Bush failed to move strongly on Global Warming. America's trees are now in danger.
- From: "aol@xxxxxxx" <geneccc@xxxxxxxxx>
- Date: Fri, 23 Jan 2009 07:56:49 -0800 (PST)
GRANTS PASS, Ore. – Trees in old growth forests across the West are
dying at a small, but increasing rate that scientists conclude is
probably caused by longer and hotter summers from a changing climate.
While not noticeable to someone walking through the forests, the death
rate is doubling every 17 to 29 years, according to a 52-year study
published in the Friday edition of the journal Science. The trend was
apparent in trees of all ages, species, and locations.
"If current trends continue, forests will become sparser over time,"
said lead author Phillip J. van Mantgem of the U.S. Geological
Survey's Western Ecological Research Center.
"Eventually this will lead to decreasing tree size," he said. "This is
important because it indicates future forests might store less carbon
than present."
Old growth forests, particularly those in the Northwest, store large
amounts of carbon, making them a resource in combatting global
warming, said Jerry Franklin, a professor of forest ecology at the
University of Washington. But as trees die, they decompose and give
off carbon dioxide, contributing to the amount of greenhouse gases.
Young forests store very little carbon, and it takes hundreds of years
to replace old growth, he said.
The researchers considered several other possible causes for the
higher death rate — air pollution, overcrowding of young trees, the
effects of logging, large trees falling on small ones, and a lack of
forest fires, which keep forests healthy. But the data showed the
trend affected trees young and old, in polluted and clean air, in
crowded and sparse stands and at different elevations.
The likely cause, they concluded, was warmer average temperature
across the West, about 1 degree over the study period, said co-author
Nathan L. Stephenson, also of the USGS Western Ecological Research
Center. That results in greater stress on the trees from lack of
water, leaving them vulnerable to disease and insects.
.
- Prev by Date: Re: This group has become an Anachronism...good riddance
- Next by Date: Republicans liked the Good Old Days when you could machine gun workers
- Previous by thread: Re: Americas biggest spender
- Next by thread: Republicans liked the Good Old Days when you could machine gun workers
- Index(es):
Relevant Pages
|
Loading
