Beaver Damming Alleviates Water Woes - and Combats Global Warming; a New DVD Shows How.
Beaver activity can alleviate serious water problems - and even help combat the climate crisis, according to a talk by Beavers: Wetlands & Wildlife (BWW) biologist Sharon Brown at a recent environmental conference in China.
"Freshwater wetlands have been rated as the world's most beneficial land-based ecosystem," explained biologist Brown, "because they cleanse the water, host rich biodiversity and moderate the flow of streams, which in turn decreases droughts and erosion upstream as well as costly flood damage downstream. Beavers build leaky dams that enhance these functions. For example, up to 90 percent of the silt in a stream can be removed by a beaver dam."
More recently, scientists around the world have recognized that wetlands play a significant role in climate regulation because their lush plant life takes up carbon dioxide, a major greenhouse gas. "Since beavers work for free," Brown said, "promoting and protecting beaver wetlands can be a cost-effective way to alleviate global warming and other serious environmental problems, such as the quantity and quality of available water."
Beavers are native to North America, Europe and Asia, including China, where they are considered "vulnerable" with only an estimated 800 animals surviving in the far West. Beaver populations worldwide were hunted to near extinction in the past, because of the value of their fur. Today sixteen countries are actively working to restore healthy beaver populations due to growing awareness that this species' greatest value is not its lustrous pelt, but instead, its ability to restore vital wetlands.
"For decades beavers have been relocated to arid states in the U.S. West to restore wetlands, raise water tables and create fish habitat," Brown said. Because there are many dry areas in China too, she suggested studying that country's beaver population to see whether relocation of beaver pairs to huge areas reforested with hybrid poplar might be feasible to improve the local water quality and quantity. Beaver cutting of poplar is called sustainable harvesting as it stimulates new growth from the trees' roots.
