On parle régulièrement (et à juste titre) de la disparition progressive de la forêt amazonienne. On parle beaucoup moins de la disparition de la forêt nord-américaine. Or celle-ci prend une ampleur tout à fait considérable en raison d’une combinaison de facteurs au nombre desquels, bien sûr, le réchauffement climatique global et la diminution de l’épaisseur de la couche d’ozone, résultats de l’activité industrielle débridée et du mode de vie totalement déraisonnable promus par le modèle occidentalo-américaniste de développement. Parmi les conséquences, notamment une multiplication d’incendies de forêts catastrophiques et la transformation de nombreuses régions en prairies ou en déserts. Ces conséquences contribuent à leur tour au réchauffement global, créant ainsi une boucle de rétroaction aggravante supplémentaire.
Ce n’est évidemment pas l’idéologie judéo-christano-capitalo-néolibérale de Georges Bush et de ses fans qui va arranger les choses. On peut donc s’attendre à ce que cela ne fasse qu’empirer de plus en plus… Alleluiah, mes frères !...
Référence : http://dieoff.org/page47.htm
“AMERICA’S TREES ARE DYING
by Charles E. Little (1995)
After 30 years as an environmental-policy analyst, journalist and author Charles Little spent three years traveling across the US, visiting forests and woodlands in 13 states. In the process, he interviewed the country’s top forest scientists, met with government and university researchers, and reviewed hundreds of scientific papers and reports. His discoveries are profoundly disturbing. The following excerpts have been adapted for the Journal from Little’s new book, The Dying of the Trees: The Pandemic in America’s Forests.
The trees are dying. Not only in the rainforests of Brazil and Southeast Asia, where they are felled by the chainsaws of international greed, local poverty and ecological ignorance, but also in Europe and right here in the US.
From the cedars of Alaska to the palms of Florida, from the maples of Canada and New England to the pines and incense cedars of the Sierra Nevada, the incidents of death and decline are increasing at an alarming rate.
Some argue that the progression of tree death and forest decline in this century, and especially since World War II, is either coincidence or simply a matter of selective reporting. Everything is all right; it is just the natural ebb and flow of nature. But that is not what I have learned from the scores of scientific scholars I have interviewed, and the mountain of papers I have studied. They say something else. What these distinguished sources are describing is a pandemic—an epidemic that is everywhere.
In the US, the trees are dying on the ridges of the Appalachian mountain chain and in the sugar bush of Vermont. They are dying in the mid-South border states, in the thick forests of central Michigan, on the mountainsides of Colorado and California, along the Gulf of Mexico, in the deserts of the Southwest and they are dying in the Northwest—even before they are cut.
IN THE BEGINNING
When we destroy forests, we destroy not only the trees that had occupied the landscape, but possibly future trees as well. Replacement forests of second-growth trees are less able to resist drought and cold, adventitious pests, and diseases, because they grow only in simplified stands, not in the vigorous, complex forest ecosystems that evolved naturally over eons.
The primitive forests encountered by the early British, Dutch and French colonists were filled with trees of mythic proportions and biblical age. White pines reached 200 feet in height. Great stands of hemlocks, more permanent than Gothic cathedrals, were common. Black walnut trunks measured five and six feet through the middle. Chestnuts spread 200 feet from branch tip to branch tip. Graceful arching trunks of elms sheltered the nurslings with dappled shade. Magnolias, crabapples, loblolly bays and basswoods perfumed Southern woodlands.
America’s primordial forests stretched from the barrier islands on which the first British colonists landed 400 years ago to the prairies of the Middle West. It was said that a tree squirrel could travel from the Atlantic shore to the Mississippi River without once dropping to the ground.
In the northern latitudes, between Maine and Minnesota, an unbroken coniferous woodland prevailed, giving way to hardwoods in the lower latitudes in a largely unblemished blanket of green from the Great Lakes to Louisiana.
THE DEATH OF THE DOGWOODS
One such remnant is the Catoctin Woods in Maryland, a profuse Eastern deciduous forest, with impressively tall oak, hickories, maples and tulip poplars. Even the most ordinary specimens reach over 100 feet and intermingle their topmost branches at such a great distance from the ground that the canopy seems almost a kind of intermediate sky. When one walks in such woods, the scale and sheer numbers of the big trees are such that their presence merges into a kind of forest atmosphere.
