PhotosynEB {plantecophys}

Coupled leaf gas exchange model with energy balance

Description

As Photosyn, but calculates the leaf temperature based on the leaf's energy balance. Including sensible and long-wave heat loss, latent heat loss from evaporation, and solar radiation input.

#'Warning:Do not provide GS as an input to PhotosynEB directly; the results will not be as expected (filed as issue #27)

Usage

PhotosynEB(
  Tair = 25,
  VPD = 1.5,
  Wind = 2,
  Wleaf = 0.02,
  StomatalRatio = 1,
  LeafAbs = 0.86,
  RH = NULL,
  ...
)

FindTleaf(gs, Tair, ...)

Arguments

Tair

Air temperature (C)

VPD

The vapour pressure deficit of the air (i.e. not the leaf-to-air VPD) (kPa).

Wind

Wind speed (m s-1)

Wleaf

Leaf width (m)

StomatalRatio

The stomatal ratio (cf. Licor6400 terminology), if it is 1, leaves have stomata only on one side (hypostomatous), 2 for leaves with stomata on both sides (amphistomatous).

LeafAbs

Leaf absorptance of solar radiation (0-1).

RH

The relative humidity of the air (i.e. not calculated with leaf temperature) (in percent).

...

Further parameters passed to Photosyn. Note that Tleaf is not allowed as an input, since that is calculated by PhotosynEB from energy balance.

gs

For FindTleaf, the stomatal conductance (mol m-2 s-1).

Details

Uses the Penman-Monteith equation to calculate the leaf transpiration rate, and finds Tleaf by solving the leaf energy balance iteratively. In the solution, it is accounted for that stomatal conductance (via the dependence of photosynthesis on Tleaf) and net radiation depend on Tleaf.

Also included is the function FindTleaf, which calculates the leaf temperature if the stomatal conductance is known. The limitation to this function is that input stomatal conductance (gs) is not vectorized, i.e. you can only provide one value at a time.