I have performed a Detrended Correspondence Analysis for species composition of different replicate survey sites and constructed a site ordination plot. Sites were classified into habitat types, so I have identified sites in different habitats within the ordination plot using symbols.
Now. I want to illustrate the species that contribute most to the dispersion of sites within the ordination plot (i.e. indirectly explore what species characterise particular habitats). To do this I want to construct species vectors with a truncated length (otherwise all 122 species will appear in the plot!).
My question is: can I do this? I haven't seen it before, the only vectors I have seen in DCAs are vectors showing continuous environmental variables measured at the site but not included in the analysis (i.e. an indirect gradient analysis using an unconstrained ordination). I think the answer is yes, since species vectors are often used in MDS plots... but I'd feel more comfortable if someone confirmed by understanding.