sgf.randarea {CTFS} | R Documentation |
Counts the number of species, genera and families of the individuals
found in a given single defined area of a plot. There area is
defined by quaddim
with a randomly selected initial corner.
This function only identifies a randomly selected point and the
corners of an area of given size starting from that point. It calls
sgf.area
to do the counting.
sgf.randarea(census1, spp.info, quaddim = c(100, 100), alivecode = c("A"), mindbh = NULL, plotdim = c(1000, 500), unidennames = c("**", "UNID", "uniden", "UNIDEN"))
census1 |
name of the datafame of a single census |
spp.info |
name of dataframe that contains each
species and information about it, eg. bcispp.info |
quaddim |
dimensions (x,y) of the randomly selected area in meters |
alivecode |
character, codes of the variable status
that indicate the tree is alive. The most general valid categories are: "A" and
"AB" and "AS". The default for this function is "A" |
mindbh |
Minimum DBH for inclusion in computation |
plotdim |
plot dimensions, x,y lengths in meters |
unidennames |
vector of codes for unidentified species, codes vary among sites and datasets |
Only one randomly selected area is subsetted and values computed
with each run of this function. All areas are squares. For other
shapes use spp.randarea.range
Pay attention to the default values of alivecode
and
mindbh
. Any tree with alivecode
not equal to
“A” has a dbh
= NA and so will not contribute to the
results of this computation. Setting mindbh
to some value
other than NULL will affect the trees that are included in the
calculation. Use mindbh
to select trees larger than 10 mm
dbh. Use alivecode
to select trees to be counted as being
alive but have no dbh
measurement.
Returns a vector of the following information for the defined area.
n.ind |
number of individuals |
n.spp |
number of species |
n.gen |
number of genera |
n.fam |
number of families |
r.sppgen |
ratio of number of species to number of genera |
r.sppfam |
ratio of number of species to number of families |
r.genfam |
ratio of number of genera to number of families |
Rick Condit, Suzanne Lao and Pamela Hall
## Not run: 1. default use gives the total number of species, genera, families for a randomly selected area of a given size. Run multiple times to see that different values are computed each time. sgf.randarea(bci90.full,bcispp.info) ## End(Not run)