sgf.meanarea {CTFS}R Documentation

Mean Number of Species, Genera and Families for Replicates of Randomly Selected Areas

Description

Computes the mean and standard deviations of the number of species, genera and families of the individuals for a given number of relicates of randomly selected areas. There area is defined by quaddim with a randomly selected initial corner. It calls sgf.area to do the counting.

Usage

sgf.meanarea(census1, spp.info, quaddim = c(100, 100), 
        alivecode = c("A"), mindbh = NULL, plotdim = c(1000, 500), 
        replicates = 50, unidennames = c("**", "UNID", "uniden", "UNIDEN"))

Arguments

census1 name of the datafame of a single census
spp.info name of dataframe that contains each species and information about it, eg. bcispp.info
quaddim dimensions (x,y) of the randomly selected area, in meters
alivecode character, codes of the variable status that indicate the tree is alive. The most general valid categories are: "A" and "AB" and "AS". The default for this function is "A"
mindbh Minimum DBH for inclusion in computation
plotdim plot dimensions, x,y lengths, in meters
replicates number of randomly selected areas to sample
unidennames vector of codes for unidentified species, codes vary among sites and datasets

Details

The number of samples is determined by replicates. Areas must be rectangles but do not need to be squares. Only one area shape and size is used in each function call. For a range of area types and sizes use sgf.meanarea.range.

Pay attention to the default values of alivecode and mindbh. Any tree with alivecode not equal to “A” has a dbh = NA and so will not contribute to the results of this computation. Setting mindbh to some value other than NULL will affect the trees that are included in the calculation. Use mindbh to select trees larger than 10 mm dbh. Use alivecode to select trees to be counted as being alive but have no dbh measurement.

Value

Returns a vector of the means and standard deviations of the following information.

mn.nind mean number of individuals
sd.nind standard deviation of the number of individuals
mn.nspp mean number of species
sd.nspp standard deviation of the number of species
mn.ngen mean number of genera
sd.ngen standard deviation of the number of genera
mn.nfam mean number of families
sd.nfam standard deviation of the number of families
mn.rsppgen mean of the ratio of number of species to number of genera
sd.rsppgen standard deviation of the ratio of the number of species to number of genera
mn.rsppfam mean of the ratio of number of species to number of family
sd.rsppfam standard deviation of the ratio of the number of species to number of family
mn.rgenspp mean of the ratio of number of genera to number of families
sd.rgenspp standard deviation of the ratio of the number of genera to number of families

Author(s)

Rick Condit, Suzanne Lao and Pamela Hall

See Also

CTFS.diversity

Examples

## Not run: 
1. almost default use, with fewer replicates to get a result in a
shorter amount of time

sgf.out <- sgf.meanarea(bci90.full,bcispp.info,replicates=10)

## End(Not run)

[Package CTFS version 1.00 Index]