Submitted to: CO2 and Water Workshop
Publication Type: Abstract Only
Publication Acceptance Date: August 17, 2002
Publication Date: N/A
Technical Abstract: The increasing concentration of carbon dioxide in the atmosphere is expected to reduce the stomatal conductance of crop plants, which will affect water use by crops. This, combined with reductions in conductance in other plant communities, will potentially influence the global water cycle and the climate system. The magnitude of the reduction in stomatal conductance varies greatly among crop species, and within species it varies with other environmental factors such as light, temperature, and humidity. This review summarizes current knowledge of the mechanisms by which carbon dioxide affects stomatal conductance, including the involvement of photosynthetic acclimation to elevated carbon dioxide in reductions in conductance, and reviews mechanisms by which other environmental factors affect the magnitude of the carbon dioxide effect on conductance. It also summarizes the experimental data on the magnitude of the effect of doubling the current concentration of carbon dioxide on the stomatal conductance of all crop species which have been examined to date.