STORMS PROVIDE INTERESTING ENVIRONMENTAL PERSPECTIVES
by Whit Gibbons
February 1, 2004
We all know
that adversity should be viewed as opportunity. Thus, as I sat last night
warmed only by burning logs in the fireplace and surrounded by a dozen
candles for light, I knew that the ice storm that had eliminated all electrical
power for the last three days must be an opportunity. Living in the dark
and cold surely should provide ecological perspectives that are not readily
apparent when the furnace is blowing warm air, lights are blazing, and
hot coffee is ready minutes after you turn the pot on in the morning.
"storm" may be a bit of an overstatement, because we usually
associate wind with a storm, and an ice storm can be as gentle as a light,
misty rain. The only catch is that while it is raining, the temperature
hovers at or slightly below the freezing mark. The precipitation is not
snow but instead steady light rain that coats limbs, leaves, and power
lines, and then freezes before reaching the ground. The buildup is gradual.
The effects can be devastating for those of us dependent on electricity,
and on roads free of ice and fallen trees.
ancestors would be wondering what the problem is. Doesn't it always get
dark at night and cold in the winter? Someone who lived in a cave or teepee
would assume you just went to bed earlier on a winter night as always
and got up later the next morning. A rainy night in the 1800s that left
trees drooping from the weight of ice was no different from any other
night. You went into your candle-lit, stove-warmed house when it got dark.
Getting your car out of the driveway on a sheet of ice was not an issue.
of an ice rain can be an absolutely beautiful sight with an awesome sound
track, another form of Nature's no-charge entertainment. I stood on the
back porch absolutely enthralled with the gunfire popping of trees, as
limbs and even foot-diameter trunks broke like kindling. Northerners may
have impressive blizzards, but a southern ice storm is not to be trifled
with by man or beast.
From an ecological
perspective, ice storms can be instructive about how plants and animals
can be well adapted for one type of weather but be at the mercy of the
elements for another. Evergreen, or nondeciduous, trees such as pines,
cherry laurel, and live oaks do well in a cold sunny winter because they
continue to photosynthesize, producing sugars for nourishment. But seeing
broken, twisted evergreen shrubs and trees across the landscape brings
to mind the point that an advantage in one situation can be a cost in
species vary greatly. Longleaf and loblolly pines are better adapted to
cold conditions than the more southerly slash pines. And although a longleaf
or loblolly may forfeit a few limbs, many slash pines are unlikely to
make it through a first-class ice storm. Laden with a sheet of ice, their
more brittle limbs break, and with their more shallow root systems even
a slight wind will make the entire tree topple over. Slash pines do best
in Florida and other points south where ice storms are unlikely to occur.
perils of being evergreen, magnolia trees with their big leaves seem less
affected by a steady drizzle of freezing rain that coats every living
and nonliving thing in the region. Native magnolias may fare better because
of an adaptation less prevalent in many other nondeciduous trees. Magnolias
have a heavy waxy coating on the leaf surface that sheds water like a
duck's back. In addition, magnolias have drip tips at the ends of the
leaves, which point directly downward, so that water hitting the leaf
collects in the furrow down the middle and is immediately escorted to
the ground. Thus the rain usually does not stay on a magnolia leaf long
enough to freeze, although natural pruning will still take its toll of
magnolias with weakened or diseased limbs.
biological and ecological issues remain to be contemplated about how nature's
creatures, including us, respond to ice storms. But I think I'll save
those for tonight, while I am under the covers during 12 hours of dark
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