I am very new with this... I am trying to perform a SAS analysis on several sites about the incidence of an insect over time measuring damage inflicted on planted young pine seedlings in pine clearcuts. We have the following factors:

SITE, TIME, PINE SPECIES, BLOCKS (within SITES).

Site and block(site), species and time are fixed. But because the design implies measuring over time every plant placed within each block (5 plants per species per block) and each plant is independent of each other in other blocks and sites, I considered the following script:

proc mixed data=SITES covtest;

class SITE TIME BLOCK PLANT SPECIES;

model damage=TIME|SITE|SPECIES BLOCK(TIME*SITE);

repeated TIME /subject=PLANT*SPECIES(B*SITE);

run;

I remember that also provides the same output if /subject=PLANT(SPECIES*B*SITE)

Thank you very much.