scholarly journals The role of termite CH<sub>4</sub> emissions on the ecosystem scale: a case study in the Amazon rainforest

2021 ◽  
Vol 18 (8) ◽  
pp. 2609-2625
Author(s):  
Hella van Asperen ◽  
João Rafael Alves-Oliveira ◽  
Thorsten Warneke ◽  
Bruce Forsberg ◽  
Alessandro Carioca de Araújo ◽  
...  
Keyword(s):  
Emission Factor ◽  
Field Studies ◽  
Amazon Rainforest ◽  
Ch4 Emission ◽  
Termite Mound ◽  
Flux Chamber ◽  
Termite Mounds ◽  
Ch4 Emissions ◽  
Current Emission

Abstract. The magnitude of termite methane (CH4) emissions is still an uncertain part of the global CH4 budget and current emission estimates are based on limited field studies. We present in situ CH4 emission measurements of termite mounds and termite mound subsamples performed in the Amazon rainforest. Emissions from five termite mounds of the species Neocapritermes brasiliensis were measured by use of a large flux chamber connected to a portable gas analyser measuring CH4 and CO2. In addition, the emissions of mound subsamples were measured, after which the termites were counted so that a termite CH4 and CO2 emission factor could be determined. Mound emissions were found to range between 17.0 and 34.8 nmol mound−1 s−1 for CH4 and between 1.1 and 13.0 µmol mound−1 s−1 for CO2. A termite emission factor of 0.35 µmol CH4 gtermite-1 h−1 was found, which is almost twice as high as the only other reported value for the Amazon. By combining mound emission measurements with the termite emission factor, colony sizes could be estimated, which were found to range between 55–125 thousand individuals. Estimates were similar to literature values, and we therefore propose that this method can be used as a quick non-intrusive method to estimate termite colony size in the field. The role of termites in the ecosystem's CH4 budget was evaluated by use of two approaches. Termite mound emission values were combined with local mound density numbers, leading to an estimate of 0.15–0.71 nmol CH4 m−2 s−1, on average, emitted by termite mounds. In addition, the termite CH4 emission factor from this study was combined with termite biomass numbers, resulting in an estimate of termite-emitted CH4 of ∼1.0 nmol m−2 s−1. Considering the relatively low net CH4 emissions previously measured at this ecosystem, we expect that termites play an important role in the CH4 budget of this terra firme ecosystem.

scholarly journals The role of termite CH<sub>4</sub> emissions on ecosystem scale: a case study in the Amazon rain forest

2020 ◽  
Author(s):  
Hella van Asperen ◽  
João Rafael Alves-Oliveira ◽  
Thorsten Warneke ◽  
Bruce Forsberg ◽  
Alessandro Carioca de Araujo ◽  
...  
Keyword(s):  
Rain Forest ◽  
Emission Factor ◽  
Field Studies ◽  
Ch4 Emission ◽  
Termite Mound ◽  
Flux Chamber ◽  
Termite Mounds ◽  
Ch4 Emissions ◽  
Amazon Rain Forest

Abstract. The magnitude of termite methane (CH4) emissions is still an uncertain part of the global CH4 budget and current emission estimates are based on limited field studies. We present in-situ CH4 emission measurements of termite mounds and termite mound sub samples, performed in the Amazon rain forest. Emissions of five termite mounds of the species Neocapritermes brasiliensis were measured by use of a large flux chamber connected to a portable gas analyser, measuring CH4 and CO2. In addition, the emission of mound sub samples was measured, after which termites were counted, so that a termite CH4 and CO2 emission factor could be determined. Mound emissions were found to range between 17.0–34.8 nmol mound−1 s−1 for CH4 and between 1.6–13.5 μmol mound−1 s−1 for CO2. A termite emission factor of 0.32 μmol CH4 gtermite−1 h−1 was found, which is twice as high as the only other reported average value for the Amazon. By combining mound emission measurements with the termite emission factor, colony sizes could be estimated, which were found to range between 50–120 thousand individuals. Estimates were similar to literature values, and we therefore propose that this method can be used as a quick non-intrusive method to estimate termite colony size in the field. The role of termites in the ecosystems CH4 budget was evaluated by use of two approaches. Termite mound emission values were combined with local termite mound density numbers, leading to an estimate of 0.15–0.71 nmol CH4 m−2 s−1 on average emitted by termite mounds. In addition, the termite CH4 emission factor from this study was combined with termite density numbers, resulting in an estimate of termite emitted CH4 of ~1.0 nmol m−2 s−1. Considering the relatively low net CH4 emissions previously measured at this ecosystem, we expect that termites play an important role in the CH4 budget of this Terra Firme ecosystem.

