Features of the composition and productivity of Tuloma river’s estuarine hydrofytocenoses

Abstract

Abstract The species composition and productivity of communities of higher aquatic vegetation in the Tuloma River estuary, in the North-Western part of the Kola Peninsula, is studied. Samples with streamside vegetation were taken several times during the 2019 growing season from the littoral and sublittoral zones. Subsequent investigations revealed that macrophyte growth begins in April (offshoots of Ranunculus schmalhausenii), the mass germination period is estimated at the end of May to early June (representatives of the genera Potamogeton, Callitriche). The beginning of the growing season is influenced by ice conditions. The last vegetative plants are found in November (Potamogeton, Elatine, Batrachium). Analysis of the species composition of the samples revealed that the most environmentally plastic plants are water-starwort (r. Callitriche), pondweed (Potamogeton perfoliatus L) and water moss (Fontinalis sp.): occurring in the drained zone and on the sublittoral. The production of the studied phytocenoses reaches its peak in August (up to 110 g/m2 of absolutely dry mass), the main contribution to which is made by pondweeds. The distribution of accumulated phytomass over the horizons shows that the communities that are least susceptible to drainage are characterised by maximum productivity. These results may be important when monitoring hydrobiocenoses of the Tuloma river basin.