change arrow colour when plotting rda

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Dear all,
can enyone please tell me how to change the colour of the arrows of the
environmental variables when plotting a contrained ordination done in rda?
They are in blue, but i want black.
I've tried any possible combination I can think of in plot(), arrows(),
ordiplot() and plot.cca() and none of them would work.

Mariano,

You should have tried text() or points():

m <- rda(varespec ~ Al + P + K, varechem)
plot(m, type="n") # an empty plot
text(m, display="bp", col=2) # add red arrows

The text() function draws both arrows and labels, and points() only
unlabelled arrows.

See ?text.cca, ?points.cca for details and further arguments.

Cheers, Jari Oksanen