Is there a virgin forest in your neighborhood?
Some things in the natural world overwhelm you with power and grandeur. If you've stood on the Hurricane Deck beneath the Bridal Veil at Niagara Falls, if you've confronted the full-size African elephant near the front entrance of the Natural History Museum of the Smithsonian in Washington, DC, if you've leaned against the railing and gazed into the Grand Canyon, you know the truth of that statement.
The remaining old-growth forests of the eastern United States aren't that way. Not necessarily.
The tree didn't look like much. A gimpy, gnarly post oak, it clung to the edge of a rocky, southwest-facing bluff in the Ozark Mountains of northwest Arkansas, directly above an old rock shelter at which archaeologists have documented thousands of years of human occupation. Twisted, stunted, wind-tortured, the tree was maybe 15 inches in diameter, and if it was 20 feet tall I'd be surprised. Its snaggled, broken-ended branches erupted in unpredictable directions, like a mad scientist's hair.
"This is one of my favorite trees," said Dave Stahle (pronounced Stay-lee), gently resting a palm on the moss-covered bark. "He's 250 years old, exactly."
Stahle tends to refer to his trees as "he" instead of "it." He's pretty fond of them, even though he's a thoroughly professional scientist who refuses to let sentiment get in the way of his good judgment. A casual perusal of the book titles on his cluttered desk prove the point: Telecommunications Linking Worldwide Climate Anomalies. Climate Change: The IPCC Scientific Assessment.
IPCC, it turns out, stands for "Intergovernmental Panel on Climate Change," a United Nations-affiliated group with big-time political clout. Pretty heavy reading material. Typical office fodder for a Ph.D. egghead.
But Dave Stahle isn't your typical Ph.D. egghead. True, he teaches undergraduate and graduate-level courses at the University of Arkansas in Fayetteville. True, he's the director of the Tree Ring Laboratory at UA. True, he refers to himself as a dendrochronologist or a paleoclimatologist, depending on his mood when you ask him. Translated into English, those jawbreaker words mean he's a guy who analyzes tree-ring growth to trace climatic changes and other disturbances back through time.
Stahle has teamed with fellow UA dendrochronologist Malcolm Cleaveland. Long story short, their work involves taking small, pencil-size plugs out of living and dead trees with a Swedish increment borer, a specialized tree-boring tool. Then they count backward in time as they tick off the annual growth rings one by one.
Using these techniques, Stahle and Cleaveland can tell with remarkable accuracy what the weather's been each year for the lifespan of a tree. By matching up older, dead trees from the same site, it's possible to construct an overlapping tree-ring chronology--often for more than a thousand years. The value of this exercise lies not only in learning weather patterns over hundreds of years past but also in determining how long current weather patterns might last.
The pair's primary thrust as dendrochronologists/paleoclimatologists (whew!) is interesting enough in its own right. For example, they've discovered that swings in spring/summer rainfall over Arkansas and the southern Great Plains are fairly cyclic but not uniform. Rather, drought years tend to cluster together. Ditto wet years. It's not uncommon to have back-to-back droughts or three or four dry years crammed into a five- or six-year period. Unusually wet years tend to cluster in similar fashion.
Because of their work, Stahle now believes there's a lot more old-growth than most of us believe. The current thinking in scientific circles is that little old-growth timber remains in the eastern United States. Stahle doesn't agree.
"I have made the rather outlandish claim that there are literally thousands of acres of old-growth forest on public and private land in the eastern U.S.," Stahle says. "Most of these remaining old forests have no commercial value, or they're growing on very poor sites that are unsuitable for agriculture, or both. Because ours is a profit-driven society and there's never been any profit to be made in cutting the trees, they're still standing."
Last winter, Stahle and Cleaveland constructed a computer model for sampling Enders soil sites in the Arkansas Ozarks, targeting south-facing exposures where summer drought and heat are felt with a vengeance. These sites are the most likely to have "trashy," non-commercial timber--and, therefore, according to Stahle's theory, the most likely to have been left unbothered and natural.
Stahle randomly chose 50 sampling locations from the 640 sites located by the computer, and he and his cohorts ran transects on all 50 during the late winter and spring of 1992. They found old-growth forest on 20 of the sites, a 40 percent hit ratio. If you use acres as the yardstick, 18.7 percent of the total surface area of the 50 sample sites was old-growth, with trees up to 400 years old--pretty close to the max for a post oak.
"Based on these figures, there are more than 70 square miles of existing old-growth forest just in the Boston Mountain portion of the Ozarks," Stahle says. "And that's just on the Enders soil type on south-facing slopes. There are several other likely soil types and slope aspects we haven't even sampled yet."