scholarly journals A compact and stable eddy covariance set-up for methane measurements using off-axis integrated cavity output spectroscopy

2007 ◽  
Vol 7 (4) ◽  
pp. 11587-11619 ◽  
Author(s):  
D. M. D. Hendriks ◽  
A. J. Dolman ◽  
M. K. van de Molen ◽  
J. van Huissteden
Keyword(s):  
Eddy Covariance ◽  
Measurement Techniques ◽  
Power Spectra ◽  
Statistical Testing ◽  
Ch4 Emission ◽  
Flux Chamber ◽  
Night Time ◽  
Ch4 Emissions ◽  
Cavity Output ◽  
Set Up

Abstract. A DLT-100 Fast Methane Analyser (FMA) from Los Gatos Research (LGR) Ltd. is assessed for its applicability in a closed path eddy covariance field set-up. The FMA uses off-axis integrated cavity output spectroscopy (ICOS) combined with a highly specific narrow band laser for the detection of CH4 and strongly reflective mirrors to obtain a laser path length of 2×10³ to 20×10³ m. Statistical testing, a calibration experiment and comparison with high tower data showed high precision and very good stability of the instrument. The measurement cell response time was tested to be 0.10 s. In the field set-up, the FMA is attached to a scroll pump and combined with a Gill Windmaster Pro 3 axis Ultrasonic Anemometer and a Licor 7500 open path infrared gas analyzer. The power-spectra and co-spectra of the instrument are satisfactory for 10 Hz sampling rates. The correspondence with CH4 flux chamber measurements is good and the observed CH4 emissions are comparable with (eddy covariance) CH4 measurements in other peat areas. CH4 emissions are rather variable over time and show a diurnal pattern. The average CH4 emission is 50±12.5 nmol m−2 s−1, while the typical maximum CH4 emission is 120±30 nmol m−2 s−1 (during daytime) and the typical minimum flux is –20±2.5 nmol m−2 s−1 (uptake, during night time). Additionally, the set-up was tested for three measurement techniques with slower measurement rates, which could be used in the future to make the scroll pump superfluous and save energy. Both disjunct eddy covariance as well as slow 1 Hz eddy covariance showed results very similar to normal 10 Hz eddy covariance. Relaxed eddy accumulation (REA) only matched with normal 10 Hz eddy covariance over an averaging period of at least several weeks.

scholarly journals Methane Emission Factor in Italian Mediterranean Buffalo According to Production Management

2020 ◽  
pp. 11-19
Author(s):  
Nunzia Ciriello ◽  
Lorenza Albano ◽  
Giuseppe Auriemma ◽  
Raffaele Palomba ◽  
Giuseppe Grazioli ◽  
...  
Keyword(s):  
Emission Factor ◽  
Production Management ◽  
Animal Origin ◽  
Tier 2 ◽  
Ch4 Emission ◽  
Ch4 Emissions ◽  
Environmental Consequences ◽  
Gross Energy ◽  
Emissions Factor ◽  
The Stability

