Spatial and seasonal variability of diffusive carbon flux in contrasting reservoirs: magnitudes and contribution of the aquatic surface and exposed sediment

Mapping Intimacies ◽

10.34019/ufjf/te/2021/00004 ◽

2021 ◽

Author(s):

◽

José Reinaldo Paranaíba Vilela Alves Teixeira

Keyword(s):

Seasonal Variability ◽

Carbon Flux ◽

Carbon Emission ◽

Co2 Flux ◽

Spatial And Temporal Variability ◽

Emission Rates ◽

Ch4 Flux ◽

Tropical Regions ◽

Spatially Resolved ◽

Carbon Dioxide Co2

Reservoirs are globally significant sources of carbon dioxide (CO2) and methane (CH4) to the atmosphere. The patterns of spatial and temporal variability in CO2 and CH4 emission from reservoirs are still poorly studied, especially in tropical regions where hydropower is growing rapidly. We performed spatially resolved measurements of dissolved CO2 and CH4 surface water concentrations and their gas-exchange coefficients (k) to compute diffusive carbon flux from four contrasting tropical reservoirs across Brazil during different hydrological seasons. Diffusive CO2 emissions were higher during the dry season than during the rainy season, whereas there were no consistent seasonal patterns for diffusive CH4 emissions. Our results reveal that the magnitude and the spatial within-reservoir patterns of diffusive CO2 and CH4 flux varied strongly among hydrological seasons. River inflow areas were often characterized by high seasonality in diffusive flux. Areas close to the dam generally showed low seasonal variability in diffusive CH4 flux but high variability in diffusive CO2 flux. Overall, we found that reservoir areas exhibiting highest emission rates (‘hotspots’) shifted substantially across hydrological seasons. Estimates of total diffusive carbon emission from the reservoir surfaces differed between hydrological seasons by a factor up to 7 in Chapéu D’Úvas reservoir, up to 13 in Curuá-Una reservoir, up to 4 in Furnas reservoir, and up to 1.8 in Funil reservoir, indicating that spatially-resolved measurements of gas concentrations and k need to be performed at different hydrological seasons in order to constrain annual diffusive carbon emission.

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Gas emissions from dairy barnyards

Animal Production Science ◽

10.1071/an15598 ◽

2016 ◽

Vol 56 (3) ◽

pp. 355 ◽

Cited By ~ 2

Author(s):

J. M. Powell ◽

P. A. Vadas

Keyword(s):

Co2 Flux ◽

N2o Flux ◽

Sand Soil ◽

Gas Emissions ◽

Nutrient Runoff ◽

Ch4 Flux ◽

Before And After ◽

Health Need ◽

Carbon Dioxide Co2 ◽

Cow Comfort

Dairy cattle spend considerable time in outside barnyards. Nine barnyards were constructed to examine impacts of surface materials (bark, sand, soil) and timing of cattle corralling (before and after 3–14-day corralling periods) on fluxes of carbon dioxide (CO2), methane (CH4), ammonia (NH3), nitrous oxide (N2O) and CO2 equivalents (CO2eq). Surface, year, and surface*year interactions accounted for 64%, 6% and 16% of CO2 flux variability. Average CO2 flux from bark (2552 mg/m2.h) was 3.1–3.9 times greater than from sand or soil, especially after bark replenishment. Timing, year, timing*year and surface*year accounted for 40%, 17%, 14%, and 17% of CH4 variability. Average CH4 flux after corralling (10.6 mg/m2.h) was 3.8 times greater than before corralling, and 5.2 times greater the year following bark replenishment. Timing accounted for 67% of NH3 variability. After corralling, NH3 fluxes (1622 µg/m2.h) were 95 times greater than before corralling. Timing, surface, surface*timing and timing*year accounted for 33%, 10%, 24% and 13% of N2O variability. Average N2O flux after corralling (2252 µg/m2.h) was 3.7 times greater than before corralling. Surface and surface*year accounted for 71% and 16% of CO2eq variability. Average CO2eq flux from bark (3188 mg/m2.h) was 2.5–3.0 times greater than sand or soil. Greatest CO2eq flux occurred the year after bark replenishment. Tradeoffs between gas emissions, nutrient runoff and leaching, and cow comfort and health need to be assessed more fully before recommending beneficial practices for barnyard surface type and management.

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Forest stand age information improves an inverse North American carbon flux estimate

Biogeosciences Discussions ◽

10.5194/bgd-10-4781-2013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 4781-4817 ◽

Cited By ~ 2

Author(s):

F. Deng ◽

J. M. Chen ◽

Y. Pan ◽

W. Peters ◽

R. Birdsey ◽

...

