Are abandoned wooded pastures suitable refugia for forest species?
Is the species composition of the forest community in abandoned pastures different from that in ancient ungrazed forests? Do abandoned wooded pastures serve as refugia for forest species? Which factors influence forest species communities and the diversity of pastures more than 50 years after abandonment?
Doupovské hory, Czech Republic.
The species composition of the forest plant community was assessed in 90 plots located in abandoned pastures with different continuities of woody vegetation. The abandoned pastures were compared to 111 other plots located in ancient ungrazed forest. The effects of forest continuity, isolation, pH, canopy cover and terrain were analysed using CCA and GLMs.
The forest species communities in abandoned pastures differ from those in ancient ungrazed forests. The number of forest species in abandoned pastures was relatively high. However, abandoned pastures lack some species considered as indicators of ancient forests in Europe. The abandoned wooded pastures and more recently overgrown pastures generally lacked the same set of species in comparison to ancient forests. Additionally, we found no regular association of ancient forest indicators with wooded pastures compared to more recently overgrown pastures. The forest species communities in abandoned pastures are significantly influenced by continuity, soil pH (KCl) and habitat isolation. Forest species richness depends on continuity (with significantly more species in the abandoned wooded pastures than in most recently overgrown pastures). Furthermore, species richness is negatively correlated with habitat isolation particularly under the open canopy.
Abandoned pastures and wooded pastures offer suitable habitats for forest species. However, these forest communities remained unsaturated after more than a half-century of succession. Surprisingly, pastures with a long continuity in woody cover (wooded pastures) were not better refugia for forest species than more recently overgrown pastures. The importance of habitat isolation, soil pH and light conditions for forest species community composition and richness was confirmed.