Intraguild predation and species exclusions in amphipods: The interaction of behaviour, physiology and environment
Intraguild predation and species exclusions in amphipods: The interaction of behaviour, physiology and environment
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DOI：
10.1046/j.1365-2427.1996.00106.x
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发表时间：
1996-10-01
影响因子：
2.7
通讯作者：
Platvoet, D
中科院分区：
文献类型：
--
作者：
Dick, JTA;Platvoet, D
1.野外调查、室内实验和群落动态的计算机模拟结果表明，两种水生端足类竞争种群的复杂分布可能是由于群体内捕食、生理适应和环境之间的相互作用.钩虾（Gammarus pulex）和钩虾（G.虎尾鱼都在西欧的淡水和低盐沃茨中生长。然而，欧洲本土的G. pulex排除了入侵的北美G. tigrinus从淡水的相对低的电导率，而相反发生在较高的电导率。此外，这些物种的共存模式存在很大的时空波动性.在荷兰和爱尔兰的实验室实验表明，这些物种之间经常发生蜕皮个体的相互捕食。然而，捕食频率差异有利于G。蚤属在离子条件下，这一物种是生理适应（淡水）。另一方面，在G.虎尾鱼是生理适应（寡盐水）。4.一个数学模型，它扩展了逻辑方程，包括相互intraguild捕食，模拟相关的人口参数的值范围内的相互作用。这表明G.当平衡的瞬时相互捕食率与已知的更大的生殖输出相结合时，蚤状蚤将被排除在外。提格里诺斯。然而，这种生殖优势是克服任何相对较小的偏见，有利于G的瞬时捕食率。pulex，从而排除了G.提格里诺斯。即使在G.虎斑龙相对较大。此外，该模型产生的“开关”的物种优势，是由繁殖率和相互捕食的相对值。转换所需的时间可以解释在野外观察到的这些物种明显共存的短暂时期。因此，这些物种的复杂群落动态可以从行为、生理和环境因素介导的物种相互作用强度的变化来理解。
1. Data from field surveys, laboratory experiments and computer simulations of community dynamics revealed that a novel interaction among intraguild predation, physiological adaptation and environment may explain the complex distributions of two putatively competing aquatic amphipods.2. Gammarus pulex and G. tigrinus both thrive in fresh and oligohaline waters in western Europe. However, the native European G. pulex excludes the invading North American G. tigrinus from freshwaters of relatively low conductivity, whereas the reverse occurs at higher conductivities. Additionally, there is much spatio-temporal fluctuation in the patterns of coexistence of these species.3. Laboratory experiments in The Netherlands and Ireland revealed that mutual predation of moulting individuals occurred frequently between these species. However, predation frequencies were differentially in favour of G. pulex under the ionic conditions to which this species is physiologically adapted (freshwater). On the other hand, predation was not differential under the ionic conditions to which G. tigrinus is physiologically adapted (oligohaline water).4. A mathematical model, which extends the logistic equation to include mutual intraguild predation, simulated interactions over a range of values of relevant population parameters. This indicated that G. pulex would be excluded when balanced instantaneous rates of mutual predation were combined with the known greater reproductive output of G. tigrinus. However, this reproductive advantage is overcome by any relatively small bias in the instantaneous rate of predation favouring G. pulex, leading to the exclusion of G. tigrinus. This occurs even when the reproductive advantage to G. tigrinus is relatively large. Moreover, the model generated 'switches' in species dominance that are determined by the relative values of reproductive rate and mutual predation. The time taken to 'switch' may explain the transient periods of apparent coexistence of these species observed in the field.5. The complex community dynamics of such species may thus be understood in terms of variation in the intensity of species interactions mediated by behavioural, physiological and environmental factors.