Wisconsin School

Wisconsin School A group of ecologists, led by J. T. Curtis and his associates, who developed a range of simple ordination methods in 1950 and later, while studying the vegetation of Wisconsin. In the most widely applied scheme, density–frequency-dominance (DFD) values are estimated for all species recorded in the field. Importance values derived from these enable identification of leading dominants. Stands with the same leading dominant are grouped together and importance values for all species recalculated within the groups. These values are used to assign climax adaptation numbers and subsequently a continuum index is derived. Later developments, notably by Bray and Curtis (1957), improved the way in which stand similarities were expressed and portrayed graphically, by using a similarity index calculated from stand data rather than using the subjectively assessed continuum index. See also COEFFICIENT OF SIMILARITY.