Data from: Top predators and habitat complexity alter an intraguild predation module in pond communities

Predator diversity and habitat complexity frequently influence species interactions at lower trophic levels, yet their joint investigation has been performed infrequently despite the demonstrated importance of each individual factor. We investigated how different top predators and varying habitat complexity influence the function of an intraguild predation module consisting of two larval salamanders, intraguild predator Ambystoma annulatum and intraguild prey A. maculatum. We manipulated predator food webs and habitat complexity in outdoor mesocosms. Top predators significantly influenced body condition and survival of A. annulatum, but habitat complexity had minimal effects on either response. A three-way interaction among the covariates top predator identity, habitat complexity and A. annulatum survival influenced body condition and survival of A. maculatum via a density mediated indirect effect. Different top predator combinations had variable effects in different habitat complexity treatments on intraguild predator (A. annulatum) survival that subsequently influenced intraguild prey (A. maculatum) body condition and survival. Future work should consider how different top predators influence other food web components, which should vary due to predator attributes and the physical environments in which they co-occur.

捕食者多样性与生境复杂性通常会对低营养级的物种互作产生显著影响，尽管二者各自的重要性已得到充分证实，但针对两者的联合研究却相对匮乏。本研究旨在探究不同顶级捕食者与梯度变化的生境复杂性，如何调控由两种幼虫钝口螈构成的集团内捕食（intraguild predation）模块：集团内捕食者环纹钝口螈（Ambystoma annulatum）与集团内猎物斑钝口螈（A. maculatum）。我们在野外中型实验围隔（mesocosms）中对捕食者食物网与生境复杂性进行了操控处理。顶级捕食者对环纹钝口螈的体能状况与存活率存在显著影响，而生境复杂性对这两项响应指标的作用则极为有限。协变量顶级捕食者身份、生境复杂性以及环纹钝口螈存活率三者间的三维交互作用，通过密度介导的间接效应，对斑钝口螈的体能状况与存活率产生影响。不同的顶级捕食者组合，在不同生境复杂性处理下对集团内捕食者（环纹钝口螈）存活率的影响存在差异，这一差异进而作用于集团内猎物（斑钝口螈）的体能状况与存活率。未来的研究应考量不同顶级捕食者对其他食物网组分的调控效应，而这类效应会因捕食者自身属性及其共存的物理环境而异。