CTFS.growth {CTFS}R Documentation

Overview of Analysis of Growth Rates in Tropical Tree Populations

Description

Provides an overview for the analysis of growth 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 GROWTH RATES

growth Annual Growth Rates by Categories (User defined groups)
growth.dbh Annual Growth Rates by DBH Classes
growth.eachspp Annual Growth Rates by Species
growth.indiv Annual Growth Rates for each Tree

FUNCTIONS FOR FORMATTING RESULTS

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

LIST OF FUNCTIONS CALLED BY USER FUNCTIONS

rndown5 Rounds down DBH where measurement was less precise than 1 mm
trim.growth Removes extreme values of growth using user defined limits
fill.dimension Fills all the dimensions of a 2 dimensional array
fill.1dimension Fills all the dimensions of a 1 dimensional array

COMPUTATION OF GROWTH

The annual growth rate for a single tree is computed as:

growth = ( dbh1 - dbh0 ) / (time1 - time0)

where dbh0 and dbh1 are the diameters of the tree at the initial and subsequent census, respectively;
where time0 and time1 are the census dates for the initial and subsequent census, respectively expressed in years;

The mean growth rate, meangrow, is the mean of the growth rate for all trees in the population as defined by the provided file. The mean growth rate is expressed in mm per year.

The relative growth rate for a single tree is computed as:

RGR = ( logdbh1 - logdbh0 ) / (time1 - time0)

with variables as described above.

The mean relative growth rate, meanRGR, is the mean of the relative growth rate for all trees in the population as defined by the provided file. The mean relative growth rate is expressed as 1 / years.

The meandbh and meantime is the mean of the dbh and census intervals, respectively, for the trees used for the mean growth rate computation.

Before computing the growth rate, the ``status'' of a tree is determined. The tree must have been recorded as ``A'', alive at both censuses. Therefore, recruits and trees that died are not used for computing growth rates. Also, the time of the census must be recorded for both censuses.

The 95% confidence intervals are computed using a t-distribution.

Author(s)

Rick Condit and Pamela Hall

See Also

CTFS.groupcats


[Package CTFS version 1.00 Index]