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]