With its graceful branches and luminous leaves, the Eastern flowering dogwood, Cornus florida, is perfectly suited to a life under this overarching canopy. But the showy bracts—the creamy white leaflike coverings for the blossoms themselves—no longer gleam in the deep woods. Now the dogwoods are mostly dead in the Catoctin mountains, victims of a virulent form of fungal infection called “anthracnose” that has been killing off C. florida from southern New England to Alabama. Anthracnose, a combination of the Greek words for coal (anthra) and disease (nosos), describes the dark brown blotches found on infected leaves. In 1988, a study by forest scientists Manfred Mielke and Keith Langdon revealed that 79 percent of the Catoctin’s dogwoods were dead and the rest were dying.
Before the scourge of anthracnose, the dogwoods, with more than 400 medium-to-large trees per acre, gave the woods a human scale. But now a whole layer of life had been extinguished. Questions arise: What of the plants and creatures that live below the understory—the mosses and grasses and lovely ground covers; the mayapple, ferns and violets? What of the birds, such as the cedar waxwing and robin, who love the bright fall berries of dogwood—would they absent themselves from these woods? What of the big trees themselves—will some subtle change in the chemistry of the forest soils make their own survival more difficult?
A PLAGUE ON BOTH COASTS
The first notice taken that something might be amiss with the dogwood occurred some 3000 miles to the west, when in 1976 Ralph Byther and Roy Davidson, plant pathologists with the Western Washington Research and Extension Center in Puyallup, Washington, received a diseased Pacific dogwood branch (similar to the Eastern flowering dogwood) from a correspondent living near Vancouver, Washington, across the Columbia River from Portland, Oregon. Anthracnose is the ordinary term plant pathologists use to describe a set of disease symptoms in a wide variety of trees—oaks, sycamores, even citrus—that are attacked by fungus. But the coal-dark blotches on the dogwood leaves Byther and Davidson were investigating was not caused by any ordinary fungus. This fungus, belonging to the genus Discula, was a species that could not be identified because it had never been seen before.
A new virulent form of fungus had suddenly and unaccountably appeared on both coasts at the same time and was wiping out dogwoods by the thousands, spreading outward in widening circles like a silvicultural version of the bubonic plague.
Is the lovely dogwood sending us a sign, a warning, as its last gift before it disappears altogether?
FOREST DEATH IN NEW ENGLAND
Amid the tinkling glasses of tourists in the lounge of the Woodstock Inn, former-Vermont Forest Commissioner Mollie Beattie (now chief of the US Fish and Wildlife Service) spoke candidly and earnestly. “If you ask me if there’s a connection between pollution and the maple dieback,” she began, “I would say yes. If you want proof, that’s another matter. In the chronology of a forest, a decline taking 25 years is a sudden eruption, but human consciousness does not take it in that way. To us the change is so slow as to be unobservable. Nobody knows what the natural level of mortality is. It’s not that there’s no science. It’s that science is asking the wrong questions.”
Beattie also discussed the fate of other forest trees in New England; how the ozone-sensitive white pine seemed to be disappearing; how beech trees had been dying at the rate of ten percent a year in the Adirondacks of New York State. The largest US fabricator of stairway parts—the Visador Corporation—now finds it can no longer count on beech wood for lumber and must substitute tulip poplar, a somewhat weaker hardwood. Beattie fears the butternut might actually become extinct.
CHANGING CLIMATE: DYING TREES
In Alaska, a warming trend has been taking place during most of this century that coincides with the decline of the Alaska cedar as well as an increase in atmospheric CO2. In recent years, the protective snow cover has all but disappeared along the coasts due to the warming trend, causing the cedars to die.
At the opposite corner of the US, sabal palms (Sabal texana) are dying. Francis E. Putz, a botanist with the University of Florida, has found that the sabal palms—50-foot cousins of the palmetto—were dying along a 200-mile stretch of Florida’s Gulf Coast.
Putz suspects that rising sea levels have exposed the palms’ roots to toxic levels of salt water. As he told a New York Times reporter, “Areas that today support salt marsh vegetation were forested in the 1940s. Twenty million years ago Florida was a series of islands. Maybe it is going to be that again.” If the global warming scenario suggested by the National Academy of Sciences is correct, sea levels may rise as much as two feet by the end of the 21st century, which would submerge not only the palms, but most of the state of Florida.
