growth.dbh {CTFS} | R Documentation |
Computes annual growth rate for all trees for DBH classes. Two growth rates can be computed: simple change in dbh over time and relative growth rate. Unrealistically high and low values are removed from the summary values. Growth rate in mm dbh per year, relative growth rate in % change in dbh per year, standard deviation or 95% confidence limits, and sample size are provided. Two datasets must be used, one for each census.
growth.dbh(census1, census2, dbhclass = c(10, 100, 300), rounddown = FALSE, method = "I", stdev = FALSE, 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 |
dbhclass |
a vector of lower values for dbh categories |
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. |
method |
character indicating the type of growth rate to be
calculated. When "I" the annual change in dbh is provided. When
"E" the relative growth rate is provided. see
CTFS.growth for more details on method . |
stdev |
logical value in caps. When TRUE, the standard deviation of growth is provided. When FALSE, a 95% condfidence interval is provided. The confidence limits are not computed. |
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 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 vector for classbreak
can be created outside of the
function and reference by setting classbreak
equal to that
vector.
The results of growth.dbh
can be organized into
dataframes with the use of assemble.demography
.
growth.dbh
returns a list of arrays with the
following named components. Values are provided for each DBH class.
$N0 |
the number of trees used to compute growth rate |
$rate |
the annual mean growth rate in mm per year or % per year,
type determined by the argument method |
$clim |
the 95% confidence limit based on a normal distribution |
$dbhmean |
the mean dbh in mm for trees used to compute growth rate |
$meanyrs |
mean number of years between census for trees used in growth rate computation. |
$date0 |
mean date of first census |
$date1 |
mean date of second census |
Rick Condit
## Not run: 1. Default use of growth.dbh() growth.dbh.out <- growth.dbh(tst.bci90.full, tst.bci95.full) growth.dbh.out$rate 2. User defined DBH classes dbh.vct = c(10,20,30,40,50,100,300) growth.dbh.out <- growth.dbh(tst.bci90.full, tst.bci95.full, classbreak=dbh.vct) growth.dbh.out$rate ## End(Not run)