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Ice Storm Damages Trees - Press Release, 2000
News release
issued December 28, 2000, effective immediately. For media inquiries, contact Caroline Booth Lara, Communications Specialist, (580)
224-6379.
email: cblara@noble.org
Massive Ice Storm Takes Heavy Toll on Trees
ARDMORE, Okla. Many residents
of Southern Oklahoma and North Central Texas will spend the next several days
or perhaps weeks cleaning up fallen limbs and branches from one of the worst
ice storms in decades.
Large amounts of rain totaling several
inches in many areas combined with temperatures at or below freezing
for more than 48 hours damaged multiple millions of trees across the
region. From Wichita Falls to Broken Bow, from Dallas to Oklahoma City, homeowners,
landscapers, pecan producers, ranchers and many others face similar decisions
on how to deal with damaged trees.
The decision-making process boils
down to three basic options, according to Noble Foundation horticulturists Scott
Landgraf, Steve Upson and Dooly Barlow: Do nothing, treat the damage to minimize
long-term impact on the tree; or remove the tree and replant, if desired.
Trees with little or no apparent
damage
For trees with little on
no limb breakage, the best bet might be to leave the trees alone. Chances are
excellent that they will survive. A coating of ice in and of itself doesn't
harm most trees, unless the added weight breaks the limbs. Ice can actually
serve as an insulator, keeping the branches at around 32 degrees even if the
air temperature drops below that point.
Bent trees with little or no apparent
breakage
Trees that are bent but
not visibly broken are excellent candidates for recovery (provided the trunk
is not cracked or split), but might need a little extra care, especially if
aesthetics are important.
Many pines, for example, bend rather
than break, Foundation horticulturists explained. A young pine tree, for example,
could be manually straightened once the ice melts and supports (guide wires)
could be attached far enough up the trunk to make sure the tree's straight vertical
growth isn't interrupted.
Trees with a few broken limbs
Trees with a relatively
small percentage of missing limbs also stand an excellent chance of recovery.
But as the percentage of damaged or broken limbs increases, so does stress on
the tree. And increased stress can make the tree more vulnerable to diseases
or insect damage.
Deciding if and how to treat a tree
with broken limbs could depend upon the location and extent of the damage. Broken,
cracked, or badly twisted limbs should be removed as close as possible to their
points of origin; in other words, don't leave "stubs" if at all possible. Stubs
can serve as a point of entry for certain diseases and insect pests.
Heavy, dangling limbs on large trees
present a potential threat to people and property beneath and are best removed
by professionals.
Chances of disease or insect infestation
can be reduced by making a smooth cut through each damaged branch below the
break at an angle that allows water to drain. An optional application of pruning
paint or other suitable sealant can sometimes help the tree heal itself and
prevent further damage.
Trees with a broken crown and/or
major limb damage
If a large part of the
tree's top (crown) is broken off, the tree might be a candidate for removal
and replacement, especially if the appearance of the tree is a major consideration,
since it might never regain its original symmetry. Trees stripped of more than
half of their major branches also should be considered for removal. Such trees
might survive, but probably at the expense of a shortened life span as well
as an odd shape or growth pattern.
If the breakage of a large branch
exposes a cavity (or hollow) within that branch or the main trunk or
if there is evidence of disease in the heartwood of the tree it would
be prudent to go ahead and remove the tree to prevent future headaches.
Even if a damaged tree still appears
to be healthy, a person might want to plant a new tree to replace it. A tree
that is heavily stressed from this type of damage could have a short life span.
Planting a new tree even if the old one is left in place might
be a wise option, according to Foundation horticulturists.
In many cases homeowner's policies
will cover the removal of trees or branches that fall onto covered structures
as well as any damages to the buildings themselves. But coverage varies from
company to company, so property owners should contact their agents for specific
information.
Uprooted trees
For small, uprooted trees
with most of the root ball still intact, the best bet is to carefully restore
the tree to its original position and brace the trunk. Treat with root stimulator
in spring and keep it well watered and fertilized if possible. Large uprooted
trees should be removed, since most of the root system is probably separated
from the trunk.
Factors that influence ice storm
damage to trees
The amount of damage a
tree sustains is the result of several factors, including the size and type
of tree and how it has been trained, maintained and/or pruned.
A tree with a strong architecture
is naturally able to resist wind and ice damage.
Another factor in how much damage
a tree sustains is the "twig density," that is, the number of small branches
that serve as focal points for ice to accumulate. Evergreens and deciduous trees
that "hold" their leaves into or through the winter season are likewise highly
susceptible to ice storm damage.
Water oaks, for example, often keep
their leaves into the cold season, Foundation horticulturists said. The remaining
leaf surfaces allow large quantities of ice to accumulate during an ice storm,
which can result in serious damage to the tree.
Other facts that influence ice accumulation
and subsequent damage include the intensity and duration of the freezing rain,
the temperate at the time the rain falls, the direction and speed of the wind,
the condition of the tree's root system, the degree of saturation of the soil,
and the relative location of the tree.
"For example, the native pecan trees
in certain areas are a disaster," Landgraf said. "The elevation apparently had
a lot to do with this. Those on top of the hills seem to have been damaged the
most. Those pecan trees in the creek bottoms seem to have sustained a lot less
damage."
For those who earn all or part of
their livelihoods from fruit or pecan production, the jury is still out on the
long-term impact of the ice storm, Landgraf said. Right now, it seems, people
are still "picking up the pieces" of what Mother Nature left behind.
Illustrations on types of ice storm
damage to trees can be found on-line at http://www.noble.org/Press_Release/Ag/IceDamage2000/index.htm.
For detailed information on tree
damage, removal, replacement, and selection options, contact your local Extension
office.
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Ice
Damage Photos with Captions
The Samuel Roberts Noble Foundation,
headquartered in Ardmore, Okla., is a non-profit organization conducting agricultural,
forage biotechnological, and plant biology research; providing grants to numerous
non-profit charitable, educational and health organizations; and assisting farmers
and ranchers through educational and consultative agricultural programs.
To learn more, check out the Noble
Foundation Web site at http://www.noble.org.
More news releases available at www.noble.org/Press_Release
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