Hypothetical data from Shipley (2009).
Simulated data from a hypothetical study beginning in 1970 in which 20 sites site are chosen differing in latitude lat. Five individual trees tree of a particular species are chosen within each site. Each tree is followed every second year year until 2006 or until it dies (thus, repeated measures). At each site, in each sample year, and for each living individual you measure the cumulative degree days DD until bud break, the Julian date (day of year) Date of bud break, the increase in stem diameter per tree Growth, and a binary variable indicating survival (1) or death (0) Survival during the subsequent growing season
Shipley, Bill. "Confirmatory path analysis in a generalized multilevel context." Ecology 90.2 (2009): 363-368.
http://www.esapubs.org/archive/ecol/E090/028/Shipley.dat