The macrophyte flora and overall features of some relict lakes of the Kama-Bakaldino mires (Nizhny Novgorod oblast)

The study of the flora of aquatic plants and the characteristics of vegetation in a number of the lakes that are related to the Kama-Bakaldino Mires (Bol’shoe and Maloe Plotovo, Bezrybnoe, Ryabinovskoe and Krasnoe), located in the Vorotynetz district of the Nizhny Novgorod region (in the interfluve of the Kerzhenets and Vetluga Rivers). The systematic structure of the combined flora of aquatic plants is represented by 50 taxa (including one hybrid Sparganium × longifolium ) belonging to 5 divisions, 7 classes, 18 orders, 24 families and 33 genera. The species number of partial floras ranged from 29 to 52. A geographical and ecological analysis of the flora has been carried out. The habitats of aquatic plant populations ( Chara strigosa, Fontinalis dalecarlica, Isoëtes lacustris, I. echinospora, Sparganium gramineum, Potamogeton praelongus and Caulinia flexilis ) are characterized. These plants are listed in the the regional and federal Red Data Book and have the south border of their home range crossing the territory of the Nizhny Novgorod region. We proposed to include in the regional Red Book an extremely rare species in the middle regions of the boreal region - Scorpidium scorpidioides , which was discovered on the territory of the Nizhny Novgorod region (Lake Krasnoe) for the first time. On the basis of the dominant-determinant system, the prodromus of lake vegetation is presented, comprised 29 associations, 13 formations, 5 groups of formations and 3 classes of formations. The types of lake overgrowth of lakes were revealed. On the basis of the available literature data, slight changes in the types of overgrowth of Lake Bolshoye and Maloye Plotovo over the past 50 years, caused by natural succession processes have been shown.