VALLISNERIA SPIRALIS L. (HYDROCHARITACEAE) IN UKRAINE: DISTRIBUTION AND COENOTIC ACTIVITY

Abstract

Results of the study of features according to the distibution of Vallisneria spiralis in Ukraine have been indicated. Chorological data obtained by the analysis of herbarium collection specimens and Ukrainian literature sources were generalized; a list of the known localities of this species was compounded. It has been established that this species is rather common in the Steppe zone of Ukraine, rare in the Forest-Steppe zone and very rare in the Forest zone (Ukrainian Polissya). Vallisneria spiralis is recorded now from the territories of  Kyiv city and 18 administrative regions, but from eight of them (Vinnytsia, Donetsk, Kirovohrag, Poltava, Sumy, Khmelnytskyi, Cherkasy and Chernihiv regions) the species is known only for literature sources; the latter ones need confirmations by herbarium data. From seven administrative regions (Volyn, Zakarpattia, Ivano-Frankivsk, Luhansk, Lviv, Ternopil and Chernivtsi regions) no data about the distribution of Vallisneria spiralis were presented. Based on original reobotanical releves carried out in summer of 2019 in the mouth of Dnipro river
within Kherson region and published data of other authors ecological and coenotical features of the distribution of higher aquatic communities with considerable participation of Vallisneria spiralis (plant cover is the more than 25%) were analyzed. It has been established that this species is diagnostic for two syntaxa of association rank from the higher aquatic vegetation belonging to alliance Potamogetonion Libbert 1931 from order Potamogetonetalia Koch 1926
and class Potamogetonetea Klika in Klika & Novák 1941. They are Potameto perfoliatiVallisnerietum spiralis Losev & Golub in Golub & al. 1991 and Ceratophyllo demersiVallisnerietum spiralis Lazić ex Davydova & Davydov in Davydov & Davydova 2020 ass. nova. The first association was repeatedly indicated for the territory of Ukraine. The presence of the second association early superficially cited from Ukraine as «Ceratophyllo demersiVallisnerietum spiralis Lazić 2006» was confirmed. It was found that the latter name is invalidly published so it has been validizated based on geobotanical data of authors.