Selective predation and productivity jointly drive complex behavior in host-parasite systems
Selective predation and productivity jointly drive complex behavior in host-parasite systems
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DOI：
10.1086/426601
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发表时间：
2005-01-01
影响因子：
2.9
通讯作者：
Cáceres, CE
中科院分区：
文献类型：
--
作者：
Hall, SR;Duffy, MA;Cáceres, CE
寄生虫成功侵入宿主种群以及由此产生的宿主-寄生虫动态在很大程度上取决于宿主社区的其他成员，例如捕食者。我们并不完全了解捕食强度和选择性如何影响宿主-寄生虫动态，因为捕食者密度、捕食者觅食行为和生态系统生产力之间的相互作用尚未得到充分探索。通过修改标准的易感感染模型，我们展示了生产力如何调节捕食者在稳定的宿主-寄生虫系统中的饱和和选择性觅食行为所引起的复杂行为。当捕食者强烈偏爱被寄生的宿主时，宿主-寄生虫系统可能会振荡，但捕食者也可以创造替代的稳定状态、阿利效应和寄生虫的灾难性灭绝。在后三种情况下，寄生虫难以侵入和/或在生态系统中持续存在。当捕食者具有中等选择性时，这些更复杂的行为变得不那么重要，但宿主-寄生虫系统可以沿着捕食者控制的梯度从稳定状态切换到振荡状态，然后再回到稳定状态。令人惊讶的是，在较高的生产力下，中立地选择或避免寄生宿主的捕食者可以催化寄主和寄生虫的灭绝。因此，两个敌人之间的协同作用可能会给宿主带来灾难性的后果。如此多样化的结果强调了宿主与寄生虫相互作用发生的群落和生态系统环境的至关重要性。
Successful invasion of a parasite into a host population and resulting host-parasite dynamics can depend crucially on other members of a host's community such as predators. We do not fully understand how predation intensity and selectivity shape host-parasite dynamics because the interplay between predator density, predator foraging behavior, and ecosystem productivity remains incompletely explored. By modifying a standard susceptible-infected model, we show how productivity can modulate complex behavior induced by saturating and selective foraging behavior of predators in an otherwise stable host-parasite system. When predators strongly prefer parasitized hosts, the host-parasite system can oscillate, but predators can also create alternative stable states, Allee effects, and catastrophic extinction of parasites. In the latter three cases, parasites have difficulty invading and/or persisting in ecosystems. When predators are intermediately selective, these more complex behaviors become less important, but the host-parasite system can switch from stable to oscillating and then back to stable states along a gradient of predator control. Surprisingly, at higher productivity, predators that neutrally select or avoid parasitized hosts can catalyze extinction of both hosts and parasites. Thus, synergy between two enemies can end disastrously for the host. Such diverse outcomes underscore the crucial importance of the community and ecosystem context in which host-parasite interactions occur.