Beaver Dams Helped Shape American Landscape: Study

Next time you're enjoying the natural beauty of a river valley, you can thank the local beavers for their contribution.

The far-reaching impact of beavers isn't a new discovery for scientists; the creatures' ability to redirect rivers, create wetlands and shape neighboring forests is well-understood. But a new study in the January 2012 issue of Geology has shown that beavers can be responsible for a significant amount of earth formation in some areas, meaning that generations of beaver activity can alter the very shape of valleys where beavers live.

Researchers from Colorado State University's Department of Geosciences conducted the study in Beaver Meadows, a section of Colorado's famous park, using ground penetrating radar (GPR) to search for dam-sized disturbances beneath the surface of the soil. They observed "30%-50% of the alluvium [the loose soil that settled after the area's glaciers receded thousands of years ago] is beaver-related sedimentation."

The impact of beavers in Beaver Meadows can be extended to other, similar river valleys in mountainous regions, and the range of beavers in pre-Columbian times was so large that the creatures' may have had much more to do with our country's landscape than we previously thought. Discovery News quotes Ellen Wohl, co-author of the study, who comments that "Beavers were present from the arctic tundra to the deserts of northern Mexico, so they would have been in every U.S. state but Hawaii."

These results, coupled with previous observations that beaver dams can foster fertility in surrounding soils and even protect drinking water, seem to show that we haven't appreciated the busy creatures nearly as much as they deserve. And if the growing beaver population in the Bronx is any indication, maybe they can help out in urban areas as well.