[R-sig-eco] population model with proportions as responses

[Zoltan Botta-Dukat]

Dear Milos,


> It could be a problem that the predictors (forest_percent + meadow_percent + plowland_percent) are non-independent, but I don't know if it's a big problem. Maybe someone else could weigh in on that.

Such strong linear relationship between predictors (collinearity) is a 
big problem. If all predictor included, the model becomes ill-defined. I 
suggest including only two of them. Choose the pair of predictor that 
lead to most easily interpretable model (probably choosing the two 
extreme habitat is the best solution).

Best wishes

Zoltan


-- 
Botta-Dukát Zoltán
--------------------------------
Ökológiai és Botanikai Intézet
Magyar Tudományos Akadémia
Ökológiai Kutatóközpont
--------------------------------
2163. Vácrátót, Alkotmány u. 2-4.
tel: +36 28 360122/157
fax: +36 28 360110
botta-dukat.zoltan at okologia.mta.hu
www.okologia.mta.hu


Zoltán BOTTA-Dukát
--------------------------------
Institute of Ecology and Botany
Hungarian Academy of Sciences
Centre for Ecological Research
--------------------------------
H-2163 Vácrátót, Alkomány u. 2-4.
HUNGARY
Phone: +36 28 360122/157
Fax..: +36 28 360110
botta-dukat.zoltan at okologia.mta.hu
www.okologia.mta.hu