scholarly journals The effect of a reciprocal peat transplant between two contrasting Central European sites on C cycling and C isotope ratios

2010 ◽  
Vol 7 (3) ◽  
pp. 921-932 ◽  
Author(s):  
M. Novak ◽  
L. Zemanova ◽  
F. Buzek ◽  
I. Jackova ◽  
M. Adamova ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Isotope Composition ◽  
210Pb Dating ◽  
Methane Emissions ◽  
Peat Bogs ◽  
Transplant Experiment ◽  
Emission Rates ◽  
Organic Matter Quality ◽  
Δ13c Values ◽  
Carbon Quality

Abstract. An 18-month reciprocal peat transplant experiment was conducted between two peatlands in the Czech Republic. Both sites were 100% Sphagnum-covered, with no vascular plants, and no hummocks and hollows. Atmospheric depositions of sulfur were up to 10 times higher at the northern site Velke jerabi jezero (VJJ), compared to the southern site Cervene blato (CB). Forty-cm deep peat cores, 10-cm in diameter, were used as transplants and controls in five replicates. Our objective was to evaluate whether CO2 and CH4 emissions from Sphagnum peat bogs are governed mainly by organic matter quality in the substrate, or by environmental conditions. Emission rates and δ13C values of CO2 and CH4 were measured in the laboratory at time t=18 months. All measured parameters converged to those of the host site, indicating that, at least in the short-term perspective, environmental conditions were a more important control of greenhouse gas emissions than organic carbon quality in the substrate. Since sulfate reducers outcompete methanogens, we hypothesized that the S-polluted site VJJ should have lower methane emissions than CB. In fact, the opposite was true, with significantly (p<0.01) higher methane emissions from VJJ. Additionally, as a first step in an effort to link C isotope composition of emitted gases and residual peat substrate, we determined whether multiple vertical δ13C profiles in peat agree. A high degree of within-site homogeneity in δ13C was found. When a specific vertical δ13C trend was seen in one peat core, the same trend was also seen in all the remaining peat cores from the wetland. The δ13C value increased downcore at both CB and VJJ. At VJJ, however, 20 cm below surface, a reversal to lower δ13C downcore was seen. Based on 210Pb dating, peat at 20-cm depth at VJJ was only 15 years old. Increasing δ13C values in VJJ peat accumulated between 1880–1990 could not be caused by assimilation of atmospheric CO2 gradually enriched in the light isotope 12C due to fossil fuel burning. Rather they were a result of a combination of isotope fractionations accompanying assimilation and mineralization of Sphagnum C. These isotope fractionations may record information about past changes in C storage in wetlands.

scholarly journals The effect of a reciprocal peat transplant between two contrasting Central European sites on C cycling

2009 ◽  
Vol 6 (5) ◽  
pp. 10007-10034
Author(s):  
M. Novak ◽  
L. Zemanova ◽  
F. Buzek ◽  
I. Jackova ◽  
M. Adamova ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Isotope Composition ◽  
210Pb Dating ◽  
Methane Emissions ◽  
Peat Bogs ◽  
Transplant Experiment ◽  
Organic Matter Quality ◽  
Δ13c Values ◽  
Carbon Quality ◽  
Ch4 Production

Abstract. An 18-month reciprocal peat transplant experiment was conducted between two peatlands in the Czech Republic. Both sites were 100% Sphagnum-covered, with no vascular plants, and no hummocks and hollows. Atmospheric depositions of sulfur were up to 10 times higher at the northern site Velke jerabi jezero (VJJ), compared to the southern site Cervene blato (CB). Forty-cm deep peat cores, 10 cm in diameter, were used as transplants and controls in five replicates. Our objective was to evaluate whether CO2 and CH4 production potentials in Sphagnum peat bogs are governed mainly by organic matter quality, or by environmental conditions. Production rates and δ13C values of CO2 and CH4 were measured in the laboratory at time t=18 months. All measured parameters converged to those of the host site, indicating that, at least in the short-term perspective, environmental conditions were a more important control of greenhouse gas emissions than organic carbon quality. Since sulfate reducers outcompete methanogens, we hypothesized that the S-polluted site VJJ should have lower methane emissions than CB. In fact, the opposite was true, with higher methane emissions from VJJ. As a first step in an effort to link C isotope composition of emitted gases and residual peat substrate, we determined whether multiple vertical δ13C profiles in peat agree. A high degree of within-site homogeneity in δ13C was found. The δ13C value increased downcore at both CB and VJJ. However, 20 cm below surface, a reversal to lower δ13C downcore was seen at VJJ. Based on 210Pb dating, peat at 20 cm depth at VJJ was only 15 years old. Increasing δ13C values in VJJ peat accumulated between 1880–1990 could not be caused by assimilation of atmospheric CO2 gradually enriched in the light isotope 12C due to fossil fuel burning.

