PREDICT
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DOI：
10.2307/1941677
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发表时间：
1995-10-01
期刊：
影响因子：
4.8
通讯作者：
ABRAMS, PA
中科院分区：
文献类型：
--
作者：
ABRAMS, PA
本文讨论了资源生产力与共存消费物种多样性之间的两种关系。单调递增曲线最近在经验和理论基础上都被驳回，而单峰（“驼峰形”）曲线得到了支持。单峰曲线归因于竞争排斥的增加，通常是由于在高生产率下限制资源的异质性降低。本文认为：(1)存在许多可行的机制，可以在存在竞争的情况下产生单调曲线；(2)生产率降低异质性，从而增加竞争排斥这一假说的任何主要变体都没有得到实证支持；(3)单峰曲线存在其他原因，其中一些或全部与先前观察到的生产率-多样性关系一致。需要更多的理论和实证工作来了解不同竞争机制所产生的关系，以及在不同的观察方案下最常观察到的关系。
This article discusses two types of proposed relationships between resource productivity and the diversity of coexisting Consumer species. Monotonically increasing curves have recently been dismissed on both empirical and theoretical grounds, while unimodal (''hump-shaped'') curves have been supported. Unimodal curves have been attributed to increased competitive exclusion, usually as the result of decreased heterogeneity in limiting resources at high productivities. This article argues that: (1) there are many viable mechanisms that can produce monotonic curves in the presence of competition; (2) there is little empirical support for any of the major variants of the hypothesis that productivity decreases heterogeneity, which increases competitive exclusion; and (3) there are alternative reasons for unimodal curves, some or all of which are consistent with previously observed productivity-diversity relationships. Additional theoretical and empirical work is required to understand what relationships follow from different mechanisms of competition, and what relationships are most frequently observed under different observational protocols.