The Alaska Vegetation Classification - Alaska Geobotany Center ...

SolifluctlowDownslope movement ("flowing soil") of earth materials resulting fromfrost action characteristic of areas with cold arctic or alpine climate.Solum-The upper and most weathered part of a soil profile, above the parentmaterial. in which processes of soil formation are active. The solum in mature soilsconsists of the A- and B-horizons.Sphagnum moss-Moss plants of the genus Sphagnum.Spruce bog-A loosely applied term describing confined areas of organic terrainwhere coniferous trees are a prominent feature of the vegetational cover.Stand-A concrete (vs. abstract) aggregation of plants of more or less similaruniformity in physiognomy, species composition, spatial arrangement, and conditionto distinguish it from adjacent communities, Concrete stands, which we sample ormeasure, are aggregated into abstract communities. and communities are furtherabstracted into a general vegetation.SteppeTemperate zone vegetation dominated by grasses and occurring in climateswhere zonal soils are too dry to support trees. Open grass or other herbaceous vegetation,the plants or tufts discrete but averaging less than their diameters apart.Stones-Rock fragments 25 to 60 centimeters (10 lo 24 in) in diameter.Stone strlpes-Patterned ground with bands of fine rock debris that alternate withchannels filled with coarse rock fragments and are oriented parallel to the directionof the steepest slopes.Stony-Refers to a soil containing stones in numbers that interfere with or preventtillage.Strand-That portion of the shore between high and low water on beaches, spits,reefs, and so forth.Stratum (vegetation)-A horizontal layer in a community in which the plants areabout the same height.Structure (soil)-The arrangement of primary soil particles into compound particlesor aggregates that are separated from adjoining aggregates.Structure (vegetation)-(I) The spatial distribution pattern of life forms in a plantcommunity, especially with regard to their height, abundance, or coverage within theindividual layers: (2) the three components of vegetation structure are (a) verticalstructure (stratification into layers), (b) horizontal structure (spatial distribution ofindividuals and species populations), and (c) quantitative structure (abundance ofeach species).SubalpIneThe first distinctive type of vegetation, usually open forest, below thealpine tundra.Subarctic-Perlaining lo regions immediately outside the Arctic Circle. Often interpretedas constituting a biotic transition belt (the forest-tundra ecotone) between thetreeless arctic zone and the forested boreal zone.Subarctic forest-The northern part of the boreal forest, characterized by openstands of small conifers, chiefly black spruce, with abundant lichens on the ground.Subarctic woodland-See forest, open boreal.274