speaking of trees
Speaking of trees....this showed up in my mailbox this am...
Chestnut Trees To Spread Across Landscape Again
Source: NEWSWISE/Science News
A Purdue University researcher is working to restore the American
chestnut, an important wildlife tree and timber resource that dominated
the landscape from Maine to Mississippi before it was driven to
near-extinction by a fungal disease introduced about 100 years ago.
Doug Jacobs, assistant professor of forestry in the Hardwood Tree
Improvement and Regeneration Center at Purdue and director of the
Indiana chapter of the American Chestnut Foundation, studies how well
American chestnut trees grow in plantations, research essential to
future reintroduction plans. He also is developing a blight-resistant
hybrid to be used in future planting projects.
In a paper to be published in the April issue of Forest Ecology and
Management, Jacobs reports that American chestnut in a study plantation
grew as much as 77 percent taller and 140 percent wider than two other
forest species - black walnut and northern red oak - in the same
plantation over an eight-year period.
On average, the chestnut trees in the plantation grew to 6.4 meters in
height, while black walnuts and northern red oaks only grew to 4.4 and
3.6 meters, respectively, in the same time period.
"This data tells us that American chestnut is such a fast-growing
species that it should do very well in future restoration programs,"
Jacobs said. "A lot of other species are much more sensitive, grow more
slowly or just don't make it, but this tree tends to just explode out of
Jacobs' research is part of a larger initiative by the American Chestnut
Foundation to restore the tree to its historic range. The species was
nearly decimated by a fungal disease known as chestnut blight, which was
inadvertently introduced in the United States on imported Asian chestnut
seedlings. The fungus enters through injuries in the tree's bark,
spreads to the inner layers and blocks the flow of nutrients through the
tree, eventually killing it.
Jacobs said the disease first appeared in 1904, and within 40 years, it
had spread to every area of the tree's range. "Nearly every tree in the
range was killed," Jacobs said. "Ninety-nine point nine percent were
killed in that 40-year period."
The fungus persists to this day, killing chestnut trees that sprout
throughout the former range. A blight-resistance breeding program,
however, offers promise to re-establish the tree throughout the eastern
United States, Jacobs said. Isolated mature trees are occasionally found
today in parts of the tree's native range, and the American Chestnut
Foundation's state chapters use these trees as a resource in the
breeding program, Jacobs said.
"It's important to the program that we have trees from multiple areas,"
he said. "The state chapters allow us to develop regional breeding
programs to produce seed specific to the climate and other variables in
Jacobs and his colleagues at the Hardwood Tree Improvement and
Regeneration Center are developing blight-resistant hybrids for eventual
planting throughout Indiana. He has established a large test stand of
hybrid trees at Purdue's Horticulture Park, and as part of his
continuing work to develop a blight-resistant line, he plans to
inoculate these trees with the fungus to determine their degree of
"By 2006, we expect to have blight-resistant chestnut seeds to release
on a limited basis," Jacobs said. "In another 10 to 12 years, we'll see
significant quantities of seeds planted throughout the landscape."
The breeding program involves many generations of crosses between
American chestnuts and the blight-resistant Asian chestnut, Jacobs said.
By crossing hybrids, the breeding program will produce trees that are
genetically 94 percent American chestnut and 6 percent Asian chestnut.
Trees with this genetic makeup exhibit the resistance of the Asian
chestnut but have the growth characteristics of the American chestnut,
American chestnut formerly played a vital role in the eastern forests of
the United States, where it made up nearly one out of every four trees,
Jacobs said. "Chestnut is a wonderful wildlife tree," he said. "It is
unusual among forest trees in that it can be counted on to produce a
good seed crop every single year - chestnuts were a valuable resource to
many species of mammals and birds."
It also was a highly prized timber tree, he said. "Chestnut is an
extremely rot-resistant wood," Jacobs said. "Its rot-resistance, coupled
with its fast growth rate and its straight form, make it an ideal tree
for utility poles and mid-grade furniture production."
Jacobs said he expects to see blight-resistant American chestnut become
widely available in another 10 years and suggests that the majority of
plantings be done in the Midwest, where there is an abundance of
Larry R. Severeid of the Walnut Council International Office also
contributed to this research, and funding was provided by the American
Chestnut Foundation and Purdue University.
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