Something old is new again.
After decades trapped in a belief that no virgin forest survived east of the Mississippi, since the 1980's, a new perspective on ancient forests has sprouted in environmentalism, silviculture, forestry, and public policy. Awareness is spreading that significant acreages survived three centuries of a narrowly industrial forestry and industry-driven science. Both sentiment and science urge that these rare remnant survivors should be identified, protected and studied.
Also gaining acceptance is that many forests have remained undisturbed for over a century, and have regenerated into old growth—or nearly old growth—conditions. This has created a new class of second-growth old growth—or "secondary old growth"—and encouraged signicant changes in forest policy and practices consistent with our emerging and urgent necessity to develop a sustainable forestry.
A third process fostering a new consciousness about old growth is the emergence of ecological science, and ecological forestry in particular.
What is old growth?
A common misperception is that "old growth" means a pristine forest that is "virgin"—that has never been cut for timber—with huge trees that are hundreds of years old. While nearly all virgin forests are old growth, many virgin forests don't meet this commonly-held image, and old growth includes more than large trees and uncut forests.
More broadly, old growth includes any forest that has matured into a community with substantial numbers of trees that are elder for their species. Precise numbers for a minimum age vary with each species, type of forest and growing conditions. A general rule for northern hardwoods is at least six tree per acre over 150 years old, while certain pine forests are ancient at 100 years.
Most eastern forests were cut in early European and American settlement (1700s and 1800s). But since then, some has remained undisturbed for a century or more, and is now features many old growth characteristics. While not virgin, these forests are classified as "secondary old growth"—or second growth old growth.
Most broadly, old growth is not defined by the trees, but embraces the maturity, complexity and diversity of the entire forest community. An ancient forest is not just trees, but also the shrubs, herbs, ferns, fungi, insects, birds, mammals, reptiles, and all. Even topsoil, topography and geology are elements to evaluate in qualifying a forest as old growth.
For a general introduction to definition of old growth, read "Defining Old Growth: Criteria to Evaluate Ancient Forests"
How old is an old growth forest?
No single number can answer this question. There are too many species, forest types, and extreme growing environments. Some species are long-lived, surviving centuries, even a millennia (eg. Baldcypress), while other species are ancient less than a century (eg. Cottonwood).
Where are old growth forests in the East?
Where are the East's finest old growth forests?