title: Estimating greenhouse gas emissions at the soil-atmosphere interface in forested watersheds of the US Northeast.
abstract: Although anthropogenic emissions of greenhouse gases (GHG: CO2, CH4, N2O) are unequivocally tied to climate change, natural systems such as forests have the potential to affect GHG concentration in the atmosphere. Our study reports GHG emissions as CO2, CH4, N2O, and CO2eq fluxes across a range of landscape hydrogeomorphic classes (wetlands, riparian areas, lower hillslopes, upper hillslopes) in a forested watershed of the Northeastern USA and assesses the usability of the topographic wetness index (TWI) as a tool to identify distinct landscape geomorphic classes to aid in the development of GHG budgets at the soil atmosphere interface at the watershed scale. Wetlands were hot spots of GHG production (in CO2eq) in the landscape owing to large CH4 emission. However, on an areal basis, the lower hillslope class had the greatest influence on the net watershed CO2eq efflux, mainly because it encompassed the largest proportion of the study watershed (54 %) and had high CO2 fluxes relative to other land classes. On an annual basis, summer, fall, winter, and spring accounted for 40, 27, 9, and 24 % of total CO2eq emissions, respectively. When compared to other approaches (e.g., random or systematic sampling design), the TWI landscape classification method was successful in identifying dominant landscape hydrogeomorphic classes and offered the possibility of systematically accounting for small areas of the watershed (e.g., wetlands) that have a disproportionate effect on total GHG emissions. Overall, results indicate that soil CO2eq efflux in the Archer Creek Watershed may exceed C uptake by live trees under current conditions.
authors.affiliation: College of Environmental Science and Forestry (SUNY-ESF), The State University of New York, 1 Forestry Drive, Syracuse, NY, 13210, USA.|Tectonic Engineering and Surveying Consultants P.C., Mountainville, NY, 10953, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Gomez
authors.affiliation: College of Environmental Science and Forestry (SUNY-ESF), The State University of New York, 1 Forestry Drive, Syracuse, NY, 13210, USA. pgvidon@esf.edu.
authors.forename: Philippe
authors.initials: P
authors.lastname: Vidon
authors.affiliation: College of Environmental Science and Forestry (SUNY-ESF), The State University of New York, 1 Forestry Drive, Syracuse, NY, 13210, USA.
authors.forename: Jordan
authors.initials: J
authors.lastname: Gross
authors.affiliation: College of Environmental Science and Forestry (SUNY-ESF), The State University of New York, 1 Forestry Drive, Syracuse, NY, 13210, USA.
authors.forename: Colin
authors.initials: C
authors.lastname: Beier
authors.affiliation: College of Environmental Science and Forestry (SUNY-ESF), The State University of New York, 1 Forestry Drive, Syracuse, NY, 13210, USA.
authors.forename: Jesse
authors.initials: J
authors.lastname: Caputo
authors.affiliation: College of Environmental Science and Forestry (SUNY-ESF), The State University of New York, 1 Forestry Drive, Syracuse, NY, 13210, USA.
authors.forename: Myron
authors.initials: M
authors.lastname: Mitchell
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D001272:Atmosphere / Q000737:chemistry; D002245:Carbon Dioxide / Q000032:analysis; D057231:Climate Change; D004784:Environmental Monitoring / Q000379:methods*; D065928:Forests; D005740:Gases / Q000032:analysis; D017752:Greenhouse Effect; D008697:Methane / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis; D012621:Seasons; D012987:Soil / Q000737:chemistry; D053833:Wetlands
chemical_list: D000393:Air Pollutants; D005740:Gases; D012987:Soil; D002245:Carbon Dioxide; D009609:Nitrous Oxide; D008697:Methane
keywords: CO2 equivalent; Greenhouse gas budget; Topographic index; Watershed