The environmental impact of greenhouse gases caused by livestock farms plays a fundamental role due to the implications and environmental consequences that livestock practices entail, affecting the stability of the entire ecosystem connected to them, especially as a consequence of the growing demand for products of animal origin. The aim of this work was to quantify the CH4 emissions factor in lactating buffaloes by comparing four different types of livestock management: family, conventional, organic and sustainable. To determine the enteric CH4 emissions from buffalo, information about animal production and farm management was analyzed, and the CH4 emission factor was calculated using the IPCC Tier 2 model. ANOVA was conducted to evaluate significant differences between the farms; Pearson’s correlation was used to evaluate the relationship between parameters. In a conventional farm, the CH4 emission factor for buffalo was 27.69 kg CH4/head/yr compared to 22.77 and 21.61 kg CH4/head/yr respectively for organic and family-run. These data may also depend on the higher protein and fiber content in the administered unifeed. Furthermore, the ratio of enteric emissions factor of CH4 / gross energy intake ratio reflected these data (12.04 vs 10.93 vs 10.16 vs 10.65 for conventional, organic, sustainable, and family-run farms, respectively).

scholarly journals Termite mounds contain distinct methanotroph communities that are kinetically adapted to elevated methane concentrations

2019 ◽  
Author(s):  
Eleonora Chiri ◽  
Chris Greening ◽  
Stefan K. Arndt ◽  
Philipp A. Nauer
Keyword(s):  
Reaction Rates ◽  
Termite Mound ◽  
Predominant Role ◽  
Termite Mounds ◽  
Upland Soil ◽  
Methane Oxidizing Bacteria ◽  
Kinetics Of ◽  
Micromolar Range

AbstractTermite mounds have recently been confirmed to mitigate approximately half of termite methane (CH4) emissions, but the aerobic methane-oxidizing bacteria (methanotrophs) responsible for this consumption have not been resolved. Here we describe the abundance, composition, and kinetics of the methanotroph communities in the mounds of three distinct termite species. We show that methanotrophs are rare members of the termite mound biosphere and have a comparable abundance, but distinct composition, to those of adjoining soil samples. Across all mounds, the most abundant and prevalent particulate methane monooxygenase sequences detected were affiliated with Upland Soil Cluster α (USCα), with sequences homologous to Methylocystis and Tropical Upland Soil Cluster also detected. The Michaelis-Menten kinetics of CH4 oxidation in mounds were estimated from in situ reaction rates. The apparent CH4 affinities of the communities were in the low micromolar range, which is one to two orders of magnitude higher than those of upland soils, but significantly lower than those measured in soils with a large CH4 source such as landfill-cover soils. The rate constant of CH4 oxidation, as well as the porosity of the mound material, were significantly positively correlated with the abundance of methanotroph communities of termite mounds. We conclude that termite-derived CH4 emissions have selected for unique methanotroph communities that are kinetically adapted to elevated CH4 concentrations. However, factors other than substrate concentration appear to limit methanotroph abundance and hence these bacteria only partially mitigate termite-derived CH4 emissions. Our results also highlight the predominant role of USCα in an environment with elevated CH4 concentrations and suggest a higher functional diversity within this group than previously recognised.

Methane emissions from young and mature dairy cattle

2016 ◽  
Vol 56 (11) ◽  
pp. 1897 ◽  
Author(s):  
C. A. Ramírez-Restrepo ◽  
H. Clark ◽  
S. Muetzel
Keyword(s):  
New Zealand ◽  
Emission Factor ◽  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Dry Matter Intake ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Age Related ◽  
The Mean

Daily methane (CH4) emissions (g) and CH4 yield (g/kg dry matter intake) were measured from 10 dairy heifers (<1 year old) and nine rumen-fistulated cows (>6 years old) fed ryegrass (Lolium perenne) chaffage indoors. The CH4 emissions were estimated using the sulfur hexafluoride tracer technique in four ~5-day periods beginning in June 2008 and repeated 4, 6 and 7 months later. Respiratory chambers were used in four ~13-day periods beginning in November 2008 and repeated 2, 5 and 6 months later. Third and fourth sulfur hexafluoride tracer periods overlapped with the first and second chamber measurement periods, respectively. Averaged over the four measurement periods the CH4 yields determined using both techniques were similar for heifers and cows. The mean CH4 yield estimated by the sulfur hexafluoride tracer technique was 25.3 ± 0.52 for heifers and 24.1 ± 0.55 for mature cows, whereas the mean CH4 yield measured in respiratory chambers was 23.7 ± 0.66 for heifers and 23.6 ± 0.66 for mature cows. Averaged over the eight measurements irrespective of technique, CH4 yields for heifers (24.5 ± 0.42) and cows (23.8 ± 0.43) were similar. There was also no difference between CH4 methods for assessing CH4 yield during the overlapping measurement periods. It was concluded that no consistent differences in CH4 yield existed between heifers and mature cows. Therefore, we do not recommend adoption of an age-related emission factor for cattle in the national inventory calculations for New Zealand.

