Greenhouse gas dynamics in streams and riparian floodplains located within forested landscapes of the US Northeast

Greenhouse gas (GHG) dynamics along the stream-riparian continuum in forested systems have recently been the focus of many studies, but few have addressed the variability of dissolved GHG concentrations in interstitial water at these sites or GHG fluxes at these sites. This study measured dissolved concentrations of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) at sites with contrasting geomorphic characteristics and hydrochemistry. Sites that were wet and mucky in riparian areas and pools with fine textured bed sediments were "hotspots" for CO2 and CH4. Examination of GHG fluxes at the soil-atmosphere interface across various locations indicated that the reaches in lowlands and influenced by a wetland were hotspots of CH4 production, whilst reaches with relatively drier floodplain were "hotspots" of CO2 emissions. N2O fluxes were low in magnitude, but soils acted as both sinks and sources of N2O across the watershed.