【温室气体通量】Feike A Dijkstra Stephen A Prior G Brett Runion H Allen Torbert Hanqin Tian Chaoqun Lu and Rodney T Venterea. Effects of elevated carbon dioxide and increased temperature on methane and nitrous oxide fluxes: evidence from field experiments. Frontiers in Ecology and the Environment 2012 10: 520–527. http://dx.doi.org-10.1890-120059
Abstract
Climate change could alter terrestrial ecosystems which are important sources and sinks of the potent green-house gases (GHGs) nitrous oxide (N2O) and methane (CH4) in ways that either stimulate or decrease the magnitude and duration of global warming. Using manipulative field experiments we assessed how N2O and CH4 soil fluxes responded to a rise in atmospheric carbon dioxide (CO2) concentration and to increased air temperature. Nitrous oxide and CH4 responses varied greatly among studied ecosystems. Elevated CO2 often stimulated N2O emissions in fertilized systems and CH4 emissions in wetlands peatlands and rice paddy fields; both effects were stronger in clayey soils than in sandy upland soils. Elevated temperature however impacted N2O and CH4 emissions inconsistently. Thus the effects of elevated CO2 concentrations on N2O and CH4 emissions may further enhance global warming but it remains unclear whether increased temperature generates positive or negative feedbacks on these GHGs in terrestrial ecosystems.
【氮沉降】Pamela H Templer Robert W Pinder and Christine L Goodale. Effects of nitrogen deposition on greenhouse-gas fluxes for forests and grasslands of North America. Frontiers in Ecology and the Environment 2012 10: 547–553. http://dx.doi.org-10.1890-120055
Abstract
Human activities have substantially elevated the atmospheric deposition of reactive nitrogen (N) onto terrestrial ecosystems of North America. Some of this N can stimulate carbon (C) storage in terrestrial ecosystems but the fertilization effect of added N can be diminished by elevated concentrations of tropospheric ozone (O3) and by chronically high N deposition. In this review we discuss spatial patterns and effects of N deposition and tropospheric O3 on net greenhouse-gas fluxes in North American forest and grassland ecosystems. While projected rates of ammonia emissions and deposition are expected to remain unchanged projected declines in nitrogen oxide (NOx) emissions within the US will likely lead to reductions in total N deposition and O3. The net effect of these changes in N deposition onto forests and grasslands will likely initiate declines in C sequestration attributed to N deposition over the next 40 years.
【氧化亚氮排放】Rodney T Venterea Ardell D Halvorson Newell Kitchen Mark A Liebig Michel A Cavigelli Stephen J Del Grosso Peter P Motavalli Kelly A Nelson Kurt A Spokas Bhupinder Pal Singh Catherine E Stewart Andry Ranaivoson Jeffrey Strock and Hal Collins. Challenges and opportunities for mitigating nitrous oxide emissions from fertilized cropping systems. Frontiers in Ecology and the Environment 2012 10: 562–570.
【氧化亚氮排放】Rodney T Venterea Ardell D Halvorson Newell Kitchen Mark A Liebig Michel A Cavigelli Stephen J Del Grosso Peter P Motavalli Kelly A Nelson Kurt A Spokas Bhupinder Pal Singh Catherine E Stewart Andry Ranaivoson Jeffrey Strock and Hal Collins. Challenges and opportunities for mitigating nitrous oxide emissions from fertilized cropping systems. Frontiers in Ecology and the Environment 2012 10: 562–570.
