Beavers May Help Mitigate Climate Change Effects
A Canadian National Park's Wetlands were Healthier During Drought
Oct 16, 2009
The ever-changing status of the beaver (Castor canadensis) in the eyes of humans may be taking yet another turn. Initially a financial boon to fur traders, more recently the beavers’ dam building skills have resulted in them being considered a pest species as they cut down trees and flood fields.
Climate Change May Cause Drought But Beavers May Reduce Its Impact
But it is predicted that climate change will result in more frequent and longer lasting droughts, particularly in North America. And here the beaver may play an important role in ensuring a steady supply of open water.
A study by Glynnis Hood and Suzanne Bayley from the University of Alberta, showed that where beavers were present there was 60 percent more open water available during drought seasons than when the beavers were absent. If, as the climate change models predict, droughts will be on the increase, the availability of that much more water may be the key to some species survival.
Importance of Beavers in Wildlife Habitat Restoration
Several studies have come out suggesting that the beaver’s water management skills may aid other wildlife species, including songbirds whose populations are declining worldwide. As the importance of wetlands in maintaining balanced ecosystems is increasingly being recognized, the role of the beaver in creating and maintaining wetlands is just beginning to be appreciated.
The Elk Island National Park Study of Beavers and Drought
It has been shown that when beavers are present, degraded streams improve and water tables are recharged. Plants and wildlife have a steady source of water. But it wasn’t until Hood and Bayley reviewed the history of beaver presence in Elk Island National Park in Alberta that the scope of their impact on the ecosystem was recognized.
The scientists were able to show that even when drought conditions were extreme, beavers were able to reduce wetland loss. In 2002, drought hit Elk Island National Park. The beavers went to work digging channels to connect areas of open water, building dams to block seepage and deepening ponds.
To ensure that what they were observing was the result of the presence of beavers, Hood and Bayley looked closely at areas where beaver presence had varied over the 54 years being reviewed. By comparing conditions during drought years in the same areas with and without the presence of beavers they were able to prove that it was the beavers who were managing the environment to increase open water during drought conditions.
The study has resulted in a push for protection of existing beaver populations and for reintroduction of the species into areas where they have been trapped out. And the return of beavers to areas where they previously existed is now being welcomed. It is hoped that beavers will be in place to help mitigate the expected impact of climate change in North America.
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