I did a simple experiment with trees: 5 species (sp
) and two management (trt
). I assessed the diameter (diam
) through the time (month=1:24
) and I'm interesting in the factors interaction effect, I mean if the management is suitable for some species.
The dataset has some limitations since it is not balanced, so in 2 out of 10 factors combinations (sp*trt
) I have 4 trees (subjects) and for the rest there are 5 trees:
sp trt trees
1 A L 5
2 A W 5
3 B L 5
4 B W 5
5 C L 5
6 C W 5
7 P L 4
8 P W 5
9 T L 5
10 T W 4
I fitted the following model:
m1 <- lmer(diam ~ trt * sp * month + (1|tree), data = dat1)
I'm not sure if I'm doing right, mainly if the model is right...
If the model is correct, and the anova is the following table:
Analysis of Variance Table
Df Sum Sq Mean Sq F value
trt 1 0.12110 0.12110 17.3756
sp 4 0.06761 0.01690 2.4251
month 1 0.33917 0.33917 48.6659
trt:sp 4 0.00436 0.00109 0.1564
trt:month 1 0.15814 0.15814 22.6900
sp:month 4 0.24445 0.06111 8.7687
trt:sp:month 4 0.19109 0.04777 6.8547
What is it meaning about the effects?