The precise effects of natural and disturbed terrestrial systems on the atmospheric CH4 pool are uncertain. This study was conducted to quantify and compare CH4 fluxes from a variety of ecosystems in central Iowa. We investigated agricultural systems under different management practices, a hardwood forest site, native and restored prairies, and a municipal landfill. Flux measurements were obtai...

The global warming potential (GWP) of methane (CH4) is 25 times the GWP of carbon dioxide (CO2); as such, controlling CH4 emissions at municipal solid waste (MSW) landfills is an urgent task. Oxidation of CH4 using soil covers and bio-enhanced covers as a CH4 mitigation strategy is receiving great attention from environmental professionals. Biochar-amended soil covers are proposed to effectivel...

Emission of methane (CH4), a potent greenhouse gas, from tropical reservoirs is of interest because such reservoirs experience conducive conditions for CH4 production through anaerobic microbial activities. It has been suggested that Indian reservoirs have the potential to emit as much as 33.5 MT of CH4 per annum to the atmosphere. However, this estimate is based on assumptions rather than actu...

Methane (CH4) is only a trace constituent of the atmosphere but an important greenhouse gas. Although groundwater is unlikely to be a major source of atmospheric CH4, its contribution to the CH4 budget of the UK has up to now been poorly characterised. Groundwater CH4 concentrations have been measured on 85 samples from water-supply boreholes and a further eight from other miscellaneous water s...

Traditionally, methane (CH4) emission from terrestrial plants is thought to originate from belowground microbial metabolism under anaerobic conditions, with subsequent transport to the atmosphere through stems. However, a recent study reported aerobic CH4 emission from plants by an unrecognized process, a result that has since been questioned. We investigated CH4 emissions under aerobic conditi...

Together with water vapour and carbon dioxide (CO2), methane (CH4) is an important greenhouse gas, because of its strong global warming potential of 23×CO2 on a 100year time scale. The atmospheric mixing ratio of CH4 has increased with 151 ± 25%, since pre-industrial times. About 60% of the global CH4 emission is of antropogenous origin. From the natural sources (wetlands, termites, oceans, CH4...

[1] Despite considerable research, large uncertainties exist in the various area-scales budgets of CH4 flux between soils and the atmosphere. We postulated that small wetlands greatly contribute to the CH4 budget in semiarid regions, where wetland contributions are often assumed to be insignificant. To test this hypothesis, small riparian mires of the Xilin River basin in Inner Mongolia were se...

Understanding the dynamics of methane (CH4 ) emissions is of paramount importance because CH4 has 25 times the global warming potential of carbon dioxide (CO2 ) and is currently the second most important anthropogenic greenhouse gas. Wetlands are the single largest natural CH4 source with median emissions from published studies of 164 Tg yr(-1) , which is about a third of total global emissions...

A 2-year field and incubation experiment was conducted to investigate δ(13)C during the processes of CH4 emission from the fields subjected to two water managements (flooding and drainage) in the winter fallow season, and further to estimate relative contribution of acetate to total methanogenesis (Fac ) and fraction of CH4 oxidized (Fox ) based on the isotopic data. Compared with flooding, dra...

The permafrost on the North Slope of Alaska is densely populated by shallow lakes that result from thermokarst erosion. These lakes release methane (CH4 ) derived from a combination of ancient thermogenic pools and contemporary biogenic production. Despite the potential importance of CH4 as a greenhouse gas, the contribution of biogenic CH4 production in arctic thermokarst lakes in Alaska is no...