Virgin, natural woodlands were transformed into elements of the traditional cultural landscape when their structure and species composition were heavily influenced by historical or modern silvicultural uses (e. g. woodland pastures, reforestation partly with non-native species; Pott and Huppe 1991; Zerbe 2004). The habitat continuity of such woodlands can still be quite high when it is a question of transformed, pristine forests. The continuity on reforested former agricultural land, however, is comparably
low. For parts of Europe, more recent reforestations have been differentiated from old-growth forests through landscape historical methods (Peter – ken and Game 1984; Peterken 1994; Wulf and Kelm 1994; Verheyen et al. 2003). According to these studies, the forest types differ in their species richness and in the presence of indicator species of old-growth forests.
The development of two peri-urban forests in Switzerland and in Germany illustrates possible overlaps between culturally determined and pristine natural forests. The Sihlwald has been fundamentally shaped by the long-term procurement of wood for the firewood needs of the city of Zurich (Broggi 1992). The Saarkohlenwald near Saarbrucken has also been shaped by traditional forestry uses – and additionally through small – scale mining activities (Rosler 2004). The goal in both cases of allowing a peri-urban wilderness to emerge by abandoning former uses will lead over the course of time to a convergence of the stands with the species composition and structure of a pristine woodland.
