Virgin Hardwood Forest Soils of the Southern Appalachian Mountains: I. Soil Morphology and Geomorphology
1987
Daniels, W. L. | Everett, C. J. | Zelazny, L. W.
Little is known about the characteristics of undisturbed soils in the eastern USA, since few exist. Eight sites with virgin forest soils formed under southern Appalachian hardwood vegetation were studied in the Joyce Kilmer Memorial Forest, an unlogged watershed in western North Carolina. Sites ranged in elevation from 720 to 1200 m with only two on <50% slopes. Generally, soils were quite deep and highly weathered because of high rainfall (>200 cm), weatherable feldspathic parent material, and no accelerated erosion. Average solum depth was 90 cm, while depth to metasandstone bedrock was typically >1.3 m. Deeply weathered saprolites were commonly encountered. Soils on northerly aspects had thick umbric epipedons and more organic matter than soils on south-facing slopes. Organic matter contents of A1 horizons ranged from 45 to 170 g/kg and surface horizons contained moderate coarse and medium crumb structure. Most soils had cambic horizons and clay contents that decreased with depth. Argillic horizons were present only at low elevations on south-facing slopes. While the majority of soils were formed in colluvium, significant amounts of deep soils in residuum occurred on sideslopes and appeared stable. The present-day land-forms appear to be significantly influenced by periglacial activity. Windthrow appears to have mixed the surfaces of these soils. Due to their decreasing clay content with depth, oxidic mineralogy, and low CEC, these soils resemble tropical forest soils.
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