Fortin Daniel, Buono Pietro-Luciano, Schmitz Oswald J, Courbin Nicolas, Losier Chrystel, St-Laurent Martin-Hugues, Drapeau Pierre, Heppell Sandra, Dussault Claude, Brodeur Vincent, Mainguy Julien
Chaire de Recherche Industrielle CRSNG-Université Laval en Sylviculture et Faune, Département de Biologie, Université Laval, Québec, G1V 0A6, Canada
GIREF, Chaire de Recherche Industrielle du CRSNG en Calcul Scientifique, Département de Mathématiques et de Statistique, Université Laval, Québec, G1V 0A6, Canada Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario, Canada.
Proc Biol Sci. 2015 Aug 7;282(1812):20150973. doi: 10.1098/rspb.2015.0973.
Trophic interactions in multiprey systems can be largely determined by prey distributions. Yet, classic predator-prey models assume spatially homogeneous interactions between predators and prey. We developed a spatially informed theory that predicts how habitat heterogeneity alters the landscape-scale distribution of mortality risk of prey from predation, and hence the nature of predator interactions in multiprey systems. The theoretical model is a spatially explicit, multiprey functional response in which species-specific advection-diffusion models account for the response of individual prey to habitat edges. The model demonstrates that distinct responses of alternative prey species can alter the consequences of conspecific aggregation, from increasing safety to increasing predation risk. Observations of threatened boreal caribou, moose and grey wolf interacting over 378 181 km(2) of human-managed boreal forest support this principle. This empirically supported theory demonstrates how distinct responses of apparent competitors to landscape heterogeneity, including to human disturbances, can reverse density dependence in fitness correlates.
多猎物系统中的营养相互作用在很大程度上可能由猎物分布决定。然而，经典的捕食者 - 猎物模型假定捕食者与猎物之间的相互作用在空间上是均匀的。我们构建了一种考虑空间因素的理论，该理论预测栖息地异质性如何改变猎物因捕食而面临的死亡风险在景观尺度上的分布，进而改变多猎物系统中捕食者相互作用的性质。该理论模型是一种空间明确的多猎物功能反应，其中物种特异性的平流 - 扩散模型解释了单个猎物对栖息地边缘的反应。该模型表明，替代猎物物种的不同反应可以改变同种聚集的后果，从增加安全性变为增加捕食风险。对在面积达378181平方公里的人工管理北方森林中相互作用的濒危北方驯鹿、驼鹿和灰狼的观察结果支持了这一原理。这一得到实证支持的理论证明了明显的竞争者对景观异质性（包括对人类干扰）的不同反应如何能够逆转适合度相关因素中的密度依赖性。
