Evaluating a remote wetland functional assessment along an alteration gradient in coastal plain depressional wetlands

Authors: BACKHAUS, P.J. - Pennsylvania State University; LEE, S. - University Of Maryland; NASSRY, M. - Pennsylvania State University; McCarty, Gregory; BROOKS, R.P. - Pennsylvania State University

Submitted to: Journal of Soil and Water Conservation Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2020
Publication Date: 11/1/2020
Citation: Backhaus, P., Lee, S., Nassry, M., McCarty, G.W., Brooks, R. 2020. Evaluating a remote wetland functional assessment along an alteration gradient in coastal plain depressional wetlands. Journal of Soil and Water Conservation Society. 75(6):727-738. https://doi.org/10.2489/jswc.2020.00094.
DOI: https://doi.org/10.2489/jswc.2020.00094

Interpretive Summary: Wetlands are known to be critical sources of ecosystem services, but continue to be degraded or lost due to anthropogenic activities. Wetlands provide unique ecosystem services unavailable from other habitats and provide more of these services per area when compared to other ecosystem types. Functional assessments of wetlands at watershed and regional scales have been limited by lack of proper assessment tools. This pilot study evaluated the use of an ecosystem assessment tool (i.e., Watershed-based Preliminary Assessment of Watershed Functions) to predict the functional variety and performance of wetlands that have undergone wetland restoration. This study addressed the concern that functions evaluated by the tool may not adequately assess the specific functional goals targeted by a restoration. Additionally, the range of conditions present in a restored wetland as it develops over time could limit evaluation of the ecosystem services important for the health of agricultural landscapes. Results of our study indicate that this tool can differentiate varying levels of restoration condition, but refinement will be necessary to assess functional restoration goals such as biogeochemistry and water quality. Our evaluation of this field-based assessment method suggests the potential for functional characteristics to be incorporated in future iterations of ecosystem service assessment for agricultural landscapes.

Technical Abstract: As anthropogenic disturbance continues to degrade wetland condition, it is imperative to inventory wetland functions to mitigate potential loss of ecosystem services. Field-based functional assessments are costly and time intensive, prohibiting their widespread use at landscape scales. These obstacles can be avoided by basing functional assessments on publicly-available remote sensed data. This pilot study examined the use of the Watershed-based Preliminary Assessment of Wetland Function (W-PAWF) in the assessment of wetland restoration sites. The W-PAWF was used to assess 15 depression wetlands in the Mid-Atlantic Coastal Plain. These sites spanned a human alteration gradient (i.e., natural wetlands, restored wetlands, and prior converted croplands) to determine the efficacy of the assessment’s sensitivity to variation in the assemblage and performance of wetland functions. Field-based rapid assessment methods were used to verify the assessment and detect potential functional gaps of importance to wetland restoration. Results indicate that W-PAWF can differentiate varying levels of restoration condition, but refinement will be necessary to assess functional restoration goals such as biogeochemistry and water quality. An evaluation of the field-based assessment methods and an alternate remote functional assessment system suggest the potential for these functional characteristics to be incorporated in future iterations of the assessment.