protectedAreaSelection {ConnMatTools}

Function to select optimal network of protected areas based on connectivity

Description

This function finds the optimal network of protected areas based on connectivity using the eigenvalue perturbation approach described in Nilsson Jacobi & Jonsson (2011).

Usage

protectedAreaSelection(
  conn.mat,
  nev = dim(conn.mat)[1],
  delta = 0.1,
  theta = 0.05,
  M = 20,
  epsilon.lambda = 1e-04,
  epsilon.uv = 0.05,
  only.list = T,
  ...
)

Arguments

conn.mat

a square connectivity matrix.

nev

number of eigenvalues and associated eigenvectors to be calculated.

delta

the effect of protecting site i (e.g. increase in survival or fecundity in protected areas relative to unprotected areas). Now a single value, in future it will be possible to specify site-specific values. The perturbation theory used in the construction of the algorithm assumes delta to be small (e.g. delta=0.1). However, higher values give also good results.

theta

the threshold of donor times recipient value that a site must have to be selected.

M

the maximal number of sites selected from each subpopulation even if there are more sites above the threshold theta

epsilon.lambda

Threshold for removing complex eigenvalues.

epsilon.uv

Threshold for removing eigenvectors with elements of opposite signs of comparable magnitude.

only.list

Logical, whether the function return only the list of selected sites or also the predicted impact of each selected site on the eigenvalues

...

Additional arguments for the eigs function.

Value

If only.list is TRUE, just returns the list of selected sites. If FALSE, then result will be a list containing selected sites and predicted impact of each selected site on the eigenvalues.

Author(s)

Marco Andrello [e-mail]

References

Jacobi, M. N., and Jonsson, P. R. 2011. Optimal networks of nature reserves can be found through eigenvalue perturbation theory of the connectivity matrix. Ecological Applications, 21: 1861-1870.