density_dependence_dispersing: Density-dependent proportions of populations dispersing

In steps-dev/steps: Spatially- and Temporally-Explicit Population Simulator

Density-dependent proportions of populations dispersing

Description

The proportion of populations dispersing will be density dependent in a simulation. Proportions of populations in each life stage dispersing is adjusted based on available carrying capacity. If life-stages are set by the population_density_dependence_functions, these will be used to determine how close the population is to carrying capacity. If no life-stages are set or density dependence is set to NULL in population_dynamics, the function will consider all life-stages in the calculation.

Usage

density_dependence_dispersing(maximum_proportions = 1)

Arguments

maximum_proportions

A single value or vector of the maximum proportions (between zero and one) of individuals in each life stage that disperse - default is 1. If maximum proportions are specified as a single number, then all life-stages use that value, however, a vector of maximum proportions (equal in length to the number of life-stages) can also be specified. Maximum proportions are multiplied by the calculated proportions based on carrying capacity so to prevent stages from dispersing, set corresponding values to zero.

Value

An object of class dispersal_proportion_function

Examples

# Example of a proportion function that disperses all populations based on their approach
# to carrying capacity

## Not run: 
prop_dispersal <- density_dependence_dispersing()

kb_dispersal <- kernel_dispersal(dispersal_proportion = prop_dispersal,
                      max_distance = 2000,
                      dispersal_kernel = exponential_dispersal_kernel(distance_decay = 1000))

ls <- landscape(population = egk_pop, suitability = egk_hab, carrying_capacity = egk_k)

pd <- population_dynamics(change = growth(egk_mat), dispersal = kb_dispersal)

simulation(landscape = ls, population_dynamics = pd, habitat_dynamics = NULL, timesteps = 20)

## End(Not run)

steps-dev/steps documentation built on Dec. 9, 2023, 10:51 p.m.