HR: 0830h
AN: A11F-0040    [PDF]
TI: Nitrous Oxide Emissions From Interior Chaparral in the Southwestern United States
AU: * Herring, J A
EM: jherring@prescott.edu
AF: Prescott College, 220 Grove Ave, Prescott, AZ 86301 United States
AU: Crews, T
EM: tcrews@prescott.edu
AF: Prescott College, 220 Grove Ave, Prescott, AZ 86301 United States
AU: Muro, A
EM: amuro@prescott.edu
AF: Prescott College, 220 Grove Ave, Prescott, AZ 86301 United States
AB: Amidst the growing tide of interest in global trace gas budgets and process studies, scant attention has been paid to arid and semi-arid ecosystems ($<$500mm of annual precipitation). This paper reports on chamber and eddy covariance measurements of nitrous oxide fluxes made in the interior chaparral in the Central Arizona Highlands. The interior chaparral is a highly unusual ecosystem in the temperate latitudes because nitrogen fixing woody shrubs dominate the vegetation community. The bimodal nature of the annual precipitation regime leaves extended dry periods during which little denitrification can take place, thus allowing for the potential buildup of soil nitrate levels. Summer wet season precipitation could then lead to significant emissions of nitrous and nitric oxides. Measurements taken during the wet summer season of 2003 were used to quantify fluxes of nitrous oxide at a site dominated by Cercocarpus betuloides and Ceanothus greggi, both actinorhizal N-fixing plants. These measurements confirmed the presence of significant nitrous oxide fluxes. The results are used to draw some preliminary conclusions about the overall contribution to nitrous oxide emissions from chaparral in the Southwestern United States.
DE: 0315 Biosphere/atmosphere interactions
DE: 0322 Constituent sources and sinks
DE: 0330 Geochemical cycles
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting