Indicate site conditions with community weighted mean values of traits or with mode of gradient classes (sum of species amplitudes).

Description

Calculates community weightes mean trait values, like mean Ellenberg indicator values. Alternatively (method = 'mode') environmental conditions can be calculated according to th econcept of sums of amplitudes of species along ecological gradients.

Usage

isc(veg, trait.db, ivnames, keyname = 'LETTERCODE', method = c('mean', 'mode'), 
weight, db, ...)
showindiplot(veg, trait.db, plotid, weight, keyname = 'LETTERCODE')

Arguments

Details

Zero trait values will be handled as NA values.

Value

Vector with the ecological classification of sites. Either mean trait values or mode of gradient classes.

Author(s)

Florian Jansen jansen@uni-greifswald.de

Examples

## Not run: 
db <- 'elbaue'
veg <- tv.veg(db, cover.transform='sqrt', check.critical = FALSE)
site <- tv.site(db, verbose = FALSE)
# Exclude plots with very high water level fluctuation
veg <- veg[site$SDGL < 60,]
veg <- veg[,colSums(veg) > 0]
site <- site[site$SDGL < 60,]
# Load species trait value database
traits <- tv.traits(db)

# Mean indicator values of Ellenberg F values
mEIV_F <- isc(veg, traits, 'OEK_F', method = 'mean')
plot(site$MGL, mEIV_F, xlab = 'Mean groundwater level')

## End(Not run)
## Not run: 
# Mode (most frequent level) of Ellenberg F values
library(reshape)
traitmat <- cast(traits, LETTERCODE ~ OEK_F)
traitmat <- traitmat[,-14]
ilevel <- isc(veg, traitmat, ivnames= as.character(1:12), method = 'mode')
boxplot(site$MGL ~ ilevel)

## End(Not run)

Results