steps (version 1.3.0)

fire_effects: Fire effects with regeneration

Description

Modifies the landscape by multiplying habitat suitability values by a weighted sum of previous fire intensities based on a user specified regeneration function. By default, the regenerative function is an inverse linear relationship to time, however, this function can be replaced with a response that takes into account other factors of habitat restoration (e.g. growth/re-growth curves of vegetation).

Usage

fire_effects(
  fire_layers,
  effect_time = 3,
  regeneration_function = function(time) {
     -time
 }
)

Arguments

fire_layers

the name(s) of spatial layer(s) in the landscape object with fire disturbances used to alter the habitat object for each timestep (number of layers must match the intended timesteps)

effect_time

the number of timesteps that the fire layer will act on the habitat object

regeneration_function

a function that determines how fast the landscape will regenerate after a fire event

Examples

# Fire (stored in the landscape object and called "fires") acts on the landscape for
#five years with an exponentially decaying intensity.

if (FALSE) {
regen <- function (time) {-exp(time)}

plot(1:5, regen(1:5), type = "l")

fire <- fire_effects(fire_layers = "fires", effect_time = 5, regeneration_function = regen)

ls <- landscape(population = egk_pop, suitability = egk_hab, "fires" = egk_fire)

pd <- population_dynamics(change = growth(egk_mat))

sim <- simulation(landscape = ls,
           population_dynamics = pd,
           habitat_dynamics = list(fire),
           timesteps = 20)
           
plot(sim, object = "suitability", type = "raster", timesteps = 1:9)
}