Classification and boundary vagueness in mapping presettlement forest types

Presettlement forest types were mapped as fuzzy sets from point data representing trees contained in General Land Office survey notes (ca.1850) for Chippewa County, Michigan. The resulting representation agreed with a polygon map of the same forest types at 66 percent of the locations (represented as grid cells) in the county. Boundary vagueness was defined in relation to the slope of a linear function fitted to the negative relationship between entropy of forest types and distance to polygon boundaries. The similarity between forest type compositions (i.e., classification ambiguity) was shown to account for 55 percent of the variation in boundary vagueness.