Year: 2008

http://pressherald.mainetoday.com/story.php?id=164111&ac=PHnws

Rare blackbirds spotted in Maine
For the third year, rusty blackbirds show up in the Unity Bird Count
as well as in Blue Hill and Portland.

Blethen Maine News Service
January 22, 2008

UNITY BIRD COUNT
WHEN: Dec. 14, 2007
COUNTERS: 38
WHERE: Covered a 15-mile radius
SPOTTED: 2,631 birds; 44 species, including 440 black- capped
chickadees, 400 European starlings and three bald eagles

UNITY — Reports of the rusty blackbird’s demise may have been greatly
exaggerated.

Bird watchers who took part in the annual Christmas Bird Count in the
Unity area last month once again came across the rare songbirds.

That was surprising, since the species is believed to have dwindled
in number by 90 percent during the past 20 years and historically
comes no closer to Maine than New Jersey in the winter, said David
Potter, a Unity College professor who has led the Unity Bird Count
for 11 years.

“This is the third year we’ve seen (rusty blackbirds) at Unity
College,” Potter said. “Some of the experts are surprised they’re
wintering in Unity, Maine.”

According to the National Audubon Society, rusty blackbirds migrate
north in the spring, settle into nests near still water, then migrate
to southeastern states in the late fall.

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The Scientist Volume 22 | Issue 1 | Page 38

<http://www.the-scientist.com/2008/01/1/38/1/#>

A Sensitive Reaction
Global warming could speed up decomposition, but how much might
decomposition speed up global warming?

By Kerry Grens

To understand what might happen in the sky as carbon increases and the atmosphere warms, Matthew Wallenstein at Colorado State University is looking to the ground. Beneath our feet and spread from Pole to Pole are countless numbers of microorganisms, which are decomposing organic matter and releasing many tons of carbon into the atmosphere each year.

Like any other chemical reaction, “we know that decomposition is sensitive to temperature,” says Eric Davidson, a senior scientist at the Woods Hole Research Center in Falmouth, Mass. As temperatures rise, decomposition speeds up, and more carbon gets released into the atmosphere. This additional carbon can then create a positive-feedback loop, raising temperatures higher and thus continuing to speed decomposition. The question Wallenstein wants to answer is: Will decomposition escalate global warming?

Wallenstein is trying to understand the mechanisms underlying an unexplained phenomenon that scientists have observed in a number of soil-warming experiments: Respiration rates from soil initially rise in response to elevated temperature, but then taper off.1 “In a sense there’s some kind of natural break in the system that would bring this positive feedback to a halt,” says Jerry Melillo at the Marine Biological Laboratory. For example, in a 10-year study Melillo led in the Harvard Forest, the response to warming, as measured in carbon flux, jumped an average of 28% in each of the first six years, but by the tenth year didn’t respond at all to warming.2 In other words, the researchers found that, with elevated temperatures, decomposition (and therefore carbon dioxide) rises, but then returns to normal with time, breaking down the positive-feedback loop. Why?

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“For most people in the region, the news hasn’t
quite sunk in. Between 2000 and 2006 the seven
states of the Colorado basin added five million
people, a 10 percent population increase.
Subdivisions continue to sprout in the desert,
farther and farther from the cities whose own
water supply is uncertain.”
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National Geographic
February 2008

Drying of the West

The American West was won by water management.
What happens when there’s no water left to manage?
http://ngm.nationalgeographic.com/ngm/2008-02/drying-west/kunzig-text.html

When provided with continuous nourishment, trees, like people, grow complacent.

Tree-ring scientists use the word to describe
trees like those on the floor of the Colorado
River Valley, whose roots tap into thick
reservoirs of moist soil. Complacent trees aren’t
much use for learning about climate history,
because they pack on wide new rings of wood even
in dry years. To find trees that feel the same
climatic pulses as the river, trees whose rings
widen and narrow from year to year with the river
itself, scientists have to climb up the steep,
rocky slopes above the valley and look for
gnarled, ugly trees, the kind that loggers
ignore. For some reason such “sensitive” trees
seem to live longer than the complacent ones.
“Maybe you can get too much of a good thing,”
says Dave Meko.

Meko, a scientist at the Laboratory of Tree-Ring
Research at the University of Arizona, has been
studying the climate history of the western
United States for decades. Tree-ring fieldwork is
hardly expensive-you need a device called an
increment borer to drill into the trees, you need
plastic straws (available in a pinch from
McDonald’s) to store the pencil-thin cores you’ve
extracted from bark to pith, and you need gas,
food, and lodging. But during the relatively wet
1980s and early ’90s, Meko found it difficult to
raise even the modest funds needed for his work.
“You don’t generate interest to study drought
unless you’re in a drought,” he says. “You really
need a catastrophe to get people’s attention,”
adds colleague Connie Woodhouse.

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