Beaver canals and their environmental effects are much less studied than beaver dams, despite being widespread in some beaver-inhabited areas. In this study, we completed a systematic review of previous research on the structure and ecosystem effects of beaver canals to provide an increasingly holistic understanding of these landscape features. Specifically, we: 1) summarized why, where, when, and how beaver develop canals; 2) chronicled all published descriptions on beaver canal morphology; and 3) summarized the literature on the environmental effects of beaver canals. Thirty-one relevant studies were identified and incorporated into this review. Beaver canals have been identified in numerous environments ranging from largely undeveloped mountainous regions to heavily developed agricultural landscapes. Beaver primarily develop canals to increase accessibility to riparian resources, facilitate transport of harvested resources, and to decrease predation risk. As with beaver dams, beaver canals exhibit large structural variability, particularly in lengths, which can be over 0.5 km. Widths of about 1 m and depths of about 0.5 m are common. Beaver canals alter watershed hydrology by creating new aquatic habitats, connecting isolated aquatic features, and diverting water into colonized areas. Beaver canals have been identified as favored habitats for several biotic species and are sometimes used during critical life stages (e.g. dispersal). In addition to increasing overall floral and faunal species richness and diversity, beaver canals may benefit biota by mitigating habitat fragmentation and climate change impacts. Based on the results of this review, incorporating beaver canals into stream restoration practices may be environmentally beneficial.

中文翻译：

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海狸运河及其环境影响

海狸运河及其环境影响的研究比海狸水坝要少得多，尽管在一些海狸栖息地广泛存在。在这项研究中，我们完成了对先前关于海狸运河结构和生态系统影响的研究的系统回顾，以提供对这些景观特征的日益全面的理解。具体来说，我们： 1）总结了海狸开发运河的原因、地点、时间和方式；2) 记录了所有已发表的关于海狸管形态的描述；3) 总结了有关海狸运河环境影响的文献。确定了 31 项相关研究并将其纳入本综述。海狸运河已在许多环境中被发现，从大部分未开发的山区到高度发达的农业景观。Beaver 主要开发运河以增加对河岸资源的可达性，促进收获资源的运输，并降低捕食风险。与海狸水坝一样，海狸运河表现出很大的结构可变性，特别是在长度方面，可能超过 0.5 公里。大约 1 m 的宽度和大约 0.5 m 的深度是常见的。海狸运河通过创造新的水生栖息地、连接孤立的水生特征以及将水分流到殖民区域来改变流域水文。海狸运河已被确定为几种生物物种的有利栖息地，有时在关键的生命阶段（例如传播）使用。除了增加整体花卉和动物物种的丰富度和多样性外，海狸运河还可以通过减轻栖息地破碎化和气候变化影响来使生物群受益。