MetaSim: Simulation of Stochastic Metapopulation Models
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.
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.
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).
References
Stevens. M.H.H. (2009) A Primer of Ecology with R. Use R!
Series. Springer.