Methane flux from northern peatlands

Nature ◽  
1985 ◽  
Vol 315 (6021) ◽  
pp. 652-654 ◽  
Author(s):  
Robert C. Harriss ◽  
Eville Gorham ◽  
Daniel I. Sebacher ◽  
Karen B. Bartlett ◽  
Patricia A. Flebbe
Keyword(s):  
Methane Flux ◽  
Northern Peatlands

scholarly journals Methane flux from drained northern peatlands: Effect of a persistent water table lowering on flux

1993 ◽  
Vol 7 (4) ◽  
pp. 749-769 ◽  
Author(s):  
Nigel T. Roulet ◽  
R. Ash ◽  
W. Quinton ◽  
Tim Moore
Keyword(s):  
Water Table ◽  
Methane Flux ◽  
Northern Peatlands

Episodic fluxes of methane from subarctic fens

1992 ◽  
Vol 72 (4) ◽  
pp. 441-452 ◽  
Author(s):  
J. Windsor ◽  
T. R. Moore ◽  
N. T. Roulet
Keyword(s):  
Seasonal Pattern ◽  
Methane Flux ◽  
Spatial And Temporal Variability ◽  
Surface Layers ◽  
Overburden Pressure ◽  
Episodic Events ◽  
Episodic Event ◽  
Before And After ◽  
Peat Profile ◽  
Northern Peatlands

Measurements of methane flux from northern peatlands to the atmosphere are complicated by high spatial and temporal variability. We quantified the variability of methane flux from two subarctic fens near Schefferville, northern Quebec, using a static chamber technique. Within the seasonal pattern of increasing fluxes associated with the warming of the peat profile, episodic fluxes of methane were observed. One set of episodic events occurred during the spring thaw of the upper layers of the peat, which released methane stored in ice over the winter. The second set, generally of short duration (< 2 d), occurred in mid-summer and appeared to be related primarily to the lowering of the water table. In four of six subjectively-identified, episodic fluxes during the 1990 summer the flux during the episodic event was equal to or greater than the upper 95% confidence level of the three fluxes before and after the event (t-statistic probabilities ranged from < 0.001 to 0.038). Mechanisms to account for these episodic fluxes of methane include increased methane diffusivity, removal of overburden pressure and reduced rates of methane consumption in the surface layers of the peat. Omission of these episodic fluxes could lower estimates of seasonal methane emissions by 7–22%. Key words: Peatlands, fens, methane

MICROBIAL COMMUNITIES AND DIFFERENTIAL METHANE FLUX IN ARCTIC GAS HYDRATE MOUNDS

2017 ◽  
Author(s):  
Stella C. Ross ◽  
◽  
Scott Klasek ◽  
Wei-Li Hong ◽  
Marta E. Torres ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Gas Hydrate ◽  
Methane Flux

Ecosystem modeling of methane and carbon dioxide fluxes for boreal forest sites

2001 ◽  
Vol 31 (2) ◽  
pp. 208-223 ◽  
Author(s):  
Christopher Potter ◽  
Jill Bubier ◽  
Patrick Crill ◽  
Peter Lafleur
Keyword(s):  
Carbon Dioxide ◽  
Boreal Forest ◽  
Land Surface ◽  
Net Primary Production ◽  
Ground Cover ◽  
Methane Flux ◽  
Growing Season ◽  
Ecosystem Model ◽  
Heat Fluxes ◽  
Water Levels

Predicted daily fluxes from an ecosystem model for water, carbon dioxide, and methane were compared with 1994 and 1996 Boreal Ecosystem–Atmosphere Study (BOREAS) field measurements at sites dominated by old black spruce (Picea mariana (Mill.) BSP) (OBS) and boreal fen vegetation near Thompson, Man. Model settings for simulating daily changes in water table depth (WTD) for both sites were designed to match observed water levels, including predictions for two microtopographic positions (hollow and hummock) within the fen study area. Water run-on to the soil profile from neighboring microtopographic units was calibrated on the basis of daily snowmelt and rainfall inputs to reproduce BOREAS site measurements for timing and magnitude of maximum daily WTD for the growing season. Model predictions for daily evapotranspiration rates closely track measured fluxes for stand water loss in patterns consistent with strong controls over latent heat fluxes by soil temperature during nongrowing season months and by variability in relative humidity and air temperature during the growing season. Predicted annual net primary production (NPP) for the OBS site was 158 g C·m–2 during 1994 and 135 g C·m–2 during 1996, with contributions of 75% from overstory canopy production and 25% from ground cover production. Annual NPP for the wetter fen site was 250 g C·m–2 during 1994 and 270 g C·m–2 during 1996. Predicted seasonal patterns for soil CO2 fluxes and net ecosystem production of carbon both match daily average estimates at the two sites. Model results for methane flux, which also closely match average measured flux levels of –0.5 mg CH4·m–2·day–1 for OBS and 2.8 mg CH4·m–2·day–1 for fen sites, suggest that spruce areas are net annual sinks of about –0.12 g CH4·m–2, whereas fen areas generate net annual emissions on the order of 0.3–0.85 g CH4·m–2, depending mainly on seasonal WTD and microtopographic position. Fen hollow areas are predicted to emit almost three times more methane during a given year than fen hummock areas. The validated model is structured for extrapolation to regional simulations of interannual trace gas fluxes over the entire North America boreal forest, with integration of satellite data to characterize properties of the land surface.

