Table 2.
Symbols for Fig. 5
| Quantity | Symbol | Value (25 °C) | Units |
|---|---|---|---|
| Molar volume of water, liq. | 1.807 × 10−5 | m3 mol−1 | |
| Diffusivity, water in air | D | 2.5 × 10−5 | m2 s−1 |
| Molar concentration of air | c | 40.86 | mol m−3 |
| Gas constant | R | 8.3145 | m3 Pa mol−1 K−1 |
| Reference temperature | T | 298.15 | K |
| Reference vapour mole fraction | χ* | 0.0313 | – |
| Transpiration | E | – | mol m−2 s−1 |
| Hydraulic conductivity | k | – | mol m−1 Pa−1 s−1 |
| Stomatal conductance | g s | mol m−2 s−1 | |
| Boundary layer conductance | g bl | mol m−2 s−1 | |
| Tortuosity | τ | 1.5 | – |
| Volume fraction | φ | – | – |
| Cell diameter | l c | m | |
| Subscripts and superscripts | |||
| Wall path | w | ||
| Cell-to-cell path | c | ||
| Symplast | sym | ||
| Apoplast | apo | ||
| Plasmamembrane | p | ||
| Vapour path | v | ||
| Mesophyll | m | ||
| Stomata | s | ||
| Boundary layer | bl | ||
| Bundle sheath | b | ||
| Isothermal vapour path | ψ | ||
| Leaf | L | ||
| Surface area | S | ||
| Xylem | x | ||
| Radial (from xylem) | r |