“Nature Does Work, If You Let It”
March 10, 2025
Dr. Emily Fairfax understands if you don’t think much about beavers.
But listening to her opine about their conservation credentials might have you questioning everything you think you know about the impact a single species can have on the health of our wetlands, and climate as a whole.
The University of Minnesota assistant professor and former Walton Family Foundation fellow has spent a career researching the ecohydrology of riparian areas, particularly those that have been impacted by beaver damming.
Before she came to this work, “I thought beavers were just this weak animal that didn’t do anything particularly impressive,” she jokes. Now? “I would describe beavers as the most selfish, stubborn and hard-working architect and engineer you’ve ever met.”
Far from “dinky little structures,” Emily says she has seen beaver dams in northern Minnesota that are six-feet tall and 300-feet long. “They literally hold back lakes.”
At one time in North America, around 400 million beavers fastidiously shaped the continent’s geography via these mega-structures, gnawing and stacking their way to evolutionary security. The wetlands that beaver ponds and dams created at one time covered more than 300,000 square miles, saturating – and thereby fire-proofing – a landmass the size of Texas.
The idea that beaver-created wetlands can protect against wildfires and drought has rebounded in popularity as the planet faces the growing reality of climate change-related natural disasters. The Walton Family Foundation’s Environment Program supports building resilient wetlands through nature-based solutions.
Land managers typically focus on cutting firebreaks, tree thinning or prescribed burning as a way to make forested landscapes resilient to wildfire. However, Emily’s research shows that beaver-created wetlands can also be an effective tool to increase wildfire resilience with natural firebreaks.
These wetlands offer humans a blueprint of how to successfully adapt to climate change, Emily says.
“The working theory in the field is that beavers basically learned all of their engineering during periods of extreme climate change. Beavers aren’t a super mobile species, but as the climate was shifting, they knew how to cut trees. If they could make a pond they could stay put,” rather than migrate or die at the whims of the climate.
Through her own research, Emily is proving out this theory. In one paper, Emily and a team looked at 10,000 years of beaver occupancy in Grand Teton National Park. Using ancient sedimentary DNA, they found that beavers were able to persist through periods of drought in the American West that lasted up to 200 years.
But this toughness was tested as non-Indigenous people flooded the continent. The beaver population plummeted. The threats came first from trappers and hunters meeting European demand for their fur. In later years, they were targeted by farmers and ranchers who viewed beaver activity as a nuisance.
The irony, says Emily, is that “we nearly pushed them to extinction, and now as their population rebounds, we’re facing our own challenges that they have the potential to support us on. It turns out nature does work if you let it.”
Today, Emily’s research focuses on how we can use beavers to repair and grow wetlands, and where beaver activity isn’t possible, mimic their structures to mitigate natural disasters.
With beavers, “We can radically transform a landscape, and you don’t need a lot of them to do it.” Emily says it takes just one family of beavers to maintain a very large area of engineered wetland habitat.
Beaver wetlands have a strong connection to our water supply, especially in the West. Water starts as mountain snow and flows down high mountain streams.
Beaver wetlands slow down the water and cleans it before it progresses down the stream. This preserves natural stream flow and makes our rivers – and water supply – cleaner.
For wildfire prevention, beaver activity thins forests and brush. Because beavers prefer to swim rather than walk, they also dig canals, which Emily likens to “little water highways for beaver families.”
The resulting transit operations have a secondary benefit, acting like drip irrigation lines across a floodplain, protecting not only the beavers but everything that lives within its territory.
Emily says it’s a well-documented phenomenon. “You can read trapper journals, you can read homesteader journals, you can read Indigenous oral histories that have been written down, and for hundreds and hundreds of years people have been saying that the fire didn’t burn the beaver wetland.”
The best part, says Emily, is that beavers are so self-driven to build, that they require nearly zero encouragement beyond dropping them into a landscape.
“We get the water purification, we get the drought resistance, the fire and flood mitigation. The wetlands they create drive better biodiversity and carbon sequestration. The redundancy of ecosystem services that they provide is incredible.”
Where beaver activity isn’t possible Emily says human-engineered “beaver dam analogs” have the potential to support wetland creation and fire mitigation. “Beaver dam analogs have shown to be pretty effective for ponding. But if you asked a beaver how good we are at building beaver infrastructure, you’d get laughed out of the room. When a beaver sees a human structure, they usually take it over, something they would never do to an active beaver dam due to their territorial nature. They do this only because they see our structures as inferior, broken or abandoned.”
Emily cautions that there is a maintenance component to beaver dams that humans will likely never be able to replicate.
“They are out there packing mud onto that thing every day. They’re keeping it watertight, they’re adjusting it, they’re changing the height, they’re changing the dimensions, they’re routing water around with new canals. We just don’t have the money or interest in having someone dedicated to maintaining a two-kilometer stretch of stream 365 days a year.”
She also understands the ongoing resistance to beavers, which can flood croplands and put financial strain on farmers if there are no grant programs to offset losses. As wetland and river banking credits improve, and climate impacts grow, Emily believes farmers, ranchers and timber producers will begin to understand the benefit of having a natural irrigator on their properties.
She is also optimistic at the growing interest in beavers and other animals as nature-based climate tools. “Every time I talk to people, they want to engage in the conversation, even if it’s to argue with me. People care, even if it’s not in alignment with what I’m hoping.”
And while beavers are the big dramatic engineer, there are other ecosystem engineers that beaver interest has the potential to draw attention towards. “They’re opening the door to people thinking a lot more broadly about nature-based solutions and nature as an ally in climate change. Prairie dogs, buffalo, insects, sea otters…all of these things are shaping the physical environment.”
Using our “human brains and human tools,” Emily says the goal now is to increase the pace and scale of beaver dam analogs, while also encouraging the beavers to come back on their own.
“We are at maybe 10% of the historic [beaver] population. We’re never going to get to 100%. The land is very different now. And beavers take a long time to reproduce. But we also don’t have that much time to figure out how to restore riverscapes, especially in places that are really stressed by drought and climate change like the Colorado River Basin.”
Through beavers, Emily believes we have the opportunity to learn more about ourselves.
“Beavers want a lot of water, and they want it spread out. It’s what keeps them safe. It’s what grows their food. If their dam breaks, they’ll fix it. If they need more water or space for their family, they will build another dam. The only other species that makes and maintains wetlands are humans.” But in this regard, humans are still learning. “At the end of the day,” she says, “nothing beavers like a beaver.”
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