MetaSim: Simulation of Stochastic Metapopulation Models

In primer: Functions and Data for the Book, a Primer of Ecology with R

Description

Originally focused on creating a community of core-satellite species, this function allows simulation of several metapopulation models, where colonization and extinction rates are stochastic draws from uniform distributions, with specified means and ranges.

Usage

MetaSim(
  Time = 50,
  NSims = 1,
  method = "hanski",
  ci = 0.25,
  e = 0.25,
  phi = 0.75,
  p0 = 0.5,
  D = 0.5
)

Arguments

Time	A scalar for the number of time steps over which to simulate each population.
NSims	A scalar for the number of simulations, which is analogous to the number of species in the community.
method	A character string, in quotes, specifying which metapopulation model to use: "hanksi", "gotelli", "lande", "levins". See "See Also" below.
ci	Scalar for mean colonization rate.
e	Scalar for mean extinction rate.
phi	A scalar for the relative variability in rates. See Details.
p0	Initial proportion of sites occupied for each species.
D	Parameter for habitat destruction; applies to only the "lande" model.

Details

phi is one half of the relative range of each rate (colonization and extinction). For each time step, each rate is drawn from a uniform distribution, Unif(rate-phi, rate+phi). Thus, the range is 2*phi, and center on the specified mean (ci or e).

Value

Function returns a list with these components.

method	The method used (default is "hanski").
time	The integer sequence of times, from 0 to the value of the argument Time.
Ns	Time by NSims matrix of observed population sizes.
Parameters	A named vector of the parameters used for the simulations.

Author(s)

Hank Stevens <[e-mail]>

References

Stevens. M.H.H. (2009) A Primer of Ecology with R. Use R! Series. Springer.

See Also

gotelli, hanski, levins

Examples

out <- MetaSim(NSims=2)
pops <- out$Ns
matplot(out$t, pops, type='l')
title(sub=paste(out$method, "model"))

primer documentation built on Jan. 7, 2021, 1:07 a.m.