John Pastor, University of Minnesota Duluth, Duluth and Yosef Cohen, University of Minnesota, St. Paul
Moose, an important game species in northern Minnesota, can affect their habitat by eating hardwoods, thereby tending to convert the forest to conifers. The nutrient-poor needle litter of conifers depresses the fertility of the soil, which in turn can affect the recovery of the preferred hardwood species after moose populations decline. To study this problem, several grids of sampling points were established on Isle Royale National Park to monitor changes in distribution of vegetation and soil fertility during a moose population cycle. During the next five years of funding, vegetation and soil changes will be documented during the recovery phase of the moose population after a crash from 2500 animals in 1996 to 500 animals in 1998.
This work is highly cited in the scientific literature and in several biology textbooks as an example of how large mammals can affect the productivity and soil fertility of ecosystems. This project will fund a Ph.D student and give undergraduate students the benefit of research in a National Park famous as a textbook example of ecological interactions. A model of moose foraging developed in this work will also be modified as a teaching tool. Finally, data and knowledge from this project will be made available to land and wildlife managers to assist in management of a popular National Park.
