The job of a beaver is to build a dam and lodge across creeks using tree branches, vegetation, rocks, and mud. They chew down trees for building material. Dams impound water and lodges serve as shelters. Their infrastructure raises the water table and creates wetlands used by many other species, and because of their effect on other organisms in the ecosystem, they are considered a keystone species.
This storage of water can change the vegetation type as well as the moisture content in the live and dead fuel. Wetlands usually do not burn in a wildfire and they can serve a barrier to its spread.
However, beavers can also be a nuisance and can damage crops, timber, roads, ditches, gardens, and pastures by cutting trees, burrowing, or flooding areas.
The BeaversandBrush.com website is a not-for-profit publication, “Created by Californians seeking to protect California from wildfire. We can help one another to safety by welcoming back native beavers and traditional prescribed burning of brush.”
Photos from their website show the change in a creek after beavers moved in.
An article by Lucy Sherriff at the Sierra Club’s website explores how beavers can change the landscape, including their effects on wildland fires.
[Dr. Emily] Fairfax began to carry out the scientific research that she had hoped to find. Using satellite images, she mapped vegetation around beaver territories before, after, and during wildfires (footage of wildfires in progress can show how a fire moves through a landscape). She visited field sites in California, Colorado, Idaho, Oregon, and Wyoming and found sections of creek that did not have beavers were on average more than three times as affected by fire—burning a bigger area—than areas where beavers had built dams.
“I expected some of the time beaver dams would work,” says Fairfax. Instead, she found the presence of beavers had significant effects. “It didn’t matter if it was one pond or 55 ponds in a row. If there were beaver dams, the land was protected from fire. It was incredible.”
Fairfax hopes her research will help change California’s strict rules around beaver relocation, the way policy is already changing in Washington, especially as wildfires in California have reached record-breaking levels over the past several years.
Meanwhile, Fairfax’s research on beavers and wildfires is only beginning. “I set out to ask a question: Do beavers keep the land green during fires, yes or no?” she says. “The answer was yes. But that’s not the end of the story. Why? How? Does this happen everywhere? What if you have a tight canyon? I’m digging into the specifics now, so people can implement this and actually use beavers for fire prevention. I would love to be able to call someone up and tell them how many beaver dams they need in their creek.
“Right now I have so little advice on how to do it. But at least I can now say it works.”
The two-minute video below is a brief introduction to beavers. It appears to be an excerpt from an episode of “Nature”, titled, “Leave it to Beavers.”
