title: Fluxes of N2O, CH4 and CO2 in a meadow ecosystem exposed to elevated ozone and carbon dioxide for three years.
abstract: Open-top chambers (OTCs) were used to evaluate the effects of moderately elevated O3 (40-50 ppb) and CO2 (+100 ppm) and their combination on N2O, CH4 and CO2 fluxes from ground-planted meadow mesocosms. Bimonthly measurements in 2002-2004 showed that the daily fluxes of N2O, CH4 and CO2 reacted mainly to elevated O3, while the fluxes of CO2 also responded to elevated CO2. However, the fluxes did not show any marked response when elevated O3 and CO2 were combined. N2O and CO2 emissions were best explained by soil water content and air and soil temperatures, and they were not clearly associated with potential nitrification and denitrification. Our results suggest that the increasing O3 and/or CO2 concentrations may affect the N2O, CH4 and CO2 fluxes from the soil, but longer study periods are needed to verify the actual consequences of climate change for greenhouse gas emissions.
authors.affiliation: Department of Biological and Environmental Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland. teri.kanerva@helsinki.fi
authors.forename: Teri
authors.initials: T
authors.lastname: Kanerva
authors.forename: Kristiina
authors.initials: K
authors.lastname: Regina
authors.forename: Kaisa
authors.initials: K
authors.lastname: Rämö
authors.forename: Katinka
authors.initials: K
authors.lastname: Ojanperä
authors.forename: Sirkku
authors.initials: S
authors.lastname: Manninen
mesh_terms: D000393:Air Pollutants / Q000378:metabolism / Q000633:toxicity; D002245:Carbon Dioxide / Q000378:metabolism / Q000633:toxicity*; D002980:Climate; D017753:Ecosystem; D004781:Environmental Exposure / Q000009:adverse effects; D004785:Environmental Pollutants / Q000378:metabolism / Q000633:toxicity*; D007887:Fabaceae / Q000737:chemistry; D019684:Magnoliopsida / Q000737:chemistry; D008697:Methane / Q000378:metabolism; D009609:Nitrous Oxide / Q000378:metabolism; D010083:Oxidants, Photochemical / Q000378:metabolism / Q000633:toxicity; D010126:Ozone / Q000633:toxicity*; D006109:Poaceae / Q000737:chemistry; D012621:Seasons; D012989:Soil Pollutants / Q000032:analysis; D014887:Weather
chemical_list: D000393:Air Pollutants; D004785:Environmental Pollutants; D010083:Oxidants, Photochemical; D012989:Soil Pollutants; D002245:Carbon Dioxide; D010126:Ozone; D009609:Nitrous Oxide; D008697:Methane