scholarly journals Environmental and taxonomic controls of carbon and oxygen stable isotope composition in <i>Sphagnum</i> across broad climatic and geographic ranges

2018 ◽  
Vol 15 (16) ◽  
pp. 5189-5202 ◽  
Author(s):  
Gustaf Granath ◽  
Håkan Rydin ◽  
Jennifer L. Baltzer ◽  
Fia Bengtsson ◽  
Nicholas Boncek ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Large Scale ◽  
Net Primary Productivity ◽  
Isotope Composition ◽  
Explanatory Power ◽  
Isotopic Signature ◽  
Co2 Uptake ◽  
Δ13c Values ◽  
Site Variation ◽  
Species Specific

Abstract. Rain-fed peatlands are dominated by peat mosses (Sphagnum sp.), which for their growth depend on nutrients, water and CO2 uptake from the atmosphere. As the isotopic composition of carbon (12,13C) and oxygen (16,18O) of these Sphagnum mosses are affected by environmental conditions, Sphagnum tissue accumulated in peat constitutes a potential long-term archive that can be used for climate reconstruction. However, there is inadequate understanding of how isotope values are influenced by environmental conditions, which restricts their current use as environmental and palaeoenvironmental indicators. Here we tested (i) to what extent C and O isotopic variation in living tissue of Sphagnum is species-specific and associated with local hydrological gradients, climatic gradients (evapotranspiration, temperature, precipitation) and elevation; (ii) whether the C isotopic signature can be a proxy for net primary productivity (NPP) of Sphagnum; and (iii) to what extent Sphagnum tissue δ18O tracks the δ18O isotope signature of precipitation. In total, we analysed 337 samples from 93 sites across North America and Eurasia using two important peat-forming Sphagnum species (S. magellanicum, S. fuscum) common to the Holarctic realm. There were differences in δ13C values between species. For S. magellanicum δ13C decreased with increasing height above the water table (HWT, R2=17 %) and was positively correlated to productivity (R2=7 %). Together these two variables explained 46 % of the between-site variation in δ13C values. For S. fuscum, productivity was the only significant predictor of δ13C but had low explanatory power (total R2=6 %). For δ18O values, approximately 90 % of the variation was found between sites. Globally modelled annual δ18O values in precipitation explained 69 % of the between-site variation in tissue δ18O. S. magellanicum showed lower δ18O enrichment than S. fuscum (−0.83 ‰ lower). Elevation and climatic variables were weak predictors of tissue δ18O values after controlling for δ18O values of the precipitation. To summarize, our study provides evidence for (a) good predictability of tissue δ18O values from modelled annual δ18O values in precipitation, and (b) the possibility of relating tissue δ13C values to HWT and NPP, but this appears to be species-dependent. These results suggest that isotope composition can be used on a large scale for climatic reconstructions but that such models should be species-specific.

scholarly journals Environmental and taxonomic controls of carbon and oxygen stable isotope composition in <i>Sphagnum</i> across broad climatic and geographic ranges

2018 ◽  
Author(s):  
Gustaf Granath ◽  
Håkan Rydin ◽  
Jennifer L. Baltzer ◽  
Fia Bengtsson ◽  
Nicholas Boncek ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Large Scale ◽  
Net Primary Productivity ◽  
Isotope Composition ◽  
Isotopic Signature ◽  
Δ13c Values ◽  
Geographic Ranges ◽  
Lower Elevation ◽  
Site Variation ◽  
Species Specific

