Greenhouse Gas Production Research Articles

Greenhouse gas emissions resulting from conversion of peat swamp forest to oil palm plantation

Conversion of tropical peat swamp forest to drainage-based agriculture alters greenhouse gas (GHG) production, but the magnitude of these changes remains highly uncertain. Current emissions factors for oil palm grown on drained peat do not account for temporal variation over the plantation cycle and only consider CO2 emissions. Here, we present direct measurements of GHGs emitted during the conversion from peat swamp forest to oil palm plantation, accounting for CH4 and N2O as well as CO2. Our results demonstrate that emissions factors for converted peat swamp forest is in the range 70–117 t CO2 eq ha−1 yr−1 (95% confidence interval, CI), with CO2 and N2O responsible for ca. 60 and ca. 40% of this value, respectively. These GHG emissions suggest that conversion of Southeast Asian peat swamp forest is contributing between 16.6 and 27.9% (95% CI) of combined total national GHG emissions from Malaysia and Indonesia or 0.44 and 0.74% (95% CI) of annual global emissions.

Characterization of Bacterial and Fungal Communities Reveals Novel Consortia in Tropical Oligotrophic Peatlands.

Despite their importance for global biogeochemical cycles and carbon sequestration, the microbiome of tropical peatlands remains under-determined. Microbial interactions within peatlands can regulate greenhouse gas production, organic matter turnover, and nutrient cycling. Here we analyze bacterial and fungal communities along a steep P gradient in a tropical peat dome and investigate community level traits and network analyses to better understand the composition and potential interactions of microorganisms in these understudied systems and their relationship to peatland biogeochemistry. We found that both bacterial and fungal community compositions were significantly different along the P gradient, and that the low-P bog plain was characterized by distinct fungal and bacterial families. At low P, the dominant fungal families were cosmopolitan parasites and endophytes, including Clavicipitaceae (19%) in shallow soils (0-4cm), Hypocreaceae (50%) in intermediate-depth soils (4-8cm), and Chaetothyriaceae (45%) in deep soils (24-30cm). In contrast, high- and intermediate-P sites were dominated by saprotrophic families at all depths. Bacterial communities were consistently dominated by the acidophilic Koribacteraceae family, with the exception of the low-P bog site, which was dominated by Acetobacteraceae (19%) and Syntrophaceae (11%). These two families, as well as Rhodospirillaceae, Syntrophobacteraceae, Syntrophorhabdaceae, Spirochaetaceae, and Methylococcaceae appeared within low-P bacterial networks, suggesting the presence of a syntrophic-methanogenic consortium in these soils. Further investigation into the active microbial communities at these sites, when paired with CH4 and CO2 gas exchange, and the quantification of metabolic intermediates will validate these potential interactions and provide insight into microbially driven biogeochemical cycling within these globally important tropical peatlands.

The environmental benefits of improving packaging waste collection in Europe

Collecting more waste via source separation waste collection systems is an essential part of increasing resource efficiency, achieving European recycling targets and closing the loop in a circular economy. Huge variation in the capture rates of packaging waste (paper, plastic, metal, composite material and glass) exists in Europe, even between municipalities with similar characteristics, which suggests there is great potential to increase the amount of these materials that can be recovered. In order to assess the environmental impacts linked to higher collection rates, a Life Cycle Assessment model was built that considers the reduced need for virgin materials as the system’s loops are closed. An extra 18 million tonnes of waste could be collected annually in Europe if best practice collection strategies were to be deployed, leading to a 13% reduction in greenhouse gas production associated with the packaging and packaging waste. Although high collection performance is crucial for efficient resource use, improving source separation waste collection systems alone will not be enough to achieve recycling targets; material losses must be reduced throughout the value chain, i.e. at the sorting and recycling stages. By evaluating the circularity and environmental implications of current waste management, it can be shown at which points in the system the most improvement needs to be made for each material in order to facilitate the transition towards a circular economy.

