Concepts

These pages explain what PhytKit's models are and how it fits them. Read them when you want to know what a parameter means, why a fit came out the way it did, or which model to choose.

• How fitting works: the optimizer, bounds, fixed parameters, convergence, and fits the data can't pin down.
• Photosynthesis models: FvCB C3, von Caemmerer C4 and the empirical model; temperature responses; mesophyll conductance; soft constraints.
• Stomatal conductance models: Buckley–Turnbull–Adams and Medlyn.
• Plant hydraulics models: xylem vulnerability and pressure–volume curves.
• Soil water retention models: van Genuchten and four related models.
• LI-600 porometry: why the LI-600 overestimates conductance, how the correction works, and how A is estimated from conductance.

For every model's parameters, defaults and bounds, see Models and parameters.