9. Plants

The plants module in the FEST model is used in two ways. The first way is to set plants parameters used by other processes. One example is the leaf area index, a parameter that is used by soil balance module to compute evapotranspiration using Penman-Monteith equation. When multiple values of the same parameter are available for different time, the user can pack all values in a multidimensional NetCDF file, so that the FEST model can update the parameter value when a new map supersedes the old one. The second way of using the plants module is to simulate the plants growth and mortality with a dynamic model approach. In this case, the plants parameter are treated as state variables that are updated in time by the FEST model.

The plants module is activated by filling the specific section in the main configuration file ( Section 3.6 ). This chapter describes the plants configuration file.

The parameters to define are listed and described in Table 9.1.

Table 9.1 Definition of keywords in plants configuration file

Keyword	Description	Requirements
plants-simulation	Set whether to simulate plants dynamic. 0 = plants dynamic is not simulated	MANDATORY
[vegetation-fraction]	Map of percentage of pixel covered by vegetation. (0-1)	Optional. Required by soil balance to compute evaporation and transpiration components. It can be be set with scalar keyword
[lai]	Map of leaf area index (m²/m²)	Optional. Required by soil balance to compute evaporation with Penman-Monteith or energy balance solving. It can be set with scalar keyword
[vegetation-height]	Map of vegetation height (m)	Optional. Required by soil balance to compute evaporation with Penman-Monteith or energy balance solving. It can be set with scalar keyword
[min-stomatal-resistance]	Map of minimum leaf stomatal resistance (s/m)	Optional. Required by soil balance to compute evaporation with Penman-Monteith. It can be set with scalar keyword

An example of plants.ini configuration file follows.

plants-simulation = 0

[vegetation-fraction]
  file = ./data/fv.asc
  format = esri-ascii 
  epsg = 3003
  
[lai]
  file = ./data/lai.nc
  format = net-cdf
  variable = lai
  epsg = 3003
  sync-initial-time = 1

[vegetation-height]
  scalar = 2.3

[min-stomatal-resistance]
  scalar = 30.