Evaluating Aspen Responses to Changes in Elk Abundance, Distribution and Behavior Following Wolf Reestablishment in West-Central Yellowstone National Park

摘要: The reintroduction of wolves to Yellowstone National Park created a unique “natural experiment” study trophic interactions in large-scale terrestrial system among wolves, elk, and aspen. This utilized data from long-term elk demography that was established prior wolf reintroduction. Significant changes the abundance distribution Madison headwaters herd were observed following reestablishment. spatial arrangement these made it possible directly test for occurrence density-mediated cascade. objectives this answer questions: 1) there marked decrease browsing pressure on aspen where densities declined, 2) corresponding plant-growth response indicating released pressure? Historical conditions height 31 stands assess cascade Browse morphology declined dramatically compared experienced persistent heavy throughout period. A major decline along with modest increase leader longevity detected, supporting hypothesis However, magnitude growth weak, suggesting not dominant limiting factor area may be more strongly limited by bottom-up regulation.