Water use efficency (WUE) in C4 plants

Range 2-5 g CO2 per kg H2O
Organism Biosphere
Reference Nobel, P. S. "Plant Physiology", 3rd ed. p.406 bottom paragraph
Comments P.406 bottom paragraph: "Even though photosynthesis and transpiration depend on environmental conditions, we can still make some generalizations about WUE for different types of plants. Specifically, WUE’s averaged over a day for mature leaves are usually 1 to 3 gCO2/(kg H2O) for C3 plants, 2 to 5 gCO2/(kgH2O) for C4 plants, and 10 to 40 g CO2/(kg H2O) for CAM plants. C4 plants have approximately double the WUE of C3 plants because C4 plants tend to have lower gas-phase conductances (which conserves water with a relatively small negative effect on photosynthesis) and higher liquid-phase conductances (which affects photosynthesis positively) than do C3 plants. However, maximizing WUE may not always be adaptive, e.g., water is generally not limiting for an aquatic plant."
Entered by Ron Milo - Admin
ID 100672