The Phytocoenotic Potential of Pastures on the Sand Massifs of the Don Basin

The phytocenotic potential of pasture ecosystems of the Tsimlyanskii sand massif using the ecological scales of humidity, soil reaction, and soil richness in mineral nitrogen of G. Ellenberg is studied. This work is based on landscape-bioecological and ecological-morphological research methods using methods for studying the structure, stability and development of plant communities. It has been established that the family types Poaceae, Fabaceae, and Asteraceae play the greatest role in projective coverage. The predominant life form of vegetation at all sites studied are is 40–71%. The average productivity of phytocenoses is 156–287 g/m². The species composition and productivity of pasture phytocenoses changes noticeably depending on the humidity, physicochemical properties, and the richness of the soil in mineral nitrogen. On moist, non-drying, slightly acidic soils with an average nitrogen content, edificators are Agrostis canina L., A. tenuis Sibth., Thlaspi arvense L., Typha angustifolia L., T. latifolia L., Tanacetum vulgare L., Phragmites australis (Cav.) Trin. ex Steud., and Scirpus lacustris L. Under average moisture conditions, on slightly acidic soils with an average nitrogen content, edificators are Achillea millefolium L., Astragalus arenarius L., Elytrigia repens (L.) Nevski, Medicago falcata L., and Phleum pratense L. Under average moisture conditions, on slightly acidic soils rich in mineral nitrogen, edificators are Apera spica-venti (L.) P.Beauv., Atriplex tatarica L., and Calamagrostis epigeios (L.) Roth. Under average moisture conditions, on neutral soils with an average nitrogen content, edificators are Artemisia abrotanum L., Cirsium incanum (SG Gmel.) Fisch., Gypsophila paniculata L., Inula germanica L., Juncus gerardii Loisel., and Senecio erucifolius L. On dry, slightly acidic soils with an average nitrogen content, edificators are Chamaecytisus ruthenicus (Fisch. ex Wol) and Festuca valesiaca Gaudin. On dry, slightly acidic and mineral nitrogen-poor soils, edificators are Anisantha tectorum (L.) Nevski, Artemisia campestris L., A. maritima L., A. marschalliana Spreng., A. scoparia Waldst. & Kit., Bromopsis inermis (Leyss.) Holub, Crepis tectorum L., Koeleria glauca (Spreng.) DC., Leymus racemosus (Lam.) Tzvelev, Potentilla incana P. Gaertn., B. Mey. & Scherb., Psammophiliella muralis (L.) Ikonn., and Stipa capillata L. Under conditions of sufficient and variable moisture, on neutral and slightly acidic soils with an average nitrogen content, edificators are Agropyron cristatum L. and Thlaspi arvense L. In the brome–bushgrass–wormwood (Bromopsis inermis, Calamagrostis epigeios, Artemisia marschalliana) community, there is a large proportion of therophytes (22.9%), which indicates anthropogenic pressure on this territory.