=======================Electronic Edition========================
RACHEL’S ENVIRONMENT & HEALTH WEEKLY #476
—January 11, 1996—
News and resources for environmental justice.
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THE DYING OF THE TREES
If you read newspapers or magazines looking for information about
forests, what do you find? You find stories about the
destruction of rain forests in South America, and about the
logging battle raging in the Pacific Northwest over the spotted
owl. Except for these two issues, forest problems don’t make the
news. But forest problems are pervasive, and are as important in
their own way as toxics problems. To put it bluntly, trees are
sick and dying everywhere in the U.S. At first blush this seems
like an extreme statement. But a new book, THE DYING OF THE
TREES by Charles Little, will convince you it is true. [1]
This book gives a detailed picture –from New England to Oregon
and California, from Alaska to Florida, across the upper midwest,
across the southern border states, and even into the desert
southwest where the giant saguaro cactus is in major decline –of
trees sick and dying. It seems clear that the dying trees are one
more sign of danger, one more omen warning us that something is
terribly wrong.
Why are the trees dying? The reasons are many and varied. In
New England, New York, North Carolina, Tennessee, Georgia, Ohio,
Indiana and Kentucky it’s a combination of acid rain and clear
cuts; in California it’s killer smog; in Arizona and New Mexico
and elsewhere it’s excessive ultraviolet light filtering through
the earth’s damaged ozone shield; other places, it’s pesticides,
or it’s toxic heavy metals released by burning coal and oil; in
Alaska and Florida it’s rising temperatures and rising sea levels
from global warming; in Colorado, Oregon, and Washington state
it’s destructive forestry practices (clearcut logging, and fire
suppression) that leave forests weakened, unable to withstand
extremes of weather or attacks by insects or funguses. In most
places, in truth, it’s probably various combinations of all these
factors. Scientists are playing catch-up now, conducting studies
that may explain the complicated causes of widespread tree death.
But, as with toxics problems, if we postpone action until the
scientists have described the problems completely, we’ll get the
answers too late to do any good.
Answers come slowly. Hubert “Hub” Vogelmann, a botanist at the
University of Vermont, wanted to study an undisturbed forest, so
in 1965 he made a thorough survey of Camel’s Hump, a 4083-foot
peak in the Green Mountains. So far as he knew, he was
describing a healthy ecosystem. He measured the types and sizes
of the trees, and various other aspects of the ecosystem. He had
no particular purpose in mind, other than to gather knowledge
about nature.
Periodically, he re-surveyed Camel’s Hump, and a pattern began to
emerge. The trees were dying. His survey in 1979, compared to
the baseline study of 1965, showed a 48% loss of red spruce; a
73% loss of mountain maple; a 49% loss of striped maple; and a
35% loss of sugar maple.
By examining tree rings, and by other studies, Hub Vogelmann was
able to show that the health of Camel’s Hump had begun to decline
in the period 1950-1960. Similar studies in the Black Forest of
Germany, and in southern Canada, revealed that the most likely
cause was acid rain.
Acid rain occurs when coal and oil are burned, releasing sulfur
which combines with rain (or fog or snow) to make acid
precipitation. Acidity is measured in units called pH. Pure
water has a pH of 7 –it is “neutral” –neither acidic nor
alkaline. Pure rainwater has a pH of 5.6 –slightly acidic
because, while in the air, rain absorbs carbon dioxide to form a
weak solution of carbonic acid.
After World War II the U.S. saw a massive rise in use of fossil
fuels, coal and oil. The resulting smoke was obvious, and
obviously harmful; in Donora, Pennsylvania (south of Pittsburgh)
in 1948, half the people in the town fell ill for 3 days because
of coal smoke in the air. Twenty people died. In London,
England, in 1952, coal smoke killed 4000 people during a
pollution episode. [2]
The official response in the 1950s was to build smoke stacks
hundreds of feet tall, to dilute the pollution. Today the Ohio
River valley is still dotted by enormous coal-burning power
plants with stacks as high as 700 or even 1000 feet. These tall
stacks allow the sulfurous pollution to travel 1000 miles or
more, where it forms acid rain across the Adirondack mountains of
New York, and across northern New England and southern Canada.
In Vermont, the rain has a pH of 3.8 to 4.0. The pH scale is
“logarithmic” so a change from normal (5.6) down to 4.6 means the
rain has gotten ten times as acidic as normal; at 3.6 the rain is
100 times as acidic as normal.
It wasn’t until 1972 that Eugene Likens (then at Cornell
University) and F. Herbert Bormann at Yale discovered acid rain.
But meanwhile acid rain had been falling on northern New York and
New England and on southern Canada for about 20 years.
What Hub Vogelmann has been able to show by studying Camel’s Hump
for 30 years is that acid rain doesn’t just affect the trees; it
affects the soil and thus the entire ecosystem. Soil contains a
large amount of aluminum, but it occurs in the form of aluminum
silicates; in that form, aluminum is not available to the roots
of plants. But acid rain dissolves the silicates, releasing the
aluminum and making it available to plants. When plants get
aluminum into their roots and their vascular system, the roots
