CO2 and Temperature Effects on Two Subtropical Grassland Species: A C3 Legume and C4 Stoloniferous Grass.
Entry ID:
USDA.ARS.CGERU.CO2tempFlorida
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Summary
(Adapted from an Abstract Presented at ARS Carbon Storage Workshop)
THE PROBLEM: After maximal deforestation in the Eastern USA, and
particularly the Southeastern USA, much land returned naturally to
forests or was converted to managed grasslands. Although much
attention has been given to Southeastern forests as a potential sink
for carbon, little attention ... has been given to managed grasslands,
although carbon accumulation in soil of grasslands can sometimes be
greater than that of forests. This project includes a study of carbon
accumulation under a C3 and a C4 species at ambient and doubled (700
ppm) CO2, and at temperature regimes.
APPROACH: Rhizoma peanut and bahiagrass have been grown in 1.8-m X
4.0-m plots along four segments of four temperature-gradient
greenhouses in a formerly cultivated field soil since 1995 at
Gainesville, Florida, and in outside comparison
plots. The actual temperatures were determined by outside
temperatures. The temperatures along the four segments ofthe
controlled gradient were baseline, +1.5C, +3.0C, and
+4.5C. Two of the temperature-gradient greenhouses were exposed to
ambient CO2 and two were exposed to elevated CO2 (700
ppm). Measurements of leaf and canopy photosynthetic rates were made
periodically over the season. Harvests were conducted four to five
times per year, and plant separated into leaf, stem, rhizome or
stolon, and root components. In 1998, the bahiagrass plots were split
into two levels of N fertility, with high fertility added to the
system.
Soil samples have been collected in each of the four temperature
segments in each of the four temperature-gradient greenhouses in
February in 1995 (pre-establishment), 1996,1997 and 1998. Samples
will again be collected in February 1999 and 2000. The planned
completion date for biological responses and sampling is December
1999, if funds can be obtained.
The soil sampling techniques were as follows. Soil was sampled to a
depth of 20 cm with a 2.5-cm- diameter core. Nine core samples were
taken and pooled for each sampling replication from each rhizoma
peanut and bahiagrass plot of each greenhouse. Four replicate samples
of nine cores each were taken. This technique gave four samples per
plot X two species X four temperature segments per greenhouse x four
greenhouses = 128 soil samples. Similar sampling was conducted on two
each outside plots for rhizoma peanut and bahiagrass for an additional
16 soil samples, or 144 total per year.
The soil samples were air-dried for at least one week. Then the
organic fragments of roots and rhizoma/stolons were separated from the
soil by sieving to let only 2 mm fragments and smaller pass through a
screen. Both the separated plant parts and the soil were dried for
24hr at 38C (100F). The sieved soil samples were dried for
another 24 hr at 48C (120F). These soils have been saved for
carbon (C) and nitrogen (N) analysis by the Carlo-Erba technique The
samples have not-been analyzed yet.
FINDINGS: Productivity of leguminous C3 rhizoma peanut has been about
30% greater under elevated CO2. Even the C4 bahiagrass productivity
has been about 10-15% greater under elevated CO2. We anticipate
greater soil organic matter accumulation under elevated CO2 when
thesamples are analyzed.
FUTURE PLANS: Continue temperature gradient greenhouse studies through
1999 if funds can be found for CO2. Publish an engineering paper on
the function of temperature-gradient greenhouses. Finish analyses of
biological responses of the grassland species to CO2 and temperature,
and publish the results. Analyze and publish information on soil
carbon accumulation under the treatments.
Geographic Coverage
Spatial coordinates
| N: 31.0 |
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S: 28.0 |
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E: -80.0 |
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W: -84.0 |
Data Set Citation
Dataset Creator:
L.H AlIen, Jr., T.R. Sinclair, K.J. Boote, L.E. Sollenberger, F.B. Fritschi, Y.
Dataset Title:
CO2 and temp. effects on two subtropical grassland species: A C3 legume (rhizoma
Dataset Release Date:
1999
Dataset Release Place:
Gainesville, FL
Dataset Publisher:
USDA-ARS-SAA Crop Genetics and Environmental Research Unit
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Temporal Coverage
Start Date:
1995-02-01
Stop Date:
2000-02-01
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Location Keywords
Science Keywords
ISO Topic Category
Platform
Quality
unknown
Access Constraints
unknown
Use Constraints
unkown
Ancillary Keywords
Data Set Progress
Originating Center
Data Center
Personnel
LEON
HARTWELL
ALLEN, JR.
Role:
INVESTIGATOR
Role:
TECHNICAL CONTACT
Phone:
352-392-8194
Fax:
352-392-6139
Email:
lhajr at gnv.ifas.ufl.edu
Email:
lallen at gainesville.usda.ufl.edu
Contact Address:
Crop Genetics and Environmental Research Unit
Center for Medical, Agricultural and Veterinary Entomology
1700 SW 23rd Dr.
City:
Gainesville
Province or State:
FL
Postal Code:
32608
Country:
USA
TYLER
B.
STEVENS
Role:
DIF AUTHOR
Phone:
(301) 614-6898
Fax:
301-614-5268
Email:
Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory
City:
Greenbelt
Province or State:
MD
Postal Code:
20771
Country:
USA
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Publications/References
Sinclair, T.R., L.H. AlIen, Jr., and G.M. Drake. 1996. Temperature
gradient chambers for Ie~earch on global environment
change. II. Design for plot smdies. Biotronics24:~9-108.
Fritschi, Felix B. 1996. Establishment growth of perennial peanut and
bahiagrass in response to carbon dioxide and temperature. M.S. Thesis,
University of Florida, 213 pp.
... Liu, P.-H. 1998. Designing an improved controller for regulating CO2
concentration in temperature gradient chambers. M.E. Thesis,
University of Florida, 75 pp.
Fritschi, F.B., K.J. Boote, L.E. Sollenberger, and
L.H. Alien. 1999. Carbon dioxide and temperature effects on forage
crops: I. Photosynthesis and biomass production. Global Change Biology
5. (In Press).
Fritschi, F.B ., K.J. Boote, L.E. Sollenberger, and L.H. Alien.
effects on forage crops: II. Tissue composition and nutritive value.
1999. Carbon dioxide and temperature
Global Change Biology5: (In Press).
Creation and Review Dates
Last DIF Revision Date:
1999-09-10
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