BIOGEOCHEMICAL STORAGE AND TRANSFORMATION OF SEDIMENTS FROM GEOGRAPHICALLY ISOLATED WETLANDS IN AGRICULTURE LANDSCAPES

Abstract

Geographically Isolated Wetlands (GIWs) provide many beneficial ecosystem services including biogeochemical storage and processing. However, due to the absence of hydrologic connectivity to surface waters, they lack legal protections leading to a knowledge gap of their potential in processing and storing substantial quantities of nutrients and elements alike. The Dougherty plain of Southwest Georgia contains upwards of 11,000 small GIWs. Yet the region is also characteristic of having intensive row-crop agriculture that has the potential to transport materials into nearby GIWs. This study aims to assess nutrient storage in the sediment of GIWs in agriculture wetlands. It was discovered that agriculture GIWs receive two-magnitudes higher sediment per mg cm-2 yr-1, stores 25 tons of carbon and 13 tons of phosphorus. Historic phosphorous concentrations peaked in 1970 coinciding with the onset of intensive agriculture practices. A surface sediment survey assessed agriculture wetlands differ in composition having elevated agriculturally associated elements.