Tuesday, August 5, 2008: 2:10 PM
102 E, Midwest Airlines Center
Joseph Bump1, Rolf O. Peterson2, John A. Vucetich2 and Douglas Smith3, (1)School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, (2)School of Forest Resources & Environmental Science, Michigan Technological University, Houghton, MI, (3)Wolf Project, Yellowstone Center for Resources, Yellowstone National Park, WY
Background/Question/Methods Some studies support a positive correlation between the presence of large, terrestrial carnivores and the maintenance of biodiversity, but mechanistic links between top terrestrial predators and biodiversity remain poorly understood. In terrestrial communities biodiversity is strongly related to soil resource heterogeneity. Here we demonstrate that large carnivores configure landscape heterogeneity through prey carcass distribution. A 50-year record comprised of >3600 moose carcasses from Isle Royale National Park, USA, showed that wolves modulate heterogeneity in soil nutrients, soil microbes, and plant quality by clustering prey carcasses over space. We also analyzed soils and grasses at wolf-killed elk sites in
Yellowstone National Park and found parallel results.Results/Conclusions
Despite being well-utilized by predators, moose carcasses resulted in elevated soil macronutrients and microbial biomass, shifts in soil microbial composition, and elevated leaf nitrogen for at least 2-3 years at kill sites. For wolf-killed prey in Yellowstone National Park, USA, elk carcasses resulted in elevated soil macronutrients and leaf nitrogen for at least 3-4 years at kill sites. Wolf-killed moose were deposited in some regions of Isle Royale at up to 12× the rate of deposition in other regions. Carcass density also varied temporally, changing as much as 19-fold in some locations during the 50-year study period. This variation arises from spatiotemporal variation in wolf behavior and forest composition. This study identifies a top terrestrial predator as a mechanism generating landscape heterogeneity, demonstrating reciprocal links between large carnivore behavior, ecosystem function, and biodiversity.