Development and application of the Hydric Soil Technical Standard

Abstract

AbstractThe concept of hydric soils evolved over time with advances in soil science and wetland resource management. Hydric soils are identified in the field by examining morphological characteristics, including organic matter accumulation and redoximorphic features that form in response to prolonged periods of saturation and anaerobic conditions. The Hydric Soil Technical Standard (HSTS) was developed to provide a quantitative procedure for evaluating the hydric status of a soil based upon direct measurements of saturation, anaerobic conditions, and precipitation normality. In practice, the HSTS is used for (a) identifying hydric soils when a field indicator of hydric soils may not be present (e.g., naturally problematic or disturbed soils); (b) evaluating the current functional hydric status of a soil; (c) developing new field indicators of hydric soils; and (d) proposing changes to existing field indicators of hydric soils. The HSTS procedures have progressed over several decades with new approaches to soil analysis, including novel methods to document anaerobic conditions. The following review describes the development of the hydric soils concept and provides guidance for measuring each HSTS component. Practical approaches for collection and submission of HSTS data to the National Technical Committee for Hydric Soils, the group responsible for approving approaches to hydric soil identification in the United States, are also discussed. Expanding the understanding and application of the HSTS promotes technical accuracy, transparency, and efficient decision making in support of hydric soil and wetland resource management.