JACKSON, Wyo. — Aspen trees that have been in decline on the National Elk Refuge for decades are showing some signs of bouncing back on parts of the preserve in northwest Wyoming, according to new research.
"There's some evidence that, at least on the extreme north end of the refuge, some aspen regeneration has been taking place," refuge biologist Eric Cole said.
The refuge is undertaking a study with Montana State University to quantify how many young aspens are positioned to survive and where they're located, Cole said.
"What we're most interested in is the capacity of the stand to regenerate, as measured by the number of young trees in the stand and their rate of height growth," he said.
Aspen trees, which are a food source for wintering elk and other ungulates, need to reach a height of at least 8 feet to be impervious to browsing and to ensure a shot at reaching adulthood.
Jenny Edwards, the graduate student heading the project, is assessing the makeup of 35 different tree stands spread out around the north end of the refuge.
"The measurements I take and the observations I note tell a story of browsing," Edwards said in a refuge statement. "You can learn how an area has been used by wildlife."
Southern portions of the 25,000-acre preserve weren't included in the study because heavy browsing makes quick work of young trees, Cole said.
"The aspen stands on the south end of the refuge are a lost cause," Cole said. "There's no potential for regeneration."
"Woody plant communities in general on the refuge are subject to high browsing," he said. "What we found on the extreme north end of the refuge is the exception, not the rule."
The study will help refuge managers understand why woody plants have been on the decline and to what extent aspens are recovering in the hillier, northern portions of the refuge, Cole said.
The refuge is working on a conservation plan that includes maintaining sufficient numbers of aspen trees.