Thursday, March 22, 2007

RESEARCH NEWS: Deer Impacts in Pennsylvania Forests Are Pandemic

Browse Monitoring Uncovers Troubling Data in State Woodlands

HARRISBURG, Pa., March 22 /PRNewswire-USNewswire/ -- Preliminary
findings from ongoing, extensive state forest studies of the effect of
white-tailed deer populations on woodland regeneration show habitat damage
is the heaviest in the north central and Pocono Mountains areas of the
state, Department of Conservation and Natural Resources Secretary Michael
DiBerardinis said today.

"Like our past surveys from the air, this unprecedented study on the
ground of what deer eat, or browse, is proving to be an invaluable tool in
understanding deer densities and distribution in our state forestlands, and
it is guiding future DCNR efforts to ensure forest regeneration and healthy
habitat," said DiBerardinis.

"And, like those aerial counts, these browse-study findings are just a
single snap-shot in time, incapable of documenting whether forest habitat
health is improving or declining. They will, however, provide a meaningful
baseline to compare in future trend analyses."

The browse studies, which were conducted last year and covered almost
90 percent of the state forest system, showed findings the secretary deemed

"Across the entire state forest system, less than 25 percent of the
41,650 plots showed desirable regeneration, and almost 45 percent of the
plots lacked any new, woody growth," DiBerardinis said. "The problem is
more acute in the state's north central 'big woods' section where almost 50
percent of the study plots show no woody regeneration and only about 20
percent desirable regeneration. The most severely browsed habitats were
documented in the north central and Pocono regions of the state.

"For these reasons, it would be premature to draw any conclusions that
would support an increased deer herd, even in areas where we observed
relatively low-browse damage," DiBerardinis said.

The secretary applauded the commitment of Bureau of Forestry personnel
from 19 of the state's 20 state forest districts who undertook the browse
studies during early spring in 2006.

"Never has there been an undertaking of this magnitude in which data
from 1,600 miles of transects was entered into the bureau database for
analysis," said DiBerardinis. "These researchers are foresters first, but
they also are hunters and naturalists and all are dedicated to restoring
forests to a healthy level where deer and other wildlife have sufficient
food and cover."

"We will use this detailed vegetation analysis in conjunction with past
aerial surveys to help guide our management decisions and adjust our
efforts to steer hunters to certain state forest areas in the 2007-2008
hunting season," DiBerardinis said.

Transects, which are lines for ecological measurements, were spaced two
miles apart. They were sampled by visiting vegetative plots every 200 feet,
recording woody species, and assigning a browsing category to that species
at that plot. Also, presence or absence data was recorded for "desirable"
and "undesirable" woody vegetation at every plot.

Woody plants include trees, shrubs and vines. Woody plants dominate the
vegetation wherever conditions are favorable for plant growth. Deer feed on
the leaves, twigs and buds of these plants.

Other survey findings include:
-- Data gathered aided in development of a preliminary deer-browsing
preference index for woody species observed, which will help guide
future monitoring efforts and provide browse intensity indicators;

-- Across the state, the proportion of plots with desirable regeneration
(24.45 percent) and lack of woody regeneration (44.45 percent) indicate
browsing has not been suppressed long enough for a widespread
regeneration response;

-- Identifying browsing impact from lowest to most severe, the Forest
Districts ranked as follows: relatively lightly browsed with better
regeneration -- Lackawanna, Buchanan, Michaux, Tiadaghton, Tuscarora,
Gallitzin, and Cornplanter; relatively moderately browsed with less
regeneration -- Moshannon, Susquehannock, Rothrock, Forbes, Bald Eagle,
and Tioga; relatively severely browsed with poor regeneration --
Weiser, Kittanning, Wyoming, Sproul, Delaware and Elk;

-- Monitoring will continue to locate other areas of continued
excessive browsing where deer harvests should be increased, and these
efforts will be coordinated in the State Forest Management Plan.

Details on the 2006 state forest deer browse study, as well as DCNR's
aerial surveys and other information on deer, can be found online at and select "State Forests."


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