High Competition with Low Similarity and Low Competition with High Similarity: Exploitative and Apparent Competition in Consumer‐Resource Systems
High Competition with Low Similarity and Low Competition with High Similarity: Exploitative and Apparent Competition in Consumer‐Resource Systems
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DOI：
10.1086/286153
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发表时间：
1998-07
期刊：
影响因子：
--
通讯作者：
P. Abrams
中科院分区：
文献类型：
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作者：
P. Abrams
本文研究了资源捕获能力的相似性与利用共同资源的两个消费物种之间的竞争程度之间的关系。大多数分析都是基于罗伯特·麦克阿瑟提出的消费者资源模型。与文献和教科书中的许多说法相反，竞争的测量可能会随着相似性的增加而减少，当两个物种的资源捕获率的相似性非常低时，竞争测量可能会最大。无论是用接近平衡的竞争系数来衡量竞争，还是用当竞争者被移除时物种的种群密度成比例地增加来衡量，都可能发生低相似的高竞争。然而，这两个衡量标准可能有很大的不同，并且可能随着给定的相似性变化而朝着相反的方向变化。相似性和竞争之间这种违反直觉的关系所需的一般条件是，消费物种对成功繁殖的资源需求相对较低，并且资源是自我繁殖的。同样的条件也经常通过明显的竞争导致一种或多种资源被排除在外，麦克阿瑟的模型总是如此。分析了各种其他竞争模式，并确定了最有可能产生较大竞争影响且几乎没有重叠的情况。
This article investigates the relationship between the similarity of resource capture abilities and the amount of competition between two consumer species that exploit common resources. Most of the analysis is based on a consumer‐resource model introduced by Robert MacArthur. Contrary to many statements in the literature and in textbooks, measures of competition may decrease as similarity increases and may be greatest when similarity of the two species' sets of resource capture rates is very low. High competition with low similarity may occur whether competition is measured by a competition coefficient near equilibrium or is measured by the proportional increase in a species' population density when its competitor is removed. However, these two measures may differ considerably and may change in opposite directions with a given change in similarity. The general conditions required for such counterintuitive relationships between similarity and competition are that the consumer species have relatively low resource requirements for successful reproduction and that the resources be self‐reproducing. These same conditions also frequently lead to exclusion of one or more resources via apparent competition, and this is always true of MacArthur's model. A variety of other models of competition are analyzed, and circumstances most likely to produce large competitive effects with little overlap are identified.