Experimental Design: Investigating the Effects of Soil Structure and Texture on Organic Matter Storage and Processing Rates in Tidal Freshwater Wetland Sediments.

Nitrogen (N) pollution is one of the leading causes of water quality deterioration in the Chesapeake Bay watershed. To meet total maximum daily loads (TMDLs) initiatives, the Chesapeake Bay Program has mandated 85,000 acres of tidal and non-tidal wetlands be restored by 2025. While the majority of these wetlands will be reestablished on agriculture land, tidal freshwater wetlands (TFWs) are ideal habitats to restore because they are major N reservoirs and biogeochemical hotspots of denitrification.  Located in the upper estuary between fresh and saline environments, TFWs intercept and reduce available N in surface and ground water, thus reducing the effects of N in downstream coastal habitats. Restored wetland ecosystem are often structurally and functionally dissimilar from their natural counterparts.  Restoration practices disrupt soil structure and change site heterogeneity, which impacts organic N availability and processing by the microbial community. Wetland microorganisms primarily mediate N processing, however, soil texture and physiochemical properties ultimately determine substrate availability and subsequent processing by the microbial community. The effects of soil disturbance on N biogeochemical cycling are well documented in terrestrial systems, but there is a lack of understanding in TFW habitats.  This poster introduces a study to investigate the importance of soil structure and texture on organic matter storage and N processing in TFW soils.