[R-sig-eco] envfit and NMDS

[Erin Nuccio]

Hello list,

I commonly see envfit used for NMDS, and am curious if envfit is considered a non-metric vector fitting tool.  This question came up during a conversation with a colleague who only uses envfit with PCoA, because they are concerned that to do this would be problematic for the same reason you are not supposed to correlate environmental variables with NMDS axes (you can't correlate something that's non-metric with a metric variable).  To me, it seems like by projecting the metric variable into non-metric space, you're essentially making it non-metric, and the correlation would be fine.

If anyone could weigh in and clear up the confusion, that would be great.  Thanks,
Erin