Riparian Zone Denitrification Potential within Urban Impacted Forests of the Tampa Bay Watershed.

Population growth and land use change has presented coastal areas with considerable challenges for the conservation of water resources while sustaining the communities.  Urbanization and associated increase in impervious surfaces have been established to be detrimental to water quality. The major nutrient implicated for water quality deterioration in many water bodies in coastal regions, including our study site, is nitrogen (N).  Riparian zones have been shown to have disproportionately greater denitrification rates relative to most other surrounding landscapes.  Our research objective of this study is to determine the denitrification potential of common riparian forest types in a coastal-urban landscape.  Due to anthropogenic alteration to vegetation and hydrology, riparian zones within relatively close proximity to urbanized areas will likely exhibit some degree of diminished denitrification potential relative to riparian zones in less disturbed rural areas.  Soil samples will be collected from varying distances perpendicular to the riparian zone, and the microbial denitrification potential of these soils will be measured using the acetylene block method.  This method allows for the obtainment of denitrification enzyme activity (DEA) assays which will be analyzed through gas chromatography. The long-term goal is to understand the fate and transport of N in urbanized watersheds within a coastal plain environment and the role vegetation plays in improving water quality in urban areas. We believe the future results will provide some inference on how riparian based denitrification potential has been impacted by urbanization in the Tampa Bay watershed.