Here's why:
* Ecosystem Engineers: Beavers are incredibly skilled at modifying their environment. They build dams, which create ponds and wetlands, significantly altering the landscape.
* Habitat Creation: The dams and wetlands created by beavers provide habitat for a wide variety of other species, including fish, amphibians, birds, and mammals. They also create a rich biodiversity by increasing the heterogeneity of the environment.
* Water Regulation: Beaver dams can help regulate water flow, reduce erosion, and improve water quality.
* Nutrient Cycling: The wetlands created by beavers act as natural filters, trapping nutrients and sediment, which can improve the overall health of the ecosystem.
Therefore, beavers are considered foundation species because they have a large and often disproportionate impact on the structure and function of their ecosystems.