Study of Forest Regeneration Shows Little Recovery from Deer Browsing
Photo

A new study by the Department of Conservation and Natural Resources shows deer herd size in State Forests still does not allow adequate recovery of forests from over-browsing by deer.

DCNR’s Bureau of Forestry conducted widespread habitat browsing surveys across the State Forests in late winter 2006 to assess forest regeneration conditions and the current levels of overwinter deer browsing.

Plot data from 41,657 individual plots providing 88 percent coverage of the State Forest System were included in the study. The results were tabulated by each DCNR Forest District.

With only 24.45 percent of the test plots showing desirable regeneration and 44.45 percent with no woody regeneration, the results indicated that browsing has not been down long enough for widespread regeneration response. 43.70 percent of the plots show undesireable woody regeneration was prevalent.

DCNR said this study will serve as a baseline for future studies of the impacts of overbrowsing by deer.

DCNR also recently posted its updated 2007 State Forests Deer Management Plan which concluded, “despite all the advances of the deer management program, meaningful population reductions have not been documented on a statewide level….”

The plan also notes the conclusion of other recent research— “The most notable research to date has been the hunter movement study (Diefenbach 2004). This study documented hunter behavior over two hunting seasons, finding most hunters hunted on relatively flat areas within 1/3 mile of a road within the study area. It also validates the perception of our (DCNR) staff that there are large areas with virtually no hunting pressure that will require additional tools and incentives.”

A 2005 study commissioned by Audubon PA, Managing White-tailed Deer in Forest Habitat From an Ecosystem Perspective, made this dramatic statement about the impact of deer on the Commonwealth’s forests, “(the) regeneration of most tree species does not occur unless the affected areas are fenced to exclude deer.”

High deer populations have greatly altered forest understories. The abundance of native wildflowers and other forest-floor plants has been greatly diminished, shrub species have been dramatically decreased or eliminated, and the variety of tree species has declined.

To the casual observer the woods still look green, but they are much altered. In place of the diverse, multi-storied vegetation that was the norm, there are just a few species, either not preferred by deer or resilient to repeated browsing.

Consider these other facts from a House Agriculture and Rural Affairs Committee hearing on deer and wildlife damage in 2006—

· There is an estimated $90 million in crop loss and $73 million in damage to our forests every year by deer, according to the Department of Agriculture;

· Over $78 million in property damage occur in the over 39,000 deer/car collisions each year in Pennsylvania, not counting the deaths and injuries to the people involved. This is the highest of any state in the nation;

· The incidence of Lyme disease, a debilitating and sometimes fatal illness spread by deer ticks, has increased by over 9,000 percent between 1987 and 2004, according to the Department of Health; and

· State taxpayers lose $18 million a year in deferred and lost timber stumpage sales.

A copy of Browsing Impact Report for the Pennsylvania State Forests is available online.

Link: The Game Commission Released Its 2006-07 Deer Harvest Numbers


3/16/2007

Go To Preceding Article     Go To Next Article

Return to This PA Environment Digest's Main Page