Kuijper D P J, Sahlén E, Elmhagen B, Chamaillé-Jammes S, Sand H, Lone K, Cromsigt J P G M
Mammal Research Institute, Polish Academy of Sciences, ul. Waszkiewicza 1d, 17-230 Białowieża, Poland
Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Skogsmarksgränd, 901 83 Umeå, Sweden.
Proc Biol Sci. 2016 Oct 26;283(1841). doi: 10.1098/rspb.2016.1625.
Large carnivores are frequently presented as saviours of biodiversity and ecosystem functioning through their creation of trophic cascades, an idea largely based on studies coming primarily out of relatively natural landscapes. However, in large parts of the world, particularly in Europe, large carnivores live in and are returning to strongly human-modified ecosystems. At present, we lack a coherent framework to predict the effects of large carnivores in these anthropogenic landscapes. We review how human actions influence the ecological roles of large carnivores by affecting their density or behaviour or those of mesopredators or prey species. We argue that the potential for density-mediated trophic cascades in anthropogenic landscapes is limited to unproductive areas where even low carnivore numbers may impact prey densities or to the limited parts of the landscape where carnivores are allowed to reach ecologically functional densities. The potential for behaviourally mediated trophic cascades may be larger and more widespread, because even low carnivore densities affect prey behaviour. We conclude that predator-prey interactions in anthropogenic landscapes will be highly context-dependent and human actions will often attenuate the ecological effects of large carnivores. We highlight the knowledge gaps and outline a new research avenue to study the role of carnivores in anthropogenic landscapes.
大型食肉动物常被视为生物多样性和生态系统功能的拯救者，因为它们能引发营养级联效应，这一观点主要基于主要来自相对自然景观的研究。然而，在世界大部分地区，尤其是欧洲，大型食肉动物生活在并正回归到人类强烈改造过的生态系统中。目前，我们缺乏一个连贯的框架来预测大型食肉动物在这些人为景观中的影响。我们回顾了人类活动如何通过影响大型食肉动物的密度、行为或中型食肉动物或猎物物种的密度、行为来影响大型食肉动物的生态作用。我们认为，在人为景观中，密度介导的营养级联效应的潜力仅限于非生产性区域，在这些区域，即使食肉动物数量少也可能影响猎物密度，或者仅限于景观中食肉动物能够达到生态功能密度的有限部分。行为介导的营养级联效应的潜力可能更大且更广泛，因为即使食肉动物密度低也会影响猎物行为。我们得出结论，人为景观中的捕食者 - 猎物相互作用将高度依赖于具体情境，人类活动通常会削弱大型食肉动物的生态影响。我们强调了知识空白，并概述了一条研究食肉动物在人为景观中作用的新研究途径。
