© 2001 Heron Publishing—Victoria, Canada
Acclimation of whole-plant Acacia farnesiana transpiration to carbon dioxide concentration
W. A. Dugas (1), H. W. Polley (2), H. S. Mayeux (2) and H. B. Johnson (2)
1. Blackland Research and Extension Center, Texas Agricultural Experiment Station, 720 E. Blackland Road, Temple, TX 76502, USA
/ 2. Grassland, Soil and Water Research Laboratory, USDA-ARS, 808 E. Blackland Road, Temple, TX 76502, USA / Received August 2, 2000
Summary
Transpiration per unit leaf area of Acacia farnesiana (L.) Willd. plants grown at a CO2 concentration ([CO2]) of 385 μmol mol–1 was about twice that of plants grown at 980 μmol mol–1. However, when plants grown for more than a year at 980 μmol mol–1 were exposed to 380 μmol mol–1 for 9 days, they transpired at half the rate of those that had been grown at 380 μmol mol–11. Similarly, plants grown at 380 μmol mol–1, when exposed to 980 μmol mol–1, transpired at twice the rate of those grown at 980 μmol mol–1. Thus, the effects of elevated [CO2] on whole-plant transpiration, like those on photosynthesis, respiration and stomatal conductance, cannot reliably be extrapolated
from measurements made during short-term exposure to elevated [CO2].
Keywords:
climate change, CO2, global change, heat balance, sap flow, stem flow.
