Beavers as Restoration Agents
Vibrant ecosystems evolved over millennia in response to beaver created landscape changes. In the absence of beavers these valuable ecosystems collapse. When beavers return to the landscape biodiversity flourishes and watersheds are healthier.
Following beaver extirpation due to the fur trade, many streams in western North America became badly incised due to erosion. When a streambed drops due to incision so does the water table. When the incision is severe the water table drops too low for the roots of nearby plants to reach, the native vegetation dies off, and a barren, arid landscape with a loss of biodiversity is the result. A once vibrant area becomes a desolate dust bowl due to stream incision.
Beaver dams reverse and heal incision. However, some streams are so badly incised and teh vegetation is so degraded that they are inhospitable to beavers. In these situations manmade Beaver Dam Analogs (BDA) can be used to quickly promote sediment deposition. Scientific studies of BDA’s have proven their effectiveness.
As the streambed rises due to sediment deposition, so does the groundwater. Native plants and wildlife begin to return as a stream recovers. Once the streambed has risen to the point where it is hydrologically reconnected to the floodplain and the native vegetation has returned, beavers will often relocate to the stream. They will then build their own dams which augment the restoration process, expanding wetlands that attract myriads of species.
Control Beaver Damming with Flow Devices
Occasionally beavers build dams that can cause significant property, health or safety issues for people.
When conflicts do occur the flooding threat can often be resolved with well-designed water control flow devices. Flow devices are usually the most long-term, cost-effective, humane, and environmentally friendly beaver management tool available.
See the Flow Devices section for many different examples of successful flow devices.
Tree Protection from Beaver Chewing
Beavers chop down trees with their teeth for food and building dams and lodges. In addition, like all rodents their teeth never stop growing so chewing wood helps keep them sharp and prevents them from growing too long.
Protecting trees from beaver chewing is a very common concern for homeowners. Fortunately there are ways to protect selected trees without destroying the beaver and its wetland ecosystem.. Most of the following tree protection techniques are inexpensive, reliable, and relatively easy for nearly any person to do in a short period of time.
Commercial fur trapping by European colonists gave rise to the exploration of North America, but it nearly resulted in the extinction of the beavers (Castor Canadensis). In the 20th century as beavers began to return to their historic North American range, beaver-human conflicts sometimes arose and beaver trapping was typically used to resolve these conflicts. However, beaver trapping is usually a short term solution to beaver problems because new beavers will be attracted by the habitat and recolonize the trapped area.