Indirect Mutualism: Variations on a Theme by Stephen Levine
Indirect Mutualism: Variations on a Theme by Stephen Levine
复制标题
DOI：
10.1086/283637
复制
发表时间：
1980-09
期刊：
影响因子：
--
通讯作者：
J. Vandermeer
中科院分区：
文献类型：
--
作者：
J. Vandermeer
虽然自然界中一些最壮观的种间相互作用显然是互利的，但相对较少的研究，经验或理论，旨在了解这种基本的，也许是普遍的相互作用形式（Risch和Boucher 1976）。本文试图在Vandermeer和Boucher（1978）的基础上扩展Levine（1976）的工作，从而为“间接互惠”（S. James和D. Boucher，in prep.）或“利基增强”（Dodson 1970）。我还认为，这种形式的相互作用可能在群落组织中极其重要，至少在某些营养层次上是如此。Vandermeer和Boucher（1978）使用简单的线性分析，对互惠互动的基本形式进行了分类。与Gause和Witt对竞争的分析（Gause and Witt 1935）类似，Vandermeer和Boucher提出了八种性质不同的结果，通过一个简单的两种群微分方程系统预测。表1概述了这8起案件。他们的结果有两个特点在这里特别重要，第一，相互作用可能是稳定的或不稳定的，第二，互利主义者可能是任意相互的或强制相互的。请注意，系统的局部稳定性（表1第一栏中的行标题）与通常意义上的生物学结果几乎没有关系。也就是说，在种间竞争的情况下，如果局部分析表明两个物种的稳定共存是自动保险的。然而，从表1中可以看出，互惠共生并不存在这种对应关系。当系统在数学上不稳定时，生物共存是可能的。互利主义者既可以是专性的，也可以是兼性的，这是显而易见的，而且在理论上也是至关重要的，因为生物学的结果取决于这种二分法（见表1）。专性互惠现象已经通过假设负承载能力（Vandermeer and Boucher 1978）来建模，这里继续采用这种方法。Levine（1976）扩展了麦克阿瑟（1968，1972）流行的消费者方程，将资源之间的相互作用包括在内。莱文方程示意性地显示在图1中。Levine指出，对于各种各样的参数值，只要资源是竞争性关联的，两个消费者就“有效地”相互关联。这种有效的积极关系谢雷称为间接互惠，并以直观明显的方式产生。如果消费者所需的一种资源通过与另一种资源竞争而保持在相对较低的生物量，
Although some of the most spectacular interspecific interactions in nature are obviously mutualistic, relatively little research, empirical or theoretical, has been aimed at understanding this basic and perhaps prevalent form of interaction (Risch and Boucher 1976). In this paper I attempt o extend the work of Levine (1976) in the context of the basic summary provided by Vandermeer and Boucher (1978), thereby providing a theoretical framework for the concept of "indirect mutualism" (S. James and D. Boucher, in prep.) or "niche enhancement" (Dodson 1970). I furthermore suggest that this form of interaction is likely to be extremely important in community organization, at least at some trophic levels. Vandermeer and Boucher (1978), using simple linear analysis, have categorized the basic forms of mutualistic interactions. In a fashion similar to Gause and Witt's analysis of competition (Gause and Witt 1935), Vandermeer and Boucher presented eight qualitatively distinct outcomes, predicted by a simple two-species system of differential equations. Their eight cases are summarized in table 1. Two features of their esults are of particular importance here, first hat the interactions may be stable or unstable, and second that mutualists may be facultatively mutual or obligately mutual. Note that the local stability of the system (the row headings as they appear in the first col. of table 1) has very little to do with the biological outcome in the usual sense. That is, in the case of interspecific competition, ifa local analysis indicates tability coexistence of the two species is automatically insured. However, no such correspondence exists with mutualism, as can be seen in table 1. Biological coexistence is possible when the system is mathematically unstable. That mutualists can be either obligate or facultative isobvious, and theoretically crucial since biological outcomes depend on this dicotomy (see table 1). The phenomenon of obligate mutualism has been modeled by assuming a negative carrying capacity (Vandermeer and Boucher 1978), an approach continued here. Levine (1976) extended the popular consumer esource quations of MacArthur (1968, 1972) to include interactions between resources. Levine's equations are shown diagramatically infigure 1. Levine noted that for a wide variety of parameter values the two consumers are "effectively" mutualistically associated with one another, as long as the resources are competitively associated. This effectively positive relationship shere called indirect mutualism, and is generated in an intuitively obvious fashion. If a resource required by a consumer is maintained at a relatively low biomass through competition with another resource, any factor