recruitment {CTFS}R Documentation

Annual Recruitment Rate by Categories (User defined groups)

Description

Computes annual recruitment rate for all trees or any user defined categorization of trees. Any two census datasets can be provided in order of date of census. The annual recruitment rate and other statistics are computed for user defined categories.

Usage

recruitment(census1, census2, mindbh=10, alivecode = c("A", "AB", "AS"), 
        split1 = NULL, split2 = NULL)

Arguments

census1 name of census datafile for first census, must be a dataframe, must be of same length as census2
census2 name of census datafile for second census, must be a dataframe, must be of same length as census1
mindbh minimum DBH in census1 for inclusion in computation.
alivecode character, codes of the variable status that indicate the tree is alive. The most general valid categories are: "A" and "AB" and "AS".
split1 a vector of categorical values of the same length as census which groups trees into classes of interest for which mortality values are computed. This vector can be composed of characters or numbers.
split2 a second vector of categorical values of the same length as census which groups trees into classes of interest for which mortality values are computed. This vector can be composed of characters or numbers.

Details

See CTFS.recruitment for details on the computation of recruitment rates and associated functions.

Any two censuses on a datafile must be used. They do not have to be sequential, only that census1 has to be before census2.

The vectors split1 and split2 must be of the same length as census1 and census2 but can contain NA.

Take care when creating a split vector based on dbh. The only valid dbh for a recruit is in the second census of any given interval. Recruits do not have a valid dbh for the first census of an interval as they are not large enough yet to enter the census. If the first census is used, then no recruits will be identified. So a dbh vector should be based on the dbh of the tree in the second census. The inverse is true for mortality. Therefore the same dbh split vector CANNOT be used for computations of recruitment and mortality. Use a dbh vector based on the census1 for mortality and on census2 for recruitment.

The results of recruitment can be organized into dataframes with the use of assemble.demography.

Value

recruit returns a list of arrays with the values of split1 as the first dimension and the values of split2 as the second dimension of the array. The array contains the following named components:

$N1 the number of living trees at the second census
$R the number of trees that were recruited between the first and second census
$rate the recruitment rate in %/year
$lower the lower 95% confidence
$upper the upper 95% confidence
$time mean number of years between census for trees used in recruitment rate computation.
$date0 mean date of first census
$date1 mean date of second census


If the vector(s) split1 and split2 are provided by the user, then recruitment rates and associated statistics are computed for each value of the vectors. The vectors are nested so that recruitment rates is computed for each category of split2 within each category of split1. recruitment values are returned for all levels of each vector and if no value can be computed then 0 or NA is returned as appropriate.

Author(s)

Rick Condit and Pamela Hall

See Also

CTFS.recruitment

Examples

## Not run: 
1. Default use of recruit()
rec.out <- recruitment(tst.bci90.full,tst.bci95.full)
rec.out

2. Create a vector of habitat for each tree based on the quadrate 
location of tree

habitat.vct <- sep.quadinfo(tst.bci90.full,bciquad.info)
rec.hab.out <- recruitment(tst.bci90.full,tst.bci95.full,split1=habitat.vct)

## End(Not run)

[Package CTFS version 1.00 Index]