Home

Physical Geography
  Tectonics and Geology
  Climatic Change
  Climate at Present and in the Past
  Soils
  Rivers, Lakes, Seas and Wetlands
  Permafrost
  Biodiversity

Biomes & Regions
  Arctic Environments
  Boreal Forests
  Mixed and Deciduous Forests
  Steppe and Forest-steppe
  Arid Environments
  The Mountains of Northern Russia
  The Mountains of Southern Siberia
  The Caucasus
  The Mountains of Central Asia
  Lake Baikal
  The Far East

Environmental Problems
  Radioactive Contamination
  Oil and Gas Development
  Air Pollution
  The Aral Sea Problems
  Deforestation and Degradation of Forests
  Nature Protection and Conservation

Images of Russian Nature
  Geographic Index
  Systematic Index
  Alphabetical Index

Nature Reserves
  Northern Russia
  Central Russia
  Povolzhye (Volga river basin)
  Southern Russia
  Ural Mountains
  Western Siberia
  Eastern Siberia
  Far East


Ôîòîãðàôèè ïðèðîäû Ðîññèè
  Ãåîãðàôè÷åñêèé êàòàëîã
  Ñèñòåìàòè÷åñêèé êàòàëîã
  Àëôàâèòíûé êàòàëîã


Nature Landscapes of the World
  Europe
  Asia
  North America
  South America
  Africa
  Australia
  Antarctic

Field Ecology Education
  Instructive Videos
  Instructive Manuals


Ýêîëîãè÷åñêèé Öåíòð Ýêîñèñòåìà íà Facebook Ýêîëîãè÷åñêèé Öåíòð Ýêîñèñòåìà ÂÊîíòàêòå

Þòóá êàíàë Ýêîñèñòåìà YouTube EcosystemaRu

Ñêà÷àòü íàøè ïðèëîæåíèÿ èç ìàãàçèíà RuStore
Ñêà÷àòü íàøè ïðèëîæåíèÿ èç ìàãàçèíà RuMarket Ñêà÷àòü ïðèëîæåíèÿ Ýêîñèñòåìû èç ìàãàçèíà NashStore
Ñêà÷àòü ïðèëîæåíèÿ Ýêîñèñòåìû èç ìàãàçèíà GetApps Xiaomi
Ñêà÷àòü ïðèëîæåíèÿ Ýêîñèñòåìû ÝêîÃèä èç ìàãàçèíà Google Play / Play Market
Ñêà÷àòü ïðèëîæåíèÿ Ýêîñèñòåìû ÝêîÃèä èç AppStore / iTunes
Âèäåî-360 ïî ýêîëîãèè íà íàøåì Youtube êàíàëå

Bird Decoys for European Birds: Songs, Calls, Sounds, Bird voices - application for Android download from Google Play / Play Market for free



Share this page with your friends:



( ) : : = = + +


Russian Nature

Home | Physical Geography | Biomes & Regions | Environmental Problems | Images of Russian Nature | Nature Reserves

Our Field Ecology Center published more than 180 methodical materials for nature studies. Some of them are in English:
Mobile educational application: Ecological Field Studies Techniques on Play.Google Mobile field guide Birds of North America: Songs and Calls Decoys on Play.Google WILD FLOWERS OF RUSSIA Field Identification Guide on Play.Google Mobile field guide Birds of Russia on Play.Google Mobile field guide Birds of Russia Songs, Calls and Voices on Play.Google Mobile field guide Birds of Europe Songs, Calls and Voices on Play.Google Mobile field guide Birds of Europe Songs, Calls and Voices on Play.Google
Mobile Educational Apps and Field Identification Guides for Russian, European and American Birds
Applications for Android and iOS are available at GooglePlay and AppStore


Please put an active hyperlink to our site (www.rusnature.info) when you copy the materials from this page

Biomes and Regions of Northern Eurasia

The Arctic Environments

<<< Arctic Vegetation: Zonality and Regional Divisions | Biomes & Regions Index | Tundra Vegetation >>>

