SHOULD VISIT GLACIER BAY
August 2, 2009
frequently tell young ecologists that to fully appreciate the earth's
myriad mutualistic and competitive plant and animal interactions they
must visit the tropics. Seldom does anyone suggest visiting the other
end of the environmental spectrum--the frozen northland. I hereby correct
that oversight by recommending a trip to Glacier Bay National Park (GBNP)
in southeastern Alaska.
encompasses 5,150 square miles, is the largest national park. It is larger
than the states of Rhode Island and Delaware combined. About 20,000 years
ago, following the end of the last ice age, the region warmed up. The
phenomenon of retreating ice revealed open rocky terrain that became habitable
by wildlife, a consequence of microscale climate change in a formerly
unvegetated habitat. During the ensuing, relatively warmer, times, the
region became biologically productive to a level that humans, the Tlingits,
inhabited the region. Then came the so-called Little Ice Age. Giant glaciers
formed in Alaska and advanced down the valleys, forcing the Tlingits inland
to warmer areas in the 1600s. As in earlier ice ages, the region was covered
with thousands of square miles of snow, glaciers, and other forms of ice--and
no open water.
George Vancouver of England sailed to the region in 1794. His ship's log
did not mention Glacier Bay as a majestic place to visit. Simple explanation.
At the time, 215 years ago, the bay was not majestic. It was barely a
bay. Instead of an expanse of water, Vancouver found a hunk of ice known
as the Grand Pacific Glacier, solid-packed ice roughly 20 miles wide and
three-fourths of a mile thick. In 1879, 12 years after Seward's Folly
had been purchased from Russia, came another visitor, John Muir. He traveled
by water 40 miles farther up Glacier Bay than Vancouver had. In less than
a century, a solid, impenetrable glacier had retreated almost 50 miles,
leaving a scoured valley filled with navigable seawater. Today, the face
of the glacier has retreated another 25 miles, creating a wide, 65-mile-long
bay with numerous fjords and more than a dozen side glaciers, most of
which retreat farther every year.
President Calvin Coolidge designated Glacier Bay and surrounding areas
as a national monument. Congress made it a national park in 1980, and
the United Nations recognized the area as a world heritage site in 1992.
This vast and impressive region deserves all the environmental recognition
and protection we can give it. The wildlife is astounding--on land, sea,
and in the air. Humpback whales, seals, and sea otters abound. Puffins,
bald eagles, and glaucous-winged gulls add another level of environmental
magnificence. And bears, moose, and mountain goats inhabit a land often
covered by magnificent virgin spruce forests.
views concerning Alaska and its natural resources run the gamut. Some
people see a land where rugged independence translates into unrestrained
oil exploration in the Arctic National Wildlife Reserve and clear-cutting
in old-growth national forests. Others feel just as strongly that unspoiled
habitats and environmental sustainability should be the order of the day.
Some of the debates will not be resolved for decades.
at least, is not debatable. Glacier Bay offers a fascinating environmental
lesson in ecosystem development. Starting at the cold end, near the face
of the glacier, only mosses and lichens cover the exposed rocky surfaces.
Along the many cascading streams of melting ice that flow into the bay,
willows develop after a few years. Then come alder and cottonwoods, followed
eventually by hemlocks and spruce forests. Although any plant might appear
at any time, the biological succession is a relatively orderly process
from lichens to mature spruce forests. Soon after plants become established
the terrestrial mammals appear--moose, mountain goats, bears, and wolves.
Birds and sea mammals arrive when the waterways open up, providing an
abundance of fish. The ecosystem is elegant in its simplicity and offers
many lessons in ecology.
with the common wisdom that young ecologists should visit wild tropical
ecosystems with their intricate evolutionary relationships created over
eons. Indeed anyone interested in nature would benefit from such a visit.
But I also recommend a visit to Glacier Bay, which offers a simple yet
dramatic view of how ecosystems are born.
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