Photo credit: dailyinvention/Creative Commons
When engineers are called in to restore degraded streams and rivers, the focus is typically on reestablishing flow. This requires the dismantling of old damns, dredging, and the rebuilding of valley bottoms.
These human engineers, a new study suggests, would be better off taking advice from natures' own landscape-altering builders: beavers. The pools and ponds created by beaver dams, it turns out, are essential sources of biodiversity and centers of river health.Melinda Daniels, an associate professor of geography at Kansas State University, explained:
A lot of rivers are in trouble and need work and restoration, but it's amazing how little we know about the systems we're trying to fix...we know they're broken, but we don't exactly know what they should look like because we know so little about how many of our river systems function.
Her research suggests that leaving dams—even man-made dams—in place or partially in place, allows the critical ecosystems they have allowed to develop continue to flourish. Such ponds would simulate the natural effect of beaver dams in areas that do not benefit from them.
Engineers "can use these natural analogs to produce an ecosystem that looks a lot more like the one that was there before the colonists arrived," Daniels said, add that "we can restore rivers in a way that mimics the naturally diverse beaver streams, and we can save a lot of money in the process."
Though a bit counter-intuitive, it's a lesson from nature that seems to benefit everyone.