Because of their spatially explicit and interactive nature, com-putational loads for FLMs may be intractable when the site-scaleprocesses simulated become too complex. Thus, FLMs typicallysimplify these processes in order to simulate relatively large land-scapes (Mladenoff, 2004). Information tracked at each site in earlyFLMs is either aggregated as the presence or absence of species’age cohorts (e.g., in LANDIS) (Mladenoff and He, 1999) or forest