CTFS.growth {CTFS} | R Documentation |
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.
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.
Rick Condit and Pamela Hall