Abstract. Rain-fed peatlands are dominated by peat mosses (Sphagnum sp.), which for their growth depend on elements from the atmosphere. As the isotopic composition of carbon (12,13C) and oxygen (16,18O) of these Sphagnum mosses are affected by environmental conditions, the dead Sphagnum tissue accumulated in peat constitutes a potential long-term archive that can be used for climate reconstruction. However, there is a lack of adequate understanding of how isotope values are influenced by environmental conditions, which restricts their current use as environmental and palaeoenvironmental indicators. Here we tested (i) to what extent C and O isotopic variation in living tissue of Sphagnum is species-specific and associated with local hydrological gradients, climatic gradients (evapotranspiration, temperature, precipitation), and elevation; (ii) if the C isotopic signature can be a proxy for net primary productivity (NPP) of Sphagnum; and (iii) to what extent Sphagnum tissue δ18O tracks the δ18O isotope signature of precipitation. In total, we analysed 337 samples from 93 sites across North America and Eurasia using two important peat-forming Sphagnum species (S. magellanicum, S. fuscum) common to the Holartic realm. There were differences in δ13C values between species. For S. magellanicum δ13C decreased with increasing height above the water table (HWT, R2 = 17 %) and was positively correlated to productivity (R2 = 7 %). Together these two variables explained 46 % of the between-site variation in δ13C values. For S. fuscum, productivity was the only significant predictor of δ13C (total R2 = 6 %). For δ18O values, ca. 90 % of the variation was found between sites. Globally-modelled annual δ18O values in precipitation explained 69% of the between-site variation in tissue δ18O. S. magellanicum showed lower δ18O enrichment than S. fuscum (−0.83 ‰ lower) . Elevation and climatic variables were weak predictors of tissue δ18O values after controlling for δ18O values of the precipitation. To summarise, our study provides evidence for (a) good predictability of tissue δ18O values from modelled annual δ18O values in precipitation, and (b) the possibility to relate tissue δ13C values to HWT and NPP, but this appears to be species-dependent. These results suggest that isotope composition can be used at a large scale for climatic reconstructions but that such models should be species-specific.

Comparisons of methodologies for measuring methane emissions from sheep

1998 ◽  
Vol 1998 ◽  
pp. 53-53
Author(s):  
Angela R. Moss ◽  
S. Jarvis ◽  
P. J. Murray
Keyword(s):  
Methane Emissions ◽  
Emission Rates ◽  
Ruminant Animal ◽  
Grazing Sheep ◽  
The Uk ◽  
Tunnel System

Agriculture is one of the major sources of methane in the UK and the major contribution is that from the ruminant animal. Most current inventories include evaluations of emission rates determined from ammals in respiration chambers. Methodolgy has been developed at IGER, North Wyke which enables measurements to be made with grazing animals (tunnel system). Preliminary measurements have indicated that methane emissions from grazing sheep in the tunnel system were lower than reported values for zero-grazed grass determined in chambers. The objective was to determine if these observed differences were a result of methodological differences.

scholarly journals Methane transport from the active layer to lakes in the Arctic using Toolik Lake, Alaska, as a case study

2015 ◽  
Vol 112 (12) ◽  
pp. 3636-3640 ◽  
Author(s):  
Adina Paytan ◽  
Alanna L. Lecher ◽  
Natasha Dimova ◽  
Katy J. Sparrow ◽  
Fenix Garcia-Tigreros Kodovska ◽  
...  
Keyword(s):  
Global Warming ◽  
Active Layer ◽  
Lake Water ◽  
Large Fraction ◽  
Methane Flux ◽  
Methane Emissions ◽  
Arctic Lakes ◽  
The Arctic ◽  
Emission Rates ◽  
Toolik Lake

Methane emissions in the Arctic are important, and may be contributing to global warming. While methane emission rates from Arctic lakes are well documented, methods are needed to quantify the relative contribution of active layer groundwater to the overall lake methane budget. Here we report measurements of natural tracers of soil/groundwater, radon, and radium, along with methane concentration in Toolik Lake, Alaska, to evaluate the role active layer water plays as an exogenous source for lake methane. Average concentrations of methane, radium, and radon were all elevated in the active layer compared with lake water (1.6 × 104 nM, 61.6 dpm⋅m−3, and 4.5 × 105 dpm⋅m−3 compared with 1.3 × 102 nM, 5.7 dpm⋅m−3, and 4.4 × 103 dpm⋅m−3, respectively). Methane transport from the active layer to Toolik Lake based on the geochemical tracer radon (up to 2.9 g⋅m−2⋅y−1) can account for a large fraction of methane emissions from this lake. Strong but spatially and temporally variable correlations between radon activity and methane concentrations (r2 > 0.69) in lake water suggest that the parameters that control methane discharge from the active layer also vary. Warming in the Arctic may expand the active layer and increase the discharge, thereby increasing the methane flux to lakes and from lakes to the atmosphere, exacerbating global warming. More work is needed to quantify and elucidate the processes that control methane fluxes from the active layer to predict how this flux might change in the future and to evaluate the regional and global contribution of active layer water associated methane inputs.

