US Forest Service Inventory and Analysis section on the status of Pennsylvania's Forests. A recent report entitled Pennsylvania’s Forests (2009 data) provides useful insights into the health and condition of the state’s woodlands. In the past, statewide forest inventories conducted by the US Forest Service were periodic -- every 10 to 15 years. Starting in 2004 the data are collected annually and reported on a five year cycle.
Pennsylvania’s forest land area is stable, with some parts of the state gaining while others are losing forest cover. This has been the case since the mid-1960s. Land use patterns suggest the forest land area stability is a function of offsetting of development in the southern tier as agriculture declines in the northern tier counties. The amount of forest cover has relatively constant at about 59 percent or about 16.7 million acres.
Most of this forest land, about 71 percent, is held privately by individuals, families, partnerships, and other entities not in the business of harvesting and using trees. A recent Penn State study estimated there are 738,000 individual private ownerships in the state. Most of these ownerships are small parcels. About 420,000 of these ownerships are smaller than 10 acres, and about 25 percent of the private forest is in ownerships of less than 20 acres. Statewide there are only about 25,000 privately owned forest tracts larger than 100 acres in size.
From a removal perspective, Pennsylvania is still growing more wood than it uses. Forest industry harvests trees for many uses and it is a major part of the state’s rural economy. The 2009 data finds that the growth to remove ratio is 2:1 for timberland – the forest is growing twice as much than is harvested.
The report conveys concerns about potential impacts from non-native insects and diseases that are increasingly affecting forests. Among these are gypsy moth, hemlock wooly adelgid, emerald ash borer, Asian long-horned beetle, thousand cankers disease, sudden oak death, and the list goes on. Added to this are the rapid invasion and expansion of non-native exotic plants that are filling our old fields and woodlands with aggressive competitors.
A truly problematic concern is the continuing failure to establish adequate tree regeneration (the next generation of trees) in woodlands disturbed by harvesting and other events. Using guidelines developed by the USDA Forest Research Lab near Warren, Pennsylvania, the 2009 inventory assessed adequacy of tree regeneration. When there was canopy disturbance sufficient to initiate and sustain seedling growth and development, only four of ten acres had sufficient desirable regeneration to replace the overstory.
To read the full news release by Dr. Jim Finley, Professor of Forest Resources at Penn State, click here. October 23, 2013.