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By Melanie S. Welte
Des Moines, Iowa (AP) 10-09
Mark Widrlechner is out to save a species from extinction.
It’s the native ash tree, and although it provides $25 billion worth of timber and decorates backyards across North America, an unstoppable bug has slowly killed millions of trees in 13 states and could cause the species’ ultimate demise – unless Widrlechner is successful.
The horticulturist for the federal Agriculture Research Service in Iowa
is heading an effort to collect tens of millions of ash seeds from
across the U.S. that can be frozen and ready to plant when researchers
figure out how to kill or control the emerald ash borer.
The process is tedious since seeds must be hand-picked from branches
only in the fall. But scientists hope to avoid what happened to the
American elm, chestnut and butternut trees, which were nearly wiped out
by disease.
Widrlechner said the ash borer is especially devastating because it can
kill very young trees and reduce the possibility that the species
develops a tolerance.
“This one to me looks like it’s much more likely to lead to extinction
if we don’t do anything about it,” predicted Widrlechner, who also is a
professor at Iowa State University in Ames.
Ash trees are used commercially for baseball bats, kitchen cabinets and
other products, and dominate the landscape in parts of the Midwest.
In Kansas and Nebraska, they account for 25 percent to 35 percent of
trees and up to 60 percent in some North Dakota communities. In Iowa
alone there are an estimated 88 million ash trees, state experts said.
The eastern U.S. produces nearly 114 million board feet of ash saw
timber valued at $25 billion, according to the 2009 manual by the
Department of Agriculture on the emerald ash borer. The potential
impact on the urban landscape could include 30 million to 90 million
trees and cause $20 billion to $60 billion in damage, the report
estimated.
The insect is native to Asia and was first identified in the U.S. in
2002, when it was spotted in Michigan. It’s now found in Illinois,
Indiana, Kentucky, Maryland, Michigan, Minnesota, Missouri, New York,
Ohio, Pennsylvania, Virginia, West Virginia and Wisconsin.
Federal and state agencies tried to limit the ash borer’s movement
through quarantines, but scientists agree that there’s no way to stop
the insect’s spread unless new techniques are developed.
“This pest is one like we’ve never dealt with before,” said John
Bedford, pest response program manager with the Michigan Department of
Agriculture. “It doesn’t seem to leave much in its wake.”
In parts of Michigan, “a majority of the ash trees are dead and gone,” he said.
Crews have collected at least 2 million seeds from stands of green,
white, black, blue and pumpkin ash – only about 10 percent of the
number needed to ensure the diversity of each species is represented,
Widrlechner estimates.
Noel Schneeberger, an entomologist with the U.S. Forest Service, said
billions of ash trees are scattered across the U.S., Mexico and Canada.
The seed collection project began in New England in 2007, then expanded
to Wisconsin, Illinois and Missouri. It also includes the Forest
Service, the National Resources Conservation Service, the Bureau of
Land Management, the Interior Department, several state forest
agencies, American Indian tribes, botanical gardens and even people
with ash trees in their yards.
Ash seeds grow in clusters on branches with anywhere from a dozen to 50
seeds hanging in a group. The seeds are hand-picked in the fall and put
in paper bags, then dried and sorted. Seeds shared with researchers are
put in large jars and refrigerated, Widrlechner said.
Seeds in the “base collection,” which will be used to replenish the ash
species, are sealed in plastic and stored in a walk-in freezer. Some
remain at the North Central Regional Plant Introduction Station in
Ames, and some are sent to the National Center for Genetic Resources
Preservation in Fort Collins, Colorado.
The adult beetles are relatively harmless and nibble on leaves, but the
larvae are deadly. They drill into trees, eat through the vascular
tissue and stop the flow of water. An infested tree can die within a
few years, and the emerging generation of beetles moves to other trees,
Widrlechner said.
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