Virgin Hardwood Forest Soils of the Southern Appalachian Mountains: II. Weathering, Mineralogy, and Chemical Properties

Eights undisturbed soils derived from feldspathic meta‐sediments in the Joyce Kilmer Memoiral Forest were studied. Gibbsite was common throughout all soils, and inceased in aboundance in the clay fraction with depth. The clay content in most soils decreased with depth, with intergrade 2:1 type minerals occurring as the dominant phyllosilicates in surface horizons. Kaolinite was low in all soils, but was more abundant in south‐facing soils. Gibbsite abundance was not aspect dependent. The silt fractions contained appreciable quantities of weathered 2:1 type minerals similar in type to the clays. The coarse sand fractions wee almost entirely quartz, while the fine sands contained quartz, weathered 2:1 minerals, and feldspars. The CEC of the mineral surfaces in these soils was extremely low. Soil CEC was almost entriely derived from organic matter, and was typeically <3 cmol/kg in subsurface horizons. Levels of exchangeable Ca and Mg, acid extractable P, and total‐N were very low below surface horizons. These soils have weathered in a wet (>200 cm precipitation) temperate environment and resemble some tropical soils. Erosion could severely damage the natural productivity of these soils. The addition of oxidic mineralogy classes to certain Inceptisol families is recommended.