sgf.randarea {CTFS}R Documentation

Number of Species, Genera and Families for Randomly Selected Area

Description

Counts the number of species, genera and families of the individuals found in a given single defined area of a plot. There area is defined by quaddim with a randomly selected initial corner. This function only identifies a randomly selected point and the corners of an area of given size starting from that point. It calls sgf.area to do the counting.

Usage

sgf.randarea(census1, spp.info, quaddim = c(100, 100), 
        alivecode = c("A"), mindbh = NULL, plotdim = c(1000, 500), 
        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
unidennames vector of codes for unidentified species, codes vary among sites and datasets

Details

Only one randomly selected area is subsetted and values computed with each run of this function. All areas are squares. For other shapes use spp.randarea.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 following information for the defined area.

n.ind number of individuals
n.spp number of species
n.gen number of genera
n.fam number of families
r.sppgen ratio of number of species to number of genera
r.sppfam ratio of number of species to number of families
r.genfam ratio of number of genera to number of families

Author(s)

Rick Condit, Suzanne Lao and Pamela Hall

See Also

CTFS.diversity

Examples

## Not run: 
1. default use gives the total number of species, genera, families for
a randomly selected area of a given size.  Run multiple times to see
that different values are computed each time.

sgf.randarea(bci90.full,bcispp.info)

## End(Not run)

[Package CTFS version 1.00 Index]