Beaver play a crucial role as a ‘keystone’ species, restoring wetland eco-systems and producing a network of enriched riparian habitats.
Ponds created from damming provide beaver with a food source as well as protection from predators. They promote growth of aquatic vegetation and create a favoured habitat for invertebrates which in turn encourages greater amphibian and mammal life – including otter, water vole, frog, newt and dragonfly.
The coppicing of trees and other vegetation reduces canopy cover and creates further habitat diversity as well as providing a supply of dead wood. Increased light levels encourage growth of under-storey plants and aquatic flora as well as a growing abundance of invertebrates – with further benefits to a wide range of species including birds such as duck, heron, woodpecker and kingfisher.
Fish numbers increase as a result of changes in water chemistry and increased food availability.
Flooding from dams can cause tree deaths, although this is nearly always over a relatively limited area and itself contributes to an enriched eco-system.