Reducing the number of deer in Pennsylvania has allowed the state's forests to begin to recover from decades of overbrowsing, but the problem is not yet solved.
That's the conclusion drawn by two ongoing studies.
The USDA Forest Service has been monitoring deer impacts on forest vegetation on a mix of public and private ground since 2001. The Department of Conservation and Natural Resources, which manages the state's public forests, conducted its largest monitoring effort last spring.
Both projects have a similar goal -- to determine whether forests that have been unable to regenerate key species like oaks and aspen have recovered to the point that deer populations should be allowed to increase.
The answer, scientists say, is no.
That doesn't mean forest conditions haven't improved, said Will McWilliams, a USDA Forest Service researcher in Newtown Square. They have. The percentage of plots sampled that had adequate regeneration have increased from 47.8 percent to 49 percent, he said.
"This increase is not quite statistically significant, but it is certainly in the desired direction," McWilliams said.
The research done exclusively on state forests has produced similar results. With fewer deer in the woods, fewer tree and plant stems are being overeaten.
According to the final report resulting from DCNR's study, nearly 89 percent of the woody stems observed fell into the "lightly browsed" category, rather than the "moderately" or "severely" browsed categories.
The bad news, according to the DCNR study, is that only 24 percent of the plots sampled had adequate regeneration and 44 percent had no regeneration.
That means the forests simply need more time -- with deer populations at something like current levels -- to recover, DCNR Secretary Michael DiBerardinis said.
"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," he said.
There is hope for the future, though, said Merlin Benner, DCNR's wildlife biologist. There are already places in the state where the agency can do timber cuts and get regeneration without having to fence deer out.
When that's happening in more places -- something that could happen fairly quickly -- the deer herd can be allowed to increase.
"I don't think we're going to have to wait 30 or 100 years like some people have said to see a response," Benner said.
'Big' problems persist
As might be expected, the inability of state forests to regenerate is most acute in the state's north central 'big woods' section.
There, almost 50 percent of the study plots show no woody regeneration, and only about 20 percent show desirable regeneration.
Weiser, Kittanning, Wyoming, Sproul, Delaware and Elk state forests are the worst in the state, according to DCNR's study, ranking as "relatively severely browsed with poor regeneration."
Forbes State Forest -- located in Southwestern Pennsylvania -- and Moshannon, Susquehannock, Rothrock, Bald Eagle, and Tioga state forests are "relatively moderately browsed with less regeneration."
Lackawanna, Buchanan, Michaux, Tiadaghton, Tuscarora, Gallitzin, and Cornplanter state forests are "relatively lightly browsed with better regeneration."The Tribune Review
