[R-sig-eco] how to calculate "axis variance" in metaMDS, pakage vegan?

[Tyler Smith]

Maria Dulce Subida <mdsubida at icman.csic.es>
writes:

> Nevertheless you should take into account that the stress usually 
> increases with increasing quantity of data.

I think this is the key point. The stress will always increase with
increasing data, as it is harder to capture the information content of 10
variables on 2 axes than it is to capture the information content of 3
variables on 2 axes. Similarly, stress will always go down as you
increase the number of axes you use, for the same reason. So I'm not
convinced that any of these 'rules of thumb' (i.e., > 0.3 is a 'bad'
ordination) really make much sense. Please correct me if I'm wrong!

Cheers,

Tyler