322
Land-Ocean Systems in the Siberian Arctic: Dynamics and History
ranges from pelitized to clay loam). The vegetation consists of mesic cotton grass-dwarf
willow-moss and sedge-dwarf shrub-moss communities (Deschampsia borealis, Carex
arctisib irica, Salix polaris, Alopecurus alpin us; a well-developed moss layer of mostly
Tomentypnum nitens and Aulacomnium turgidum); up to 80 % cover; the soil cover is a
composite of Rentzi-gelic Leptosols regions bordered by Molli-gelic Gleysols surrounded by a
background Distri-gelic Gleysol.
18 - Saturated surfaces at various hypsometric levels with angles of inclination close to 0°
Here the nanorelief is spotty and weakly striped and the vegetation is sedge-dwarf shrub-moss
(Carex arctisibirica, C.concolor, Salix polaris, sometimes S.reptans; in the moss layer:
Tomentypnum nitens); up to 90 % cover; the soils are a nanocomplex of Stagni-gelic Leptosol
regions surrounded by Molli-gelic Gleysol borders, separated by Distri-gelic Gleysols.
19 - Watersheds on the northern macros lope of Byrranga Glavnaja Ridge, consisting of finegrained material with occasional rock outcrops
The rudiments of striped patterned ground and thermokarst depressions are present as well.
Generally speaking, they belong to another landscape: the intermountain kettles of the Ugolnaja
river depression. The vegetation is close to that of the arctic tundra subzones (small role of
dryas in community composition and its replacement by Salix polaris). The vegetation here
comprises 3 elements: A) Weathered bedrock outcrops support sparse (3-5 % cover) forblichen vegetation between stones on a fragmented Distri Regosols; B) Mesic hummocky-spotty
dwarf willow-sedge-moss tundra with 50-80 % cover (Salix polaris, Carex arctisibirica; in the
moss layer: Tomentypnum nitens, Ptilidium ciliare) on Molli-gelic- and Umbri-gelic Gleysols;
C) Thermokarst microdepressions and striped patterned ground with continuous wet sedgemoss vegetation (Carex concolor, Eriophorum scheuchzeri, E.polistachyon; mosses:
Tomentypnum nitens) on Dysri-ge\ic Geysols.
20 - Polygonal surfaces on nearly horizontal slopes of the lower portions of watersheds
These features also occur in the previous landscape type. This paisa bog complex is generated
through the natural draining of small lakes. The vegetation comprises 2 elements as a result of
differences in microrelief: A) Paisa remnants with moist sedge-moss vegetation (Carex
arctisibirica, Luzula nivalis, Calamagrostis holmii; moss layer consists of Polytrichum
strictum, Dicranum spsp.,.); the soils are Dystri-gelic Gleysols; B) Flat depressions with wet
moss-sedge-cotton grass vegetation (Carex concolor, Eriophorum polistachyon, E. medium;
the sparse moss layer consists of Meesia triquetra, Limprichtia revolvens); the soils are Fibrigelic Hystosols; the cover is continuous throughout the complex.
Valleys
21 - Deep V-shaped valleys of large mountain streams with abrupt scree slopes and with rock
outcrops on the upper slopes
This is one of the most structurally complicated units. It includes almost all of the unit #6 units
(the abrupt slopes). The elements of relief and vegetation vary even more here, because of the
variety of exposures; the range of flora supported is much greater. The slope surfaces show
evidence of the elements of ecological succession. The main elements are: A) Scree with sparse
(cover < 5%) herbs (Arabis petraea s.l., Cerastium beeringianum, Saxifraga spsp., Poa
glauca et al.) on Dystri-gelic Regosols and Dystri-gelic Regosols; B) Forb-dryas boulder debris
(Dryas punctata, Hierochloe alpina, Festuca auriculata, Astragalus alpinus, Potentilla
uniflora et al.) on fragmented Eutri-gelic Regosols; C) Mountain dry-mesic herbaceous
Land-Ocean Systems in the Siberian Arctic: Dynamics and History
ranges from pelitized to clay loam). The vegetation consists of mesic cotton grass-dwarf
willow-moss and sedge-dwarf shrub-moss communities (Deschampsia borealis, Carex
arctisib irica, Salix polaris, Alopecurus alpin us; a well-developed moss layer of mostly
Tomentypnum nitens and Aulacomnium turgidum); up to 80 % cover; the soil cover is a
composite of Rentzi-gelic Leptosols regions bordered by Molli-gelic Gleysols surrounded by a
background Distri-gelic Gleysol.