Think about that. And Stahle says this phenomenon isn't restricted to the Ozarks. It holds true wherever poor soil types and unfavorable agricultural conditions occur in forested areas throughout the eastern deciduous forest, from eastern Oklahoma and Kansas all the way to the Atlantic Ocean. He has found ancient oak forests growing along the bluff line at the Delaware Water Gap in northern New Jersey, trees that were already mature during America's westward expansion.
Stahle is convinced that substantial remnants of old-growth forest remain over this entire eastern deciduous area. If you apply his already-documented Ozark percentages to the entire region, you come up with the astounding figure of five million acres, or 8,000 square miles, of old-growth. That's an area the size of New Jersey.
"That theory hasn't been proved yet," Stahle cautions. "The proportion of old-growth remaining in a state like Virginia may not be quite as high as in Arkansas, because Virginia has been settled much longer. But on the other hand, there's old-growth all over eastern Oklahoma. I'm confident that, overall, the proportion of remaining old-growth is similar to what we've documented in the Boston Mountains."
Why have these remnants of ancient forest escaped public notice? Because they don't look like what we think an ancient forest ought to look like. I'll bet a dollar against a doughnut that when somebody says "virgin forest," you conjure up a park-like place with trunks as big around as Volkswagens. Now that you've lost the doughnut, listen again:
"Those types of ancient forest were cut long ago. But these poor-site forests don't fit that stereotype, and most people just don't realize what they're looking at. I know some places right here in Fayetteville where 300-year-old post oaks are growing in front yards."
Stahle and Cleaveland have also done extensive tree-ring work with baldcypress, a species especially valuable to dendrochronology because of its ability to live a long time. Stahle has sampled baldcypress stands in North Carolina that are more than 1,600 years old, and he's found numerous sites in east Arkansas with trees over 500 years old. One site, on Bayou DeView, has more than a few l,000-year-old trees.
"And that's just their provable age," Stahle said. "Most of them are hollow." Judging from the average thickness of the rings and the diameter of the center rot, Stahle is confident some of these graybeards are 1,300 years old.
Think about that--some of the trees growing right now in east Arkansas were already mature before the Crusades began in medieval Europe. By the time DeSoto tramped through them on his way to fame, glory, and an early death, they were already 750 years old.
Again, poor trees on poor sites is the key to their survival; these ancient cypresses grow shoulder to shoulder along the boggy, unfarmable bayou channels, and most are twisted, shaky, overmature, and generally worthless for lumber.
But don't get the notion these ancient cypresses are worthless for everything. Ditto the moss-covered post oaks growing above the Indian bluff shelter. Ditto again the 1,600-year-old cypresses in North Carolina and the ancient Water Gap oaks. These ancient trees, besides documenting a long climatological record, stand as reminders of a time when man was merely a part of the land rather than its conqueror.
Sure, these trees are twisted and lightning-scarred and snaggle-limbed. Few take your breath away. But they were here long before America was born, and they'll still be here when our great-great-grandchildren have great-great-grand--silently guarding the unfarmable corners of the world, faithfully maintaining the record of the rings.
Jim Spencer is a public-affairs writer for the Arkansas Game and Fish Commission.
HOW TO FIND YOUR OWN ANCIENT FOREST
Ancient forests aren't as rare as most people think. Dr. Dave Stahle has some tips that should enable any observant wanderer to pick out these remnants of the virgin forests that once blanketed the eastern United States:
"First, look for the poorest sites in the area," Stahle says. "Almost all the merchantable timber was cleared or heavily logged long ago, and everyone knows we have very little of that type of virgin forest left. Most people don't think about the marginal types of forest cover as being examples of virgin timber, but in many cases that's exactly what they are.
"In mountain country, this means the tops of rocky ridges, the steeper the better. It also means south-facing exposures mostly, although steep, north-facing slopes also contain a fair percentage of old-growth. Once you find these sites, look at the trees themselves. Really ancient trees have a certain blunted look about them. Their upper limbs are broken, and they're gnarled and bent. Many of the older specimens will be leaning.
"The true hallmark of an ancient upland forest, though, is that the larger trees will have a noticeable twist to their trunks. This is a definite sign of advanced age. You can see it in the alignment of the bark or, where the bark has been damaged by fire or disease, in the grain of the wood itself. The tree looks like a corkscrew. It looks like it's been wrung out like a wet towel.
"In the overflow bottoms, on the other hand, concentrate your search for ancient trees in the cypress-tupelo brakes that can be found along most of the major rivers and bayous. Look for places that are almost always flooded, especially those that are densely stocked with doghair stands of cypress or tupelo.
"In general, look for the hardest, harshest country you can find, whether in the mountains or the flatlands. You're probably not going to locate a big expanse of old-growth stuff, but you'll be surprised at how many little patches of it there are to be found."
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|Title Annotation:||Tree Facts; includes related article on identifying remnants of virgin forests; remnants of old-growth forests|
|Date:||Jan 1, 1993|
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