Keyword(s):

Carbon Flux ◽

Age Factors ◽

Carbon Sources ◽

Co2 Flux ◽

Forest Stand ◽

Atmospheric Co2 ◽

Stand Age ◽

Ecosystem Carbon ◽

Net Ecosystem Carbon Exchange ◽

Carbon Dioxide Co2

Abstract. Atmospheric inversions have become an important tool in quantifying carbon dioxide (CO2) sinks and sources at a variety of spatiotemporal scales, but associated large uncertainties restrain the inversion research community from reaching agreements on many important subjects. We enhanced an atmospheric inversion of the CO2 flux for North America by introducing spatially-explicit information on forest stand age for US and Canada as an additional constraint, since forest carbon dynamics are closely related to time since disturbance. To use stand age information in the inversion, we converted stand age into an age factor, and included the covariances between sub-continental regions in the inversion based on the similarity of the age factors. Our inversion results show that, considering age factors, regions with recently-disturbed or old forests are often nudged towards carbon sources, while regions with middle-aged productive forests are shifted towards sinks. This conforms to stand age effects observed in flux networks. At the sub-continental level, our inverted carbon fluxes agree well with continuous estimates of net ecosystem carbon exchange (NEE) upscaled from eddy covariance flux data (EC) based on MODIS data. Inverted fluxes with the age constraint exhibit stronger correlation to these upscaled NEE estimates than those inverted without the age constraint. While the carbon flux at the continental and sub-continental scales is predominantly determined by atmospheric CO2 observations, the age constraint is shown to have potential to improve the inversion of the carbon flux distribution among sub-continental regions, especially for regions lacking atmospheric CO2 observations.

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The use of forest stand age information in an atmospheric CO<sub>2</sub> inversion applied to North America

Biogeosciences ◽

10.5194/bg-10-5335-2013 ◽

2013 ◽

Vol 10 (8) ◽

pp. 5335-5348 ◽

Cited By ~ 11

Author(s):

F. Deng ◽

J. M. Chen ◽

Y. Pan ◽

W. Peters ◽

R. Birdsey ◽

...

Keyword(s):

North America ◽

Carbon Flux ◽

Age Factors ◽

Carbon Sources ◽

Co2 Flux ◽

Forest Stand ◽

Atmospheric Co2 ◽

Stand Age ◽

Net Ecosystem Carbon Exchange ◽

Carbon Dioxide Co2

Abstract. Atmospheric inversions have become an important tool in quantifying carbon dioxide (CO2) sinks and sources at a variety of spatiotemporal scales, but associated large uncertainties restrain the inversion research community from reaching agreement on many important subjects. We enhanced an atmospheric inversion of the CO2 flux for North America by introducing spatially explicit information on forest stand age for US and Canada as an additional constraint, since forest carbon dynamics are closely related to time since disturbance. To use stand age information in the inversion, we converted stand age into an age factor, and included the covariances between subcontinental regions in the inversion based on the similarity of the age factors. Our inversion results show that, considering age factors, regions with recently disturbed or old forests are often nudged towards carbon sources, while regions with middle-aged productive forests are shifted towards sinks. This conforms to stand age effects observed in flux networks. At the subcontinental level, our inverted carbon fluxes agree well with continuous estimates of net ecosystem carbon exchange (NEE) upscaled from eddy covariance flux data based on MODIS data. Inverted fluxes with the age constraint exhibit stronger correlation to these upscaled NEE estimates than those inverted without the age constraint. While the carbon flux at the continental and subcontinental scales is predominantly determined by atmospheric CO2 observations, the age constraint is shown to have potential to improve the inversion of the carbon flux distribution among subcontinental regions, especially for regions lacking atmospheric CO2 observations.

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Air–sea carbon flux from high-temporal-resolution data of in situ CO<sub>2</sub> measurements in the southern North Sea

10.5194/bg-2020-442 ◽

2020 ◽

Author(s):

Steven Pint ◽

Gert Everaert ◽

Hannelore Theetaert ◽

Michiel B. Vandegehuchte ◽

Thanos Gkritzalis

Keyword(s):

