ABSTRACT
In closed depressions subject to ponding, hydric soil morphology is indicated simply by the presence of 5% or more distinct or prominent redox concentrations as soft masses or pore linings in a layer 5 cm or more thick within the upper 15 cm (Hurt et al. 1996). In these “redox depressions,” soils are determined to be hydric primarily on the basis of landscape position and documentation of at least seasonal ponding. There is no fixed requirement for Munsell value or chroma in the soil matrix. The accompanying notes state, “Most often soils pond water because of two reasons: they occur in landscape positions that collect water and/or they have a restrictive layer(s) that prevent water from moving downward through the soil” (Hurt et al. 1996). Such flat or depressional landscapes may be created by a variety of geological processes. Examples of depressional features include glacial kettles, vernal pools, playas, till plain swales, and potholes. Water can be received directly as rain, from throughflow, overland flow, or from groundwater discharge (Mausbach and Richardson 1994). Most simply, inflow exceeds the capacity of the system to remove the water, at least for a significant period of time in most years.