Carbon Isotope Composition of the Halophyte Disphyma clavellatum (Haw.) Chinnock (Aizoaceae), as Affected by Salinity

1983 ◽  
Vol 10 (5) ◽  
pp. 437 ◽  
Author(s):  
TF Neales ◽  
MS Fraser ◽  
Z Roksandic
Keyword(s):  
Acid Metabolism ◽  
Diffusion Processes ◽  
Isotope Composition ◽  
Titratable Acidity ◽  
Co2 Assimilation ◽  
Carbon Isotope Composition ◽  
Diurnal Pattern ◽  
Δ13c Values ◽  
Net Co2 Assimilation ◽  
Appreciable Increase

The δ13C values of the leaves of Disphyma clavellatum (Aizoaceae) systematically became less negative as the salinity in the root environment increased from 0 to 500 mol m-3 NaCl. The maximum shift of δ13C was from -26.1‰ to -20.0‰. Similar increases in salinity did not, however, result either in a change in the diurnal pattern of net CO2 assimilation or in an appreciable increase in the fluctuations of titratable acidity. It is suggested that salinity induced the observed shift in δ13C values, not by effecting change in the mode of carboxylation towards that of crassulacean acid metabolism (CAM), but by affecting the degree of limitation of CO2 assimilation by diffusion processes. It is concluded therefore that, in D. clavellatum, CAM is not induced by salinity, as it is in Mesembryanthemum crystallinum.

Stable isotope composition of subfossil Cerastoderma glaucum shells from the szczecin bay brackish deposits and its palaeogeographical implications (South Baltic Coast, Poland)

2012 ◽  
Vol 77 (2) ◽  
pp. 245-250 ◽  
Author(s):  
Ryszard K. Borówka ◽  
Wacław Strobel ◽  
Stanisław Hałas
Keyword(s):  
Environmental Conditions ◽  
Isotope Composition ◽  
Thermal Conditions ◽  
Stable Isotope Composition ◽  
Radiocarbon Dates ◽  
Szczecin Lagoon ◽  
Baltic Coast ◽  
Carbon And Oxygen Isotope ◽  
The Mean ◽  
Second Period

The environmental conditions of the Szczecin Bay, which existed prior to Szczecin Lagoon, have been reconstructed on the basis of the stable carbon and oxygen isotope (18O and 13C) analysis and radiocarbon dates obtained for subfossil shells of Cerastoderma (Cardium) glaucum. The shells in the collected core were well preserved in their life positions, representing a geochemical record of past temperature variation over the middle Holocene. Three major periods with different thermal conditions have been distinguished in the interval ~ 6000–4300 cal yr BP, when the important Littorina regional transgression took place. During the first period, 6000–5250 cal yr BP, water temperature decreased by 1.4°C, and then remained constant over the second period (5250–4750 cal yr BP). In contrast, during the third period (4750–4300 cal yr BP) both δ-values were highly variable and the mean summer temperature (March–November) increased by about 3.5°C. During first two periods, δ18O and δ13C were significantly correlated, indicating stability of the environmental conditions.

scholarly journals Influence of elevated carbon dioxide concentrations on methane emission and its associated soil microflora in rice ecosystem

2021 ◽  
Vol 13 (SI) ◽  
pp. 26-34
Author(s):  
S. K. Rajkishore ◽  
M. Maheswari ◽  
K. S. Subramanian ◽  
R. Prabhu ◽  
G. Vanitha
Keyword(s):  
Elevated Co2 ◽  
Methane Emission ◽  
Methane Flux ◽  
Methane Emissions ◽  
Soil Microflora ◽  
Mitigation Strategies ◽  
Emission Rates ◽  
Randomized Design ◽  
Dry Soil ◽  
Rice Ecosystem

The dynamics of methane emission and its associated soil microflora in rice ecosystem as a response to elevated CO2 concentrations were studied in open top chamber (OTC) conditions. The treatments consisted of three levels of CO2 (396, 550 and 750 µmol mol-1) and three levels of nitrogen (0, 150 and 200 kg ha-1) and replicated five times in a completely randomized design. The data showed that elevated [CO2] significantly (P ? 0.01) increased the DOC throughout the cropping period with the values ranging from 533 to 722 mg L-1 and 368 to 501 mg L-1 in C750 and Camb, respectively. Methane emission rates were monitored regularly during the experiment period and it was revealed that elevated [CO2] had increased the methane emissions regardless of stages of crop growth.  It was observed that methane emissions were significantly higher under [CO2] of 750 µmol mol-1 by 33 to 54 per cent over the ambient [CO2] of 396 µmol mol-1. Consistent with the observed increases in methane flux, the enumeration of methanogens showed a significant (P ? 0.01) increase under elevated [CO2] with the population ranging from 5.7 to 20.1 x 104 CFU g-1 of dry soil and 5.1 to 16.9 x 104 CFU g-1 of dry soil under C750 and Camb concentrations, respectively. Interestingly, even though higher methanotrophs population was recorded under elevated [CO2], it could not circumvent the methane emission. Overall, the results of OTC studies suggest that methane mitigation strategies need to be explored for the future high CO2 environments. 

