A comparison of measured and modeled ozone uptake into plant leaves.
Ozone uptake into plant leaves was measured in gas exchange chambers using a mass balance and a variable conductance approach. The variable conductance approach was found to more reliably measure ozone flux through stomata. Measurements using this approach were contrasted with estimates obtained by measuring stomatal conductance g(sw) and modeling ozone uptake using a diffusion equation, assuming a negligible ozone concentration in the substomatal cavity. Actual measurements of uptake were close, but slightly higher than modeled values, providing some support to the idea that substomatal ozone concentrations are close to zero. However, the difference between measured and modeled uptake values suggests either that (i) variable conductance approach measures more ozone uptake than caused by stomatal uptake alone or (ii) ozone conductance is underestimated.
Wang
D
D
School of Natural Resources, University of Vermont, Burlington, Vermont 05405, USA.
Hinckley
T M
TM
Cumming
A B
AB
Braatne
J
J