Influence of Dye Sensitizers on Charge Dynamics in SnO2 Nanoparticles Probed with THz Spectroscopy

Using dye-sensitized water-splitting photoelectrochemical cells is a promising way to satisfy an increasing demand for energy without significant production of greenhouse gases. These cells commonl...

Development of life cycle assessment of an emerging technology at research and development stage: A case study on single-wall carbon nanotube produced by super growth method

The frontier of lifecycle assessment (LCA) case studies has moved from understanding conventional technologies to analyzing emerging technologies at the research and development (R&D) phase. One new challenge in LCA that aims to deal with this phenomenon is the development of methods to estimate the environmental impacts of emerging technologies in the R&D phase while considering manufacturing at scale. This study proposes a simple and feasible method that allows LCA practitioners to consider scaling effects of energy consumption during production in a case study of the super growth method of producing carbon nanotubes. In this case, the greenhouse gas (GHG) impact of producing 1 kg of carbon nanotubes decreases from 47.05 t-CO2eq to 21.33 t-CO2eq by scaling up the process. Although the total GHG impacts at the commercial scale estimated from the lab scale inventory are similar to those estimated from the pilot scale inventory, the share of GHG emissions of materials are different because of a change in substrate and a change from batch processing to continuous processing. Carbon nanotube production by the super growth method is competitive with those made by other processes from the viewpoint of GHG impact and product quality.

Impact of inulin and yeast containing synbiotic on calves' productivity and greenhouse gas production.

Aim:The research aimed to determine the impact of synbiotic: 6 g of prebiotic inulin and 5 g of probiotic Saccharomyces cerevisiae strain 1026 on calves’ productivity and greenhouse gas (GHG) production.Materials and Methods:The research was conducted with 10 Holstein Friesian and Red Holstein (Bos taurus L.) crossbreed calves of mean age 33±6 days and initial body weight 73.4±12.75 kg. We added the synbiotic into the diet of five dairy crossbreed calves (SynG) and five calves in control group (CoG) received non-supplemented diet. The duration of the experiment was 56 days. The weight of calves and amount of methane (CH4) and carbon dioxide (CO2) in the rumen were determined on day 1, 28, and 56. On day 56, three calves from each group were slaughtered. Meat samples were assessed for some indicators of meat quality. The main methanogens were detected in the rumen fluid and feces.Results:The weight gain during the whole experiment period of 56 days was higher in the SynG (62.6±13.75 kg) compared to CoG (36.8±7.98 kg) calves (p<0.01). There were no significant differences in the levels of protein (%), fat (unsaturated and saturated – %), and cholesterol (mg/100 g) in meat samples from both groups. At the end of the experiment, the amount of CH4 in calves’ rumen in CoG was higher (Me=792.06 mg/m3, interquartile range [IQR] 755.06-873.59) compared to SynG (Me=675.41 mg/m3, IQR 653.46-700.50) group (p<0.01). The values for CO2 were also increased in CoG (Me=4251.28 mg/m3, IQR 4045.58-4426.25) compared to SynG (Me=3266.06 mg/m3, IQR 1358.98-4584.91) group (p=0.001). There were no significant differences in the calves’ weight and certain methanogen species in rumen liquid and feces on the 56th day of the experiment. Significantly higher results in the parameter total prokaryotes (V3) (bacteria+archaea) in rumen fluid were in SynG, whereas significantly higher results in the parameter total methanogens Met630/803 in rumen fluid were in CoG, p<0.05.Conclusion:The main results showed that the synbiotic can increase the daily weight gain in calves and decrease the amount of GHG in rumen but does not impact different methanogen species in rumen liquid and feces and meat protein, fat, and cholesterol levels.

