Relationship Among the Forest Types of Indiana

The 36 least disturbed hardwood stands in Indiana were selected for analysis of the characteristics and interrelationships of the five forest types. The types were defined by the species importance sums for the four species—groups: oak—hickory, beech—maple, other upland mesophytic species, and lowland—depressional species. From the matrix of stand similarities derived by applying Motyka's coefficient to species importance values, relationships among the five forest types were indicated by cluster and ordination analyses. Both methods grouped stands of three types as extremes (oak—hickory, beech—maple, and lowland—depressional) and two mixed types as intermediates (western mesophytic and mixed woods). Within each extreme type some variant stands represented gradations toward another type. Edaphic controls of the forest types in Indiana are indicated by the patterns of the ordination distribution of substrate factors: drainage profiles, available moisture, permeability, texture of the A horizon, source of the parent material, pH of the B horizon, and degree of development of the soil.