Predation‐Competition Interactions for Seasonally Recruiting Species
Predation‐Competition Interactions for Seasonally Recruiting Species
复制标题
季节性招募物种的捕食竞争相互作用
作者：
J. J. Kuang;P. Chesson
在一个固定环境中季节性招募物种的模型中，我们研究了捕食和竞争对物种共存的交互影响。对于这些物种，生活史参数，如最大生产力和存活率，在波动依赖型物种共存中具有重要作用，因为它们将非线性引入种群增长率，并引起内生种群波动，从而激活被称为“相对非线性”的共存机制。在这种机制下，不同物种的生长速度的非线性必然不同，对竞争和捕食的波动也必须做出不同的贡献。这两个特征都可能是与季节性招聘相关的生活史权衡的结果。相对非线性的共存可以发生在捕食或不捕食的情况下。然而，捕食可能会破坏共存。它通过减少物种之间的差异对比来做到这一点。然而，当竞争不足以引起内生种群波动时，捕食可以通过破坏平衡来实现依赖波动的共存。这个模型还复制了经典的发现，即如果选择性捕食导致竞争和捕食之间的权衡，那么选择性捕食就可以共存。我们的模型是为遭受种子捕食的一年生植物物种之间的竞争而制定的，但它也适用于多年生群落，在那里竞争和捕食限制了成年种群的招募。
We investigate the interacting effects of predation and competition on species coexistence in a model of seasonally recruiting species in a constant environment. For these species, life‐history parameters, such as maximum productivity and survival, have important roles in fluctuation‐dependent species coexistence in that they introduce nonlinearities into population growth rates and cause endogenous population fluctuations, which can activate the coexistence mechanism termed “relative nonlinearity.” Under this mechanism, different species must differ in the nonlinearities of their growth rates and must make different contributions to fluctuations in competition and predation. Both of these features can result from life‐history trade‐offs associated with seasonal recruitment. Coexistence by relative nonlinearity can occur with or without predation. However, predation can undermine coexistence. It does this by reducing variance contrasts between species. However, when competition is not sufficient to cause endogenous population fluctuations, predation can enable fluctuation‐dependent coexistence by destabilizing the equilibrium. This model also reproduces the classic finding that coexistence can occur with selective predation provided that it causes a trade‐off between competition and predation. Our model is formulated for competition between annual plant species subject to seed predation, but it also applies to perennial communities where competition and predation limit recruitment to the adult population.