Visualizing the distribution of black carbon's electron storage capacity using silver

We have developed a method that combines chemical reduction, silver tagging, and electron microscopy (EM) for visualizing the electron storage capacity (ESC) of black carbon (BC). ESC is a BC's capacity to store and reversibly exchange electrons with abiotic and microbial agents, processes that are relevant to biochemistry, greenhouse gas production, contaminant fate, and remediation. In addition to the amount of electrons BC can store, the locations and spatial distribution of ESC on and inside biochar are critical for understanding the bioaccessibility of ESC and the kinetics of redox reactions involving BC. To locate the ESC in a BC particle, we fully reduced a BC, removed excess reductant, and applied silver ion (Ag+) as a tagging agent that diffused into BC to react with functional groups where electrons were stored (i.e., ESC) to form silver nanoparticles (nAg). The nAg deposited on and inside BC were then imaged using multiple EM techniques to visualize the locations and distribution of the ESC. The method is a new and potentially useful tool for investigating ESC production and for elucidating BC-mediated redox transformation.•Novel method to probe and assess the distribution of ESC on/within BC.•Visual confirmation of significant ESC both on the surface and in the interior of BC.•A new method to incorporate silver or other redox-sensitive elements into a carbon medium.

The Energy Sector and Socio-Ecological Transformation: Europa in the Global Context

Global climate change politics is moving ahead, while policy effectiveness lags behind. The overwhelmingly capitalogenic climate change (Moore 2015; Street 2016) necessitates a global ecosocialist transformation (Yurchenko 2020). In many ways, the EU is a champion of green politics and policy, although its decarbonisation framework has been criticised for being ill-conceived, ill-prescribed and insufficient, especially in the context of internationalised production and consumption of Green House Gas (GHG) emissions. A radically socio-ecological transformation of ’global’ Europe, and the decarbonisation of the EU energy sector as a complex socio-ecological system are needed (SES; Ostrom 2012). Focusing on some 20 years of EU energy market reforms, I argue that decarbonisation aims are jeopardised without (1) public national, local and collective forms of ownership and financing of energy (generation and supply) as a common pool resource (CPR)/commons, and (2) a polycentric mode of governance (Ostrom 2010).

Evaluation of Photovoltaic System Performance: A Case Study in East Azerbaijan, Iran

Solar energy is a feasible and efficient way to reduce environmental pollution which, in turn, can decrease the production of greenhouse gases. Iran with over 300 sunny days has a high potential for producing energy, including electricity through photovoltaic (PV) systems. Regarding this fact that Iran has the enormous resources of fossil fuels such as oil and gas, the government tends to expand its energy production by renewable systems, including photovoltaics. This paper is to evaluate the efficiency of photovoltaic system in one of the major provinces of Iran. In this study, a 4.8 kW photovoltaic power station in East Azerbaijan province was investigated. First, a simulation-analysis is carried out. Then the verification of the study is done using extracted experimental data. According to the results, the photovoltaic power plant generates 8334 kWh annually. Finally, the station is economically investigated. This economic analysis is carried out in accordance with the existing tariffs and policies in Iran.

Sustainability assessment in construction industry supply network: a review

Construction industry plays important role to support human welfare by providing access for living and moving. Developed countries are characterized by having good infrastructures such as roads, bridges, office towers, residential buildings, seaports and airports. To have these infrastructures, massive construction projects must be implemented by construction industry. This industry consists of several activities such as extracting raw materials, manufacturing construction’s materials, construction projects, infrastructure operational, and after operational activities that are run by different organizations and companies. These organizations and companies configure construction industry supply networks. Despite of the positive impact of these supply networks in improving human and product mobility, these supply networks also responsible for significant negative impacts such as consuming high energy and material resources, producing greenhouse gas emission and creating waste. To monitor and maintain these negative impacts, a sustainability assessment process is required. This paper aims to review sustainability assessment process in construction industry supply networks. It was found that different indicators are required for assessing activities in each stage of supply networks.

