Hello,
My name is Xavier ,
I have a problem with Glmm and I would like you to help me.

My main objective is to explain the inter-annual abundance’s variation of fish species with the environmental variables (as temperature, salinity, flow) and biological variables (abundance of different species of zooplankton) in the global warming contexte. I have 4 species of fish who are sampling each month at the same place,from 25 years. It is the same for the other variables.

I use this type of models

Mod1<-glmmPQL ( fish_1_abundance~ Temp+Salinity+Flow+zoo1+zoo2+zoo3…,randum= 1|years, family=Gamma(link="log"),data=marin0,maxit=10000)

I have some questions?

The first is, is that this model answers exactly to my question?

I want to know if the randum effect “years” take in count the fact that there are good abundance’s years and not good?

Is it possible to add in this model a correlation term like correlation=corARMA(p=1,q=2,form=~1|years)

How is it possible to take in count the seasonality of each variable?

Is it better to extract the tendency of explicative’s variables before introduce in the model.

 

Thank a lot


Xavier 		 	   		  
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