Carbon mineralization in semi-arid northeastern Australia: the role of termites

1987 ◽  
Vol 3 (3) ◽  
pp. 255-263 ◽  
Author(s):  
John A. Holt
Keyword(s):  
Regression Analysis ◽  
Carbon Flux ◽  
Microbial Population ◽  
Carbon Mineralization ◽  
Termite Mounds ◽  
Interaction Term ◽  
Temperature Interaction ◽  
Soil Carbon Mineralization ◽  
Semi Arid

ABSTRACTThe contribution of a population of mound building, detritivorous termites (Amitermes laurensis (Mjöberg)) to nett carbon mineralization in an Australian tropical semi-arid woodland has been examined. Carbon mineralization rates were estimated by measuring daily CO2 flux from five termite mounds at monthly intervals for 12 months. Carbon flux from the mounds was found to be due to microbial activity as well as termite activity. It is conservatively estimated that the association of A. laurensis and the microbial population present in their mounds is responsible for between 4%–10% of carbon mineralized in this ecosystem, and the contribution of all termites together (mound builders and subterranean) may account for up to 20% of carbon mineralized. Regression analysis showed that rates of carbon mineralization in termite mounds were significantly related to mound moisture and mound temperature. Soil moisture was the most important factor in soil carbon mineralization, with temperature and a moisture X temperature interaction term also exerting significant affects.

A comment on scaling methane emissions from vegetation and grazing ruminants in New Zealand

2006 ◽  
Vol 33 (7) ◽  
pp. 613 ◽  
Author(s):  
Francis M. Kelliher ◽  
Harry Clark ◽  
Zheng Li ◽  
Paul C. D. Newton ◽  
Anthony J. Parsons ◽  
...  
Keyword(s):  
New Zealand ◽  
Standard Deviation ◽  
Forest Canopy ◽  
Emission Rate ◽  
Oxidative Capacity ◽  
Emission Rates ◽  
Ch4 Emission ◽  
Ch4 Emissions ◽  
Grazed Pasture ◽  
Indigenous Forest

Keppler et al. (2006, Nature 439, 187–191) showed that plants produce methane (CH4) in aerobic environments, leading Lowe (2006, Nature 439, 148–149) to postulate that in countries such as New Zealand, where grazed pastures have replaced forests, the forests could have produced as much CH4 as the ruminants currently grazing these areas. Estimating CH4 emissions from up to 85 million ruminants in New Zealand is challenging and, for completeness, the capacity of forest and pastoral soils to oxidise CH4 should be included. On average, the CH4 emission rate of grazing ruminants is estimated to be 9.6 ± 2.6 g m–2 year–1 (±standard deviation), six times the corresponding estimate for an indigenous forest canopy (1.6 ± 1.1 g m–2 year–1). The forest’s soil is estimated to oxidise 0.9 ± 0.2 g m–2 year–1 more CH4 than representative soils beneath grazed pasture. Taking into account plant and animal sources and the soil’s oxidative capacity, the net CH4 emission rates of forest and grazed ecosystems are 0.6 ± 1.1 and 9.8 ± 2.6 g m–2 year–1, respectively.

scholarly journals Prediction of photosynthesis in Scots pine ecosystems across Europe by a needle-level theory

2018 ◽  
Vol 18 (18) ◽  
pp. 13321-13328
Author(s):  
Pertti Hari ◽  
Steffen Noe ◽  
Sigrid Dengel ◽  
Jan Elbers ◽  
Bert Gielen ◽  
...  
Keyword(s):  
Scots Pine ◽  
Boreal Forests ◽  
Co2 Flux ◽  
Field Studies ◽  
Co2 Assimilation ◽  
Co2 Fluxes ◽  
New Era ◽  
Evergreen Forests ◽  
Transition Times

