Taxonomic Variation within Three Soil Mapping Units in Virginia
1985
Edmonds, W. J. | Campbell, J. B. | Lentner, M.
This study examines the taxonomic variation of mapping units in second-order soil surveys and evaluates (i) taxa in Soil Taxonomy as designators of mapping unit content, (ii) phenetic similarity of soil profiles, and (iii) soil characters as class differentiae. Taxonomic purity was not attained within 7 m at any categorical level in Soil Taxonomy and four orders were necessary for objectively designating the pedologic content of a mapping unit. Comparisons of groupings of soil profiles by Soil Taxonomy and clusters defined by phenetic similarity revealed that phenetically similar soil profiles were placed in different taxa and phenetically different soil profiles were combined in the same taxon. Any given soil character was not considered to be accessory to any other character because of low covariance. No single character could be identified as an effective differentia when evaluated in light of its loading onto the eigenvectors. Numerical methods for generalizing the data encountered in these mapping units are illustrated.
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