North Sea ◽

Carbon Flux ◽

Carbon Sink ◽

Co2 Flux ◽

Spatiotemporal Variability ◽

High Temporal Resolution ◽

Co2 Fluxes ◽

Southern North Sea ◽

Basin Scale ◽

Carbon Dioxide Co2

Abstract. An important element to keep track of global change is the atmosphere–water exchange of carbon dioxide (CO2) in the ocean as it provides insight in how much CO2 is incorporated in the ocean (i.e. the ocean as a sink for CO2) or emitted to the atmosphere (i.e. the ocean as a source). To date, only few high-resolution observation sets are available to quantify the spatiotemporal variability of air–sea CO2 fluxes. In this study, we used observations of pCO2 collected daily at the ICOS station Thornton Buoy in the southern North Sea from February until December 2018 to calculate air–sea CO2 fluxes. Our results show a seasonal variability of the air–sea carbon flux, with the sea being a carbon sink from February until June switching to a carbon source in July and August, before switching back to a sink until December. We calculated that the sink was largest in April (−0.95 ± 0.90 mmol C m−2 d−1), while in August, the source was at its maximum (0.08 ± 0.13 mmol C m−2 d−1). On an annual basis, we found a sink for atmospheric CO2 of 130.19 ± 149.93 mmol C m−2 y−1. Apart from region- and basin-scale estimates of the air–sea CO2 flux, also local measurements are important to grasp local dynamics of the flux and its interactions with biogeochemical processes.

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Variation in Soil Properties Regulate Greenhouse Gas Fluxes and Global Warming Potential in Three Land Use Types on Tropical Peat

Atmosphere ◽

10.3390/atmos9120465 ◽

2018 ◽

Vol 9 (12) ◽

pp. 465 ◽

Cited By ~ 7

Author(s):

Kiwamu Ishikura ◽

Untung Darung ◽

Takashi Inoue ◽

Ryusuke Hatano

Keyword(s):

Global Warming ◽

Soil Moisture ◽

Groundwater Level ◽

Global Warming Potential ◽

C:N Ratio ◽

Co2 Flux ◽

Nitrate Content ◽

N2o Flux ◽

Ch4 Flux ◽

In The Beginning

This study investigated spatial factors controlling CO2, CH4, and N2O fluxes and compared global warming potential (GWP) among undrained forest (UDF), drained forest (DF), and drained burned land (DBL) on tropical peatland in Central Kalimantan, Indonesia. Sampling was performed once within two weeks in the beginning of dry season. CO2 flux was significantly promoted by lowering soil moisture and pH. The result suggests that oxidative peat decomposition was enhanced in drier position, and the decomposition acidify the peat soils. CH4 flux was significantly promoted by a rise in groundwater level, suggesting that methanogenesis was enhanced under anaerobic condition. N2O flux was promoted by increasing soil nitrate content in DF, suggesting that denitrification was promoted by substrate availability. On the other hand, N2O flux was promoted by lower soil C:N ratio and higher soil pH in DBL and UDF. CO2 flux was the highest in DF (241 mg C m−2 h−1) and was the lowest in DBL (94 mg C m−2 h−1), whereas CH4 flux was the highest in DBL (0.91 mg C m−2 h−1) and was the lowest in DF (0.01 mg C m−2 h−1), respectively. N2O flux was not significantly different among land uses. CO2 flux relatively contributed to 91–100% of GWP. In conclusion, it is necessary to decrease CO2 flux to mitigate GWP through a rise in groundwater level and soil moisture in the region.

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Annual follow-up of gross diffusive carbon dioxide and methane emissions from a boreal reservoir and two nearby lakes in Québec, Canada

Biogeosciences ◽

10.5194/bg-8-41-2011 ◽

2011 ◽

Vol 8 (1) ◽

pp. 41-53 ◽

Cited By ~ 39

Author(s):

M. Demarty ◽

J. Bastien ◽

A. Tremblay

Keyword(s):

Carbon Budget ◽

Ghg Emissions ◽

Co2 Flux ◽

Reliable Estimate ◽

Minor Importance ◽

Layer Model ◽

Thin Boundary Layer ◽

Ch4 Flux ◽

Annual Carbon

Abstract. Surface water pCO2 and pCH4 measurements were taken in the boreal zone of Québec, Canada, from summer 2006 to summer 2008 in Eastmain 1 reservoir and two nearby lakes. The goal of this follow-up was to evaluate annual greenhouse gas (GHG) emissions, including spring emissions (N.B. gross emissions for reservoir), through flux calculations using the thin boundary layer model. Our measurements underscored the winter CO2 accumulation due to ice cover and the importance of a reliable estimate of spring diffusive emissions as the ice breaks up. We clearly demonstrated that in our systems, diffusive CH4 flux (in terms of CO2 equivalent) were of minor importance in the GHG emissions (without CH4 accumulation under ice), with diffusive CO2 flux generally accounting for more than 95% of the annual diffusive flux. We also noted the extent of spring diffusive CO2 emissions (23% to 52%) in the annual carbon budget.

