density–frequency–dominance (DFD measure) A combined abundance estimate used in early North American ordination schemes but now rarely used. Usually expressed as relative values, relative density is the number of a given species expressed as a percentage of all species present, relative frequency is the frequency of a given species expressed as a percentage of the sum of frequency values for all species present, and relative dominance is the basal area of a given species expressed as a percentage of the total basal area of all species present. These three measures are summed to give the importance value, which may lie between 0 and 300.
More From encyclopedia.com
Relative-importance Value , relative-importance value In ecology, a concept similar in principle to importance value, but based on original, somewhat relative, density–frequency… Climax Adaptation Number , climax adaptation number A value, in the range 1–10, assigned to species in the Wisconsin ordination scheme and based on the species' importance valu… Indifferent Species , indifferent species A species with no real affinity for any particular community, but which is not rare (as an accidental species would be). It is fi… Constellation Diagram , constellation diagram A representation of species affinities that is based on χ2 as a measure of the association between species. The reciprocal of t… preferential species , preferential species In phytosociology, a species that is present with varying abundance in several communities, but is especially abundant and vigor… accidental species , accidental species One of five classes of fidelity used by the Braun-Blanquet school of phytosociology in the description and classification of plant…
About this article
Updated About encyclopedia.com content Print Article
You Might Also Like
Dent, Hon. Charles, B.A. (Frame Lake) Government House Leader, Minister of Education, Culture and Employment, Minister of Justice and Minister Responsible for the Status of Women