HR: 13:45h
AN: NB23E-02 INVITED     [Abstracts]
TI: In-situ Investigations of N Transformations in Coastal Massachusetts Streams
AU: * Thomas, S M
EM: sthomas@mbl.edu
AF: Ecosystems Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543 United States
AU: Peterson, B J
EM: peterson@mbl.edu
AF: Ecosystems Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543 United States
AU: Merriam, J L
EM: jeff.merriam@unh.edu
AF: University of New Hampshire, 228 James Hall, 56 College Road, Durham, NH 03824 United States
AU: Potter, J D
EM: jodypotter@cisunix.unh.edu
AF: University of New Hampshire, 228 James Hall, 56 College Road, Durham, NH 03824 United States
AB: As part of the LINX II experiments, 15NO3 was added to streams in forest, agricultural, and suburban areas in northeastern Massachusetts to determine the role of land use on nitrogen export from small watersheds. Denitrification was measured in-situ by increasing the stream 15NO3 to 20,000 permil for 24 hours. Dissolved gas samples analyzed for 15N2 showed stream enrichments of up to 60 permil in suburban and agricultural streams. Agricultural streams showed enrichments of 12,000 permil of 15N2O . Although denitrification rates were much higher in suburban and agricultural streams, nitrate uptake rates were highest in the forested streams. Uptake in forested streams resulted from storage in benthic compartments rather than removal by denitrification.
DE: 0400 Biogeosciences
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly