Your model model <- aov(Biomass ~ Beech + Age + Error(Age/Stand)) has a redundancy that might be causing the problem. I can't tell without the data.
Try tree.aov <- aov(Biomass ~ Beech + Age + Error(Stand %in% Age)) A second potential problem is the class of the variables. >From the degrees of freedom, it looks like Stand is a factor. Since there is only one df for each of Beech and Age, they might be incorrectly interpreted as continuous variables instead of factors. My guess is that they should be multi-degree-of-freedom factors and aren't. Rich ______________________________________________ [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
