Aquatic vegetation (Lemnetea) in Baikal Siberia

Communities of free floating plants in the reservoirs of Baikal Siberia (incl. Irkutsk Region, Republic of Burya­tia, Zabaikalsky Territory) are described. ­Using the Braun-Blanquet approach the classification of aquatic plant communities is developed. Eight associations have been identified, belonging to three alliances and three orders. The order Ceratophyllo–Hydrocharitetalia morsus-ranae Chepinoga et Rosbakh ord. nov. and the association Utricularietum macrorhizae Chepinoga et Rosbakh ass. nov. are described as new ones. The name of the association Lemno–Spirodeletum polyrhizae Koch 1954 is typified. Numerical methods for revealing and testing diagnostic, constant and dominant species have been applied. For each association the main synonyms as well as information about structure, ecology, and general and regional distributions are provided. Some features of classification of aquatic vegetation are discussed.