scholarly journals Estimation of Livestock Methane Emissions in the Extensive Crop-Livestock Farming Areas of Bale Highland, Oromia, Ethiopia

2018 ◽  
Author(s):  
Girma Defar ◽  
Ashenafi Mengistu ◽  
Gebreyohannes Berhane
Keyword(s):  
Nutrient Balance ◽  
Methane Emissions ◽  
Emission Rates ◽  
Livestock Farming ◽  
Group Discussions ◽  
Demand And Supply ◽  
Livestock Sector ◽  
Multi Stage ◽  
Ipcc Guidelines ◽  
Increase Productivity

The study was conducted in the potential mixed farming areas of Bale highland to estimate livestock methane emissions. Using multi-stage purposive sampling, 156 households of the three wealth groups were selected based on their livelihood assets as described under methodology. Structured questionnaires, focus group discussions, key informants interview and field visits were the employed methods during the study. Feed nutrient balance was estimated based on the demand and supply while the livestock methane emissions were estimated according to the IPCC guidelines. Descriptive statistics and one-way ANOVA tests were used to analyze the data. Cattle were the dominant (84.25%) livestock owned by the households. The estimated enteric CH4 emission rate from mature cattle, growing cattle, sheep &gt;1 year, sheep &le; 1 year, horse and donkey were significantly (P&lt;0.001) higher for the better wealth group while mature cattle (69.78%) shared the highest rate. Though, higher emission rates credited to the large number of animals in the area, cattle stay crucial to the livelihoods of the households, beside the major sources of CH4. In conclusion, the estimated CH4 emissions should be focus areas of interventions. Therefore, proper husbandry and quality feed supply and promotion of farm level livestock technologies should be practiced wisely to increase productivity and protect the environment from emissions of the livestock sector.

Evaluation of oil and gas methane emissions in Romania using mobile measurements

2021 ◽  
Author(s):  
Ilona Velzeboer ◽  
Antonio Delre ◽  
Arjan Hensen ◽  
Pim van den Bulk ◽  
Charlotte Scheutz
Keyword(s):  
Central And Eastern Europe ◽  
Oil And Gas ◽  
Methane Emissions ◽  
Emission Rates ◽  
Methodological Issues ◽  
Site Specific ◽  
Heavy Tailed ◽  
Mobile Measurements ◽  
Mobile Measurement ◽  
Specific Evaluation

&lt;p&gt;Romania has been a pioneer country in oil and gas (O&amp;G) exploration in Europe and is the largest producer of O&amp;G in Central and Eastern Europe. However, many installations are old and production levels are decreasing. The ROMEO measurement campaign was carried out in Romania to evaluate methane emissions form onshore O&amp;G operations in Romania in 2019 (ROMEO, 2019). In this program, Technical University of Denmark (DTU) and TNO used mobile-van-based measurements in combination with tracer release to quantify emissions. A total set of 200 oil and gas wells, and facilities were evaluated and emissions were quantified. Methane emission rates ranged largely between about 0.02 and 38 g s&lt;sup&gt;-1&lt;/sup&gt;, following a &amp;#8220;heavy-tailed&amp;#8221; lognormal distribution. A small number of sites (5%) were responsible for 55% of the total emission. Decreasing emissions only from the few high-emitters would effectively decrease methane emissions from the investigated area. This shows the value of site-specific evaluation from the ground. In this presentation, the mobile measurement equipped vans will be shown and methodological issues will be addressed. Also the results in terms of the emission distribution will be presented. The outcome of this study can help the Romanian O&amp;G companies to set priorities in leak repair, which can then lead to a quick win in emission reduction.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;ROMEO, 2019. ROMEO - ROmanian Methane Emissions from Oil &amp; gas. URL http://romeo-memo2.wikidot.com/ (last accessed 13.01.21).&lt;/p&gt;

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