hi, hi all, > I am not quite sure what you mean by "outcome" but I try to be more precise. > I have 4 spatial scales with: > - One sample per habitat (i.e. substratum) > - Many habitats per site > - One or many sites per river
maybe, you can use a more general variable type of river (?) > - Many rivers per regions > - Two regions > Each scales is described by one or many variables: > - Habitat: type of substratum > - Site: altitude, distance from the source, slope, drainage area > - River: drainage area, altitude of the source, slope, type of geology > - Regions: 2 modalities > First I could try a nested ANOVA such as: > SR = habitat + Site / River / Region > But I am rather interested by which variables in each scales explains the > species richness variance. So something like this: > SR = substratum + (alt+dfs+sl+da) / (da+as+s+geol) / Region > But I don't know if i) if it is the good model and I dont know. In your context, the organisation of the stratification is an ecological problem. > ii) how to proceed with the lmne package. You can consult : - the documentation of the package nlme - http://zoonek2.free.fr/UNIX/48_R_2004/17.html (english version : http://zoonek2.free.fr/UNIX/48_R/13.html). In this document, there is many information about the procedure of variance decomposition with R. - http://cran.r-project.org/doc/Rnews/Rnews_2005-1.pdf (see Fitting linear mixed models in R by Douglas Bates) - etc. Regards, Pierre > > > > > > > Selon [EMAIL PROTECTED]: > > > 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 > > > > > > > > > > -------------------------------------------------------------------------- > > Ce message a été envoyé depuis le webmail IMP (Internet Messaging Program) > > > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
