Table A1.
Model variables, definitions and units
| Variable | Definition | Units |
|---|---|---|
| Ia | PPFD absorbed by the leaflet surface [eqn (1)] | μmol m–2 s–1 |
| Iout,dr, Iout,df | Total outside direct and diffuse PPFD [eqn (A1)] | μmol m–2s–1 |
| Io, Io,dr, Io,df | Incident total, direct and diffuse PPFD at the top of the canopy [eqn (4)] | μmol m–2s–1 |
| I(L)a, I(L)a,dr, I(L)a,df | Absorbed total, direct and diffuse PPFD at a given canopy depth [eqn (5)] | μmol m–2s–1 |
| L | Cumulative leaf area index at a given canopy depth [eqn (3)] | m2 leaf m–2 ground |
| Lp | Leaf area index selected for Gaussian integration [eqn (6)] | m2 leaf m–2 ground |
| LT | Total leaf area index [eqn (7)] | m2 leaf m–2 ground |
| Pn | Net leaf photosynthesis rate [eqn (1)] | μmol CO2 m–2 leaf s–1 |
| Pg | Gross leaf photosynthesis rate [eqn (2)] | μmol CO2 m–2 leaf s–1 |
| Pg(Lp) | Gross leaf photosynthesis rate at Gaussian selected canopy depth [eqn (6)] | μmol CO2 m–2 leaf s–1 |
| Pg,−1, Pg,0, Pg,1 | Gross leaf photosynthesis rate at top, middle and bottom of the canopy [eqn (7)] | μmol CO2 m–2 leaf s–1 |
| Pg,c | Whole-canopy photosynthesis rate [eqn (7)] | μmol CO2 m–2 ground s–1 |
| β | Solar elevation above the horizon [eqn (A4)] | ° |
| ρ | Canopy reflection coefficient [eqn (A2)] | |
| p (–1,0,1) | Specific factor to define top (–1), middle (0), and bottom (1) canopy depth [eqn (A5)] |
PPFD, photosynthetic photon flux density (μmol m–2 s–1)
The equation number following the definition indicates where the variable first occurs and is introduced.