clog, which prevents the plant from taking up adequate nutrients
and water. The trees are weakened, and may then fall prey to
extreme cold, or to insects or pathogens.
Acid rain not only releases aluminum into the soil. It also
releases other minerals –calcium, magnesium, phosphorus –which
are fertilizer for the tree. Acid rain releases these
fertilizers to be washed out of the soil, leaving the soil
depleted of nutrients.
But that is not the end of the problem. The roots of many trees
create a symbiotic (mutually beneficial) relationship with an
orange-colored sponge-like fungus called mycorrhiza. The tree
roots provide sustenance to the mycorrhiza, and the mycorrhiza
help the tree roots gather water and nutrients from the soil.
But acid rain kills mycorrhiza, thus further reducing the ability
of trees to absorb water and nutrients from the soil.
But that is not all. Acid rain kills off portions of the
detritus food chain. The detritus food chain is all the
microscopic creatures that “compost” leaves, twigs, pine needles,
dead branches and so forth, turning them back into soil. Because
the detritus food chain is damaged by acid rain, forest “litter”
builds up on the floor of the forest. The litter prevents new
saplings from taking root –they cannot reach through the litter
to make contact with the soil below. Furthermore, the litter
promotes the growth of ferns, which give off substances that
inhibit the growth of red spruce saplings, among others.
This is not a complete description of problems caused by acid
rain, but it gives a sense of the complexity of ecosystems, and
how they can become unbalanced by thoughtless human intrusions.
Given the high rates of tree death, and the widespread nature of
the problem –it is occurring to one degree or another in every
state in the union –one would think that the community of
botanists, forest ecosystem specialists, and U.S. Forest Service
employees would be up in arms, advocating change. But one would
be disappointed.
Throughout the book, author Charles Little describes studies and
statements by the U.S. Forest Service downplaying the importance
of tree disease and death. For example, in 1991 the Procter
Maple Research Center at University of Vermont pinpointed acid
rain and other air pollution as an important cause of decline of
sugar maples in Vermont: “We think we are looking at the early
stages of an epidemic problem,” the Center’s report said. The
following year the U.S. Forest Service issued a report saying
that 90% of the sugar maples surveyed were healthy and the
overall numbers and volume of sugar maples was increasing.
People in the maple sugar business were stunned –their own
experience was telling them something that the U.S. Forest
Service was officially denying. It turned out the Forest Service
had used a tricky way of counting dead trees; only the standing
dead were counted–those lying on the ground were not. Here’s
David Marvin, who owns a commercial “sugarbush” –a maple sugar
farm in Vermont: “I don’t want to condemn our forest sci-entists
as a group,” says Marvin, “but I am very concerned that a great
deal of forest research is funded by the federal government, by
chemical companies, and forest industry companies –and it’s very
difficult for people who depend on that funding to stick their
necks out or to help influence policy that might go counter to
what the funders are interested in. Many scientists I talk to
will not publicly say anything about the connection between air
pollution and forest decline, but privately, to a person, they
tell me, yes, we’ve got a problem.”
Forest-protection activists in the Pacific Northwest have long
considered the Forest Service a rogue agency, captured by the
forest products industry. Under the Reagan and Bush
administrations, the situation grew so extreme that when Jack
Ward Thomas took over the leadership of the Forest Service in
1992, he immediately issued six “messages” to personnel
throughout the agency. The first three messages were: (1) Obey
the law; (2) Tell the truth; (3) Implement ecosystem management.
That such orders had to be issued speaks volumes about the past
performance of this federal agency.
In 1993 there was evidence of new candor in the Forest Service.
A report issued that year said timber mortality [death], on a
volume basis, had increased 24% between 1986 and 1991, “in all
regions, on all ownerships, and for both hardwoods and
softwoods.” Hardwoods were particularly affected, and
particularly in the south, where the mortality increase was 37%.
A new candor –and a continuing candor –among scientists and
foresters will be essential. But also we need a new recognition
that there are many causes of tree death, just as there are many
causes of toxic poisoning. To fix these problems, whether tree
deaths or toxics, will require us first and foremost to study and
emulate nature, to learn to live within natural limits, and to
respect the right of non-human species to inhabit the planet.
For starters, we should cut waste, not trees. [3] If we don’t
take these lessons to heart, and soon, the trees will survive but
probably we will not.
                
                
                
                
    
–Peter Montague
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[1] Charles E. Little, THE DYING OF THE TREES; THE PANDEMIC IN
AMERICA’S FORESTS (New York: Viking/Penguin, 1995).
[3] See REHW #468 for ways to stop using wood.
trees; forests; national forests; u.s. forest service; air pollution;
acid rain; acid precipitation; fossil fuels; toxic heavy metals; electric
power plants; aluminum; ecosystem health; wildlife;