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Valaam Archipelago

Valaam ArchipelagoThe Valaam Archipelago is said to be the pearl of the Russian North. Located in the deep-water part of Lake Ladoga, the largest European lake, the Archipelago is a unique natural and cultural phenomenon. "History, nature and art are three powerful educational forces in our society. At Valaam they are joined together with an exceptional strength...", said academician Dmitry Likhachev.

Location

The Valaam Archipelago is situated in the northern part of Lake Ladoga, the largest inland water body in Europe. The total area of the lake is 18 329 km². The Valaam Archipelago is situated 30 km off the nearest shore. It comprises over 50 islands, with the total area of 36 km². The largest island of the Archipelago is Valaam Island (27.8 km²); closely adjoining it are Skitskii Island, Predtechenskii Island and Emelyanovskii Island; the rest of the islands are small. The indented coastline of the Archipelago, with its numerous straits, channels and bays, singles it out of the other islands on the Ladoga, partly explaining its exceptional appeal to visitors. The water area of the Archipelago is almost free from the influence of the rivers flowing into the Ladoga, and can thus be considered as a reference area for the central part of this lake.

Climate

The climate of the Valaam Archipelago is greatly influenced by Lake Ladoga. This is expressed in the levelling of the daily and the seasonal air temperature charts as compared to the neighbouring areas on the mainland, in a longer frost-free period and in frequent fogs. The climate of the islands is in fact close to the temperate continental one, with a cool summer and a relatively warm winter. The average annual air temperature is +3.6°. According to the average-annual long-term data, the coldest month is February (-8,6°), and the warmest one, July (+16,7°). The average relative humidity (81-83%)is the highest in Karelia. Strong winds are common. In some years, the number of days with the wind speed exceeding 15 m/s reaches 40-50.

Geological origin

The Valaam Archipelago has a tectonic origin. Its formation was associated with the rise of a block of a large intrusive body, which was part of the crystalline basement of the Ladoga basin. The width of the intrusion is about 30 km, its length, about 100 km, and its thickness, 100-120 m. The intrusion stretches latitudinally from Priozersk in the West to Salmi Village in the East. The outcrops of massive-crystalline bedrocks (ferro-gabbro-diabases, gabbro-diabases and valaamites) are uniquely large for the North-West Russia.

Relief

The tectonic origin of the islands is expressed in their relief. Solitary rocky ridges and abruptly raising massifs are divided with depressions (hollows, bays and lakes) associated with tectonic fractures. The latter gave the north-western coast of the Archipelago its fanciful appearance and separated Skitskii Island from Valaam by Sisyarvi Lake and the Monastyrskaya Bay.

Quaternary sediments

The bedrock is overlain by quaternary sediments of varying thickness and mixed lithological composition. They consist of moraine, lacustrine-glacial, lacustrine, deluvial and peatbog sediments. Altogether, about 400 types of landscape facies have been described at the Archipelago.

Soils

A considerable geomorphological diversity is reflected in the high diversity of the soils. The soil cover of the islands is represented by natural and anthropogenically transformed soils. Altogether, 14 soil types have been recorded at Valaam, the most broadly distributed ones being primitive, podzol, podzol-bog and turfy-gley bog soils, as well as ferro-metamorphic soils formed at outcrops of various magmatic rocks. Soils of the latter type are very common at the Archipelago. They are acidic, have a thickness of 40-60 cm, contain much stone debris and are well provided with nutritive elements.

Flora

Diverse microlandscapes and naturally fertile soils are the basis of the islands' rich flora, which comprises over 500 vascular plants, 45% of the total number of species recorded in Karelia. The flora is dominated by forest and grassland species (150 species in each of these two categories). Rocky, coastal, aquatic and bog plants are represented by 30-40 species in each category; there are also about 60 species of weeds. Sixty-four species are listed in the Red Data Books of Russia and Karelia. Natural characteristics of the Archipelago allowed the introduction of many trees and shrubs (54 species), and the introduced species have become an integral part of the landscape. Many of them, such as larch (Larix sibirica), fir (Abies sibirica) and oak (Quercus robur), reproduce well and occupy large areas.

The vegetation cover of Valaam is dominated by middle-taiga forests, with considerable participation of nemoral elements: maple (Acer platanoides), linden (Tilia cordata), elm (Ulmus glabra) as well as many herbaceous plants. The most common forests at Valaam are pine and spruce forests of various types. Forest ecosystems occupy about 80% of the Archipelago. The average age of the tree stand is about 130 years, the maximal age, 350 years. The features mentioned above are characteristic of virgin taiga forests, very few of which have preserved in Karelia.

