The Effects of Deer Browsing on the Vascular Species Diversity

and Percent Cover in the Ottawa National Forest,

Western Upper Peninsula, Michigan 




Deer populations are currently higher than historically documented in the eastern United States. Forestry practices and changing land use have greatly altered the face of the Mid-Western landscape, creating optimal ideal browsing conditions and habitat for the white-tailed deer (Odocoileus virginianus). Deer browsing has been studied and is greatly affecting forest composition and structure of the eastern U.S. forests. The increased numbers of deer have prompted forest managers and ecologists to more closely examine the effects of deer on the biological diversity and the regeneration of valuable timber species.


Much of the historical information regarding the affects of deer browsing on forest composition is anecdotal and there are few systematic studies in which controlled comparisons have been made. While many forest managers have observed impaired tree regeneration due to deer browsing, difficulty lies with quantifying the impact on individual species or on ecosystem processes. The challenge in designing an appropriate experiment to test for differences in forest composition due to the affects of deer browsing is to control for multiple sources of variation that affect the diversity of eastern U.S. forests. These experimental differences include the differences in vegetation, past forestry practices, relative frequency of disturbance, climatic patterns, overstory density, and microclimatic differences.


Multiple measurements are needed to assess the influence of deer on forest composition. Species diversity, percent cover, stem density and morphological measurements of preferred browse species are among the useful quantitative measurements that enable the forest manager to assess the influence of currently high deer populations on species and forested ecosystems in the eastern United States.

Next page -> Methods

Back a page - > Outline

page edited 14 dec 1999 lts