From:    Karen Claxon 
Subject: Researchers study 10,000-year-old buried forest

Researchers study 10,000-year-old buried
foresthttp://www.eurekalert.org/releases/mtun-rst022100.html

 21 FEBRUARY 2000 (21 FEBRUARY 2000 GMT)
Contact: Dr. Kurt Pregitzer
kspregit@mtu.edu
906-487-2396

Michigan Technological University

Researchers study 10,000-year-old buried forest

Researchers at Michigan Technological University and Harvard have had a
unique opportunity to study a 10,000-year-old buried forest, preserved
virtually intact in sand and water.
Their findings were published today (February 21) in the Journal of
Ecology.* The spruce forest, preserved through a highly unusual set of
circumstances at the end of the last Ice Age, was discovered by accident =
in
a sand pit located in Michigan's Upper Peninsula. Besides its uncanny sta=
te
of preservation, it's also extraordinary in its resemblance to certain
modern forests.
"The processes have transcended time," said Dr. Kurt Pregitzer, the
principal investigator and a professor in Michigan Tech's School of Fores=
try
and Wood Products. "It looks like a typical white-spruce forest you could
find today near Hudson Bay, where the tree line is advancing north. . . .=
 We
believe that the spruce trees that grew on this site were the first trees=
 to
colonize the sediment created by the retreating glacier."
While the spruce needles had fallen to what was once the forest floor, mo=
st
of the trees were upright and intact, including bark and twigs. Mosses,
spruce cones, and pollen were preserved on the ground below. Trees ranged
from 5 centimeters to 50 centimeters (about 2 to 19 inches) in diameter, =
and
the tallest ones topped 9 meters, about 30 feet. The oldest trees were ab=
out
145 years old when they died.
"Most of what we know about changes in forests has come from studies of
fossil pollen, buried in ponds and lakes," Pregitzer said. "It's unique t=
o
find an entire forest standing, so you can see everything."
The buried forest has particular relevance today, said Dr. Patrick Martin=
,
an associate professor in Michigan Tech's Department of Social Sciences.
"The forest was growing at a time when climates were warming, and many
believe that's what's happening now," he said. "It was also the time when
people first came to this part of the world, so it gives us a snapshot of
what the local environment was like then." Paleoindian artifacts, probabl=
y
dating from the same era, have been found within a few miles of the burie=
d
forest.
Dr. Theodore Bornhorst, chair of Michigan Tech's Department of Geological
Engineering and Sciences, described how the forest came to be preserved.
"It takes a real unusual set of circumstances," he said. =B3The trees wer=
e
probably killed in standing water. Then they were quickly but gently buri=
ed
many yards deep in sand carried in small streams running off a nearby
melting glacier.
"If you saw those trees standing there, you'd say oh my gosh," Bornhorst
added. "The trees still have little limblets, only 1 millimeter in diamet=
er.
The preservation rate is really astounding."
The scientists collected 140 tree cross-sections and studied an additiona=
l
70 trees at the 5-acre site. Because the forest was discovered below the
water table, researchers had to do their work in a few days' time, while
water was held back temporarily by dikes and pumps. After the scientists
completed their study, the area was allowed to reflood.
The study was made possible by a grant from the National Science Foundati=
on.
In addition to Pregitzer, Martin, and Bornhorst, the article's co-authors
are Drs. Glenn Mroz, David Reed, and Peter Laks and Shannon Brown of
Michigan Tech; Dr. David Foster of Harvard; Dr. Jason McLachelan, formerl=
y
of Harvard and now of Duke University; and Douglas Stokke, formerly of
Michigan Tech and now of Iowa State University.
The Journal of Ecology is one of the journals published by the British
Ecological Society, http:// www.demon.co.uk/bes
###
For more information contact
Dr. Kurt Pregitzer, 906/487-2396, kspregit@mtu.edu
Dr. Patrick Martin, 906/487-2070, pem-194@mtu.edu
Dr. Theodore Bornhorst, 906/487-2721, tjbornho@mtu.edu
Dr. Glenn Mroz, associate dean, Michigan Tech School of Forestry and Wood
Products, 906/487-2496, gdmroz@mtu.edu
Dr. David Reed, professor, Michigan Tech School of Forestry and Wood
Products, 906/487-2886, ddreed@mtu.edu
Attention reporters: Digital images showing trees in the 10,000-year-old
buried spruce forest are available via e-mail. To receive a copy, contact
Dean Woodbeck at dlwoodbe@mtu.edu . Please specify which format you prefe=
r:
TIFF or 300 dpi JPG
* Pregitzer, K. S. et al. (2000) A buried spruce forest provides evidence=
 at
the stand and landscape scale for the effects of environment on vegetatio=
n
at the Pleistocene/Holocene boundary. Journal of Ecology, 88, 45=AD53.


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