growth.indiv {CTFS} | R Documentation |
Computes annual growths rate for individual trees and returns a dataframe of these values for all trees. Two types of growth rates are computed: annual dbh increment (mm dbh per year), relative growth rate (% change in dbh per year). Growth rates can also be evaluated for unrealistically high and low values and removed from the summary values. The dataset must have at least 2 censuses to compute growth.
growth.indiv(census1, census2, rounddown = FALSE, mindbh = 10, err.limit = 4, maxgrow = 75)
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 |
rounddown |
logical value in caps. When TRUE, if either of
census is < 55, then the floor of the dbh value / 5 is
provided. When FALSE, no change in the dbh is made. |
mindbh |
minimum DBH in census1 for inclusion in computation. |
err.limit |
number of standard deviations: used for determining if an individual tree growth rate is too high or low for inclusion. |
maxgrow |
maximum absolute growth rate, mm per year: used for determining if an individual tree growth rate is too high for inclusion. |
See CTFS.growth
for details on the computation methods
of growth 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 results of growth.indiv
are growth rates for individual
trees, NOT MEAN GROWTH VALUES. A value is returned for
each tree. If growth is invalid then NA is returned.
growth.indiv
returns a dataframe with the
following components:
tag |
tree individual tag number |
sp |
species code |
gx |
"x" coordinate of tree within the plot |
gy |
"y" coordinate of tree within the plot |
dbh1 |
DBH at the first census as defined by user |
dbh2 |
DBH at the second census as defined by user |
years |
interval, in years, between censuses |
incgr |
annual growth; (dbh2 - dbh1) / time |
expgr |
relative growth; (log(dbh2)-log(dbh1))/time |
Rick Condit
## Not run: 1. Default use of growth.indiv(). Warning messages may result from computation of exponential growth. The values will be set to NA in the returned \strong{dataframe} growth.indiv.out <- growth.indiv(tst.bci90.full,tst.bci95.full) 2. Selecting a single species for growth.indiv() growth.alsebl.tree < -growth.indiv.out[growth.indiv.out$sp=="alsebl",] ## End(Not run)