Paper No. 18-4
Presentation Time: 9:00 AM
WATER QUALITY OF THIRTY-ONE ISOLATED WETLANDS EMBEDDED IN A LONGLEAF PINE / WIRE GRASS ECOSYSTEM REGARDING CONNECTIVITY TO EPISODIC FLOWS GENERATED FROM AGRICULTURAL RUNOFF
Isolated wetlands (wetlands surrounded by uplands), can be temporarily connected to nearby perennial surface waters (i.e. streams and rivers) due to episodic flows. The influence of episodic flows on isolated wetlands may last beyond the temporal duration of a particular event. Our objective was to determine if water quality of wetlands influenced by episodic flows differ from those that are not influenced by episodic flows. We monitored thirty-one isolated wetlands embedded in restored longleaf pine / wire grass ecosystem centrally located within the Dougherty Plain physiographic province in southwest Georgia. The Dougherty Plain is a karstic region with dense clusters of depressional wetlands originating from limesinks. Wetlands that were monitored fell into three categories: isolated from flows (no connection or NC, n=19), receiving agriculturally generated episodic through flow (agriculturally connected or AC, n=6), receiving forest or wetland spill generated episodic flow (reference connected or RC, n=6). We also monitored nine stream sites for reference purposes; three sites on a small intermittently flowing stream (Big Cypress Creek), three sites on a third order stream (Ichawaynochaway Creek), and three sites on the Flint River. Sites were sampled monthly for one year following an episodic flow event to measure coliform pathogens, nutrients (ammonium, nitrate, phosphate, dissolved carbon) and physical parameters (wetland stage, suspended solids, specific conductance, temperature, and turbidity). We found that wetlands influenced by agricultural runoff were different than isolated wetlands for several of the measured water quality parameters. Streams also differed from isolated and connected wetlands that were not influenced by agriculture. Isolated (NC) wetlands had the highest water quality followed by RC, then AG and streams when accounting for combined biological, chemical and physical water quality.