Combatting Climate Change in the Arid West One Dam at a Time

Updated: Dec 17, 2021

By Zaylah Pearson-Good


There is profound power in two orange, iron incisors that never stop growing. Beaver teeth are as strong as steel, allowing them to chop down entire trees, haul around piles of debris, and build durable dams capable of completely transforming an environment. Beavers are known as ecosystem engineers and keystone species because of the numerous and beneficial services they offer to enhance ecology, hydrology, and biodiversity in a region.


Additionally, contemporary data is now suggesting that beavers play a critical role in combating drought, wildfires, wetland degradation, and other symptoms of climate change.


In the 2021 Colorado Beaver Summit, ecohydrologist Dr. Emily Fairfax explained just how effective beavers are at protecting our landscapes against drought and wildfires. Dam building is a beaver’s first task when settling a habitat and is key to nourishing the surrounding area. Their dams slow the movement of water, allowing it to saturate the region’s soils and even seep down into the earth and recharge groundwater. Dam building both creates a moister habitat for neighboring wildlife and vegetation and it also slows evaporation rates, transforming a narrow creek bed into a thriving wetland ecosystem.


Furthermore, beavers don’t just build dams; they also dig canals that connect surface water to the surrounding soils. Dr. Fairfax shares that this behavior is a survival mechanism, since beavers are quite awkward on land and prefer to travel by water as much as possible. Therefore, beavers dig trenches around their habitat that fill with water and allow them to swim from place to place. The unintended consequence of such behavior is that neighboring soil and vegetation are fed fresh water, as if hydrated by a drip irrigation system. A wetter, more diverse environment that extends beyond a beaver’s dam, results.


Beavers Manage Drought


In Colorado alone we are experiencing droughts that are degrading, narrowing, disturbing, and shortening the flow of many of our waterways. By helping to slow evaporation rates, recharge groundwater, and saturate the surrounding landscape, beavers could play an imperative role in protecting critical habitats from seasonal and prolonged drought. For example, in a four-year study, Dr. Fairfax’s team concluded that beaver ponds in Nevada kept riparian areas lush and green for both seasonal and prolonged 3-year drought cycles. In contrast, beaverless riparian areas on the same creek bed wilted, browned, and suffered from the extended dry periods.


Beavers as Firefighters

Without addressing drought, we cannot adequately combat the ever-increasing intensity of wildfires, since parched vegetation is perfect fire fuel. By keeping the landscape hydrated, beavers act as strong firefighters. Dr. Fairfax’s research shows that riparian areas dammed by beavers are 3 times less impacted by wildfires than areas without beavers. When a fire reaches a moist environment, it slows, smolders, and reroutes, leaving unburned, healthy habitat known as refugia. Pockets of refugia are imperative to the survival of beavers, riparian habitats, and local wildlife that seek shelter in these oases during a wildfire.


Having studied different wildfires across the Western states, Dr. Fairfax also researched how effective beavers are at creating refugia during megafires.Megafires are extreme, fast-growing fires that burn 100,000 acres or more of land at a time. These destructive events have become more frequent in the past few decades as drought conditions worsen. For this reason, Dr. Fairfax examined some of Colorado’s largest wildfires on record: The Cameron Peak Fire (2020) and East Troublesome Fire (2020). Both of these megafires devastated large swaths of Colorado, with Cameron Peak burning 208,913 acres and the East Troublesome burning 193,812 acres.


Through remote sensing and rigorous data collection/analysis, Dr. Fairfax concluded that despite the magnitude of these fires, beavers not only survived, but also protected a considerable portion of the riparian area surrounding their dams. During the Cameron Peak Fire, beaver complexes created refugia for around 270 acres, which is equal to 2.7 acres of sheltered land per every one beaver dam. On the skirts of these beaver complexes, pine trees were untouched by the fire, vegetation was still lush, and beavers continued to thrive. This oasis stood in sharp contrast to the barren, ash-filled landscape that surrounded the refugia after the Cameron Peak Fire. Dr. Fairfax remembers how clearly you could observe the transition in the landscape from high-burn severity to the untouched refugia.


Beavers created around 1,500 acres of refugia during the East Troublesome Fire, which means that for every one beaver dam, nearly 3 acres of land was protected. While Dr. Fairfax feels that more research is needed, her studies continue to support the theory that beavers have the power to protect vulnerable landscapes in the arid west from drought and wildfire, as well as protect some of the neighboring species that shelter in the refugia during fire events.


Beavers Restore Wetlands and Biodiversity

Since beavers redirect waterways, irrigate soil, improve groundwater health, and reduce evaporation rates, their presence often leads to the creation or maintenance of vibrant wetland habitats. Wetland hydrologistSarah Marshall, another speaker at the Beaver Summit, reminds us that wetlands are instrumental in water filtration and carbon storage. Furthermore, nearly 80% of Colorado wildlife utilize wetland and riparian areas, so these essential habitats also promote biodiversity. Unfortunately, since European settlement, roughly half of Colorado’s wetlands have been lost. Furthermore, beaver populations have greatly suffered after the species was nearly hunted to extinction in the 1900s. Current population estimates suggest that there are around 9-12 million beavers left in North America, in contrast to 60-400 million before European settlement.


Marshall urges that given how important wetland and riparian habitats are, supporting beaver reintroduction, settlement, and protection in their historic range could be one of our best tools to address climate change in the West. She claims that it can cost up to one million dollars to restore just one mile of a mountain stream. This staggering numbers stands next to the need for nearly 30,000 miles of stream in Colorado to be restored. Given the massive long-term ecological and economical benefits to having beavers on a landscape, scientists across the country are calling for increased reintroduction, management, and protection of this keystone species. If we let them, beavers could be one of our most valuable assets as the climate crisis races ahead.


Information sourced from the 2021 Colorado Beaver Summit seminar. To learn more about the speakers and the event, visit https://coloradobeaversummit.org

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