The Eurasian beaver (Castor fiber) has a greater impact on local ecosystems than other herbivores, and the affected area exceeds the range of its presence. Its activity may change or create new habitats by modifying the availability of the biotic and abiotic resources available not only to beavers, but also to other groups of animals. Our aim was to study how beaver activity affects the benthos composition in a small river and in a beaver pond. The way in which beavers function in the case of small rivers has received little attention. The study showed a lower density of benthos above the dam (beaver pond - 1467 ind./m2) compared to the river (3147 ind./m2). Below the dam, the diversity of Trichoptera and Coleoptera was greater, while Diptera were more abundant in the beaver pond. Betidae were a constant component in the benthos assemblages and were most abundant in the beaver pond. Collectors-gatherers and predators were the most numerous in the beaver pond. Decreasing percentages of collectors-gatherers were observed with an increased abundance of collectors-filterers and shredders in the river. All of the ratio values except the P/T FFG (Predators to total of all other groups) were lower in the beaver pond compared to the river. The % EPT (Ephemeroptera Plecoptera and Trichoptera) was also greater in the beaver pond. Small differences in the physicochemical properties of the water and organic matter content in the bottom sediments were found both above and below the beaver dam.

中文翻译：

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海狸的活动是影响小河底栖生物的生态因素-以-ylica河（波兰）为例。

欧亚海狸（蓖麻纤维）比其他草食动物对当地生态系统的影响更大，受影响区域超过其存在范围。通过改变不仅可用于海狸，而且可用于其他动物的生物和非生物资源，其活动可能会改变或创造新的栖息地。我们的目的是研究海狸的活动如何影响小河和海狸池塘中的底栖动物组成。在小河的情况下，海狸发挥作用的方式很少受到关注。研究表明，与河流（3147英亩/ m2）相比，大坝（河狸塘-1467 ind./m2）上方的底栖动物密度较低。在水坝以下，海狸池塘中的翅翅目和鞘翅目的多样性更大，而双翅目更丰富。et科动物是底栖动物组合中的恒定成分，在海狸池塘中含量最高。在海狸池塘中收集者和捕食者数量最多。在河中，随着收集器，过滤器和切碎机的增加，观察到收集器-收集器的百分比下降。与河水相比，海狸池塘中除P / T FFG（捕食者占所有其他种群的总和）以外的所有比率值均较低。海狸池塘中的EPT百分比（phe翅目和鞘翅目）也更大。在海狸坝的上方和下方，发现底部沉积物中水和有机物的物理化学性质存在细微差异。在河中，随着收集器，过滤器和切碎机的增加，观察到收集器-收集器的百分比下降。与河水相比，海狸池塘中除P / T FFG（捕食者占所有其他种群的总和）以外的所有比率值均较低。海狸池塘中的EPT百分比（phe翅目和鞘翅目）也更大。在海狸坝的上方和下方，发现底部沉积物中水和有机物的物理化学性质存在细微差异。在河中，随着收集器，过滤器和切碎机的增加，观察到收集器-收集器的百分比下降。与河水相比，海狸池塘中除P / T FFG（捕食者占所有其他种群的总和）以外的所有比率值均较低。海狸池塘中的EPT百分比（phe翅目和鞘翅目）也更大。在海狸坝的上方和下方，发现底部沉积物中水和有机物的物理化学性质存在细微差异。海狸池塘中的EPT百分比（E翅目和鳞翅目）也更大。在海狸坝的上方和下方，发现底部沉积物中水和有机物的物理化学性质存在细微差异。海狸池塘中的EPT百分比（phe翅目和鞘翅目）也更大。在海狸坝的上方和下方，发现底部沉积物中水和有机物的物理化学性质存在细微差异。