Source or sink?A study on the methane flux from mangroves stems in Zhangjiang estuary, southeast coast of China

2021 ◽  
pp. 147782
Author(s):  
Chang-Hao Gao ◽  
Shan Zhang ◽  
Qian-Su Ding ◽  
Ming-Yue Wei ◽  
Huan Li ◽  
...  
Keyword(s):  
Methane Flux ◽  
Southeast Coast

scholarly journals Microbial drivers of methane emissions from unrestored industrial salt ponds

2021 ◽  
Author(s):  
Jinglie Zhou ◽  
Susanna M. Theroux ◽  
Clifton P. Bueno de Mesquita ◽  
Wyatt H. Hartman ◽  
Ye Tian ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Methane Flux ◽  
Methane Emissions ◽  
Metagenomic Data ◽  
Rrna Gene ◽  
Salt Ponds ◽  
Salt Pond ◽  
Reference Wetlands ◽  
Reference Wetland ◽  
The Impact

AbstractWetlands are important carbon (C) sinks, yet many have been destroyed and converted to other uses over the past few centuries, including industrial salt making. A renewed focus on wetland ecosystem services (e.g., flood control, and habitat) has resulted in numerous restoration efforts whose effect on microbial communities is largely unexplored. We investigated the impact of restoration on microbial community composition, metabolic functional potential, and methane flux by analyzing sediment cores from two unrestored former industrial salt ponds, a restored former industrial salt pond, and a reference wetland. We observed elevated methane emissions from unrestored salt ponds compared to the restored and reference wetlands, which was positively correlated with salinity and sulfate across all samples. 16S rRNA gene amplicon and shotgun metagenomic data revealed that the restored salt pond harbored communities more phylogenetically and functionally similar to the reference wetland than to unrestored ponds. Archaeal methanogenesis genes were positively correlated with methane flux, as were genes encoding enzymes for bacterial methylphosphonate degradation, suggesting methane is generated both from bacterial methylphosphonate degradation and archaeal methanogenesis in these sites. These observations demonstrate that restoration effectively converted industrial salt pond microbial communities back to compositions more similar to reference wetlands and lowered salinities, sulfate concentrations, and methane emissions.

Effect of biogas digested slurry-based biochar on methane flux and methanogenic archaeal diversity in paddy soil

2014 ◽  
Vol 197 ◽  
pp. 278-287 ◽  
Author(s):  
Ankit Singla ◽  
Suresh Kumar Dubey ◽  
Alpana Singh ◽  
Kazuyuki Inubushi
Keyword(s):  
Paddy Soil ◽  
Methane Flux ◽  
Archaeal Diversity

Exploring the variation in ecosystem scale methane fluxes and its drivers within a boreal mire complex

2021 ◽  
Author(s):  
Koffi Dodji Noumonvi ◽  
Joshua L. Ratcliffe ◽  
Mats Öquist ◽  
Mats B. Nilsson ◽  
Matthias Peichl
Keyword(s):  
Eddy Covariance ◽  
Land Surface ◽  
Chemical Properties ◽  
Growing Season ◽  
Small Scale ◽  
Atmospheric Methane ◽  
Flux Footprint ◽  
Growing Season Length ◽  
Methane Fluxes ◽  
Northern Peatlands

&lt;p&gt;Northern peatlands cover a small fraction of the earth&amp;#8217;s land surface, and yet they are one of the most important natural sources of atmospheric methane. With climate change causing rising temperatures, changes in water balance and increased growing season length, peatland contribution to atmospheric methane concentration is likely to increase, justifying the increased attention given to northern peatland methane dynamics. Northern peatlands often occur as heterogeneous complexes characterized by hydromorphologically distinct features from &lt; 1 m&amp;#178; to tens of km&amp;#178;, with differing physical, hydrological and chemical properties. The more commonly understood small-scale variation between hummocks, lawns and hollows has been well explored using chamber measurements. Single tower eddy covariance measurements, with a typical 95% flux footprint of &lt; 0.5 km&amp;#178;, have been used to assess the ecosystem scale methane exchange. However, how representative single tower flux measurements are of an entire mire complex is not well understood. To address this knowledge gap, the present study takes advantage of a network of four eddy covariance towers located less than 3 km apart at four mires within a typical boreal mire complex in northern Sweden. The variation of methane fluxes and its drivers between the four sites will be explored at different temporal scales, i.e. half-hourly, daily and at a growing-season scale.&lt;/p&gt;

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