Relative Ages of Wetland and Upland Surfaces as Indicated by Pedogenic Development

Abstract

The relationship between the relative age and wetness of landscape surfaces on the Atlantic Coastal Plain of the United States was investigated to determine the extent to which wetlands develop independently of surrounding non-wetland landforms. A soil-development index based on profile descriptions was applied to all soil series of Craven County, North Carolina, and compared to indices of soil wetness. There was no systematic relationship between the soil-development index and soil-hydric status, drainage classification, or water table depth. Both very wet and well-drained soil series were found at either end of a continuum from the oldest, best-developed series to the more recent, poorly-developed soils. Results suggest that any generalizations about relative ages of wetland and non-wetland surfaces or about coevolution of wetlands and uplands must be made in the context of at least three different Coastal Plain geomorphic settings: upland interfluves, stream terraces, and river valleys.

Deterministic uncertainty in landscapes

“…Finally, recent analyses of specific geomorphic, hydrologic and pedologic systems have shown or suggested deterministically chaotic behaviour. These include the surface water balance (Afouda, 1989), soil moisture dynamics at climate scales (Rodriguez-Iturbe et al, 199 l), at-a-station hydraulic geometry (Phillips, 1990(Phillips, , 1991(Phillips, , 1992c, wetland response to sea-level rise (Phillips, 1992a), evolution of river longitudinal profiles (Renwick, 1992) and channel networks (Willgoose et al, 199 1;Ijjasz-Vasquez et al, 1992), the geometry of soil-covered landscapes (Culling, 1988b), evolution of regolith covers (Arlinghaus et al, 1992;Phillips, 1993a), and generalized geomorphic mass flux models (Mayer, 1992;Phillips, 1992b).…”