New version 6.0.2 New developments for Plant Mobile Pool, Water Uptake functions and Litter Fall

The Plant Mobile Pool is active for seasonal reallocation of Nitrogen and Phosphor.

The New P model was using a common function to estimate C/P ratios and C/N ratios. However because of problems when the P or N pool are approaching zero  and a proper ratio can not be estimated some unexpected behvaivour toke place. A default value has to be assumed without for those very small N or very small P. The  default  C/N ratio was assumed to be half the value of C/N ratio for maximal C/N ratio to form litterfall when C/N ratios are increasing with time. The corresponding C/P ratio is defined as fixed value = 1000. Note that the ratio for litterfall of leaf will always start using the minimum C/N ratio or C/P ratio as long as the current C/N or C/P ratio is below the maximal threshold .

Note also that the related parameter for the rate of re-allocation to the plant (Mobile Allo Coef ) is important for the dynamics. The shooting transfer from the Mobile pool to the leaf is by the the Shoot Coef parameter.

The seasonality of the Mobile pool is governed both by the litterfall that has a separate regulations depending on the stage of the season  depending on the Plant Growth switch Litterfall. Also the Winter regulation switch has to be put on.

The newly developed P version caused a bug in the CoupModel 6.0 (introduced in the start of the year).

The Water Uptake module has got a new Switch: WaterUptake Function.

The Switch has default with a common function for all plants but the new option

with allows the 5 parameters to be individually assigned for each plant.

The new option is stongly recommended for wetlands when for instance the understorey consist of mosses having a very different regulation of water uptake compared to normal plants with a stomatal control.

 

The litterfall from above ground components of the plant was always feeding a surface Litter Pool that was then mixed into the uppermost soil layers. Typical following leaf or  stem of a tree.

For some plants like mosses they have living components that corresponds to a leaf but those are located inside the soil. To represent such plant a new parameter Position4Target has been introduced in the table: Litter fall Above ground.

Providing that you assign a value like -0.1 for the Position4Target parameter the litterfall from Leaf, Stem and Grain will be transfered directly into the Litter compartment of that layer that has a representation for this particular position. This means that no litter will be going into the surface pool or any other layers for that particular plant. Note that the mecanism of reallocation to the leaf can then be applied.

A number of bugs related to previous version have also been deleted mainly with respect to the visualisation and interface. Please update to the current version and report phenomas that are unexpected.

 

 

 

 

 

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