The Alaska Vegetation Classification - Alaska Geobotany Center ...

Ctyaquepts-Gray or olive soils with a high water table during all or most of thesummer. They generally are strongly mottled. These soils have many textures andmay have substratum of gravelly sand below 30 centimeters (12 in). Only thinaccumulations of organic matter occur on the soil surtace, and only thin dark upperhorizons occur in the mineral soil.Cryochrepts-Soils in which small or moderate amounts of organic matter havebeen incorporated into the upper portion of the mineral soil. Usually are well drainedand support forest vegetation. Textures are most often loam or silt loam but may begravelly. Many of these soils contain permafrost.Cryptogam-(I) Any plant reproducing sexually without forming seeds; (2) collectiveterm for the Thallophytes, Bryophytes, and Pteridophytes.Cushion plant-An herbaceous or low woody plant so densely branched that itforms a dense, resilient mat or cushion; for example, Silene acaulis.Diameter at breast height (d.b.h.)-The diameter of a tree, measured outside thebark, at 1.37 meters (4.5 ft) above ground level. See breast height.Decadent-Declining or decaying.Deciduous-Woody plants, or pertaining to woody plants, that seasonally lose alltheir leaves and temporarily become bare-stemmed.Density, stand-The number of plants per unit of area at a given time. Expressedas number per square meter or stems per acre.Depauperate-Describing an unusually sparse growth of undergrowth plants.Disjunct-Pertaining to discontinuous range having two or more potentially interbreedingpopulations separated by a distance precluding genetic exchange bypollination or dissemination.Distributiob(1) The geographic range of a species at any one time; (2) the patternof occurrence of individuals of a taxon in an area.DisturbancP-Any mechanism limiting plant biomass by causing its partial or totaldestruction.Diversity-An expression of the variety of species that exist in a community, or ofthe variety of communities in a landscape.Domlnanc+The degree of influence that a plant species exerts over a communityas measured by its mass or basal area per unit area of the ground surface, or by theproportion it forms of the total cover, mass, or basal area of the community.Dominant-(1) The plant species having the greatest canopy coverage; (2) the mostnumerous or vigorous species in a stand; (3) a taxon or group of taxa characterizingthe community in its larger aspects, usually preponderant either numerically or inmass.Drainage (hydrology)-Process of downward removal of water from soil, particularlyby surface and subsurface runoff and artificially by ditching and other measures forhastening removal.259