FYI
SALT LAKE CITY (AP) - Spruce trees are dying in Utah's forests,
the victims of an infestation that is natural but from which some
forests may not recover from for hundreds of years.
In the Manti-LaSal National Forest alone, an estimated 75,000
acres of spruce trees are dead or dying.
The forest will come back but not for at least 300 years.
The die-off is "pretty extreme," said Diane Cote,
Manti-LaSal's forest silviculturist. "This and what has happened
in Alaska are some of the worst we've ever documented."
A spruce beetle infestation has spread like wildfire through
drought-weakened and aged trees.
Fishlake National Forest may be next, and Dixie National Forest
also seems in danger. A spruce beetle kill has been sighted in the
Uinta Mountains, and in the Upper Provo River watershed, beetles
are killing spruce, fir and pine."
Cote said spruce beetles are a naturally occurring pest that
take old and weakened trees, but when many trees are old, crowded
together and stressed at the same time, a triggering event can have
widespread results.
The last time a big die-off happened may have been about 300 or
400 years ago. Now, this generation of trees is vulnerable.
Spraying to protect trees against beetles is difficult because
the infestation is so dense.
"There's so many bugs hitting these trees that they can't
win," Cote said. Agency workers can't move fast enough to get
ahead of them.
Forest workers spray protective chemicals on trees in some
campgrounds, trying to save "high-value" trees where the public
visits. But if a tree is tall, they can't spray all the way to its
top, and the bugs still get to it.
Logging to get rid of nearby infested trees can save some
stands. But that can't stop the spread of the spruce mortality.
"We're losing almost everything over 16 inches" in diameter,
Cote said. About 90 percent of trees more than 10 inches in
diameter are going, also.
But small trees, young ones that grew after recent lightning
strikes opened a place, have a better chance.
"While it is a catastrophic effect on spruce ... this is
normal, and the spruce will recover in time."
For a century or so, "we'll probably go through a cycle" in
which subalpine firs grow, die, catch fire because of all the dead
spruce, and grow again.
Gradually, firs will grow that seeds from the scarce remaining
spruces and will take hold.
"Over time, probably 300, 400 years," Cote said, "we'll have
a forest like we have now."

(Copyright 2004 by The Associated Press. All Rights Reserved.)