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Supplementary material to "The determination of highly time resolved and source separated black carbon emission rates using radon as a tracer of atmospheric dynamics"

10.5194/acp-2019-911-supplement ◽

2019 ◽

Author(s):

Asta Gregorič ◽

Luka Drinovec ◽

Irena Ježek ◽

Janja Vaupotič ◽

Matevž Lenarčič ◽

...

Keyword(s):

Black Carbon ◽

Carbon Emission ◽

Atmospheric Dynamics ◽

Emission Rates ◽

Time Resolved ◽

Supplementary Material

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Carbon mineralization dynamics of tropical peats in relation to peat characteristics

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d190430 ◽

2018 ◽

Vol 19 (4) ◽

pp. 1413-1421 ◽

Cited By ~ 2

Author(s):

AKHMAD R. SAIDY ◽

ZURAIDA T. MARIANA ◽

FENGKY A. ADJI ◽

ROSSIE W. NUSANTARA ◽

IRMA FITRIA ◽

...

Keyword(s):

Chemical Structure ◽

Carbon Mineralization ◽

Close Relation ◽

Carbohydrate Content ◽

Co2 Production ◽

Emission Rates ◽

Incubation Study ◽

Tropical Areas ◽

Paddy Cultivation ◽

Carbon Dioxide Co2

Saidy AR, Mariana ZT, Adji FA, Nusantara RW, Fitria I, Syahrinudin. 2018. Carbon mineralization dynamics of tropicalpeats in relation to peat characteristics. Biodiversitas 19: 1413-1421. Understanding the dynamics of carbon mineralization of peats inthe tropical areas is of essential significance in controlling carbon dioxide (CO2) gas emission rates. An incubation study of tropicalpeats sampled from 3 different sites of the Barito Basin on the Borneo Island, Indonesia (uncultivated, used for paddy cultivation for  5years and 5-10 years) was carried out to investigate a relationship between CO2 production and peat characteristics. Results of studyrevealed that land use change from uncultivated peats to paddy fields resulted in significant changes in the chemical structure of peatorganic carbon. Carbohydrate contents of the peat decreased significantly as a consequence of the conversion of natural peats to paddyfields. However, the paddy peats contained higher lignin than uncultivated peats. Changes in the chemical structure of the tropical peatsresulted in changes in carbon mineralization. Carbon mineralization of uncultivated peats ranged from 29255310 mg CO2-C kg-1 peat,while carbon mineralization of 10652678 mg CO2-C kg-1 C peat was observed for paddy peats. Moreover, carbon mineralization dataobtained from the experiment fitted properly to a two-pool C mineralization model. The developed carbon mineralization model showedthat slowly and rapidly decomposable pools have a close relation with rubbed fiber and carbohydrate content data. Thus, results of thisstudy suggested that carbon mineralization of peats could be estimated appropriately using rubbed fiber and carbohydrate content data.

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Automatic high-frequency measurements of full soil greenhouse gas fluxes in a tropical forest

10.5194/bg-2018-341 ◽

2018 ◽

Author(s):

Elodie Alice Courtois ◽

Clément Stahl ◽

Benoit Burban ◽

Joke Van den Berge ◽

Daniel Berveiller ◽

...

Keyword(s):

High Frequency ◽

Co2 Flux ◽

Appropriate Technology ◽

Flux Chamber ◽

Soil Co2 Flux ◽

Reliable Estimation ◽

Closure Time ◽

N2o Fluxes ◽

Ch4 And N2o ◽

Carbon Dioxide Co2

Abstract. Measuring in situ soil fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) continuously at high frequency requires appropriate technology. We tested the combination of a commercial automated soil CO2 flux chamber system (LI-8100A) with a CH4 and N2O analyzer (Picarro G2308) in a tropical rainforest for 4 months. A chamber closure time of 2 minutes was sufficient for a reliable estimation of CO2 and CH4 fluxes (100 % and 98.5 % of fluxes were above Minimum Detectable Flux – MDF, respectively). This closure time was generally not suitable for a reliable estimation of the low N2O fluxes in this ecosystem but was sufficient for detecting rare major peak events. A closure time of 25 minutes was more appropriate for reliable estimation of most N2O fluxes (85.6 % of measured fluxes are above MDF ± 0.002 nmol m−2 s−1). Our study highlights the importance of adjusted closure time for each gas.

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