How do ditches contribute to bryophyte diversity in managed forests in East-Central Europe?

The study focuses on identifying and assessing the effect of the presence of drainage and roadside ditches on the diversity of bryophytes in managed forests. We compared the composition of moss and liverwort species, their richness and abundance in plots that are located in ditches as well as corresponding control plots in the surrounding forests with regard to the forest type (coniferous, mixed and deciduous). ANOVA demonstrated the pronounced impact that the presence of ditches in managed forests has on an increase in bryophyte species richness. A comparison of forest and ditch types using DCA pointed to a correlation between the number of deciduous trees in the stands and an increased dissimilarity of ditch bryophytes when compared to the bryophytes of the corresponding control plots. Using the ecological indicator values, CCA confirmed the special significance of ditch settlements for hygrophilous species, which at present cannot otherwise find favorable conditions in managed forests. The study proves that ditches, and especially those with intermittent pools of stagnant water, may become a significant source of microhabitat diversity. Their presence may provide a welcome preserve for rare and protected species that cannot find suitable substrates in managed forests.