[R] species projected in a ordiplot

[santi8]

Dear all,
I'm performing a detrended correspondence analysis on vascular plant
community data (296 species), and I have a question on the species scores
projected in the ordination diagram. When I run a ordiplot all species are
projected in the output graph, but I'd like to restrict the number of
species plotted in the final graph. Some species are so rare in the data,
that no relevant information is provided on their ecological preferences,
and other species might not characterize well the analysis, then I'd like
to select these species with highest fit state. 

Any help would be much appreciated.

Giving thanks in advance

Elisa


Elisa Santi
Department of Environmental Sciences
University of Siena
Italy