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Effects of Warming and Atmospheric CO2 Enrichment on Wheat Photosynthesis and Biomass Production
Reference
Gutierrez, D., Gutierrez, E., Perez, P., Morcuende, R., Verdejo, A.L. and Martinez-Carrasco, R. 2009. Acclimation to future atmospheric CO2 levels increases photochemical efficiency and mitigates photochemistry inhibition by warm temperatures in wheat under field chambers. Physiologia Plantarum 137: 86-100.

What was done
The authors grew well watered and fertilized spring wheat (Triticum aestivum L. cv. Gazul) plants from seed to maturity out-of-doors in Salamanca, Spain, in two different years (2004 and 2005) within temperature-gradient chambers -- made of transparent polycarbonate walls and polyethylene sheet roofing -- that were maintained at ambient (370 ppm) and elevated (700 ppm) atmospheric CO2 concentrations and ambient air temperature (TA) and elevated air temperature (TE = TA plus 4C), during which time they measured several plant physiological properties and processes.

What was learned
Gutierrez et al.'s findings are perhaps best summed up by the title of their paper: "Acclimation to future atmospheric CO2 levels increases photochemical efficiency and mitigates photochemistry inhibition by warm temperatures in wheat." They report, for example, that net photosynthesis was increased by 62-72% in both years in the CO2-enriched chambers; while at the conclusion of the growing season, total plant biomass production in the CO2-enriched chambers was increased by 12-18%.

What it means
The six Spanish scientists conclude that "future increases in atmospheric CO2 and temperature may have a positive effect on photochemical efficiency" in wheat, and that their work "provides evidence that with air CO2 enrichment a reallocation of resources favoring light capture may occur."

Reviewed 16 December 2009