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Stomatal Responses to CO2: A Comparison of Woody and Herbaceous Species in Arid and Humid Climates.

DE2004820420

Publication Date	2003
Personal Author	Koch, G. W.; Ellsworth, D.
Page Count	14
Abstract	The project involved a study of a fundamental response of terrestrial vegetation to rising atmospheric carbon dioxide (CO2) concentration, namely, the change in leaf conductance to gas diffusion associated with a change in the aperture of the microscopic pores (stomata) on the surface of leaves. This 'stomatal conductance' determines the rate at which water is lost from vegetation during transpiration and the rate at which CO2 is taken up by leaves during photosynthesis. Many previous studies have documented a decrease in stomatal conductance when leaves are exposed to elevated CO2 levels similar to those expected toward the latter half of the 21st century (c. 550 ppm vs. c. 360 ppm in 1999). The consequences of a reduction in stomatal conductance are several and important: a reduction in water use by vegetation, assuming the transpiring surface area of leaves is unchanged, 2. a smaller enhancement in photosynthesis than would be realized if stomatal conductance remained unchanged in elevated CO2, 3. an increase in leaf temperature because evaporative heat loss is reduced when lower stomatal conductance cause a decrease in transpiration.
Keywords	Carbon dioxide Stomata Stomatal responses Climates Terrestrial vegetation Woody species Comparisons Herbaceous species Leaf conductance Gas diffusion Evapotranspiration Photosynthesis Atmospheric chemistry Phytosynthesis Stomatal conductance
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Brookhaven National Lab., Upton, NY.; Northern Arizona Univ., Flagstaff.; Department of Energy, Washington, DC.
Supplemental Notes	Prepared in cooperation with Northern Arizona Univ., Flagstaff. Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200412

Stomatal Responses to CO2: A Comparison of Woody and Herbaceous Species in Arid and Humid Climates.

Stomatal Responses to CO2: A Comparison of Woody and Herbaceous Species in Arid and Humid Climates.
DE2004820420

Publication Date	2003
Personal Author	Koch, G. W.; Ellsworth, D.
Page Count	14
Abstract	The project involved a study of a fundamental response of terrestrial vegetation to rising atmospheric carbon dioxide (CO2) concentration, namely, the change in leaf conductance to gas diffusion associated with a change in the aperture of the microscopic pores (stomata) on the surface of leaves. This 'stomatal conductance' determines the rate at which water is lost from vegetation during transpiration and the rate at which CO2 is taken up by leaves during photosynthesis. Many previous studies have documented a decrease in stomatal conductance when leaves are exposed to elevated CO2 levels similar to those expected toward the latter half of the 21st century (c. 550 ppm vs. c. 360 ppm in 1999). The consequences of a reduction in stomatal conductance are several and important: a reduction in water use by vegetation, assuming the transpiring surface area of leaves is unchanged, 2. a smaller enhancement in photosynthesis than would be realized if stomatal conductance remained unchanged in elevated CO2, 3. an increase in leaf temperature because evaporative heat loss is reduced when lower stomatal conductance cause a decrease in transpiration.
Keywords	Carbon dioxide Stomata Stomatal responses Climates Terrestrial vegetation Woody species Comparisons Herbaceous species Leaf conductance Gas diffusion Evapotranspiration Photosynthesis Atmospheric chemistry Phytosynthesis Stomatal conductance
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Brookhaven National Lab., Upton, NY.; Northern Arizona Univ., Flagstaff.; Department of Energy, Washington, DC.
Supplemental Notes	Prepared in cooperation with Northern Arizona Univ., Flagstaff. Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200412