Adds a connectivity constraint to a scenario object.

Adds a connectivity constraint to a scenario object.

Usage

add_constraint_connectivity(mod, method, value = NULL, resistance = NULL, ...)

# S4 method for class 'BiodiversityScenario'
add_constraint_connectivity(mod, method, value = NULL, resistance = NULL, ...)

Arguments

mod

A BiodiversityScenario object with specified predictors.

method

A character indicating the type of constraints to be added to the scenario. See details for more information.

value

For many dispersal "constrain" this is set as numeric value specifying a fixed constrain or constant in units "m" (Default: NULL). For kissmig the value needs to give the number of iteration steps (or within year migration steps). For adaptability constraints this parameter specifies the extent (in units of standard deviation) to which extrapolations should be performed.

resistance

A SpatRaster object describing a resistance surface or barrier for use in connectivity constrains (Default: NULL).

...

passed on parameters. See also the specific methods for adding constraints.

Details

• hardbarrier - Defines a hard barrier to any dispersal events. By definition this sets all values larger than 0 in the barrier layer to 0 in the projection. Barrier has to be provided through the "resistance" parameter.

• resistance - Allows the provision of a static or dynamic layer that is multiplied with the projection at each time step. Can for example be used to reduce the suitability of any given area (using pressures not included in the model). The respective layer(s) have to be provided through the "resistance" parameter. Provided layers are incorporated as abs(resistance - 1) and multiplied with the prediction.

See also

Other constraint: add_constraint(), add_constraint_MigClim(), add_constraint_adaptability(), add_constraint_boundary(), add_constraint_dispersal(), add_constraint_minsize(), add_constraint_threshold(), simulate_population_steps()