After decades of destruction by elk, the aspen tree is staging a comeback.
By Sarah L. Stewart
Attention, fall foliage hunters: The leafy clusters now turning parts of Rocky Mountain National Park a riotous shade of yellow are more than just a treat for leaf peepers. It’s a sign of progress in the park’s three-year battle to restore a balance between its dual autumn icons: the trees (aspen and riparian willow) and the elk.
Until recently, the outlook was bleak for the 365 acres of aspen and willow that overlap RMNP’s elk meadows. The four-legged shrub browsers are notorious for stripping and munching on bark, and research indicates that for at least four decades, a highly concentrated winter elk population—less migratory than most—has prevented virtually every new aspen sucker (root offshoots from the parent tree) in Moraine Park, Horseshoe Park, and Beaver Meadows from reaching maturity. Instead of regenerating into saplings, the suckers became withered nubs, and older trees died with no young offspring to take their place.
A hopeful new chapter began in 2008, when the park service approved a 20-year management plan to lethally reduce the park’s elk herd and protect its at-risk vegetation with fences. The park has since culled 131 elk to reach its target winter population of 600 to 800 animals, and has constructed about 10 seven-foot-tall fences around 44 aspen acres on elk grazing territory. “In the exclosures, there are a lot of little aspen starting to come back,” says John Mack, the park’s branch chief of natural resources. “We’re getting much more sapling regeneration.”
Though the park staff is still monitoring the plan’s success, Mack anticipates the trees will one day revive enough to remove the fences. “It may take a few years before you see more drastic results,” he says. “[But] things are improving.”