The purpose of the Florida Native Plant Society (FNPS) is to promote the preservation, conservation, and restoration of the native plants and native plant communities of Florida. This blog presents ideas and information to further the cause of Florida's native plants and ecosystems.
Wednesday, July 27, 2016
A Pine can have lightning scars that run down the trunk. Why doesn't an Oak?
by Cecilia Catron, Tarflower Chapter of the Florida Native Plant Society
(reprinted with permission from the August 2016 issue of Tarpaper)
When days are hot, as they have
been for the past month, it seems like a sensible idea to lie in or around
the pool all day, like a motionless alligator. Curds of bright, white
thunderheads rise higher and higher, expanded by the increasing heat.
Gradually air pushed from the east and west coasts meets in the middle of
the peninsula. By mid-afternoon it becomes charged by the collision of
the fronts and summer lightning is created, with or without a storm.
Have you ever noticed a stripe spiraling down the
trunk of a pine tree where lightning has stripped the outer bark off? You
may have also noticed there is no such stripe on the trunk of an oak tree.
Oaks and Pines, both dominant here in central Florida, have different
lightning survival strategies. Most pine species have long, straight
trunks. They are relatively fast-growing with soft wood. Oak trunks on the
other hand are often twisted and full of knots. They grow more slowly (except Laurel Oak, Quercus laurifolia) and the wood is very
hard, dense, and heavy.
Lightning is attracted to the tallest
tree, regardless what species it is. Energy is conducted down the
trunk of a typical pine with little to stop it since the cells are
constructed in long, continuous rows. Knotty oaks on the other hand
do not have such unobstructed cellular highways. When a knot is struck it
may explode, but a lightning bolt's energy is spent before it can progress
down the trunk, limiting damage. Good planning, oaks. Also a case for
organisms that create knots on oaks - part of the ecological give and take.
New pines grow relatively quickly to replace trees that are destroyed,
which is also a viable strategy.
Be that as it may, never take shelter under any tree to escape a storm.
Especially here in Lightning Alley nature can put on an awesome show, but
it's important to remember that a tree may be a target.