Fig. 1.

Basic geometry of the three-dimensional model with a smaller (A) and a larger (B) substomatal chamber. It includes a stomatal porus which is connected to the chamber by a stomatal channel. The model also comprises an air layer adjacent to the leaf surface which has a thickness of 35 µm. The dimension of the pore is 10 × 12 µm, the depth of the channel amounts to 10 µm. The smaller substomatal chamber has a length of 12 µm and the length of the larger chamber amounts to 30 µm. For the other model dimensions see text and the cross-sectional representations in Fig. 2.