sie {sharx}

Small Island Effect (SIE) via Breakpoint Regression

Description

Fit a breakpoint regression model to data to find threshold for the small island effect (SIE) as described in Lomolino...

Usage

sie(S, A, method = "Nelder-Mead", ...)
sieplot(x, add = FALSE, ...)

Arguments

S

untransformed species richness, vector.

A

untransformed area, vector.

x

a fitted model object of class 'sie'.

method

optimization method.

add

logical, if lines should be added to existing plot (TRUE), or a new plot is to be drawn (FALSE, default).

...

graphical arguments passed to plot.

Details

sie fits the breakpoint regression to the data, richness is log(S+0.5) transformed, area is log(A) transformed before analysis. There is a coef, summary, print method for fitted objects.

sieplot plots the observed (transformed) data and the fitted line.

Value

An S4 object of class 'sie' inheriting from class 'mle'.

Author(s)

Peter Solymos

References

Lomolino, M. V., and M. D. Weiser. 2001. Towards a more general species-area relationship: diversity on all islands, great and small. Journal of Biogeography, 28, 431–445.

Examples

data(sardata)
DAT <- sardata$islands[sardata$islands$study=="abbott1978plant",]
(x <- sie(DAT$S, DAT$A))
coef(x)
summary(x)
sieplot(x)