[R] cca and cca.predict in vegan-what sort of prediction is possible

[Neil Griffin]

Hi All

I am not clear quite how one could use cca from package vegan and the associated 
predict.cca to predict species abundance from environmental data (or if this is possible 
in a generalised way). In other words, can one derive a cca object based on known 
community data and use that to predict e.g. species abundances in a different number 
of samples based on environmental data? The help notes show that prediction is 
possible, but it seems that the number of samples is constrained to that in the original, 
"training" set. 

If this is possible, a reference or example would be much, much appreciated.

Thanks
Neil


Neil Griffin
Unilever Centre for Environmental Water Quality
Institute for Water Research, Rhodes University
PO Box 94, Grahamstown, 6140, South Africa
Email: neil at iwr.ru.ac.za 
http://www.rhodes.ac.za/institutes/iwr/
Tel: +27 46 622 2428
Fax: +27 46 622 9427