The theory of gas diffusion through stomata

Abstract

Over the last century our understanding of gas exchange between a leaf and its environment has increased greatly from the use of simple con- cepts of resistance to diffusion (e.g. Brown and Escombe, 1900) to the development of complex models and theory (see, e.g. Penman and Schofield, 1951; Monteith, 1983). Although the general concepts are now well established (see, e.g. Weyers and Meidner, 1990; Nobel, 1991; Jones, 1992) some controversial aspects, such as the diffusion of gases inside leaves (see, e.g. Parkhurst, 1994), remain. In this section, empha- sis will be on the theory of diffusion of gases through stomata. The vari- ous techniques for measuring stomatal resistance, or its reciprocal, stomatal conductance, have been extensively covered elsewhere (see, e.g. Sestak et al., 1971; Weyers and Meidner, 1990).