A NEW LOOK AT AN `OLD-GROWTH FOREST'

JEFFERSON CITY -- The phrase, "old-growth forest" evokes images of ancient trees whose massive trunks and towering crowns form living cathedrals.

Romantic notions aside, though, it would be difficult for most Missourians to describe the characteristics of an "old-growth forest.

"We might not recognize one if we were standing in it," says Greg Gremaud, natural history land specialist for the Missouri Department of Conservation (MDC). "It's easier to say `old-growth' than it is to define it. Old-growth varies widely in the size, kind and number of trees per acre. Even experts are trying to reach a consensus on what constitutes an old-growth forest."

Gremaud said MDC is devoting considerable resources to defining "old growth" so it can ensure that remnants retain their uniqueness and manage land for old-growth forests for the future.

"It takes more than big trees to make an old-growth forest," said Gremaud. "One of the primary considerations is biodiversity."

If you want to get an idea of what old-growth forest looks like in Missouri, visit Caney Mountain Conservation Area or Buffalo Hills Natural Area. You might be surprised at what you find.

What you won't find is large expanses of park-like forest with nothing but huge trees. That's not old-growth in Missouri, according to Stephen R. Shifley, project leader for the USDA Forest Service North Central Forest Experiment Station in Columbia. He said you are more likely to find a mixture of big and little trees and a forest canopy broken frequently where large trees have fallen.

You'll find islands of light wherever wind or lightning have felled big trees. A riot of saplings and underbrush compete for life-giving sunlight in those sunny patches. After a decade or two, insects, fungus and microscopic animals reduce the fallen tree to rubble, and growing trees plug the hole in the copy. As they shut out the sunlight, the undergrowth thins again.

Many of the trees in Missouri old-growth forest are large, but less than one percent have trunks larger than two feet in diameter. The old ones are truly impressive, though. A few are over 200 years old, and their trunks may soar 50 feet before sprouting branches to catch the sunlight.

Unless you look closely, you might miss an important facet of the old-growth -- diversity. Multiple layers of vegetation and adverse plant community lead to a wealth of animal species, too.

Underlying this diversity is undisturbed soil. Not that old-growth forest is immune to disturbance. Forest fires, wind storms and grazing by wild animals all played a role in shaping Missouri's old- growth forests. But natural disasters created a varied patchwork on a huge tapestry of millions of wooded acres. Undisturbed areas provided a reservoir of diversity to regenerate devastated areas.

"We still have a lot to learn about how natural disturbance processes work," said Gremaud. "That's one reason our old-growth forest is so valuable. It provides a benchmark by which to measure managed forests. It's also a natural database with a wealth of information about historic climate regimes and vegetation-soil relationships. And it is a living laboratory where we can study how forests develop and naturally maintain themselves."

Gremaud said it's hard to estimate how much old-growth forests are in Missouri. Most of what is left are isolated fragments of a few acres. These are valuable, but they are too small and too subject to changes on nearby land to remain true old-growth forest.

MDC has been designating old-growth forest tracts on state forests since 1972. About 15,500 acres of state forest already are under this type of management, and another 6,000 acres of forest are found in MDC-owned natural areas.

"The potential for old-growth forest management in the future is fantastically exciting," said Gremaud. "If we are able to get larger areas under old-growth management, we could observe the effects of fire or wind without the worry of overwhelming small tracts with disturbance. Once we understand the natural processes better, we can try to imitate them with management practices."

For the present, Missourians must be content with seeing small examples of old-growth forest. Many private and public areas have noteworthy examples of various forest types. Gremaud especially recommends: Caney Mountain Conservation Area in Ozark County; Buffalo Hills Natural Area in McDonald County, George Hamilton Woods at Cuivre River State Park, Lincoln County; and Engleman Woods Natural Area west of St. Louis.

Visit one of these areas and see what "old-growth" is like. It's well worth the effort.