Date of Award
Program or Major
Natural Resources: Water Resources
Master of Science
William H McDowell
Nitrate (NO3-) uptake and denitrification in small headwater streams can have significant implications for downstream water quality. I measured seasonal NO3- uptake and longitudinal patterns in potential sediment denitrification in a New Hampshire agriculturally influenced stream during 2009. NO3- uptake was measured through short-term NO3- enrichments and potential denitrification was measured using the Chloramphenicol-amended acetylene-inhibition method. NO3 - was taken up in autumn but not in spring or summer. In autumn, on average 87% of the daily NO3- load was taken up and a maximum of 4% was removed via denitrification. Results suggest that, in this stream, carbon availability from leaf fall drives NO3 - uptake primarily via heterotrophic assimilation. This study helps to better characterize controls on NO3- uptake and denitrification in New England, where few such studies have been conducted on agricultural streams, and where seasons are pronounced.
Dunlap, Catherine Rutherford, "Seasonal nitrate dynamics in an agriculturally influenced New Hampshire headwater stream" (2010). Master's Theses and Capstones. 543.