Aquisalids (Salorthids) and Other Wet Saline and Alkaline Soils: Problems Identifying Aquic Conditions and Hydric Soils1
Aquisalids (Salorthids) and other wet saline and alkaline soils are periodically saturated soils in arid and semiarid regions where carbonates, gypsum, and/or salts more soluble than gypsum have accumulated. Although of limited geographic extent, these soils occur in arid states of the western USA and in other countries with arid–semiarid climates. Aquisalids usually occur in flood plains, lake plains, and playas, and are subject to a fluctuating saline water table. Redoximorphic features, which are necessary for the identification of aquic conditions and hydric soils, are not well expressed in Aquisalids and other saline and alkaline soils. Thus, it is difficult to consistently identify hydric soils and to delineate associated wetlands. Redoximorphic features may be poorly expressed for the following reasons: (i) high pH, which requires low redox potentials to reduce Fe and Mn; (ii) low amounts of Fe and Mn, which are needed to produce redox concentrations and depletions; and (iii) low activity of microorganisms, which is needed for O2 consumption and use of Fe and Mn as alternative electron acceptors during respiration. Monitoring the periodicity of saturation, reduction, and microbial and chemical dynamics of Aquisalids and related soils will help us understand these soils. Until data can be collected on the dynamics of oxidation and reduction in Aquisalids and related saline and alkaline soils, alternative field indicators are suggested for the identification of potentially hydric soils.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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