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Free
Air CO2 Experiment (FACE) predicts
forest ecosystem response to elevated
carbon dioxide. Scientist is measuring
photosynthesis of pine trees,
and the experiment provides other
data on tree growth and carbon
sequestration. |
Increasing concentrations of carbon
dioxide (CO2) in the atmosphere, resulting
from fossil-fuel combustion and other
sources, are an international concern
because of the possible effects on
climate. Predictions of climate impacts
will be most reliable if based on
experiments that mimic real world
conditions, meaning they are conducted
in open-air field sites rather than
greenhouses or other enclosures. These
types of long-term, controlled field
studies in a number of different ecosystems
have been made possible by the development
of the Free-Air CO2 Enrichment (FACE)
methodology at Brookhaven National
Laboratory. The unique FACE facilities
and techniques enable scientists to
increase the concentration of trace
gases such as CO2 in the atmosphere
above the ground in a controlled way
in intact ecosystems, and to study
plant response to the altered conditions.
Several FACE facilities are operating
around the world. Research supported
by the Office of Science has revealed
differential responses among species
within a single ecosystem; increasing
CO2 causes some plants to grow faster
and larger and to use less water.
Scientific Impact:
The FACE approach gives many biologists
access to a large facility that encompasses
hundreds of individual plants in an
intact ecosystem. This is an economical
way to build an understanding of how
a particular ecosystem will respond
to rising levels of CO2, information
that is critical to understanding
and predicting overall environmental
impacts.
Social Impact: FACE
studies will help society plan for
the predicted CO2-rich atmosphere
of the future. For instance, results
from a FACE facility operated by Brookhaven
in North Carolina showed that, in
50 years, if forests worldwide were
to grow 25 percent faster than they
do now, then plant life could serve
as a "sink" for about half the expected
CO2 emissions from fossil-fuel combustion.
Reference: DeLucia,
E.H., Hamilton, J.G., Naidu, S.L.,
Thomas, R.B., Andrews, J.A., Finzi,
A., Lavine, M., Matamala, R., Mohan,
J.E., Hendrey, G.R., and Schlesinger,
W.H., "Net primary production of a
forest ecosystem with experimental
CO2 enrichment," Science
284: 1177-1179 (1999).
Schlesinger, W.H. and Andrews, J.A.,
"Soil respiration and the global carbon
cycle," Biogeochemistry 48:
7-20 (2000).
Smith, S.D., Huxman, T.E., Zitzer,
S.F., Charlet, T.N., Housman, D.C.,
and Coleman, J.S., "Elevated CO2 increases
productivity and invasive species
success in an arid ecosystem," Nature
408: 79-82 (2000).
Lüscher, A., Hartwig, U.A., Suter,
D. and Nösberger, J., "Direct evidence
that symbiotic N2 fixation in fertile
grassland is an important trait for
a strong response of plants to elevated
atmospheric CO2," Global Change
Biology 6: 655-662 (2000).
URL:
http://www.face.bnl.gov/
Technical Contact:
Dr. Roger Dahlman, Environmental Sciences
Division, Office of Biological and
Environmental Research, 301-903-4951
Press Contact: Jeff
Sherwood, DOE Office of Public Affairs,
202-586-5806
SC-Funding Office:
Office of Biological and Environmental
Research |