KNOWLEDGE BASE

Researchers studied beaver-aspen relationships at two different sites in the USA. They learned that, over time, beavers start cutting increasingly thick trees. Aspen trees also produced a chemical compound that may deter beavers, with higher concentrations found in trees which had been co-existing with the foraging beavers for longer. These findings suggested that the beaver foraging models of the time needed updating to include plant defence mechanisms.

This paper sought to understand how energy, nutrients, and materials flow in, around, and through beaver ponds. It described how beaver ponds and the surrounding area exist in 3D space - as 'patch bodies.' The researchers then showed how both beavers (through foraging and pond-building) and the landscape (for example the steepness of the stream) impact these flows.

Beavers shape aquatic ecosystems without having to put in all the energy or nutrients themselves. They do this by building dams or simply by feeding! In Quebec, Canada, researchers explored how beavers alter streams. In this now-classic study, they found that beaver dams increase sediment retention, channel area, and carbon processing relative to fast-flowing streams. These changes suggested that beavers play a vital role in stream ecosystem function and diversity, including by stabilising stream ecosystems. The authors used these insights to understand how the widespread hunting of beavers may have affected stream ecosystems across North America.

In Quebec, Canada, beavers were shown to have changed the habitat in woodland streams - creating more still (lentic) areas and fewer free-flowing (lotic) areas. This affected the quantity and types of invertebrates living there, increasing the prevalence of predator insects, for example. There was more organic matter in the slow-moving water year-round, and more inverterbrates in spring and summer. Please note, this resource is not open-access.

This book, published only in 1986, contains a study originally conducted in 1868. Within, the author describes the beaver in incredible detail, from its anatomy to its psychology. Human-beaver interactions are also described, including information on how beavers can be trapped (although methods have, of course, evolved since the 19th century). Please note, this resource is not open-access.