Soils with placic horizons on the west coast of Vancouver Island, British Columbia

Thin indurated horizons (placic) were found in coarse textured deposits in the humid west coastal region of Vancouver Island in British Columbia. Four soils representing the range of pan development were studied. The soils were classified as Placic Ferro-Humic, Mini Humo-Ferric, Placic Humo-Ferric, and Gleyed Placic Mini Ferro-Humic Podzols. The soils supported a rather luxuriant vegetative association, with one site exhibiting a bog type of vegetative cover. It was found that the indurated horizons were of two types, namely, those that had high amounts of Fe and those that seemed to concentrate Al. The role of organic matter in the formation of placic horizons is still obscure, although organic matter concentrations were largest in indurated horizons of high aluminum content. The kind of pan should be considered in classifying these soils, as existing criteria do not distinguish between different kinds of pans. In addition, the relatively large amounts of oxalate-extractable Fe and Al to depths up to 300 cm require further study.