Polar Deserts

In polar deserts, little solar radiation is available as a result of the polar night and the low position of the sun during the polar day, and much of the received radiation is reflected by snow and ice. Annual radiation budgets do not exceed 10 kcal cm-2. The growing season is very short, six to eight weeks, and is characterized by low temperatures. Apart from temperature, two other factors are of great importance for the environments of polar deserts: snow cover and wind. Heavy snowfalls are typical of the Barents province while in the Siberian provinces snow cover is lower. Thus, at Franz Josef Land the depth of the snow pack in coastal areas averages 40-60 cm (Govorukha, 1970) while in the Siberian provinces it is less than 30 cm (Semenov, 1970). Winds are strong across the polar desert biome. Snow is often blown away from raised sites and exposed slopes and is deposited in depressions and on the lower parts of slopes. Snow cover has a very different effect on vegetation in polar deserts compared to tundra. In tundra, snow cover has an insulating, protective function. In polar deserts, gradually melting snow has an extremely negative effect on the development of vegetation because it reduces the short vegetative period further. Thus, at Franz Josef Land, the most favourable conditions for the growth of plants occur where snow forms a cover about 20 cm thick and disappears by the middle of June. Where snow cover is thicker, the development of sparse vegetation is hampered further and where snow cover reaches 1 m and melts away after the middle of July, vegetation does not develop at all (Aleksandrova, 1988). Fohn winds, which form due to the relatively high topography and deep fjords, such as at Severnaya Zemlya, are important local factors. Fohn winds account for the formation of the arctic tundra oases containing such species as Salix polaris (Safronova, 1976).

Soil-forming processes are to a great extent suppressed and soils of polar deserts are skeletal. Frost weathering is the main agent which creates cryogenic types of surfaces. Freeze-sorting of substartes is a typical feature. The extremely low rates of chemical and biochemical weathering produce very little clay material; however, if clay fraction is present, the surface is often broken into polygons by fission. A characteristic feature of the polar desert polygons is their small dimensions which vary between 10 cm and 50 cm in diameter (Aleksandrova, 1988; Matveeva, 1979). Continuous vegetation often occurs in the form of moss-lichen swards developing along a network of polygons. In contrast to those of the tundra, soils of polar deserts do not have a pronounced peat horizon and gleying takes place only in favourable habitats at the southern part of the zone (Chugunova, 1979).

Polar deserts are a realm of bare rocks, shattered bedrock, and gravel. Plants are distinguished by their scarcity and by a low number of species. Closed plant cover is limited in extent in zonal habitats and is absent from a significant part of the territory, particularly from the tops of hills and nunataks. Blue-green algae dominate the soil microflora (Novikova-Ivanova, 1972). Lichens are the most abundant plants, followed by mosses; the role of flowering plants is insignificant and there are no dwarf shrubs. At Franz Josef Land, 115 species and subspecies of lichens, 102 of mosses, and 57 of flowering plants are known (Aleksandrova, 1988). At Cape Chelyuskin, 136 species and subspecies of lichens (Piyn, 1979), 74 of mosses, and 59 of flowering plants (Safronova, 1979) have been identified. At the northern edge of the polar deserts flora is even poorer: at the Zemlya Aleksandry island there are only 24 species of flowering plants and on the northern islands of Severnaya Zemlya there not more than 17 species. Crustose lichens often form a crust on the ground while flowering plant cover ranges between 1 per cent and 6 per cent (Aleksandrova, 1988). Flowering plants grow individually and their root systems do not intermingle. Biomass is low: on the Bolshoy Lyakhovsky island it does not exceed 5 t ha-1 (Rodin and Bazilevich, 1965). Species composition differs between the Barents and Siberian provinces. The majority of the Siberian and Siberian-American species occur only in the southern part of polar deserts and further north the predominance of circumpolar flora becomes stronger (Young, 1971). Detailed reviews of the flora of polar deserts are given by Aleksandrova (1980, 1988).

<<< Arctic Vegetation: Zonality and Regional Divisions | Biomes & Regions Index | Tundra Vegetation >>>

 

 


Recommend this page to your friends:


* *