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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Water Management and Conservation Research » Research » Publications at this Location » Publication #157328

Title: WILL RISING LEVELS OF ATMOSPHERIC CO2 AFFECT NDVI PREDICTIONS OF APAR?

Author
item Pinter Jr, Paul
item Kimball, Bruce
item LAMORTE, ROBERT - USDA-ARS PHOENIX
item Rokey, Ric
item Maneely, Suzette
item Wall, Gerard - Gary
item LEAVITT, STEVE - UNIV OF ARIZONA TUCSON
item OTTMAN, MICHAEL - UNIV OF ARIZONA TUCSON

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/4/2003
Publication Date: 11/6/2003
Citation: PINTER JR, P.J., KIMBALL, B.A., LAMORTE, R.L., ROKEY, R.R., MANEELY, S.M., WALL, G.W., LEAVITT, S.W., OTTMAN, M.J. 2003. WILL RISING LEVELS OF ATMOSPHERIC CO2 AFFECT NDVI PREDICTIONS OF APAR?. AGRONOMY ABSTRACTS. CD-Rom (CO2-Pinter391206-oral).

Interpretive Summary:

Technical Abstract: Satellite estimates of net primary productivity (NPP) provide continuous, long-term records of vegetation response to both natural and anthropogenic changes in global processes. Estimates are often derived from light use efficiency models that exploit biophysical relationships between the normalized difference vegetation index (NDVI) and the fraction of photosynthetically active radiation absorbed by plants (fAPAR, 0.4 to 0.7 um). We examined these relationships for cotton, wheat, and grain sorghum crops grown at Maricopa, Arizona, using the Free Air Carbon Dioxide Enrichment (FACE) facility wherein undisturbed plant canopies could be measured without the microclimatic and structural artifacts usually associated with chamber-based research. Our investigations using wide- and narrow-band radiometers revealed minimal direct effects of elevated CO2 on the NDVI versus fAPAR relationship, validating the use of this relationship for monitoring global agricultural productivity from remotely-sensed data in a rising CO2 world.