Department of Forest Biodiversity, Faculty of Forestry, University of Agriculture, al. 29 Listopada 46, 31-425 Kraków, Poland.
Institute of Biology, University of Bialystok, ul. Ciołkowskiego 1J, 15-245 Białystok, Poland.
Sci Total Environ. 2022 Jul 20;831:154919. doi: 10.1016/j.scitotenv.2022.154919. Epub 2022 Mar 29.
There is increasing awareness of the ecosystem engineering services provided by recovering populations of Eurasian beaver. By modifying aquatic environments, this species has a significant, positive influence on biodiversity. Beaver activity affects not only aquatic ecosystems but also terrestrial habitats and organisms. Our study compares and evaluates the species richness and activity of terrestrial mammals in winter at beaver ponds (N = 65) and randomly-selected reference sites along nearby watercourses unmodified by beavers (N = 65) in Poland (central Europe). Mammal assemblages were investigated near pond/watercourse edges, and also at some distance from them. The species richness of mammal and numbers of their tracks were respectively 25% and 33% greater on the beaver than on the reference sites. The higher species richness on beaver sites extended to areas 40-60 m distant from ponds, devoid any signs of beaver activity. Twenty-three mammal species were recorded on beaver sites (mean species richness 3.8 ± 1.6 SD), and 20 on reference ones (3.0 ± 1.5 SD). The numbers of tracks of grey wolf, least weasel and European polecat were higher on beaver than reference sites. Mammal species richness and activity were related to the existence of beaver ponds, but were also correlated with the numbers of snags and coverage of grass, bramble and coniferous saplings in neighbouring terrestrial habitats. Large and small carnivores occurred more frequently and were more active on beaver sites. The frequencies of occurrence of mesocarnivores, mesoherbivores and small herbivores were correlated with habitat characteristics, regardless of whether beavers were present or not. Our results highlight the fact that both pond creation and the habitat changes resulting from the presence of beavers rearrange the occurrence and activity of the terrestrial mammal assemblage.
人们越来越意识到，欧亚河狸种群的恢复为生态系统提供了工程服务。通过改变水生环境，该物种对生物多样性产生了重大而积极的影响。河狸的活动不仅影响水生生态系统，还影响陆地栖息地和生物。我们的研究比较和评估了波兰（中欧）冬季河狸池塘（N = 65）和附近未经河狸改造的水道旁随机选择的参考点（N = 65）的陆地哺乳动物的物种丰富度和活动。在池塘/水道边缘及其一定距离处调查了哺乳动物群落。在河狸栖息地，哺乳动物的物种丰富度和其足迹数量分别比参考点高 25%和 33%。河狸栖息地的较高物种丰富度扩展到距离池塘 40-60 米的无任何河狸活动迹象的区域。在河狸栖息地记录到 23 种哺乳动物（平均物种丰富度 3.8 ± 1.6 SD），而在参考点记录到 20 种（3.0 ± 1.5 SD）。灰狼、伶鼬和欧洲水貂的足迹数量在河狸栖息地比参考点多。哺乳动物的物种丰富度和活动与河狸池塘的存在有关，但也与相邻陆地栖息地的枯树数量、草、荆棘和针叶树苗的覆盖率有关。大型和小型食肉动物在河狸栖息地更频繁地出现且更活跃。无论是否存在河狸，中型食肉动物、中型食草动物和小型食草动物的出现频率都与栖息地特征相关。我们的研究结果强调了这样一个事实，即池塘的形成以及河狸存在导致的栖息地变化重新安排了陆地哺乳动物群落的出现和活动。
