In recent years, large predators have made a comeback across large parts of Europe. However, little is known about the impact that recolonizing predators may have on ecosystems with high degrees of anthropogenic influence. In Scandinavia, wolves (Canis lupus) now inhabit areas affected by intense forestry practices and their main prey, moose (Alces alces), are exposed to significant human hunting pressure. We used long-term datasets to investigate whether the return of wolves has affected moose distribution (i.e., presence and abundance) as well as browsing damage (i.e., presence and intensity) by moose on Scots pine (Pinus sylvestris). We found that the probability of moose presence and abundance increased with time since wolf territory establishment and was higher inside wolf territories than outside. Additionally, the probability of browsing damage was also higher inside wolf territories compared to outside, but wolf occurrence had no effect on browsing damage intensity. We suggest two possible underlying mechanisms behind these results: (1) wolves might select to establish territories in areas with higher moose abundance, increasing their probability of encounters, and/or (2) hunters within wolf territories reduce the number of harvested moose to compensate for wolf predation. This study highlights that the return of large predators to landscapes with strong anthropogenic influence may result in alternative effects than those described in studies on trophic cascades located in protected areas.

中文翻译：

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狼在人为景观中的生态效应：营养级联的潜力取决于环境

近年来，大型掠食者在欧洲大部分地区卷土重来。然而，人们对重新定殖捕食者可能对具有高度人为影响的生态系统产生的影响知之甚少。在斯堪的纳维亚，狼 (Canis lupus) 现在栖息在受森林密集影响的地区，它们的主要猎物驼鹿 (Alces alces) 承受着巨大的人类狩猎压力。我们使用长期数据集来调查狼的回归是否影响了驼鹿的分布（即存在和数量）以及驼鹿对苏格兰松（Pinus sylvestris）的破坏（即存在和强度）。我们发现，自狼领地建立以来，驼鹿存在和数量的可能性随着时间的推移而增加，并且在狼领地内比在狼领地外更高。此外，狼领地内的浏览伤害概率也比外高，但狼的出现对浏览伤害强度没有影响。我们提出了这些结果背后的两种可能的潜在机制：（1）狼可能会选择在驼鹿丰度较高的地区建立领地，从而增加遭遇的可能性，和/或（2）狼领地内的猎人减少收获的驼鹿数量以补偿为狼捕食。这项研究强调，大型捕食者返回具有强烈人为影响的景观可能会导致替代影响，而不是在保护区内的营养级联研究中描述的影响。我们提出了这些结果背后的两种可能的潜在机制：（1）狼可能会选择在驼鹿丰度较高的地区建立领地，从而增加遭遇的可能性，和/或（2）狼领地内的猎人减少收获的驼鹿数量以补偿为狼捕食。这项研究强调，大型捕食者返回具有强烈人为影响的景观可能会导致替代影响，而不是在保护区内的营养级联研究中描述的影响。我们提出了这些结果背后的两种可能的潜在机制：（1）狼可能会选择在驼鹿丰度较高的地区建立领地，从而增加遭遇的可能性，和/或（2）狼领地内的猎人减少收获的驼鹿数量以补偿为狼捕食。这项研究强调，大型捕食者返回具有强烈人为影响的景观可能会导致替代影响，而不是在保护区内的营养级联研究中描述的影响。