Pennsylvania's Forest 2004
Resour. Bull. NRS-20. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 86 p.
Pennsylvania's forest-land base is stable, covering 16.6 million acres or 58 percent of the land area. Sawtimber volume totals 88.9 billion board feet, an average of about 5,000 board feet per acre. Currently, only half of the forest land that should have advance tree seedling and sapling regeneration is adequately stocked with high-canopy species, and only one-third has adequate regeneration for commercially desirable timber species. Several exotic diseases and insects threaten the health of Pennsylvania's forests. Stressors such as drought, acidic deposition, and ground-level ozone pollution are adversely affecting the State's forests.
McWilliams, William H.; Cassell, Seth P.; Alerich, Carol L.; Butler, Brett J.; Hoppus, Michael L.; Horsley, Stephen B.; Lister, Andrew J.; Lister, Tonya W.; Morin, Randall S.; Perry, Charles H.; Westfall, James A.; Wharton, Eric H.; Woodall, Christopher W. 2007. Pennsylvania''s Forest 2004. Resour. Bull. NRS-20. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 86 p. https://doi.org/10.2737/NRS-RB-20.