HARRISBURG – 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 “troubling.”
“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 www.dcnr.state.pa.us and select “State Forests.”