Feds identify carbon sequestration mefchanism
armich at cox.net
Fri Sep 6 18:07:44 EST 2002
Rich Soil Good for Trapping Carbon Dioxide - Study
Fri Sep 6, 4:58 PM ET
WASHINGTON (Reuters) - A sticky protein shed by fungi living on plant roots
is responsible for absorbing and storing sizable amounts of the carbon
dioxide pollution linked to global warming ( news - web sites), U.S.
Agriculture Department scientists said on Friday.
The protein, glomalin, glues soil particles and organic matter together
which stabilizes soil and keeps carbon from escaping into the atmosphere.
Farmland and forests around the world are seen as valuable to offset carbon
emissions from cars and industrial plants, offering the potential for carbon
credit emission trading.
Kristine Nichols, a soil scientist with the USDA's Agricultural Research
Service, analyzed glomalin in soils collected from Colorado, Georgia,
Maryland and Nebraska. Tests showed that the glomalin stored nearly
one-third of the carbon absorbed by soil, an amount far greater than humic
acid which had been thought to store the most carbon.
Glomalin gives soil the rich, fertile texture readily recognized by farmers
and longtime gardeners. It lasts from 7 to 42 years in soil, depending on
conditions, researchers said.
Another USDA researcher, Sara Wright, is studying glomalin levels to measure
the amount of carbon stored in soils beneath tropical forests.
"Glomalin is unique among soil components for its strength and stability,"
Wright said. Other soil components that contain carbon are quickly degraded
and break down, she said.
"Our next step is to identify the chemical makeup of each of its parts,
including the protein core, the sugar carbohydrates, and the attached iron
and other possible ions," she said.
Global warming has been linked to the growing amount of heat-trapping gases
such as carbon dioxide in the atmosphere. Scientists say the gradual
increase in temperature may melt glaciers, increase sea levels and lead to
broad weather changes in crop-growing areas.
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