Macro- and Microhabitats of the Kuril Islands

Burke Museum, University of Washington, Seattle

The various terrestrial and aquatic habitats available on the Kuril Islands are highly varied (Ivlev, 1967; Nechaev, 1969; Marusik et al., 1992; V. Y. Barkalov to T. W. Pietsch, pers. comm., 8 June 1993). The following list was compiled primarily for spiders, but can be easily applied to all taxa selected for survey in the present proposal.

Unvegetated Upper Beach.--Including gravelly strand habitat covered at high tide, and from the upper reach of the tide to lowest vegetation. Important microhabitats: beneath stones, dried seaweed wrack, and driftwood.

Beach Meadow Zone.--The grassy band usually present between upper beach and outermost forest or other land-oriented vegetation. Important microhabitats: field layer vegetation, soil surface, driftwood, and rock outcrop surface.

Tidal Wetlands.--Including estuaries of rivers and streams. Important microhabitats: field layer vegetation and ground surface.

Freshwater Shorelines.--Shores of streams and lakes. Important microhabitats: shore vegetation (grassy, herbaceous, and shrubby), unvegetated mud surfaces, shoreline moss, emergent and overhanging foliage, beneath shoreline and gravel-bar stones, gravel bar surfaces.

Streams and Rivers.--Flowing water. Important microhabitats: open water, riffle, rapids, aquatic vegetation, waterlogged terrestrial vegetation, sticks and logs, and mud, sand, gravel, and rocky bottoms.

Swamp.--Forested wetlands. Important microhabitats: leaf litter, epiphytic and log mosses, tree trunks, beneath bark of standing dead trees, coniferous tree foliage, understory foliage, stagnant water.

Marsh or Fen.--Freshwater wetlands common especially on the islands of Kunashir, Iturup, Urup, and Zelionyi. Important microhabitats: field layer vegetation, grass/sedge litter, ground surface, stagnant water.

Bogs.--The "moss-grass mires" of Barkalov (V. Y. Barkalov to T. W. Pietsch, pers. comm., 8 June 1993). Sphagnum and hypnum bogs. Important microhabitats: bog surface moss (moist, wet, and saturated), ground surface, field layer foliage, bog shrub foliage, bog shrub leaf litter.

Deciduous Forest, Woodland, Scrub.--There are 16 distinct deciduous woodland communities in the Kurils (V. Y. Barkalov to T. W. Pietsch, pers. comm., 8 June 1993). Important microhabitats: leaf litter, beneath wood on ground, interior of rotten logs, beneath loose bark of logs and dead trees, understory foliage, ground and log moss, epiphytic moss, trunks of larger trees.

Coniferous Forest.--There are seven distinct coniferous communities on the Kurils (V. Y. Barkalov to T. W. Pietsch, pers. comm., 8 June 1993). Important microhabitats: tree foliage, epiphytic moss, trunks/bark of living trees, beneath loose bark of dead trees and logs, interior of rotten logs, beneath wood on ground, moss on ground and logs, understory foliage.

Meadow.--Large meadows and small clearings within forests are common. Important microhabitats: field layer foliage, ground surface, foliage of isolated shrubs or trees, foliage of forest-edge shrub, and tree foliage.

Savanna.--Savanna habitats, characterized by a distinct fauna and flora, exist where trees are widely separated enough to have grassy vegetation open to sunlight. Important microhabitats: field layer foliage, leaf litter (especially that associated with logs), moss, beneath loose bark on logs, dead trees, and dead branches of living trees, ground surface, beneath stones if available.

Bamboo Scrub.--Leaf litter and split stems of dead bamboo.

Heath, Prairie, and Steppe.--Treeless areas below the treeline that have a relatively continuous vegetation cover of grass, forbs, and/or shrubs. Important microhabitats: field layer grass/forb foliage, shrub foliage, beneath stones and wood on ground, ground surface.

Treeline and Alpine Habitats.--Shrubby prostrate conifers on higher mountains (e.g., on Kunashir, Iturup, and Urup). Important microhabitats: various types of vegetation, ground surface, beneath stones, snow surface.

Lithosol.--Lava surfaces that are moderately old but have no stratified soil developed. Discontinuous vegetation cover that often yields rare plants. Important microhabitats: field layer foliage, shrub foliage, beneath stones, ground surface.

Lava Sinkholes.--In relatively recent lava flows where the surface is nearly unvegetated. Bottoms of sinkholes (formed by cave passage collapse or lava subsidence) often have microcosm habitats of dense "jungle" due to the proximity of the water table and the protection provided by the walls. Important microhabitats: foliage, beneath stones, outcrop/wall and bottom surfaces.

Cave Entrance.--Twilight zone entrances of lava tube caves that invariably support distinct faunal elements (e.g., spiders), as well as otherwise rare cryptogams and bryophytes. Important microhabitats: walls, ceiling, beneath stones, in organic debris and litter, beneath woody debris.

Cave.--Dark zone, especially important for troglophile and troglobite spiders. Important microhabitats: cave floor, walls, ceiling, beneath stones, beneath woody debris, among roots penetrating cave ceiling.

REFERENCES

IVLEV, A. M. 1967. [Vegetation, in] Atlas Sakhalinskoi oblasti. Moscow: Glabnoe Upravlenie Geodezii i Kartografii pri Sovete Ministrov SSSR, 135 pp. [in Russian].

MARUSIK, Y. M., K. Y. Eskov, D. V. Logunov, and A. M. Basarukin. 1992. A check-list of spiders (Arachnida, Aranei) from Sakhalin and Kurile Islands. Arthropoda Selecta, 1(4):73-85.

NECHAEV, V. A. 1969. [Birds of the Kuril Islands] Ptitsy yuzhnykh kurilskikh ostrovov. Leningrad: Akademiia Nauk SSSR, Sibirskoe Otdelenie, 247 pp. [in Russian].