I am studying the effect of the land-use surrounding a location on the abundance of aphids on this location. To do this I fit a linear model with the land-use as independent variable and the abundance of aphids as the dependent variable. To check for spatial autocorrelation I plot the correlogram with the Moran I of the model residuals in function of the lag distance.
However I have multiple years of data: where the aphids have been observed each year together with the surrounding land-use. How can I account for this temporal effect? Should I incorporate a 'Year' variable in the linear model and can I then just look at the correlogram of the whole dataset?
Thanks in advance.