The Alaska Vegetation Classification - Alaska Geobotany Center ...

Old-growth stand-Not synonymous with old-aged forest and must be recognizedon the basis of stand characteristics rather than age of trees. Old-growth standscontain trees of wide range of sizes and ages and have a deep, multilayered canopy.They contain large standing dead snags and large down dead trees and other coarsewoody debris.Oligotrophic-(1) Describing bog formed of plants growing in waters poor innutrients, as in a raised bog; (2) pertaining to water poorly supplied with the basicnutrients needed by plants.Organic matter-The more or less decomposed material of the soil derived fromorganic sources, usually from plant remains. The term covers matter in all stagesof decay.Organic terrain-Tract of land having a surficial layer of living plant material(vegetation) and a sublayer of peat or fossilized plant detritus of any depth existingin association with various hydrological conditions and underlying mineral formations.Term used somewhat interchangeably with muskeg in Canada.Outwash, glacial-Stratified sand and gravel produced by glaciers and carried,sorted, and deposited by water originating mainly from the melting of glacial ice.Outwash fan-Material deposited by fast-flowing, heavily loaded water whosevelocity is suddenly reduced; for example, at the mouth of a gorge or ravine.Outwash plain-A land form of mainly sandy- or coarse-textured material ofglaciofluvial origin deposited gradually. An outwash plain commonly is smooth;where pitted, it generally is low in relief.Overstory-The portion of the trees forming the upper canopy in a forest stand ofmore than one story.Paludiflcatiow-Literally, "swamping." Process of mire (peat-forming ecosystem)formation over previously forested land or grassland due to climatic or autogenicprocesses leading to waterlogging and anaeroby.Parent material-(1) The great variety of unconsolidated, more or less chemicallyweathered organic and mineral material from which soil forms. Consolidated bedrockis not yet parent material by this definition. (2) The C-horizon of the soil.Patterned ground-A collective term for the more or less symmetrical forms suchas circles, polygons, nets, steps, and stripes that are characteristic of but not necessarilyconfined to ground that is subject to intensive frost action. Circles, polygons,and nets are most typically formed on level ground, and stripes and steps are foundon slopes.Peat-Layer consisting largely of organic residues originating under more or lesswater-saturated conditions through the incomplete decomposition of plant and animalconstituents; results from anaerobic conditions, low temperatures, and other complexcauses.Amorphous granularpeat-Descriptive term applied to one of the primary macroscopicelements 01 peat that is granular in nature but has no particular shape.269