EMULATE
SPRING 2019
Leave it to Beaver? In the face of climate change and increasing associated water scarcity, one promising restoration and resilience focus has emerged: beaver. Pre-colonial North American populations of Castor canadensis are estimated in a range up to 400 million individuals but were decimated to a mere estimated 100,000 individuals by the end of the beaver fashion epoch—a period from the sixteenth to the nineteenth
Beavers keep our waterways hydrated in the face of climatechange fueled drought. Their wetlands dissipate floods and slow the onslaught of wildfires. They filter pollution. They store carbon. They reverse erosion. And, whereas our infrastructure is generally inimical to life, they terraform watery cradles for creatures from salmon to sawflies to salamanders. They heal the wounds we inflict.
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centuries in which beaver hats and other garments using beaver pelt were in high fashion and extremely desirable. Thanks to the whims of fashion trends, the Castor genus—the last genus of what at one time was a 32 genera field—was saved from extinction. Two species remain within this genus: Castor canadensis, the North American beaver, and Castor fiber, the Eurasian beaver. Today, scientists estimate there are between 6 and 12 million beaver across North America and hypothesize that they have an increasingly important role to play in conservation. Researchers in the state of Washington are applying beaver conservation assumptions to plans for salmon habitat restoration. These researchers are trapping “nuisance” beaver from urban environments and repopulating them in the uplands of a number of river systems and carefully measuring the impacts they have on the relocation grounds’ functionality. What these researchers are discovering is that the presence of beaver spell good things for otherwise plunging salmon populations; one study by Dr. Michael Pollock on the Stillaguamish River Basin estimated that at some point, the river basin provided crucial habitat to some 7.1 million juvenile coho annually, but in recent years that number had plummeted to 1 million. Lack of deep pools rich with associated riparian vegetation—
