A relative density measure for mixed-species stands: tree-area ratios are more accurate than stocking charts

Relative density is an index of crowding for forest stands, expressed as the ratio of absolute density (number of trees or basal area per acre) to the density of a stand the same size and species composition at maximum density (eg an undisturbed stand). The measure is often used for stocking charts, but each applies to a specific forest type and often to a single species. A relative density measure for mixed-species stands is developed in which each species diameter class is multiplied by a conversion factor. Allegheny hardwoods in Pennsylvania are used as a case study. -P.J.Jarvis