KNOWLEDGE BASE

This study looked at how beaver dams and meanders affected the interaction of stream water with sediment below the stream. The area of study - in the USA - was pretty dry, meaning that beaver wetlands are uncommon, but dams still exist. This water-sediment interaction is important for trapping nutrients and pollutants, especially in areas damaged by livestock. The researchers found that beaver dams and meanders enhance this interaction. However, in some reaches of the stream, the trapping of sediment was longer-term than in others. Please note, this resource is not open access.

This study investigated how stream depth and width affect beavers' dam-building behaviour. In Sweden, researchers measured 39 beaver lodges without dams and 74 dam sites. Lodge sites tended to be deeper and wider than dam sites. A number of possible explanations are given but more research is needed to understand why beavers choose to build or not build a dam in a given spot.

In 1946, beavers were introduced to Tierra del Fuego in Argentina. Their population has rapidly expanded, negatively affecting local forests - particularly species of Southern beech. Between 1999 and 2001, these scientists studied beaver density in Chile, to where they had spread. The beaver population in Chile alone is now estimated at 61,300 individuals, increasing and expanding at a rate of 2.6–6.3 km/year.

This study examines how different plants grow along a river in Colorado, USA, focusing on how often they get flooded. They found that certain plants, like sandbar willows, prefer areas that flood more often, while others, like river birches, like less frequent flooding. Beavers play a role in shaping these areas, disrupting the riverbank habitats to help maintain plant life.

The study looked at genetic variation in Eurasian beavers in eastern Europe and Asia, focusing on small, isolated populations. The results show limited genetic variation despite big geographical distances. The subspecies with the most different genes is likely that way because it has been isolated for the longest time. Overall, the data suggests that the present beaver populations in eastern Europe and Asia have a single shared ancestor from around the end of the last ice age.