If you take a trip to the Blue Ridge Parkway this season to watch the leaves turn color, you’ll be treated to nice views. But much of the wooded countryside consists of second-growth forest, following long periods of attempts to farm the land. In the Eastern U.S., reserves of old-growth forest have become small and are threatened by logging and development. Some estimates indicate that our old-growth inventory has shrunk to 10 percent of what it was in the 1600s.
To the untrained eye, true old-growth forest may look untidy. Large old trees are interspersed with younger ones. Lots of plant debris, such as fallen logs and dead branches, litters the forest floor. Gaps exist where older trees have died, and sunlight enters in patches. Here and there, some large trees stand dead, leafless, in various stages of decay.
It is this kind of diversity that makes the system thrive. An old-growth forest of this type is home to more animal species than a maintained one with uniformly aged trees. Removing fallen debris from the forest floor is a practice that serves residential subdivisions because it reduces the fire hazard. But in a fully natural environment, the decaying plant litter provides a wealth of nutrients to the soil, fertilizing it to feed young growth.
In addition, the debris is home to countless types of insects which, in turn, provide food for birds and other wildlife. Bears, for example, like to eat termites, which are a good source of protein.
A prime example for forest nutrient cycles is undisturbed tropical rain forest, which is threatened everywhere but still present in Brazil’s huge back country. Removing rain forest trees in past decades for agricultural purposes revealed that, on its own, the soil was quite infertile. It soon lost all ability to sustain plant growth. In Appalachia, farmers of the 18th and 19th century learned this painful lesson, also, and the mountainous U.S. East was left to produce second-growth forest.
Joan Maloof, Professor Emeritus at Salisbury College, is an expert in old-growth forest ecology, and author of the books “Teaching the Trees: Lessons from the Forest” (2005) and “Among the Ancients” (2011). She will share her insights on the ecology and status of our native forest lands in a free and open to the public lecture in Brenau University’s Thurmond McRae Auditorium on from 5-6 p.m. Wednesday, Oct. 9.
Rudi Kiefer, Ph.D., is a professor of physical science and director of sustainability at Brenau University. His column appears Sundays and at gainesvilletimes.com.