Beginning in the late 1940s, even before most of the freeways were built in the land of the three-car garage, commuters came home from a workday in Los Angeles with red eyes, scratchy throats, chest pains and headaches. Particulate matter collected in their lungs, women’s nylons melted on their legs and trees were dying.
Today, auto-generated ozone, far from being confined to Los Angeles, is devastating trees in the distant Sierra Nevada, too. Ozone from the Central Valley travels up the steep canyons of the western flank of the Sierra on a daily basis.
In the Sierra Nevada, I visited Trent Proctor, an air resources specialist for the Sierra National Forest. “In the summer,” Proctor said, when the inversion layer of cold air covering the valley lifts, “in the southern Sierra we see ozone-injury in trees up to about 7000 feet and in the northern Sierra about 5000.” Others have found ozone-caused tree injury as high as 9000 feet.
Once the ozone is inside the cellular structure of the tree, it bleaches the chlorophyll from the needles—just like Clorox, also an oxidant—so that they lose their ability to photosynthesize and then drop prematurely.
At the headquarters of the Stanislaus National Forest, entomologist John Wenz and plant pathologist John Pronos reported that years of drought have brought widespread trouble to the mountains. “Years ago, we did a very large-scale mortality survey in the Sierra Nevada mixed conifer forest,” said Pronos, “and we came up with a normal mortality of between 0.1 and 0.3 dead trees per acre. Now we are well beyond 1.0 dead trees per acre—up to a tenfold increase.”
Wenz and Pronos also claim that the shade-loving and relatively ozone-resistant incense cedars are inexplicably dying throughout the Sierra.
LEARNING TO LOOK
We read of tree death in Europe and in the tropics, and I am telling you it is happening here in North America. Yet we look out our windows, what do we see? Trees.
I remember what West Virginia landowner and self-taught naturalist Joe Aliff told me when we were tramping through the “falling forest” in the Appalachian hollows. To see what is happening, he said, “All you got to do is look.” By that he meant something more than having one’s eyelids in the open position. And when you look, you see that the trees are dying.
I have since learned to see a world of dying trees—dying because the trunks have been bored into and the leaves have been stripped by pests; dying because fungi are girdling their bases and branches and turning their leaves to black corpses; dying because their shrunken roots can no longer absorb enough nutrients and water to keep them alive; dying from the direct effects of too much ozone in the troposphere and not enough in the stratosphere; dying because neighboring trees have been clearcut, allowing cold, heat and drying winds into their precincts; dying because of being bathed too often in the sour gases of industry; dying because the weather patterns have changed and they cannot adapt quickly enough.
The more trees that die, the more trees that will die. In the forlorn formulation of ecologist George Woodwell, climate warming from an increasing greenhouse effect could, in temperate forests especially, increase the respiration rate of trees to the degree that it may surpass the rate of photosynthesis . The tree would then no longer be a net producer of oxygen, but a net producer of carbon dioxide.
“The amount of carbon dioxide that could be injected into the atmosphere,” wrote Woodwell and longtime associate Richard Houghton in Scientific American, could theoretically approach “approximately 750 billion metric tons, or about the same amount of carbon as there is in the atmosphere currently.” Implied by this analysis is a devastating feedback loop in which trees in the vast northern hemisphere forests, instead of absorbing carbon, add to the global build-up of CO2 in a nightmarish cycle, whose finale could be a worldwide policy decision to cut down trees in order to protect the Earth’s oxygen supply!
OUR FORESTS ARE GROWING SILENT
The widespread deaths of forest-dwelling species also strongly suggest an extreme ecosystem imbalance. Increasing levels of ultraviolet-B (UV-B) radiation are leaking through the thinning stratospheric ozone shield and harming not only trees. Researchers at Oregon State University have found that the frogs living in the forest pools and streamsides of the Cascade Mountains are failing to regenerate because increased UV-B radiation scrambles the cells of frog eggs, which lay uncovered in shallow water. The decline of amphibians of all types has been noted since the 1970s. Bufo boreas, the common Western toad, is now absent in more than 80 percent of its original range. The toad is the victim of a malfunctioning immune system. Bufo periglenes, the golden toad of Costa Rica, has not been seen since 1988. In Australia, the so-called gastric-brooding frog disappeared in 1980 and is presumed extinct. In Canada, the population of the northern leopard frog, Rana pipiens, has crashed, as have the Yosemite toad and the red-legged frog in California. According to Emily Yoffe, writing in The New York Times Magazine, nearly one-third of North America’s 86 species of frogs and toads are in trouble and, worldwide, “Researchers estimate that one-quarter to one-half of the Earth’s species could be extinct in the next 30 years.”
