Landscape and Soils

Soil cover of the Ladoga region is not evenly studied with just several sites intensively investigated. Some data is available only for western and eastern coasts of the lake.

Three soil regions (ridge hollow type, lacustrine terrace plains, and boggy) were singled out on the Ladoga western shore with regard to the soil structure and the soil cover pattern (Fig. 3.3.1.1). All regions are characterized by poor soils, predominantly complex landscapes and relatively low agricultural capacity (see Annex A-3.7. for detailed description). On the other hand the whole area is a subject of intensive recreation by the citizens of St.Petersburg that affects soil cover and leads to erosion.

The eastern shore of Lake Ladoga is a low accretion plain turning into an even lower water-logged delta in the Svir river estuary. To the north of the Nizhne-Svirsky reserve sandy plains change into a lacustrine-glacial (Olonetskaya) plain encircled by mires (see Annex A-3.8 for detailed description).

The soil cover of the territory is more or less uniform (formed mainly by podsol and peaty-podzol). Considerable influence on soils and landscapes is noticeable from the economic activities. Soils in the south-eastern part of the area are considerably water-logged, which was enhanced by clear-cutting in raised areas in the recent past. Agricultural activities affect soils and landscapes of the Olonetskaya plain.

Eco-geochemical evaluation of soils, in contrast to bottom sediments, y metals and radionuclides in the surface soil layer does not exceed the background values (Panova et al., 1998). Some deposition of toxic elements in litters and humus horizons is due to their supply with atmospheric precipitation and air-borne transport.

In general soil cover of the region is affected by anthropogenic transformation that leads to its' unsuitability in several areas. Part of the formerly cultivated soils degradates due to the decrease of farmed land and destruction of the drainage networks.

The most powerful anthropogenic factor now influencing soils cover in several areas is recreation. It destroys the surface soil horizons, makes mineral soil horizons more compact and enhances erosion processes. This threat is especially dangerous for soils of the dry forest types and their thin underling layer that had been forming for long geological eras and its loss due to erosion cannot be made up for.

The Valaam archipelago, a unique ecosystem in the lake both in biological component and in soil cover and landscapes, is the most studied in terms of soils territory in Ladoga region . Most of approximations concerning soil genesis, dynamics of soil formation process, as well as soil responses to anthropogenic pressure and technogenic pollution have been made on the basis of data gathered at Valaam. For more complete understanding of processes in Ladoga region soils and implementation of soil monitoring further investigations are essential in various model sites of the whole region, but not at just one area. Enhancement of investigations of soil cover is also important because soils and landscapes are proved to be responsible for maintenance of vegetation types' diversity (see "Vegetation"), and thus for distribution of animals species (see "Fauna") in the Ladoga region.

webmaster@www.krc.karelia.ru