Tangled Roots : THE DYING OF THE TREES: The Pandemic in America’s Forests, <i> By Charles E. Little (Viking: $22.95; 262 pp.)</i>

The Adirondack woods of New York, where I live, is one of America’s healthiest forests. Protected by the state’s Constitution as “forever wild,” its 3 million acres of public land have recovered from the brutal logging of a century ago till they look like deep and virgin woods to the untrained eye. It should be a symbol of hope.

And yet there is a problem. In the classic eastern hardwoods forest, beech, birch and maple dominate. Our maples have been pressed in recent years by a number of pests--but our beeches have been decimated. The once-smooth trunk of nearly every beech for miles around blisters with ugly cankers, the result of fatal teamwork between an insect that opens a hole in the bark and a fungus that enters it. To walk through a forest of such trees is to worry.

In his powerful new book, veteran environmental writer Charles Little makes the case that this beech blister--and the hemlock-attacking woolly adelgid, the butternut canker, the anthracnose that has killed off countless dogwoods--are more than mere isolated outbreaks of the sort that have always killed trees. Instead, he insists, they are signs of the poor health of our forests. Along with trees weakened by acid rain and ozone pollution, not to mention by rotation after rotation of absurdly heavy logging and ill-advised fire policies, they signal that our entire forest ecosystem is badly stressed, and may be nearing the kind of widespread dieback that so shocked the Germans and Czechs in the 1980s.

“We have a problem on this planet that we had better see clearly and not shrink from,” he writes. “Too many trees are dying.”

America’s concern with this round of forest decline began in the northeast more than a decade ago, especially at high elevations where spruce trees had begun to die in uncommon numbers. Scientists suspected that acidic rain, caused by the sulfur compounds from the towering smokestacks of coal burning power plants in the Ohio Valley, was the culprit. When researchers studying Camel’s Hump mountain in Vermont’s Green Mountains took core samples and looked at needles under microscopes and analyzed soils, though, what they found was in some ways even scarier than the implications of the original theory. The rain had turned dangerously acidic, but it was not simply a matter of it burning the trees as it fell. It did much of its damage by liberating aluminum in the soil, which was then carried into the trees, killing off roots. Now the tree had a harder time sucking up necessary nutrients such as phosphate, calcium and magnesium, which were themselves being leached away by acid rain. There were, in other words, a “complex cascade of causes and consequences whose end is not yet in sight.”

The same effects soon began to show up in other places. The top of North Carolina’s Mt. Mitchell, for instance, the highest point in the eastern United States--so high that the top few hundred feet often sit in a polluted fog whose pH hovers between lemon juice and battery acid, and the forest is a field of gray skeletons. Or the forests of the Sierra Nevada, where ozone pollution from Southern California’s vast fleet of automobiles was clearly killing off Ponderosa pine. Or the magnificent mesophytic hardwood stands of West Virginia, where recent studies showed that the production of mast--acorns, hickory nuts, beech nuts and so forth--had fallen by half or more.

Almost as scary has been the response of the government to the crisis. The National Acid Precipitation Assessment Program (NAPAP) organized scientists to study the effects of pollution on forests in the 1980s; many of the actual studies, says Little, represented sound science. But the official conclusions and reports “seemed to have been written by someone else”--perhaps, he implies, the representatives of the logging and utility industries, who had much to lose. Time and again government reports picked the most innocuous explanations for forest trouble, even when they sounded like something from Aesop. After looking at the death zone on top of Mt. Mitchell, for instance, the NAPAP report blamed a winter ice storm and perhaps a subsequent drought; one of the scientists who had actually studied the site called the conclusions “fraudulent.”

Little also performs a valuable service by describing how poorly journalists have described this threat--and indeed all the emerging global environmental catastrophes, from the greenhouse effect to the hole in the ozone layer. Instead of seeking “perspective,” he says, reporters have gone for “balance,” which usually involves treating the few skeptics on each issue as if they possessed the same credibility as the vast bulk of scientists who agreed on the nature of the danger.

Indeed, the question of forest feeds right in to the emerging debate over global warming, the most serious of these new problems. As Little explains, trees sequester a great deal of carbon, and if they die it is released to the atmosphere, where it joins the carbon pouring from our exhaust pipes and smokestacks to accelerate the greenhouse crisis. This “positive feedback” loop, where forests stop absorbing excess carbon and instead release it, could make the warming much fiercer even than scientists currently estimate. And, of course, as the temperature heats up more and more trees will die, prevented by their roots from migrating north to more congenial climates. In short, Little is not necessarily being hyperbolic when he says we may have “crossed a threshold,” begun “the endgame.”

Given the power of his argument, a few flourishes distract unnecessarily. It is true, for instance, that the Ebola River virus may have emerged because of forest destruction; but other epochs have known plagues, and their spread is linked just as profoundly to poverty and to poor medical care.

Such quibbles aside, my only real quarrel with Little is on the question of hope. He writes that a desperate passion for trees and forests might still save our ecosystem--and I agree. But it’s been a long time since the majority of people in our society took much notice of trees or forests. We need to inspire that affection once more--not only by telling these horror stories, but also by reminding people that they are still surrounded by woods of enormous beauty. Degraded, yes, and certain to be degraded further in the years to come--but at least for now our forests can still be nurseries of human love for the wider world.