Willow communities at technogenic habitats in the middle-taiga subzone of north-east of the European part of Russia

The paper highlights the diversity of willow communities at technogenic habitats of the middle taiga subzone of north-east of the European part of Russia. Willow communities at technogenic habitats normally develop at places with excessive soil moisture content. At places with optimal soil moisture content, they are found in relatively rich loams. Four new associations are described. They are mesophytic willow communities in middle loamy, as well as residual carbonate soils – Calamagrostio arundinaceae–Salicetum capreae, forest communities surrounding them –Calamagrostio arundinaceae–Piceetum obovatae, willow communities in excessively moist meso- and oligotrophic acid soils – Polytricho communis–Salicetum phylicifoliae, willow communities in meso- and eutrophic waterlogged soils confined to groundwater outlets – Drepanoclado adunci–Salicetum myrsinifoliae. For the latter association, 3 new subassociations are described (typicum, bryetosum pseudotriquetri, philonotietosum fontanae). Mesophytic willow communities at anthropogenically disturbed territories belong to the new alliance Betulo pubescentis–Salicion capreae. Willow communities at technogenic habitats with excessive soil moisture content are described within the alliance Alno incanae–Salicion pentandrae Kielland-Lund 1981. The communities dominated with willows at technogenic habitats mainly include early-succession species. The floristic composition of communities largely depends on the particular soil type. Comparing the species composition of willow communities and forest communities surrounding them, we diagnose certain signs of restoration even at the first succession stages. For example, the willow communities include species being typical of syntaxa of forest ecosystems at advanced successional stages.