KNOWLEDGE BASE

After being reintroduced to Romania, beaver populations have grown steadily, leading to conflicts with humans and human infrastructure. Here, underground metal nets were installed to protect drainage dikes whilst allowing beavers to live naturally. This text reports on this process and concludes that, although costly, this solution ensures long-term protection of the drainage dikes and mitigates the conflict.

Studies estimating greenhouse gas emissions from beaver dams had mainly focussed on North America. This study examined the impact of Eurasian beavers in Russia's Ob River watershed. The results showed significant methane emissions as well as enhanced carbon sequestration, aiding in short-term carbon removal. Please note, this resource is not open-access.

Beavers are famous for building dams, but often they live in a river without building a dam! This study looked at what factors influence where they build dams and how those dams affect water levels. They found river depth - particularly its lowest point during summer - was a strong influence on whether dams were built. Dams raised water levels upstream, often upwards of 40 cm. This information can be helpful for landscape planning in areas where flooding could cause conflict with, for example, agriculture.

This study examined how beaver dams affect the movement of Arctic grayling fish in the USA by monitoring the fish in real life. Fish had an 88% chance of making it past any given beaver dam, although at some specific dams the probability fell to 50%. They found that, in drier conditions, fish found it harder to get past dams. The results of this study could help inform management decisions: for example, when to breach a beaver dam to help fish get by.

The concept of "nature-based solutions" (NbS) is gaining popularity. However, it is battling with its own eurocentricity and there is confusion about its benefits for sustainability. This paper compares the varying definitions by groups like IUCN and the European Commission, and tries to create a common set of NbS principles. The paper cites the beaver trials in both England and Scotland as examples of NbS in action. Please note, this resource is not open-access.