Research Progress Regarding Transition Metal-Catalyzed Carbonylations with CO&lt;sub&gt;2&lt;/sub&gt;/H&lt;sub&gt;2&lt;/sub&gt;

Ever-increasing energy demands due to rapid industrialization and urban population growth have drastically reduced petroleum reserves and increased greenhouse-gas production, and the latter has consequently contributed to climate change and environmental damage. Therefore, it highly desirable to produce fuels and chemicals from non-petroleum feedstocks and to reduce the atmospheric concentrations of greenhouse gases. One solution has involved using carbon dioxide (CO2), a main greenhouse gas, as a C1 feedstock for producing industrial fuels and chemicals. However, this requires high energy input from reductants or reactants with relatively high free energy (e.g., H-2 gas) because CO2 is a highly oxidized, thermodynamically stable form of carbon. H-2 can be generated through water photolysis, making it an ideal reductant for hydrogenating CO2 to CO. In situ generation of CO such as this has been developed for various carbonylation reactions that produce high value-added chemicals and avoid deriving CO from fossil fuels. This is beneficial because CO is toxic, and when extracted from fossil fuels it requires tedious separation and transportation. This combination of CO2 and H-2 allows for functional molecules to be synthesized as entries into the chemical industry value chain and would generate a carbon footprint much lower than that of conventional petrochemical pathways. Based on this, CO2/H-2 carbonylations using homogeneous transition metal-based catalysts have attracted increasing attention. Through this process, alkenes have been converted to alcohols, carboxylic acids, amines, and aldehydes. Heterogeneous catalysis has also provided an innovative approach for the carbonylation of alkenes with CO2/H-2. Based on these alkene carbonylations, the scope of CO2/H-2 carbonylations has been expanded to include aryl halides, methanol, and methanol derivatives, which give the corresponding aryl aldehyde, acetic acid, and ethanol products. These carbonylations revealed indirect CO2-HCOOH-CO pathways and direct CO2 insertion pathways. The use of this process is ever-increasing and has expanded the scope of CO2 utilization to produce novel, high value-added or bulk chemicals, and has promoted sustainable chemistry. This review summarizes the recent advances in transition-metal-catalyzed carbonylations with CO2/H-2 and discusses the perspectives and challenges of further research.

Integrated surface and groundwater resources allocation simulation to evaluate effective factors on greenhouse gases production

Abstract The water resources management in the developing countries calls for the adoption of the systems approach in accordance with the regulations of the Kyoto Protocol (1997) clean development mechanism. In this research, integrated modeling was carried out under multipurpose scenarios using six reservoir dams with a capacity of 10,500 MW (megawatt) to reduce the greenhouse gas productions. The simulation and development of the integrated water evaluation and planning (WEAP) model within a 50-year period, along with the development of the MODFLOW model in alluvial deposits that interacts with the river, allowed for the analysis of the integrated water resources management system of the Great Karun basin. Several scenarios were implemented following the calibration and validation of the linked integrated model. The components covered by these scenarios included the satisfaction of the in-basin and off-basin demands, the effect of the integrated consumption of water resources, and the effect of increased efficiency of irrigation networks with maximum clean hydroelectricity production and minimum aquifer level decline under drought-induced water shortage conditions. The second scenario, which generates 15,282 GWh (gigawatt-hour) of power, not only optimally meets the future and environmental demands as the best operating scenario but also minimizes the emission of the greenhouse gases in the basin.

Long-term fertilizer management in NERICA cultivated upland affects on soil bio-chemical properties

ABSTRACT This study aims to characterize soil chemical properties and microbial biomass, greenhouse gas production, and organic matter dynamics in upland rice field as affected by the long-term fertilizer managements in Uganda. Soil total C (TC) and N (TN) contents were in the relatively smaller range under different fertilizer treatments, even after 20 crop seasons. However, available phosphate contents showed positive correlation with average yield of upland rice. Incubation experiments were conducted under aerobic or under flooding conditions to measure CO2, methane, and nitrous oxide productions. After the incubation, soil samples were extracted to quantify nitrification rate for aerobic condition and ammonification rate for flooding condition. Soil microbial biomass carbon (MBC) and nitrogen were measured. Stable isotope ratio of 13C and 15N were also determined for the soil samples. CO2 production potential under aerobic condition was higher than the flooding condition. The qCO2 (CO2/MBC) in the treatment applied with compost tended to be higher than the other treatments. Positive correlation between nitrous oxide production and nitrification was found. The delta 13C values of the soil samples indicated that the effect of C4 plants before rice cultivation still remained, while the contribution of biological N2 fixation was little according to delta 15N values. These results indicate that soil microbial biomass in upland rice field of the long-term fertilizer experiment in Uganda was characterized with higher qCO2. Greenhouse gas production was affected by fertilizer management, while soil organic C before the long-term experiment still remained in the experiment.

