Smorkalov Ivan Alexandrovich

The aim of this study was to investigate the patterns of plant diversity formation on extensive green roofs in a continental climate and the role of adjacent lawns as sources of colonizing species. In 2024, extensive green roofs were established in Moscow and Yekaterinburg on two substrate types (regional and universal) at two depths (15 and 25 cm), with 3 replicates per treatment. In May 2025, regional plant species (seedlings) were planted: in Moscow —Festuca glauca Vill., Thymus serpyllum L., Achillea millefolium L.; in Yekaterinburg —Aster alpinus L., Festuca glauca Vill., Festuca rubra L., Origanum vulgareL., Dianthus acicularisFisch. ex Ledeb., Veronica spicata L. Weeds were not removed. In September 2025, species were recorded, and community similarity (Jaccard coefficient, Bray – Curtis index) was measured between lawns and roofs, as well as within roofs between different treatments, together with alpha diversity (Shannon index H', Simpson index 1-D, and evenness). In parallel, the species composition of adjacent lawns was surveyed. In total, 50–60% of roof species were also present on lawns; the Jaccard coefficient ranged from 0.14 to 0.32; H' for roofs ranged from 1.08 to 2.08 (13–15 species). Unique species of Moscow roofs were dominated by R/CR strategies (Lactuca saligna L., Lactuca serriola L., Amaranthus retroflexus L., Portulaca oleracea L., Digitariasanguinalis(L.) Scop., Gnaphalium uliginosum L., Iva xanthiifolia Nutt., Acalypha australis L., Euphorbia virgataWaldst. & Kit., Lipandrapolysperma(L.) S. Fuentes, Uotila & Borsch, Epilobium obscurumSchreb., Myosotis sparsifloraJ.C.Mikan ex Pohl, Veronica longifolia L., Festuca arundinaceaSchreb.), whereas in Yekaterinburg C/CR species dominated (Trifolium arvense L., Medicago falcata L., Lolium perenne L., Rumex obtusifolius L., Viola tricolor L., Galiumspurium L., Arenaria serpyllifolia L., Setariaviridis(L.) P.Beauv., Rudbeckia hirta L.). High spatial heterogeneity in similarity and diversity indices was observed for Moscow roofs, whereas substrate type and depth had no significant effect. Thus, lawns were the main source of spontaneous colonizers of green roofs. Vegetation succession during the first year on green roofs went through an R/CR stage, probably under the dominant influence of climatic factors.