Landtype Association: A Hierarchical Approach to Classifying Landforms in the Oregon Coast Range

摘要

In the early 1980s, Jim Maxwell, the Forest Hydrologist for the Siuslaw National Forest and John Berry, Assistant Ranger for Resources, Mapleton Ranger District, divided the area covered by the Siuslaw National Forest into landtype associations. Their map was produced by grouping soil resource inventory (SRI) landtypes with similar geologic and geomorphic characteristics into larger map polygons. They combined similar areas from the bottom up, i.e. small map units were combined to created larger ones (Berry and Maxwell, 1981). At that time, dividing a landscape into areas with common characteristics was a relatively new concept. In the mid-1970s, the idea that a hierarchy of scales existed across a landscape began to be developed. Some researchers looked at the terrestrial ecosystem (e.g. Wertz and Arnold, 1972; Wendt et al., 1975; Bailey, 1983), and developed a hierarchy that included provinces, sections, subsections, landtype associations and landtypes. Others worked with the aquatic ecosystem, and developed a hierarchy that included watersheds, stream reaches, and habitat units (e.g. Frizzell et al., 1986).