downscaleSAR: Downscale the species area relationship (SAR) or endemics...
In meteR: Fitting and Plotting Tools for the Maximum Entropy Theory of Ecology (METE)

Description Usage Arguments Details Value Author(s) References See Also Examples

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

1	downscaleSAR(x, A, A0, EAR = FALSE)

`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

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 ≤q A_0.

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

Andy Rominger <ajrominger@gmail.com>, Cory Merow

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

meteESF, meteSAR, empiricalSAR, upscaleSAR

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')