Lake Ladoga belongs to the group of lakes little overgrown by vegetation. Low temperature, low amounts of biogenic elements and rare fluctuations of the water level hinder the development of plants. At the same time despite the low level of lake's overgrowth, total area covered with vegetation exceedes 130 sq. km. The considerable area of the lake results in high floristic diversity and diversity of plant communities in the shore strip.
The lake was found to have 107 macrophyte species comprising 71 association. The dominant communities are those of reed, bulrush and perfoliate pondweed (Raspopov, Rychkova, 1997; Raspopov et al., 1998)
Easily overgrown by vegetation is the sandy and clayey littoral.
The diversity of plant communities in the rocky littoral is not high. Rocky
littoral is free of higher vegetation. The highest diversity of species and
communities is observed in the sheltered mud littoral zone found in the tops of
bays and skerries of Ladoga (Raspopov, 1961).
Which plants overgrow Ladoga shores
The main plant contributing to overgrowing of the shore is the
common reed (Phragmites australis). It occurs in 72% of the shore
communities (Raspopov, 1985). Floristically, the richest aggregation is that of
reed and aquatic plants: it comprises over 80 species. Abundant are Equisetum
fluviatile, Potamogeton perfoliatum, Potamogeton gramineus, Polygonum
amphibium.
With regard to the lakeside vegetation the Lake Ladoga shore can
be divided into three geobotanical regions (Fig. 3.3.2.1):
skerries region (skerries),
open shore region (open coasts) with the western and eastern subregions,
southern (southern geobotanical district).
The skerries region is
located in the north of the lake from Priozersk to Ristiniemi promontory. It
holds communities with Nymphaea tetragona, Sparganium minimum, Carex
aquatilis, etc. The communities are quite diverse, but their total area is
not large (about 1500 ha).
The open shore region can be subdivided into eastern and western subregions. Eastern subregion occupies the eastern shore from Ristiniemi promontory to Gabanov promontory. This subregion is characterised by a variety of litoral types and coastal vegetation communities.
Among plant communities of eastern subregion the rare
association with Littorella uniflora as well as the only location of
Scirpus lacustris (the north-western part of the Andrusovskaya bay) are
found Furthermore, in plant communities associated with the Baltic coast and
shores of large lakes that stretch along the sandy beaches of the eastern
shore to the north of the Svir river mouth a willow species (Salix
acutifolia) which had often been used to stabilize bank sands is also
included. Therefore, many flora researchers doubt its natural provenance on the
Ladoga shores (Reviews..., 1992).
The southern region covers the Lake Ladoga shore from Morjin Nos promontory to Gabanov promontory (Annex A-3.6). The region is noted for a wide littoral zone. The 5-m isobath is sometimes up to 9 km away from the water edge. The shoreline vegetation is exceptionally well-developed (it occupies about 8200 ha). However, the southern region plant communities are subjected for the most intensive anthropogenic pressure (agriculture, construction and recreation).
