I am running at the moment a GLMM with insect abundance (count data) as response variable and 3 landscape variables and temperature as (continous) explanatory variables. So, my GLMM looks like this:
insect abundance ~ v1 + v2 + v3 + temp + (1 | site)
In total, I measured insect abundance on two evenings at 60 sites and I wanted to include site as a random effect.
However, now I am a bit confused as to whether this is possible given that while insect abundance and temperature differ between these two sampling dates, landscape variables stay the same (as they did not change btw my two sampling dates of course). Hence, I have two different values for insect abundance and temperature per site, but only one value for the landscape variables.
My question is now: Can I still use 'site' as a random effect here, i.e. is this a GLMM or rather a GLM (without a random effect)?
I hope my question makes sense.
Thanks a lot!