CTFS.recruitment {CTFS}R Documentation

Overview of Analysis of Recruitment Rates in Tropical Tree Populations

Description

Provides an overview for the analysis of recruitment rates for tree populations by a variety of categories including the functions that are available, supporting functions and ways for using the options of the main functions.

Details

FUNCTIONS TO COMPUTE RECRUITMENT RATES

recruitment Annual Recruitment Rates by Categories (User defined groups)
recruitment.eachspp Annual Recruitment Rates by Species

FUNCTIONS FOR FORMATTING RESULTS

assemble.demography Reformat the Output from Demographic Functions from List to Dataframe

FUNCTIONS CALLED BY USER FUNCTIONS

find.climits Calculates confidences limits for recruitment rates
fill.dimension Fills all the dimensions of a 2 dimensional array
fill.1dimension Fills all the dimensions of a 1 dimensional array

COMPUTATION OF RECRUITMENT

The annual recruitment rate is calculated as

r = (logN1-logS) / mean(time1-time0)

where N1 is the number of live individuals at the second census,
where S is the number of surviving individuals: trees that were alive in the first census and alive in the second census,
where time1 and time0 are expressed in years and is the length of the census interval as recorded for trees in the second census (which includes all of the surviving trees.

The confidence limits are computed using find.climits which returns the number of survivors, S, out of N individuals for each confidenc interval in turn. The beta distribution is used to determine the number of S for the upper 95% and lower 5% (default probability level). Confidence limits for mortality rate are computed as from these CI for S as:

rate.CI.upper = ( logN1 - log(S.lowerCI) ) / mean(time1 - time0)
rate.CI.lower = ( logN1 - log(S.upperCI) ) / mean(time1 - time0)

Note that S.lowerCI is a lower value of S which results in a higher number of recruits and hence a higher recruitment rate. And S.upperCI is a higher value of S which results in a lower number of deaths and hence a lower recruitment rate.

Author(s)

Rick Condit and Pamela Hall

See Also

CTFS.groupcats


[Package CTFS version 1.00 Index]