A growth transition function defines how spatial objects or custom functions influence survival and fecundity. Two built-in functions are provided for the user to select, however, a user may also provide custom written functions to modify survival and fecundity throughout a simulation. Please see the tutorial vignette titled "Creating custom *steps* functions" for information on how to write custom functions for use in simulations.
modified_transition to use rasters to modify survival and fecundity
competition_density to use relationship to carrying capacity to modify survival and fecundity