Summary:

## Stomatal Resistance and Photosynthesis

The article discusses the coupling between leaf stomatal resistance, which is needed for water vapor flux, and leaf photosynthesis. Key points:

### Sunlit and Shaded Leaves
- Stomatal resistance and photosynthesis are calculated separately for sunlit and shaded leaves, using the average absorbed photosynthetically active radiation (PAR) for each.
- This gives sunlit and shaded stomatal resistance (rs^sun, rs^sha) and photosynthesis (A^sun, A^sha).

### Canopy Photosynthesis and Conductance
- Canopy photosynthesis is the sum of sunlit and shaded photosynthesis, weighted by their respective leaf area indices (L^sun, L^sha).
- Canopy conductance is the weighted sum of the inverse of leaf boundary layer resistance (rb) and sunlit/shaded stomatal resistance.

In summary, the article describes the coupled modeling of stomatal resistance and photosynthesis for sunlit and shaded leaves, and how these factors are used to calculate canopy-level photosynthesis and conductance.