Anisimov and Pospelov: The Landscape and Geobotanical Characteristics
325
Terraces
29 - Fragments of marine accumulation marine terraces at 90-100 m a.s.l., with hummocks,
and occasional large polygonal nanorelief
This region is part of the best preserved high altitude terraces, fragments of which can be found
all along the shore, but are generally not marked on the map because of their small size. They
usually occur as hills with flat or convex tops; in one case, however, in both the watersheds of
the lake and of Ledjanaja Bay, the fragment occurs as a great residual block, hilly massif. The
vegetation is classified into 3 elements: A) Forb hummocky dry communities of the terrace tops
(Carex rupestris, Potentilla uniflora, Oxytropis nigrescens, Hierochloe alpina et al.) with 5-30
% cover on Geli-lithic Leptosols; B) Slopes with dry herb-dryas vegetation (composition of
herbs is analogous, up to 60 % cover) on similar soils; C) Subnival mesic cassiope-moss
tundra of snow covered slopes (Cassiope tetragona, Carex vaginata, Taraxacum arcticum; in
the moss layer: Hylocomium splendens var.obtusifolium) with practically continuous plant
cover on similar soils.
30 - Fragments of lacustrine accumulation terraces with large polygonal surface.
These terrace fragments are generally situated 3-5 m above the present lake level. Their surfaces
are broken by cracks presumably as a result of ancient ground lodes. The surface of the
polygons between the cracks are marked by hummocky nanorelief. The edges of the terraces
are frequently marked by ice-shove ridges. The unit comprises 3 vegetation elements: A)
Denudation-spotty terrace surface with the foliose lichens and sparse (cover not more 15 %)
forb (Papaver polare, Eritrichium villosum subsp.pulvinatum, Saxifraga oppositofolia et al.)
on Distri-gelic Regosols; B) Cracks with continuous mesic herb-cassiope-moss vegetation
(Cassiope tetragona, Carex misandra, Luzula nivalis, sometimes Vaccinium minus; the moss
Rhacomitrium lanuginosum dominated completely) on Dystric Leptosols; C) Ice-shove ridge
and beach with herbaceous vegetation (Papaver lapponicum, P.pu/vinatum, Draba
subcapitata, Chrysosplenium alternifolium et al.).
31- Flooded low wet marshes of the lake.
This landscape unit occurs only once in the region, on the north-east lakeshore. The greater
portion of its surface is under water for 2-3 weeks after the spring thaw and growth therefore
begins late. The soil is composed of lake mud and mud-pebbles and shows a subtle polygonal
microrelief, especially in areas somewhat raised. This unit consists of 3 elements, the
vegetation of which form an ecological series: A) Low altitude mud and sandy-mud banks with
sparse (cover 5-10 %) wet swamp vegetation (Carex saxatilis sp. laxa, Eriophorum
scheuchzeri, E. Polistachyon and Dupontia fisheri on mollic-gleyic fluvisols; in the water:
Ranunculus gmelinii, Pleuropogon sabinii); B) Higher level sedge tussocks (Carex saxatilis
ssp. laxa), also with Carex con color, Eriophorum spsp., Pedicularis albolabiata; cover about
50%, the soils are the same; C) Highest level moist polygon-formed pebbly plots, covered
beyond by mud, with sparse, frequently caIciphilous, forbs (Arabis petraea, Oxygraphis
glacialis, Thlaspi cochleariforme, Braya purpurascens, Armeria maritima) and solitary
bushes of Salix reptans; cover 10-25 %, the soils are Dystri-gelic Leptosols.
Bogs
32 - Typical polygonal bogs on the northern shoreline region
The polygons are about 10 across and their borders reach a height of 0.5 m above the centers.
The vegetation consists of 2 elements from the polygonal bog complex: A) -Wet moss-sedge
communities of polygons (Carex concolor, C. chordorrhiza; in the fragmented moss layer:
325
Terraces
29 - Fragments of marine accumulation marine terraces at 90-100 m a.s.l., with hummocks,
and occasional large polygonal nanorelief
This region is part of the best preserved high altitude terraces, fragments of which can be found
all along the shore, but are generally not marked on the map because of their small size. They
usually occur as hills with flat or convex tops; in one case, however, in both the watersheds of
the lake and of Ledjanaja Bay, the fragment occurs as a great residual block, hilly massif. The
vegetation is classified into 3 elements: A) Forb hummocky dry communities of the terrace tops
(Carex rupestris, Potentilla uniflora, Oxytropis nigrescens, Hierochloe alpina et al.) with 5-30
% cover on Geli-lithic Leptosols; B) Slopes with dry herb-dryas vegetation (composition of
herbs is analogous, up to 60 % cover) on similar soils; C) Subnival mesic cassiope-moss
tundra of snow covered slopes (Cassiope tetragona, Carex vaginata, Taraxacum arcticum; in
the moss layer: Hylocomium splendens var.obtusifolium) with practically continuous plant
cover on similar soils.
30 - Fragments of lacustrine accumulation terraces with large polygonal surface.
These terrace fragments are generally situated 3-5 m above the present lake level. Their surfaces
are broken by cracks presumably as a result of ancient ground lodes. The surface of the
polygons between the cracks are marked by hummocky nanorelief. The edges of the terraces
are frequently marked by ice-shove ridges. The unit comprises 3 vegetation elements: A)
Denudation-spotty terrace surface with the foliose lichens and sparse (cover not more 15 %)
forb (Papaver polare, Eritrichium villosum subsp.pulvinatum, Saxifraga oppositofolia et al.)
on Distri-gelic Regosols; B) Cracks with continuous mesic herb-cassiope-moss vegetation
(Cassiope tetragona, Carex misandra, Luzula nivalis, sometimes Vaccinium minus; the moss
Rhacomitrium lanuginosum dominated completely) on Dystric Leptosols; C) Ice-shove ridge
and beach with herbaceous vegetation (Papaver lapponicum, P.pu/vinatum, Draba
subcapitata, Chrysosplenium alternifolium et al.).
31- Flooded low wet marshes of the lake.
This landscape unit occurs only once in the region, on the north-east lakeshore. The greater
portion of its surface is under water for 2-3 weeks after the spring thaw and growth therefore
begins late. The soil is composed of lake mud and mud-pebbles and shows a subtle polygonal
microrelief, especially in areas somewhat raised. This unit consists of 3 elements, the
vegetation of which form an ecological series: A) Low altitude mud and sandy-mud banks with
sparse (cover 5-10 %) wet swamp vegetation (Carex saxatilis sp. laxa, Eriophorum
scheuchzeri, E. Polistachyon and Dupontia fisheri on mollic-gleyic fluvisols; in the water:
Ranunculus gmelinii, Pleuropogon sabinii); B) Higher level sedge tussocks (Carex saxatilis
ssp. laxa), also with Carex con color, Eriophorum spsp., Pedicularis albolabiata; cover about
50%, the soils are the same; C) Highest level moist polygon-formed pebbly plots, covered
beyond by mud, with sparse, frequently caIciphilous, forbs (Arabis petraea, Oxygraphis
glacialis, Thlaspi cochleariforme, Braya purpurascens, Armeria maritima) and solitary
bushes of Salix reptans; cover 10-25 %, the soils are Dystri-gelic Leptosols.
Bogs
32 - Typical polygonal bogs on the northern shoreline region
The polygons are about 10 across and their borders reach a height of 0.5 m above the centers.
The vegetation consists of 2 elements from the polygonal bog complex: A) -Wet moss-sedge
communities of polygons (Carex concolor, C. chordorrhiza; in the fragmented moss layer: