Zeta distance decay for a range of numbers of assemblages or sites

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Description

Computes the distance decay of zeta diversity for a range of orders (number of assemblages or sites), using linear regressions.

Usage

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Zeta.ddecays(xy, data.spec, orders = 2:10, sam = 1000,
  confint.level = 0.95, method = "mean", plot = TRUE)

Arguments

xy

Site-by-coordinate data frame, with sites as rows and coordinates as columns.

data.spec

Site-by-species presence-absence data frame, with sites as rows and species as columns.

orders

Range of number of assemblages or sites at which zeta diversity is computed. All the orders must be striclty greater than 1.

sam

Number of samples for which the zeta-diversity is computed.

confint.level

Percentage for the confidence intervals of the coefficient from the linear regression.

method

Indicates which distance to consider for more than 3 sites. Method can be "mean" or "max"

plot

Boolean value (TRUE or FALSE) indicating if the outputs must be plotted.

Value

Zeta.ddecays returns a list containing the following components:

coefs

A vector of the coefficients from the linear regressions over distance for the numbers of sites specified by 'order'.

confint

The confidence intervals for the coefficients from the linear regressions.

References

Hui C. & McGeoch M.A. (2014). Zeta diversity as a concept and metric that unifies incidence-based biodiversity patterns. The American Naturalist, 184, 684-694.

See Also

Zeta.decline, Zeta.order, Zeta.ddecay

Examples

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data(BCI.spec.coarse)
xy <- BCI.spec.coarse[1:2]
data.spec <- BCI.spec.coarse[3:308]

dev.new()
zeta.ddecays <- Zeta.ddecays(xy, data.spec, sam = 100, orders = 2:5,
    plot = TRUE, confint.level = 0.95)

##########

data(Marion.species)
xy <- Marion.species[1:2]
data.species <- Marion.species[3:33]

dev.new()
zeta.ddecays.species <- Zeta.ddecays(xy, data.species, sam = 100, orders = 2:5,
   plot = TRUE, confint.level = 0.95)