[R] Nested model and variance partitioning

[bady at univ-lyon1.fr]

hi, hi all,


> Dear R users,
> I face to a nested pattern and despite the numerous examples in the help I am
> still confused.
> I sampled bugs in different habitats within sites which were within rivers
> themselves within different regions.
> The habitat correspond to different substrata (not systematically present in
> all sites). For rivers and sites, I have environemental variables (e.g.
altitude
> and slope of the site, drainage area and geology of the river) and I have
> only 2 regions. Note that sometimes I have only one site per river.
> I would like to know the part of each spatial scale described by
> environmental
> data in the species richness variance. For instance is the drainage area at
> the river scale that explains a large amount of species richness variance or
the
> altitude of the site, or the substratum, etc.


The design of our data is complex. What is your outcome ?


> I looked into the nlme package but I did not found how to proceed


The reference document about the package nlme is certainly “Pinheiro J. C. &
Bates D. M.  (2000) Mixed-effects models in S and S-plus. Springer Verlag, New
York. 528 pp.”

but there is many information about this subject on the WEB (see
http://www.google.fr/search?hl=fr&q=nlme&btnG=Recherche+Google&meta=)


Regards,

Pierre