In Europe’s forests (and to a lesser degree in the US) a mass extinction of mushrooms may be taking place. In Holland, Eef Arnolds has found that the number of viable mushroom species in test plots declined from 37 to 12 over a 20-year period. In England, mycologists report that 20 species are in decline. In general, European researchers believe that the mushroom decline is bound up with the decline of forests from pollution and related causes.
In the Midwest forests, earthworms are dying. According to ecologist Orie Loucks, studies of soil invertebrates in parts of Ohio and Indiana subject to air pollution deposition “show a 50 percent decline in the density of invertebrates and a 97 percent decline in the density of earthworms.” These extraordinary data have led Loucks and others to describe the mixed mesophytic forest as resembling an ecosystem with AIDS—a metaphor that concerns not only trees, but all the myriad species that make up a forest ecosystem and keep it operating and functioning by producing oxygen and sequestering carbon.
STRATEGIES FOR THE ENDGAME
Have we crossed the threshold? Are we now dealing with nature in another zone—the endgame? The question is: what should be done?
Should we plant trees? Yes, of course, plant billions. But can we reforest the Earth in such a way that it will stay reforested?
Reduce the pollution caused by gluttonous fossil-fuel energy use? Yes, of course. But not to the level of 1990, as the policymakers suggest and have legislated. Trees were dying long before that. The mid-50s would be closer to the mark.
Stop cutting forests? Of course. Zero cut on our national forests would be a tiny beginning. Stopping the pillage of the rainforest is a given. But have too many atoms of carbon—and too many species of virus—already been released?
End the production of CFCs? Without question. But have the chlorine atoms that have already risen to the stratosphere entrained an unstoppable feedback reaction that will cause an increasing ultraviolet bombardment of trees and forests and frogs and humans no matter what we do?
Control population and consumption? Absolutely. But would even the most extraordinary efforts in this regard come soon enough?
Environmentalism practices the language of crisis: to insist that something be done before it is too late. But what we need now is a language (and the intellectual constructs that go with it) to deal with a post-crisis environmental condition. And our response to the dying of the trees is at the heart of the matter.
In the course of my research, I have learned things I wish I had not learned. I have learned that the trees are dying. And that the more trees die, the more will die. I have learned that we have crossed the threshold. And I simply do not know how we can get back safely to the other side.
Such a conclusion can lead to despair. I think the only antidote to despair is to stay firm in the belief that, as William Wordsworth put it in Tintern Abbey, “nature never did betray the heart that loved her.”
We must begin to love her as we have never been asked to love before. Even then, it will take a century or more for environmental repair; for letting nature heal herself.
Thus have we come to the crux of the matter: the trees could save us, if we would save the trees.
******* From The Dying of the Trees: The Pandemic in America’s Forests, by Charles E. Little. Copyright Charles E. Little, 1995. Reprinted by arrangement with Viking, a division of Penguin Books USA Inc. To order the book, please call 1-800-253-6476.
THE DESERT’S DYING CACTI
According to Kate Kajtha, a biologist at Boston University, the 63,000-acre Saguaro National Monument near Tucson has lost more than 50 percent of its giant cactuses in the last 50 years due to a mysterious affliction that turns the cactus brown prematurely and causes the trunk and branches to lose their spines. “They’re dying,” Kajtha lamented. “Their arms are falling off. They’re keeling over.”
