[R-sig-eco] forward selection RDA after controlling for constraints

[Stephen Sefick]

Hello all,

I would like to run this by everyone and maybe get some hints as to what 
R functions I could use for this.  Ok, so I have macroinvertebrate 
assemblage data from across the SE.  I would like to control for 
geographic distance (lat/long), Watershed area, and year before 
submitting these data to an RDA with the rest of the environmental data 
using a variable selection technique.

Does it make sense to detrend the data using a mlm on hellinger 
transfomed abundances with the above env variables as regressors and 
then submit the residuals to rda with the rest of the env variables I am 
interested in?

Many thanks for all of the help.
kindest regards,


-- 
Stephen Sefick
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Auburn University
Biological Sciences
331 Funchess Hall
Auburn, Alabama
36849
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sas0025 at auburn.edu
http://www.auburn.edu/~sas0025
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