The Magnificence of Old Growth
Tall trees help identify old-growth forests, but so do numerous openings created by fallen trees. The downed logs don't go to waste; they slowly release their nutrients to the forest floor, feeding an explosion of new growth.
There aren’t many acres of old-growth forest left in Missouri. No remaining forest in Missouri is "pristine" in the sense of never having been affected by humans.
Fires by Native Americans and subsequent fires and open-range livestock grazing by European settlers have touched virtually every forested acre in the state.
However, there are forests that escaped the wave of harvesting and land clearing that swept though Missouri in the early 1900s. A few have experienced relatively little human impact since that time. Some tracts were left alone because they were hard to reach or because they had poor quality timber. Others simply had a string of owners who didn’t wish to harvest timber. Most such tracts are now publicly owned or otherwise protected from human disturbance.
The total area of old-growth forest remaining in Missouri depends upon how we define what is or is not "old growth." The oldest trees must be at least 100 years old, and 150 to 200 years is more commonly used as an age limit. But an old-growth forest is not defined simply by the age of its oldest trees. For example, even though they may contain some old trees, forests in which some trees have been regularly harvested are not considered old growth.
Old-growth forests require periods without severe disturbances, such as fire or drought. The absence of disturbances for long periods not only creates a forest with old trees, it also creates other characteristics associated with old-growth forests: gaps in the forest canopy where large trees have fallen, young trees growing either in the canopy gaps or in the shade of older trees, large standing dead trees and large fallen logs.
In Missouri there are about 62,000 acres of forest with some trees that are at least 130 years old. Fewer than 8,000 acres would be considered good examples of relatively undisturbed old-growth forest. Only about 800 acres would be considered excellent examples of old growth.
That works out to less than five hundredths of one percent of Missouri’s 14 million acres of forestland. These remnant old - growth forests are scattered throughout Missouri in tracts that range from about 15 to 300 acres in size. (See sidebar for places to visit old-growth forests