Neighborhood seed predation (linked)

Parameters for this behavior

Parameter name	Description
Neighborhood Predation - "p0"	The "p0" term in the seed offtake equation when in linked mode.
Neighborhood Predation - Species i "pn"	The "p_n" term for species i in the seed offtake equation when in linked mode.
Neighborhood Predation - Minimum Neighbor DBH (cm)	The minimum DBH of trees to be included when calculating the basal area composition of the neighborhood, when in linked mode.
Neighborhood Predation - Neighbor Search Radius (m)	The radius to search for trees when calculating the basal area composition of the neighborhood, when in linked mode.

How it works

This behavior is used together with the Functional response seed predation behavior (linked) behavior. The two behaviors work together to model seed predation.

The actual amount of seed eaten is calculated by the Functional response seed predation behavior (linked) behavior. This behavior then distributes the offtake according to neighborhood composition.

The behavior begins by calculating the Y values for each grid cell as in the non-linked version (masting is ignored - there is only one set of parameters). Then the Y values are adjusted so that their mean is equal to the amount of whole-plot offtake Z as calculated by the Functional response seed predation behavior (linked). The adjustments are made as follows:

Calculate logit(Z)
Calculate the logit(Ys) and subtract the minimum value from each (as well as the logit(Z)) so they will all be positive
Average the logit(Y)s
Divide logit(Z) by average logit(Y) to get a correction factor
Multiply each logit(Y) by the correction factor
Add back the same minimum value formerly subtracted
Back transform logit(Y) to Y and use when removing seeds

Then the seeds are removed according to the adjusted Y values.

This behavior can be used in the same run with the non-linked version of this behavior. The two sets of species are kept completely separate, and there are two separate sets of parameters.

This behavior may be applied to seeds of any species. Any species to which it is applied must also have a Disperse behavior applied, as well as the Functional response seed predation behavior (linked). This behavior should be placed after that behavior in the ordered list of model behaviors.

In order to make results more verifiable, Neighborhood Seed Predation produces a grid called Neighborhood Seed Predation. This grid stores the pre predation seed rain and amount of seeds eaten for each cell in the Dispersed Seeds grid. This grid has no effect on calculations but can be saved in the output file for review.