An orgy of harvesting
The even-aged nature of the state’s forests re-results from human activity. Before Europeans arrived in North America, the forests in what would eventually become Pennsylvania typically consisted of 60 percent old growth. While there is considerable debate these days about what exactly constitutes old growth, in general it means a very mature forest that has suffered few, if any, intrusions by humans. Breaks in the canopy are caused by falling trees that may be dying of old age, toppled by high winds, or struck by lightning.

By that definition, there is very little old growth left in Pennsylvania—McDill estimates just a percent or so of the state’s forest qualifies. Most of the forest is about 100 years old, regenerated after an orgy of harvesting for lumber, leather tanning, and charcoal for iron production in the late 1800s and early 1900s. Much of what was left soon burned in rampant forest fires. The railroad age made the rape of the forests possible.

Most of the forest in Pennsylvania is about 100 years old, regenerated after much of the state was clearcut in the late 1800s and early 1900s. In this view, logs were cut and ready for skidding at Elk Lick Run in Potter County. Note the size of the logs compared to the horses.

" Nobody has any recollection of what our forests ought to be because there are no living people who have ever seen what a natural forest in Pennsylvania looks like,” says McDill. "Certainly, human impacts have increased exponentially since Europeans arrived here. We need to recognize that our forests today are a human-created situation and not particularly natural.”

Forests in today’s Pennsylvania, McDill points out, are the product of more than a century of benign neglect. They simply grew back. “Most of the forests we have today are due solely to the resiliency of nature,” he says. “But we need to start regenerating the forests now—we can’t wait until it becomes crucial and then regenerate it all at once. That would perpetuate the even-age phenomenon.”

Nobody else in the Mid-Atlantic region is modeling forests the way McDill is at Penn State. “They do it in the South, in the West, in Europe and in Canada, but at least for Pennsylvania, I am the only one,” he says. “The School of Forest Resources here is close to home for DCNR, and we can tailor the solutions for the department’s problems.”