18 - Saturated surfaces at various hypsometric levels with angles of inclination close to 0°
Here the nanorelief is spotty and weakly striped and the vegetation is sedge-dwarf shrub-moss
(Carex arctisibirica, C.concolor, Salix polaris, sometimes S.reptans; in the moss layer:
Tomentypnum nitens); up to 90 % cover; the soils are a nanocomplex of Stagni-gelic Leptosol
regions surrounded by Molli-gelic Gleysol borders, separated by Distri-gelic Gleysols.
19 - Watersheds on the northern macros lope of Byrranga Glavnaja Ridge, consisting of finegrained material with occasional rock outcrops
The rudiments of striped patterned ground and thermokarst depressions are present as well.
Generally speaking, they belong to another landscape: the intermountain kettles of the Ugolnaja
river depression. The vegetation is close to that of the arctic tundra subzones (small role of
dryas in community composition and its replacement by Salix polaris). The vegetation here
comprises 3 elements: A) Weathered bedrock outcrops support sparse (3-5 % cover) forblichen vegetation between stones on a fragmented Distri Regosols; B) Mesic hummocky-spotty
dwarf willow-sedge-moss tundra with 50-80 % cover (Salix polaris, Carex arctisibirica; in the
moss layer: Tomentypnum nitens, Ptilidium ciliare) on Molli-gelic- and Umbri-gelic Gleysols;
C) Thermokarst microdepressions and striped patterned ground with continuous wet sedgemoss vegetation (Carex concolor, Eriophorum scheuchzeri, E.polistachyon; mosses:
Tomentypnum nitens) on Dysri-ge\ic Geysols.
20 - Polygonal surfaces on nearly horizontal slopes of the lower portions of watersheds
These features also occur in the previous landscape type. This paisa bog complex is generated
through the natural draining of small lakes. The vegetation comprises 2 elements as a result of
differences in microrelief: A) Paisa remnants with moist sedge-moss vegetation (Carex
arctisibirica, Luzula nivalis, Calamagrostis holmii; moss layer consists of Polytrichum
strictum, Dicranum spsp.,.); the soils are Dystri-gelic Gleysols; B) Flat depressions with wet
moss-sedge-cotton grass vegetation (Carex concolor, Eriophorum polistachyon, E. medium;
the sparse moss layer consists of Meesia triquetra, Limprichtia revolvens); the soils are Fibrigelic Hystosols; the cover is continuous throughout the complex.
Valleys
21 - Deep V-shaped valleys of large mountain streams with abrupt scree slopes and with rock
outcrops on the upper slopes
This is one of the most structurally complicated units. It includes almost all of the unit #6 units
(the abrupt slopes). The elements of relief and vegetation vary even more here, because of the
variety of exposures; the range of flora supported is much greater. The slope surfaces show
evidence of the elements of ecological succession. The main elements are: A) Scree with sparse
(cover < 5%) herbs (Arabis petraea s.l., Cerastium beeringianum, Saxifraga spsp., Poa
glauca et al.) on Dystri-gelic Regosols and Dystri-gelic Regosols; B) Forb-dryas boulder debris
(Dryas punctata, Hierochloe alpina, Festuca auriculata, Astragalus alpinus, Potentilla
uniflora et al.) on fragmented Eutri-gelic Regosols; C) Mountain dry-mesic herbaceous