Wetlands are habitats between terrestrial and aquatic ecosystems. As “middle” positions, wetlands rely on inputs from surrounding landscapes. Wetlands act as buffers, filtering polluting nutrients from inflowing waters and preventing eutrophication downstream. Wetlands have historically been drained and removing these buffers threatens water quality.
The Ohio Rapid Assessment Method (ORAM) is a metric used to categorize wetlands in Ohio between three scores. A high score of three indicates the highest quality wetland and one indicates lowest quality. This method is based on structural aspects of wetlands including size, plant community, depth, surrounding land use, and hydrological alterations and development. We aimed to determine if ORAM scores relate to ecosystem function, as indicated by nutrient concentrations and sediment phosphorus sorption characteristics. We predicted nutrient concentrations are higher in wetlands with lower ORAM scores and phosphate sorption capacity will be higher in wetlands with higher scores.
Nine palustrine scrub-shrub wetlands owned by Kent State University were identified via National Wetland Inventory (NWI) and Web Soil Survey from the U.S. Department of Natural Resources, and assigned an ORAM score. In each wetland, we sampled surface waters for water quality analyses and sediments (10cm) phosphate sorption analyses.
Wetlands near roads had higher concentrations of Cl- than those with wider buffers of forest. Inidcators of phosphate sorption capacity varied within wetlands, but were unrelated to wetland ORAM scores. Our data suggest that wetland ORAM scores do not necessarily reflect wetland nutrient cycling function.
Dr. Lauren Kinsman-Costello
Dr. Ferenc De Szalay
Wetlands are found between terrestrial and aquatic ecosystems that act as buffers, filtering polluting nutrients from inflowing waters. Wetlands have been drained and removing these buffers threatens water quality. The Ohio Rapid Assessment Method (ORAM) is used to assess wetland quality in Ohio, US. We aimed to determine if ORAM scores and ecosystem function are related, as indicated by ion concentrations and sediment phosphorus (P) sorption characteristics. We predicted that nutrient concentrations will be higher in wetlands with lower ORAM scores (indicating poor quality) and phosphate sorption capacity will be higher in higher scored wetlands. Nine wetlands were scored and sampled. Indicators of P sorption varied and were not related to ORAM score. Our data suggest that ORAM assessments do not reflect water quality function.