Some scientists suspect that air pollution from local mining smelters may be involved, but the affliction is not confined to the Tucson area; it can be found even in remote parts of the Sonoran Desert in northern Mexico. This has led researchers to consider the possibility that the rapid spread of the disease may be linked to increased ultraviolet (UV-B) radiation streaming through the thinning stratospheric ozone shield, the result of the destruction of ozone molecules by chlorofluorocarbons released from air conditioners and refrigerators. Cactus disease symptoms appear on the south side of the plant, the side getting the most sun and therefore the most UV-B rays. Tellingly, in shaded saguaros, the disease is not found at all.—CEL
FOREST DEATH IN COAL RIVER VALLEY
by John Flynn
MONTCOAL, WV—Sprawling across parts of Ohio, Pennsylvania, West Virginia, Maryland, Virginia, Kentucky, Tennessee and Alabama, the mixed mesophytic forest is the greatest hardwood forest in the world and the oldest in North America. Nearly as big as New England, the mixed mesophytic (meso, midrange and physic, plant) forest is the largest relatively unbroken stretch of deciduous woodland in the US.
In The Dying of the Trees, Charles Little calls the mixed mesophytic “the ‘mother forest’ of eastern North America—the forest that has provided the germplasm resources from which all other forests have subsequently arisen.” This summer, the Mother Forest turned sickly as the verdant greenery of southern West Virginia was abruptly transformed into an eerie backdrop of browns and yellows.
In the last ten days of July, anthracnose-like browning began to curl the foliage of yellow poplar, sycamore, red maple and redbud along a 50-mile east-to-west belt in the Coal River Valley, 40 miles west of Charleston. Blister-like lesions on petioles (leaf stems) were visible on all species. The damage—and the suddenness with which it occurred—was most easily detected in poplar trees, which are relatively free of insect and disease damage.
Between July 20-25, poplar leaves began rapidly browning and curling. The damage began on leaf blades and spread rapidly. Within a few days, yards were littered with fallen leaves. Shedding occurred in leaves of all ages. Foliage on the outer twigs of larger trees in open settings was the most severely affected. Poplars growing in moister, less-exposed settings were significantly less affected.
During the first week of August, the foliage on shagbark hickory and three species of oak—white, chestnut and chinkapin—began curling and browning. By August 20, damage was evident at all elevations.
The shedding was not drought-related, since the combined rainfall for May and June was more than three inches above the norm. Normal sunlight, while possibly a contributing factor, does not cause dark, burn-like discoloration on leaves.
With the help of Ozone Action, the Appalachia Forest Action Project (AFAP) obtained satellite readings prepared by National Oceanic and Atmospheric Administration physicist Art Neuendorffer. The readings revealed that the ozone layer was at record or near-record lows in southern West Virginia throughout July. Neuendorffer concluded that: “It’s very likely the trees were getting record amounts of UV-B.” In fact, the damage to broad-leafed species was accompanied by severe needle damage on white pines—symptoms associated with UV-B damage.
Upper-level ozone is measured by Dobson units. As Dobson units go down, UV-B exposure goes up at a rate of approximately two-to-one. During the past 16 years, southern West Virginia had a July noontime average of approximately 330 Dobson. The average for July, 1995, however, was 292 for the month and 282 for the last 20 days, with a low of 278 on July 17. This value is 16 percent below normal, suggesting that UV-B intensity could have been 30-35 percent higher than normal.
On August, 14, 1995, AFAP volunteers observed severe drooping and bending on white pine needles at several locations in Raleigh and Boone counties. The damage resembled UV-B-damage symptoms that ecologist Orie Loucks of Miami University in Oxford, Ohio, discovered in white pine in Ohio and Toronto, Canada in 1993 during the worst ozone-loss readings on record. Loucks observed similar damage in Ohio this summer when stratospheric ozone levels were again severely depressed.
Specimens of the damaged leaves were collected by the AFAP and turned over to the US Forest Service (USFS) laboratory in Morgantown, West Virginia. USFS plant pathologist Martin MacKenzie tentatively ruled out insects, fungi or chemical pollution as a cause of the damage. “The damage I observed was sun-directed,” MacKenzie concluded.
If UV-B damage is ultimately confirmed, it would mark the first evidence that the loss of stratospheric ozone has begun to damage broadleaf trees. Because of the critical need to be able to “fingerprint UV-B damage,” Loucks is calling for immediate action at the federal level. “As national policy, we simply must have the answer to this question” before next spring, he maintained.
******* John Flynn is communications director for: AFAP, 168 Middleton Avenue, Montcoal, WV 21540 304-854-2215
from fall 1995 “Earth Island Journal” Earth Island Journal is published quarterly by Earth Island Institute, 300 Broadway # 28, San Francisco, CA 94133 Phone: (415) 788-3666; fax (415) 788-7324