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Effects on Forests:
Some of the most dramatic effects on forests have been observed
in Europe. In 1983, a survey in West Germany showed that 34 %
of the country's total forest is damaged by air pollution. This
included about one half of the famous Black Forest. Switzerland
has recorded damage to 14 % of her forest trees.
Red spruce and Fraser firs are dead and dying on top of Mount
Mitchell, North Carolina. There are few signs of any plant life
reproduction there.
A large number of trees are falling prey to insect and disease
attack resulting in die back of trees in New England states as
shown in the graphic on the left.
On Camels Hump in Vermont's Green Mountains, Dr. H. Vogelmann,
professor of botany at the University of Vermont, has reported
startling evidence of tree damage. Conifers are most effected
because the needles are bathed in acid droplets all year around.Other
trees drop their leaves. Measurements of the total biomass in
the balsam fir has declined 20 % from 1965 to 1983. The red spruce
has declined a dramatic 73 % in the same time period. Lower on
the mountain sugar maples and beech trees biomass dropped 25
%.
Forests at high altitudes maybe enshrouded by clouds or fog
for much of the time. The pH of lower cloud droplets may average
3.6, which is a much lower pH than the final rain of pH 4.2.
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