Abstract. Photosynthesis provides carbon for the synthesis of macromolecules to construct cells during growth. This is the basis for the key role of photosynthesis in the carbon dynamics of ecosystems and in the biogenic CO2 assimilation. The development of eddy-covariance (EC) measurements for ecosystem CO2 fluxes started a new era in the field studies of photosynthesis. However, the interpretation of the very variable CO2 fluxes in evergreen forests has been problematic especially in transition times such as the spring and autumn. We apply two theoretical needle-level equations that connect the variation in the light intensity, stomatal action and the annual metabolic cycle of photosynthesis. We then use these equations to predict the photosynthetic CO2 flux in five Scots pine stands located from the northern timberline to Central Europe. Our result has strong implications for our conceptual understanding of the effects of the global change on the processes in boreal forests, especially of the changes in the metabolic annual cycle of photosynthesis.

scholarly journals Soil moisture control over autumn season methane flux, Arctic Coastal Plain of Alaska

2012 ◽  
Vol 9 (4) ◽  
pp. 1423-1440 ◽  
Author(s):  
C. S. Sturtevant ◽  
W. C. Oechel ◽  
D. Zona ◽  
Y. Kim ◽  
C. E. Emerson
Keyword(s):  
Large Scale ◽  
Winter Season ◽  
Methane Flux ◽  
Soil Freezing ◽  
The Arctic ◽  
Freezing Process ◽  
Unfrozen Water ◽  
Ch4 Emission ◽  
Ch4 Emissions ◽  
Autumn Season

Abstract. Accurate estimates of annual budgets of methane (CH4) efflux in arctic regions are severely constrained by the paucity of non-summer measurements. Moreover, the incomplete understanding of the ecosystem-level sensitivity of CH4 emissions to changes in tundra moisture makes prediction of future CH4 release from the Arctic extremely difficult. This study addresses some of these research gaps by presenting an analysis of eddy covariance and chamber measurements of CH4 efflux and supporting environmental variables during the autumn season and associated beginning of soil freeze-up at our large-scale water manipulation site near Barrow, Alaska (the Biocomplexity Experiment). We found that the autumn season CH4 emission is significant (accounting for 21–25% of the average growing season emission), and that this emission is mostly controlled by the fraction of inundated landscape, atmospheric turbulence, and the decline in unfrozen water during the period of soil freezing. Drainage decreased autumn CH4 emission by a factor of 2.4 compared to our flooded treatment. Flooding slowed the soil freezing process which has implications for extending elevated CH4 emissions longer into the winter season.

scholarly journals Analysis of the Role of Parent’s Lifestyle by the Authoritative Parenting Style in Girls of Grade Three of High School in Zahedan: A Cross Sectional Study

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
Azam Akbarizadeh ◽  
Khadijeh Khoeini
Keyword(s):  
High School ◽  
Parenting Style ◽  
Field Studies ◽  
Cross Sectional Study ◽  
Sample Volume ◽  
Authoritative Parenting ◽  
Cross Sectional ◽  
Authoritative Parenting Style ◽  
Political Economic

Background: Every family applies a certain educational style in individual and social education of their children. These styles are influenced by many factors, including cultural, social, political, economic styles, etc. The parents’ lifestyle is one of styles that have a great impact on parenting. In this regard, the goal of present research is analysis of the role of parent’s lifestyle by the authoritative parenting style. Methods: The research method is descriptive-analytic based on library, documentary and field studies. Statistical Society of the research is all intelligent girls of grade three in high school of Zahedan during 2015-2016 school years. Cochran formula has been used to determine the sample volume which 311 people were estimated. Spearman statistical methods and multiple regressions have been used to analyze the data. Results: The results of the research show that the lifestyle and its components have a significant correlation with authoritative parenting style and can predict it. Conclusion: The findings of this study, while having applicable aspects in this domain, can be helpful in planning supplementary remedial procedures.

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