Deciduous broadleaved trees are the most competitive life form in the Central European flora, and are thought to dominate the natural vegetation. Yet trees (or phanerophytes sensu Raunkiaer, see Ellenberg and Mueller-Dombois 1967), only make up a small proportion of the over 4500 species of phanerogams in Central Europe (see Table 2.1). Even shrub species (nanophanerophytes, N) make up less than 5 % of species, although they are common in woodland.