ON A NEW ASSOCIATION OF MEADOWS IN CLEAR-CUTTINGS OF LIGHT CONIFEROUS BOREAL FORESTS IN THE SOUTH URALS
In 2010 and 2017, the research work undertaken to study secondary autogenous successions on clear-cuttings of light coniferous boreal green moss forests in the central highlands of the South Ural Region allowed revealing vegetation communities with prevailing forest and meadow grass species. Based on the results of the Braun-Blanquet classification and comparative syntaxonomic analysis, a new association Anemonastro biarmiensis-Calamagrostietum arundinaceae ass. nov. hoc loco has been described that contains the suballiance of semi-humid meadows Polygonenion krasheninnikovii Mukhamediarova ex Yamalov in Korolyuk et al. 2016 (alliance Polygonion krascheninnikovii Kashapov ex Yamalov in Korolyuk 2016, order Carici macrourae-Srepidetalia sibiricae Ermakov et al. 1999, class Molinio-Arrhenatheretea R. Tx. 1937). Besides the meadow forbs, the communities are distinguished for the constant presence of boreal species (Luzula pilosa, Maianthemum bifolium, Trientalis europaea, Vaccinium vitis-idaea, Vaccinium myrtillus) survived after clear-cutting. The communities of the association Anemonastro biarmiensis-Calamagrostietum arundinaceae ass. nov. hoc loco are formed in a short period of time (three years after clear-cutting) and can exist for rather a long time if not economically used. With an increase in the time of succession, the projective cover also increases and coenotic positions of some meadow and forest species get stronger. Communities aged 15 years or more show higher abundance of such species as Alchemilla sp., Aegopodium podagraria, Calamagrostis arundinacea, Bupleurum longifolium, Angelica sylvestris and Stachys officinalis. The dense canopy of the communities in question does not allow germination and development of tree species and hinders the formation of a forest stand. Therefore, such communities represent the inhibition stage of restorative succession. The duration of this stage depends on the size of the clear-cutting area and is conditioned by the possibility of overgrowing with tree species from native forest sites. According to bryophyte flora analyses, the communities under study include a group of moss species that have no strict affinity to the substrate. In the early successional meadow communities there is a greater diversity of bryophytes due to the presence of ruderal species, along with typical forest mosses that grow on bare spots arising after clear cutting (Atrichum undulatum, Dicranella heteromalla, Leptobryum pyriforme, Funaria hygrometrica, Trematodon ambiguus, Pogonatum urnigerum). In 15 or 20 years after clear cutting, these species gradually disappear from the communities as the soil cover is restored and the closeness of the herb layer increases.