Devastating Avalanches Can Be Boon for Wildlife

Heaven's Peak, Glacier National Park (courtesy NPS)

Given all the snow that’s fallen around the country this winter (here in NYC we've got our second snow day today!), it seems appropriate to revisit this fascinating story by Tom Yulsman:

Even by snowy Colorado's standards, the blizzard that blanketed the state's Front Range between March 17 and 20 of 2003 was extraordinary. With a hurricane-like eye 100 miles across, the storm dumped an astounding seven feet of snow in places—not counting the drifts. And on the slopes of Pendleton Mountain west of Denver, that was just too much.

At 2 a.m. on March 23, a slab of wet snow at 12,000 feet released its tenuous grip on the peak and began to slide. The resulting avalanche scoured up all of the season's snow from the slope and swelled quickly to a width of 900 feet. As it raced downhill the white monster snatched boulders and snapped trees in half before slamming onto a frontage road along Interstate 70. When cleanup crews arrived, they found snow, rock, and splintered trees piled as high as a two-story building and covering 500 feet of the road.

Without question the avalanche, which carved a new meadow from the forest on Pendleton Mountain, was an example of nature's destructive side. But strange as it might sound, a little destruction—or “disturbance,” as ecologists call it—is not always a bad thing. What we see as devastation actually yields many ecological benefits. By redistributing water and nutrients, and opening up new wildlife habitat, avalanches boost the diversity of plant, insect, and animal species.

“Avalanches may seem like unusual or catastrophic events, but they can have a positive outcome for ecosystems,” says Steward T. A. Pickett, a plant ecologist with the Institute of Ecosystem Studies in Millbrook, New York. By sculpting meadows out of the forest, “they provide resources for plants and animals that require open habitat, and they increase the patchiness of the mountain landscape.” And as research by Pickett and other scientists has shown, a patchy landscape is often a more biologically diverse landscape.

Read the rest of the story here.