# Stomatal resistance

From AMS Glossary

## stomatal resistance

The opposition to transport of quantities such as water vapor and carbon dioxide to or from the stomata (pores) on the leaves of plants.

For water vapor, stomatal resistance where

*r*is defined as*q*_{i}and*q*_{s}are the specific humidities in the interior of the stomate cavity and at the exterior surface of the leaf, ρ is air density, and*E*is the moisture flux. The dimension of*r*is time per distance, that is, inverse velocity. This equation is analogous to that for an electrical resistance, proportional to the ratio of voltage potential divided by current flow.*See*transpiration.Oke, T. R. 1987. Boundary Layer Climates. chap. 4.