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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPACTS OF RISING ATMOSPHERIC CARBON DIOXIDE AND TEMPERATURE ON CROP GROWTH, REPRODUCTIVE PROCESSES, YIELD, AND SEED QUALITY

Location: Chemistry Research Unit

Title: Free-air CO2 enrichment (face): model analysis of gaseous dispersion arrays for studying rising atmospheric CO2 effects on vegetation

Authors
item Allen, Leon
item Beladi, S - UNIVERSITY OF FLORIDA

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 5, 2007
Publication Date: N/A

Technical Abstract: Atmospheric carbon dioxide (CO2) has risen from about 280 to 380 micromol/mol since the beginning of the industrial revolution due mainly to burning of fossil fuels. Free-Air CO2 Enrichment (FACE) arrays have been devised with large areas and undisturbed aerial conditions that allow secondary soil or gas treatments. Limitations include cost of CO2, complexity, and inability to provide CO2 X temperature interactions across controlled wide ranges of temperatures. This modeling study predicted CO2 dispersion within several types of emission arrays including ground-level area-source emitters, upwind vertical vent pipe emitters, elevated within-block area-source emitters, and combinations of each, for vegetation ranging from a tall 40-m forest to a short 0.3-m grassland. A two-dimensional vertical eddy diffusion and horizontal mass transport model was used to predict CO2 dispersion. The combination of elevated area-source emitters with upwind vertical vent pipes predicted the most uniform distributions of CO2, but the upwind vertical vent pipe emitters alone gave satisfactory distributions, and are easier to set up for experiments. As expected, predicted CO2 costs were proportional to the height and area of vegetation.

Last Modified: 8/30/2014
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