Hello,
I am looking for a workaround of "species empty" plots in a correspondence
analysis.
I tried to do a community structure analysis with a ca via decorana(), ca()
and CAIV(), but none of them allow 0 only-rows.
I have species (abs./pres) in columns and sites in rows
sp1 sp1 sp3 ...
plot1 0 1 1
plot2 0 0 0
plot3 1 0 1
.....
but on some plots no species could be found, therefore only 0 appear. I know
that this isn't interesting for a community analysis but I am interested in
the contributions of variables to the factors for a further analysis with
env. variables where it is interesting that there are no species found.
i thought about adding a "dummy" species with only presence on all sites, that
would solve the 0-only-row problem but I am not sure if that would bias the
outcome of a ca seriously.
Or is there a subcommand to allow 0 rows in a ca which I haven't seen?
thnaks Martin
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