You
Can Fool Mother Nature
Tennessee
Aquarium features winter under glass
CHATTANOOGA, Tenn. (Oct. 6, 2000) - Cold, dreary weather may
put a damper on outdoor activities, but winter is a great
time to soak up the sights in the Tennessee Aquarium's forest
under glass.
The Aquarium's Cove Forest exhibit, one of only a handful
of indoor deciduous forests, is a modern marvel. Not only
does this exhibit recreate an entire ecosystem, it also undergoes
seasonal changes just like a real cove forest.
Creating four distinct seasons in the Cove may seem like fooling
with Mother Nature, but it's really mechanical manipulation
that helps us mimic the magic of nature's winter wonderland.
It's not as simple as just turning on the air conditioner
to make it cold; many specialized systems work together to
bring the outside indoors. For example, the air temperature
in the Cove Forest in the winter is only six degrees warmer
than the outside air. This is accomplished by allowing outside
air to enter the exhibit through open vents along the exhibit
walls. Also, the large mechanical vents at the top of the
glass peaks admit various amounts of cool air. These same
vents are used in the spring and summer to allow warm air
to escape and keep the Cove Forest cool. Manipulation of the
exhibit's air system and the presence of cold outside air
create natural winter temperatures in the Cove. Temperatures
in the upper 20s are not unheard of in the exhibit during
the dead of winter.
However, it isn't enough to simply cool the air to give the
illusion of winter. The exhibit's designers wanted to duplicate
every aspect of a mountain forest, right down to the fog.
In the real cove forests of the Great Smoky Mountains, fall
and winter usher in a great deal of fog. At the Aquarium,
a high pressure misting system atomizes water to 1/10th the
diameter of a human hair, creating a dense fog. The fog hovers
in the exhibit, helping maintain the high humidity that the
native plants need and adding a nice visual effect. The fog
also helps keep the Cove cool in the summer. To add even more
realism, the exhibit's air vents are hidden in artificial
trees and rocks. This creates a gentle breeze that causes
branches and leaves to sway, helping keep the trees and shrubs
healthy by maintaining the plants' elasticity.
The wide variety of plant life is one of the most striking
features of the Cove. There are dozens of species of ferns,
mosses, wildflowers, shrubs, vines and trees. Christine Bock,
lead horticulturist, has quite a challenge dealing with the
four seasons in this indoor forest.
"It is truly amazing to see an indoor exhibit of this size
go through the changing colors of autumn and winter's shedding
of leaves, as well as new colorful flower blooms popping up
around every corner in the spring," Bock said.
Creating this seasonal atmosphere comes with its own set of
problems, however. In the summer, temperatures in an enclosed
greenhouse can become quite high. Manipulation of the air
system and the use of fog alleviate most of the summer discomfort
for the animals and visitors, but that's not enough for the
plants. In a real cove forest, soil temperatures would rarely
exceed 60°F. In the Aquarium's forest exhibit, the planters
for the trees and shrubs are shallow, and soil temperatures
could easily rise to 80-90°F without intervention. To
prevent this, chilled water lines were buried inside the planter
beds to keep the soil temperature below 60° F. These same
water lines are used in the winter to carry warm water to
help keep plant roots from freezing.
All of these mechanical manipulations allow the Cove Forest
to undergo the cycle of seasons, just like a real forest.
Even the birds in the exhibit are fooled. In the fall the
birds' singing becomes quiet as breeding and nesting cease.
Winter - after the trees have shed most of their leaves and
vines are dormant - is an excellent time to view the bird
collection.
The Cove Forest is home to approximately 43 birds, representing
21 species. Visitors have a much better opportunity to spot
individual birds like the male rose-breasted grosbeak, male
indigo bunting and the cedar waxwing. Many of the birds in
the Cove are neotropical migrants, which means that in nature
these birds will leave the Southeast and fly to Central and
South America for the winter because of weather and dwindling
food supplies. At the Aquarium the birds are given plenty
of food and shelter, so they don't feel the need to fly their
elaborate coop.
Whether the weather is blustery or balmy, come check out the
Aquarium's forest under glass to appreciate the wonder of
Mother Nature inside.
"If just one person can come to the Aquarium and get a glimpse
of the wonder, beauty and complexity of nature in our re-creation
of it, then it has all been worth it," Bock said.
The Tennessee Aquarium in Chattanooga is the largest freshwater
aquarium in the world. Built with private contributions, this
non-profit educational organization is dedicated to the understanding,
conservation and celebration of aquatic habitats. Admission
is $11.95 per adult and $6.50 per child, ages 3-12. The Aquarium
is open every day except Thanksgiving and Christmas and is
accessible to people with disabilities. For more information,
call 1-800-262-0695.
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