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#476 - The Dying of the Trees, 10-Jan-1996

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

=====

[1] Charles E. Little, THE DYING OF THE TREES; THE PANDEMIC IN
AMERICA'S FORESTS (New York: Viking/Penguin, 1995).

[2] Howard E. Hesketh, UNDERSTANDING & CONTROLLING AIR POLLUTION (Ann
Arbor, Michigan: Ann Arbor Science Publishers, 1974), pgs. 48-49.

[3] See REHW #468 for ways to stop using wood.

Descriptor terms: trees; forests; forest service; air pollution; acid
rain; acid precipitation; fossil fuels; heavy metals; electric power
plants; aluminum; ecosystem health; wildlife;