PARENT SESSION
Contributed Oral Session 164: Wetland Chemistry
Friday, August 12, 8:00 AM - 11:30 AM, Meeting Room 520 C, Level 5, Palais des congrès de Montréal

Spatial patterns of water quality and plant succession in a created riparian oxbow in Central Ohio, USA.

Fink, Daniel^*,1, Mitsch, William¹, ¹ The Ohio State University, Columbus, Ohio

ABSTRACT- This study examines the development and spatial distribution of a created wetlands effectiveness at transforming nutrient loads during river diversions in central Ohio. Forty-six macrophyte species identified in the wetland basin were wetland species. Typha sp. dominated the upper reach but there were other expanding patches dominated by Alisma plantago-aquatica, Juncus effusus, Scirpus americanus, and Eleocharis acicularis. Surface inflow for nitrate-nitrite (NO₃^--N), total Kjeldahl nitrogen (TKN), soluble reactive phosphorus (SRP), and total phosphorus (TP) averaged 1.81±0.01, 1.23±0.01, 0.033±0.001, and 0.203±0.002 mg L^-1 respectively. NO₃^-, TKN, SRP, and TP were 57.3%, -25.6%, 43.5%, and 26.3% lower respectively at the outflow than the inflow. Concentrations of SRP and TP exported from the wetland increased significantly ( = 0.05) during large flooding events compared to drier flows while NO₃^- did not. Nutrient concentrations did not change uniformly across the wetland. 92% of the NO₃^- decrease occurred in the upper reach of the wetland, which coincides with the area of greatest emergent vegetation productivity. TKN concentrations increased across this area before decreasing in the open water portion of the wetland. SRP and TP reductions were more uniform, with 53% and 47% of the total losses occurring in the emergent marsh half of the wetland.

Key words: nutrient removal, mitigation, water quality, design