Fauna

The ornithofauna of the Valaam Archipelago is very interesting. The 220 species registered there constitute 90% of the species recorded in the South of Karelia. Seventy-five of these birds nest on the Archipelago. Birds associated with closed forest landscape are the most common (over 60% of the total number of nesting birds). Also numerous are the birds associated with water. The Valaam Archipelago is the stop-over site for many migratory wetland birds and waterfowl. Throughout the summer one can spot near the islands back-throated diver (Gavia arctica), brant goose (Branta bernicla) and marine ducks such as scaup (Aythya marila), common scoter (Melanitta nigra), velvet scoter (Melanitta fusca), long-tailed duck (Clangula hyemalis) and eider (Somateria mollissima). Some ducks, including eider, nest on the Archipelago every year. On small islands there are large colonies of herring gull (Larus argentatus), common gull (Larus canus), lesser black-backed gull (Larus fuscus), common tern (Sterna hirundo) and Caspian tern (Sterna caspia). The colonies of the latter species are the only ones in Karelia.

The Valaam fauna of amphibians (3 species), reptiles (3 species) and mammals (25 species) is, unsurprisingly, much poorer than on the mainland. Rodents are the best represented order of mammals, the most common species being bank vole (Clethrionomus glareolus), water vole (Arvicola terrestris), red squirrel (Sciurus vulgaris) and muskrat (Ondatra zibethicus). The lagomorphs, the insectivores and the cloven-hoofed animals are each represented by one species, respectively: mountain hare (Lepus timidus), common shrew (Sorex araneus) and elk (Alces alces). Out of the predators, fox (Vulpes vulpes) and stoat (Mustela erminea) are resident; marten (Martes martes) and weasel (Mustela nivalis) may be present. The most common bats are northern bat (Eptesicus nilssoni), Daubenton's bat (Myotis daubentoni) and long-eared bat (Plecotus auritus). The presence of noctule bat (Nyctalus noctula) and mouse-eared bat (Myotis dasycneme) at Valaam is conjectured but remains unconfirmed.

Throughout the open water period, the islands of the Archipelago attract the Ladoga ringed seals, which use the coast or small stony islets near it for summer relaxation haul-outs. The number of seals at a haul-out may reach 300-330. Since the seals haul out close to the shore, it is relatively easy to observe their behaviour and daily activities. The islands of the Valaam Archipelago are one of the main haul-out areas of the ringed seal on the Ladoga. A considerable part of the whole population may haul out there at the same time.

Aquatic system

The aquatic system of the Archipelago comprises its Ladoga coast, including shallow areas and bays, two large lakes connected with each other and with the Ladoga, and 9 small isolated lakes. Sisyarvi, the largest lake (80.5 ha), has a complex elongated shape with several lobes. Its shores are mostly raised and in some places are formed by precipitous rocks. Shallow areas are scarce; when present, they mostly have rocky bottoms or sandy-stony, rarely sandy, sediments. For this reason, the lake is not too overgrown and is rather monotonous in character. Lake Leshchevoe, the second largest lake (23.8 ha), is situated in the southern part of Valaam; it is connected with channels with Sisyarvi and Ladoga. The lake is abundantly overgrown. Its shores are mostly sloping and in some places boggy; there are rocky stretches in the eastern part.

The forest lakes are small (0.3-3.0 ha), with dark brown water and sludgy bottom. Some of the lakes are being bogged. Most of the small lakes are connected with the Ladoga by channels, which dry in summer; the water level in the lakes is about 3 m higher than that in the Ladoga. As compared with Karelian lakes on the mainland, the lakes of Valaam Island have a higher mineralisation, an increased content of organic matter and a higher content of iron.

Hydrobiological characteristics

The phytoplankton of the Valaam aquatic system was shown to contain 343 algal taxa below the generic level, belonging to 9 phyla. Aquatic invertebrates represent zooplankton (98 species), macrobenthos (80 species) and meiobenthos (180 species). Ichtyofauna comprises 27 species. Over 70 macrophytes were noted in the small forest lakes. In all the lakes, water arum (Calla palustris) and marsh cinquefoil (Comarum palustre) can be found at the water edge. Yellow water lily (Nuphar luteum) dominates in most lakes, with the littoral areas overgrown with this plant varying from 1 to 68%.

Anthropogenic impact

The modern appearance of the Valaam landscape is the result of a long history of human assimilation of this unique area. The greatest impact was made by the activities of the orthodox Transfiguration Monastery in the 18-19th centuries. The monks made improvement felling, built roads, dug canals, introduced plants. Considerable forest areas were felled in 1919-1940, when Valaam was on the Finnish territory and a large garrison was present there; however, the clearings were immediately replanted by "Finnish" pines. The upsurge of recreation in the last four decades influenced the forest vegetation and soils. In 1989 the Valaam Monastery resumed its activity. Since that time, most of the sketes (monk hermitages) were reconstructed; an economy and a fleet were created. At present, sewage disposal plants are being tested in the main monastery complex and at Voskresenskii Skete. The recreation load put by pilgrims and tourists upon the ecosystems of the Archipelago should be assessed and, if necessary, curtailed. The state of the landfill on the island leaves much to be desired, and the lack of organised garbage collection and recovery causes concern. "Valaam Archipelago" nature park, founded in 1999, is actively involved in the solution of the environmental problems of the area.

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