Competitive exclusion between contest and scramble strategists in Callosobruchus seed-beetle modeling
Competitive exclusion between contest and scramble strategists in Callosobruchus seed-beetle modeling
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DOI：
10.1007/s10144-008-0080-x
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发表时间：
2008-04-01
影响因子：
1.7
通讯作者：
Shimada, Masakazu
中科院分区：
文献类型：
--
作者：
Ishii, Yumiko;Shimada, Masakazu
研究了一种中间竞争品系与一种争食品系在两种资源豆上的种间竞争：小豆（Vigna anguralis，小种子）和黑眼豆（Vigna unguiculata，大种子）。我们进行了单代竞争实验和多代竞争实验，然后使用离散版本的Lotka-Volterra竞争模型对系统进行了分析。估算的竞争系数表明，在两种类型的大豆中，斑孢豆菌株对中国芽孢豆菌株具有竞争优势。基于预测模型的零生长等斜线分析表明，竞争种C. maculatus在红豆中的总体优势，而竞争结果取决于黑眼豆中每个物种的初始种群大小。在多代实验中，无论两种豆的比例如何，黄斑曲霉都是成功的竞争者，而在黑眼豆系统中，中国曲霉在5次重复中有1次战胜了黄斑曲霉。当我们在预测模型中加入争夺竞争的成本或密度依赖的体重减少时，模型的改变降低了黑眼豆上中华蠋蝽在相空间上的生存区域。因此，不考虑密度相关的体型减少的竞争方程往往高估了争夺策略的优势。
Interspecific competition between an intermediate contest strain of Callosobruchus maculatus and a scramble strain of C. chinensis was investigated on two types of resource beans: the azuki (Vigna anguralis, small seed) and the black-eye bean (Vigna unguiculata, large seed). We conducted both single-generation competition experiments and multiple-generation experiments and then analyzed the system with a discrete version of the Lotka-Volterra competition model. The estimated competition coefficients showed the competitive dominance of the C. maculatus strain over the C. chinensis strain in both types of bean. Zero-growth isocline analysis based on the predicted model showed that an overall dominance of the contest species, C. maculatus, in azuki beans, whereas the outcome of competition was dependent on the initial population size of each species in the black-eye beans. In the multiple-generation experiments, C. maculatus was the successful competitor irrespective of the ratio of the two beans, whereas C. chinensis overcame C. maculatus in one of five replicates with the black-eye beans system. When we incorporated the cost of scramble competition, or density-dependent reduction in body mass into the predicted model, the model alteration decreased the survival region of C. chinensis in phase space on the black-eye bean. Thus, the competitive equations, which do not consider the density-dependent body size reduction, tend to overestimate the advantages of scramble strategists.