Moose browsing and soil fertility in the boreal forests of Isle Royale National Park

The effect of moose browsing on the nutrient cycles of boreal forest was studied using three 40-yr-old enclosures on Isle Royale, Michigan. By examining the mechanisms by which moose affect ecosystems, evidence was found indicating that; in the long term, high rates of moose browsing would depress N mineralization and net primary production through the indirect effects on recruitment into the tree stratum, and subsequent depression at litter N return and litter quality. This suggests that the effects of herbivores on ecosystems may be amplified by positive feedbacks between plant litter and soil nutrient availability.