Following Hegland et al. (2001), three types of populations were distinguished: “dynamic” populations, characterized by a large proportion of sporelings; “normal” populations, with a relative high proportion of adults but still a considerable number of young individuals; “regressive” populations, in which mature stages dominated and rejuvenation hardly occurred. These three types also mirror different colonization and (or) extinction history of local populations: dynamic populations represent relatively recent colonization events with relatively few extinctions; normal populations represent a balance between colonization and extinction; in regressive populations, extinctions clearly dominate over recruitment events.