A Soil Bulk Density Metric to Improve Rapid Assessment of Wetland Condition.

Abstract

Rapid wetland assessments are designed to require minimal field effort (e.g. half-day site visit), but still provide critical information on wetland ecological condition and functioning. Many wetland functions occur within or are supported by the soil, yet soil condition is seldom-or only minimally-included in most state rapid assessments. We focus on the Ohio Rapid Assessment Method for wetlands (ORAM) and evaluate soil bulk density as an indicator of wetland soil condition that can be incorporated into rapid wetland assessments. Soil bulk density ([Formula: see text]) is relatively easy to measure and requires only basic instrumentation. It also correlates well with more intensive metrics of soil condition (e.g. carbon content, aggregation). We sampled 45 wetlands in west-central Ohio, that exhibited a range of wetland type and ecological condition. From each wetland, we collected five soil cores (to 15-cm depth) and then analyzed the soil samples for [Formula: see text], carbon content, and water-stable aggregates. These three measurements were used to develop a four-bin [Formula: see text] metric of soil condition. Incorporating this metric into the current ORAM improved relationships with [Formula: see text] (r = 0.48 to r = 0.58) and soil condition (r = -0.53 to r = -0.64). Additional gains could be achieved with higher weighting of the [Formula: see text] metric. Alternatively, the current scoring system could be left intact, but protection of wetlands with high quality soils ensured by providing special status when [Formula: see text] is less than 0.40 g cm[Formula: see text] (highest quality) or less than 0.73 g cm[Formula: see text] (high quality).

Supplementary information: The online version contains supplementary material available at 10.1007/s13157-026-02044-9.