Vegetation with Betula humilis in Central Europe
Betula humilis is a shrubby species growing on fen peatlands, with a biogeographical range extending from Germany to Central Siberia. The aim of this study is to revise the variability of vegetation with B. humilis in Central Europe and to assess its ecological status. The results explain divergent observations of various authors and present the variability of vegetation with B. humilis in a wide geographical and ecological context. Authors describing locally the association Betulo-Salicetum repentis/Betuletum humilis, frequently described various vegetation types, of which the dominance of B. humilis was the only common trait. Because drainage benefits B. humilis in some way, it has been observed from very diverse habitats - including the full range of natural habitats of the species, as well as their, moderately to intensively, drained variants. If a separate association for shrublands with B. humilis is to be distinguished, it should involve only phytocoenoses where B. humilis is accompanied by a combination of typical non-forest fen species from the class Scheuchzerio-Caricetea nigrae. Brushwoods of B. humilis within degraded or drained peatlands that lack species of the Scheuchzerio-Caricetea nigrae class do not represent the association of B. humilis and should rather be regarded as its impoverished or degraded forms.