Floodplain meadows plant forage resources of the Central Siberian nature reserve

The investigation of forage resources for reindeer in the Central Siberian Nature Reserve (Middle Siberia, middle boreal subzone) have been started recently. The studies were carried out in the floodplain meadows of the Stolbovaya, Podkamennaya Tunguska, Yenisei Rivers and the lakeside meadow near Lake Konnoye in 2019–2022. Three meadows are located in the mountain taiga landscape to the east of the Yenisei, and the meadow of Lake Konnoe – on the plain west to the Yenisei. Grass-forb communities of the syntaxonomical order Molinietalia W. Koch 1926 were studied in the river floodplains, and the sedge-grass-forbs one – on the man-made drained shore of Lake Konnoye. In total, 93 species of vascular plants were determined. The above ground dry phytomass of the herbs and shrubs was preliminary determined using the mowing method (n = 19). Species richness varies from 11 to 23 species per 0.25 m² and averages ca. 16 species per 0.25 m². The average share of legume species in the communities is 10–15%, forbs – 20%, and grasses – 55%. In the meadows of the Podkamennaya Tunguska, 47 vascular plant species were registered in 3 mown samples (0.75 m²), of the Yenisei – 44 species in 5 samples (1.25 m²), of the Stolbovaya – 31 species in 5 samples. Within the studied samples, the average ratio of these forage plant groups are significant: forbs – 35%, ca. 120 g/m² (the most abundant species are Filipendula ulmaria (L.) Maxim., Galium uliginosum L., G. boreale L., Heteropappus biennis (Ledeb.) Tamamsch. ex Grubov, Lysimachia vulgaris L., Sanguisorba officinalis L., Thalictrum simplex L.), grasses – 30%, 100 g/m² (Agrostis stolonifera L., A. gigantea Roth, Calamagrostis purpurea (Trin.) Trin.), legumes – 20%, 70 g/m² (Medicago falcata L., Trifolium pratense L., Hedysarum arcticum B. Fedtsch., Trifolium lupinaster L., Vicia cracca L.). The proportions of horsetails, sedges + rushes, shrubs are up to 8% (less than 30 g/m²). The number of species found in the man-made meadow near Lake Konnoye is much lower than that of the riverside ones: 11 vascular plant species in total, ca. 5 species per 0.25 m², their average above ground phytomass is 140 g/m² (Glyceria triflora (Korsh.) Kom., Carex cespitosa L.; Thalictrum simplex L. predominant). Nevertheless, the rate of accumulated dead plant mass in this meadow is the highest – ca. 250 g/m² (the aboveground dead plant mass of the river floodplain meadows is removed by annual floods). Data on eatability and seasonal eating preferences are based on literature data. High rates of species diversity and feeding value (primarily high proportions of legumes and forbs) allow to consider the moderately moist flood plain meadows of the Podkamennaya Tunguska and the Yenisei Rivers as summer pastures of high quality. The quality of the damp meadow of the Stolbovaya River is much lower: lower species richness, plant mass and legumes abundance, medium or low feeding value of predominant species. The lakeside meadow is significantly inferior in quality to riverside ones in all parameters, but the abundance of the sedge and dead plant mass allows to consider it as winter and spring pasture.