

Dears lme4 users:
I'm doing a repeated measurement analysis, which seems pretty obvious to 
me, but I'm getting some strange results, which I do not 
understand. Hope you can help me!! Thanks in advance!

I'm evaluating the effects of Defoliation Treatments (4 levels), Gender 
(Male/Female) and Time on several responses (Growth , leaf production, 
inflorescence production, etc) of a palm dioecious species 

I have about 550 palms total which have been measured 3 times. My main question is whether the effects depends on the intensity of defoliation, palm gender and how this has changed through time. I am 
considering the effects of repeated measurement as Palm/Time
I am exploring with the model below, which include as fixed factors DT*G*Time and as 
random factor Palm/Time to consider the effect of repeated measurements. 

In this case, I'm using glmer, 'cos I've have counts as response variables (number of leaves, number of inflorescences, etc).

Model1<-glmer(Total leaves ~ DT * G * Time + (1 | palm/Time), family=poisson)


I've got two questions:
1) Am 
I considering the random effects correctly or not? as when I run the model there is the following message


"Number of levels of a grouping factor for the random effects
is *equal* to n, the number of observations"

2) All the models (for different response variables I have been testing) the variance for Time:Palm is always 0 (zero), 
independently of what variable I use.

Is there something wrong in how I am telling the model to include the random factors? or is correct a variance of 0.

3) If there is a variance of zero, should I remove that term and leave in 
the model just "Palm"?. That does not make sense to me...but I am not 
sure.

Generalized linear mixed model fit by the Laplace approximation 

 Formula: Total leaves ~ DT * G * Time + (1 | palm/Time) 
 AIC  BIC logLik deviance 

790.9 1060 -345.5    690.9


 Random effects:
 Groups  Name        Variance   Std.Dev.
 Time:Palm (Intercept) 0.0000e+00 0.000000
 Palm     (Intercept) 5.4377e-05 0.007374
 Number of obs: 1604, groups: fyr:NNo, 1604; NNo, 555



I will be very grateful for your comments and suggestions!

Cheers
Leo
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