meteR (version 1.2)

downscaleSAR: Downscale the species area relationship (SAR) or endemics area relationship (EAR)

Description

Compute METE SAR by downscaling from some larger area A0 to a smaller areas.

Usage

downscaleSAR(x, A, A0, EAR = FALSE)

Arguments

x

an object of class meteESF

A

numerical vector of areas (<= A0) for which the METE prediction is desired

A0

total study area

EAR

logical. TRUE computes the endemics area relatinship

Value

an object of class sar inheriting from data.frame with columns A and S giving area and species richness, respectively

Details

Downscaling is done non-iteratively (i.e. the SAD and SSAD are calculated based on state variables at the anchor scale A0) thus unlike the upscaling SAR function, downscaling can be computed for any arbitrary scale $\leq A_0$.

References

Harte, J. 2011. Maximum entropy and ecology: a theory of abundance, distribution, and energetics. Oxford University Press.

See Also

meteESF, meteSAR, empiricalSAR, upscaleSAR

Examples

data(anbo)
anbo.esf <- meteESF(spp=anbo$spp, abund=anbo$count)
anbo.thr.downscale <- downscaleSAR(anbo.esf, 2^(seq(-3, 4, length=7)), 16)
plot(anbo.thr.downscale)

## theoretical SARs from state variables only
thr.downscale <- downscaleSAR(meteESF(S0=40, N0=400), 2^seq(-1,4,by=1), 16)
thr.downscaleEAR <- downscaleSAR(meteESF(S0=40, N0=400), 2^seq(-1, 4, by=1), 16, EAR=TRUE)
plot(thr.downscale, ylim=c(0, 40), col='red')
plot(thr.downscaleEAR, add=TRUE, col='blue')