| Greenhouse gas (GHG) dynamics in forested systems have recently been the focus of many studies, but few have addressed the variability of GHG fluxes at the watershed-scale using ground-based measurements. This study measured GHG (CO2, N2O, CH4) fluxes in an Adirondack watershed, NY, across a range of locations with contrasting geomorphic characteristics and biogeochemistry. Results indicated that wetlands are "hot spots" for CH4 fluxes, with fluxes up to three orders of magnitude higher than at other sites. CO2 fluxes were greater at drier upland sites than at wetter sites, and landscape position did not significantly influence net N2O fluxes. Antecedent moisture conditions (AMC) and soil temperature could not explain variability of CH4 fluxes. Peaks in CO2 following Hurricane Irene suggest that water availability was an important variable regulating CO2 fluxes at the landscape scale. N2O emission was likely water limited during dry months, and responded weakly to precipitation events.;Key Words: Greenhouse gases, hot spots and hot moments of CO2, N2O, CH4 fluxes, antecedent moisture conditions, geomorphology, watershed-scale, forested landscape... |
