Temporal development

Some plant properties have typical temporal patterns that vary with the seasons such as LAI, albedo, canopy height and root depth and length. When the vegetation is represented as an implicit single big leaf, none of these plant properties, except for root development, are used in the simulation and therefore they are not defined. Root length is only considered when the water uptake is calculated with the SPAC approach (see Steady-state SPAC approach).

The temporal development of these characteristics can either be simulated, i.e. dynamic development, or be given to the model as parameter values, i.e. a static development. Parameter values of plant properties can either be given as parameters in a table and varied as a function of the day number, tday, or be given as driving variables in a separate file (see Crop data). For albedo an additional alternative (called “Static”) is to have a constant parameter value during the whole growing season. All of these options are determined by the switches: LaiInput, AlbedoVeg, CanopyHeightInput and RootInput. Note that it is possible to choose which of the plant properties should be static or not, so that if you, for example, choose to simulate leaf area index, you can still give the canopy height as parameter values.