Thermal Insulation and R- Value Analysis for Wall Insulated with PCM

At present all the Indians are depending on nonrenewable energy for electricity for house needs. The nature is exploited by this Nonrenewable energy, it scarce fossil fuel source and destroys mother nature. The Air conditioners are devices which is used to reduce the indoor temperature and increases the comfort level. This devices produces greenhouse gases and increasing day by day, which obviously increases Global warming. The medical experts are insisting not to use and expose more to Air conditioners as it stimulates health issues. In order to overcome these problems, an alternate solution to be found and implementing a new method of construction and materials. This is the new attempt by executing a system of cavity wall in a framed structure with circulation of liquid and air in the cavity by embedding the fluted sheets in the exterior walls of the building. The advantage of this system is reducing the thermal conductivity from outside and to reduce the consumption of electricity for air conditioning devices and increases the sustainability of natural sources. Finally the constant-R (Thermal resistivity) value is arrived for composite materials with water.

Reduced mineral fertilization coupled with straw return in field mesocosm vegetable cultivation helps to coordinate greenhouse gas emissions and vegetable production

The partial substitution of mineral fertilizers with straw in agricultural soils could help to control soil acidification, reduce the risk of eutrophication from agricultural runoff, and increase the utilization efficiency of straw. However, the effects of such coupled practices on greenhouse gas (GHG) emissions and production yields in vegetable fields are not clear. Therefore, the objectives of this study were to (1) understand methane (CH4) and nitrous oxide (N2O) emissions in response to the same amounts of straw return with varied amounts of mineral fertilizers, and (2) to identify a solution which could better coordinate GHG emissions, vegetable production yield, and the utilization of agricultural straw following disposal. We conducted four-season (lettuce-cabbage-chili-lettuce) vegetable cultivation for 1 year using a control treatment (CT), mineral fertilization only (F), and four mineral fertilization treatments plus maize straw (FS, 0.7FS, 0.6FS, and 0.5FS). We then examined seasonal changes of CH4 and N2O fluxes, CH4 and N2O cumulative emissions, soil organic carbon (SOC), nitrate nitrogen (NO3−-N) and ammonium nitrogen (NH4+-N) content, vegetable yields, global warming potential (GWP), greenhouse gas intensity (GHGI), and N2O emission factors (EF). Compared to the F treatment, the application of maize straw increased the N2O flux significantly in the FS, 0.7FS, 0.6FS, and 0.5FS treatments. In treatments with added straw, the reduced application of mineral fertilizer led to a reduction in the cumulative N2O emission; this was due to the reduced content of NO3−-N content. The lowest CH4 flux and cumulative CH4 emission were observed in the 0.7FS treatment; this may be due to a form of competitive oxidation between CH4 and NH4+-N from urea. Furthermore, the application of maize straw in combination with a full dose of mineral fertilizers led to high GWP and GHGI values, which showed increases of 88.7% and 78.8%, respectively, in comparison with the F treatment. When taking SOC storage variations into account, which were caused by straw decomposition during cultivation, we identified a negative net GHGI (NGHGI) value (− 0.0448 kg CO2-eq kg−1 yield) in the 0.7FS treatment. This indicated that the NGHGI had decreased by 116.2% relative to the F treatment when based on similar vegetable yields. Straw combined with 70% mineral fertilizer led to better GHG emissions and vegetable yield when taking into account the carbon sequestration and decomposition caused by the addition of straw.

Ways of reducing carbon dioxide from road transport

Climate change and the associated global warming affect all of us. These changes cause the melting of the glaciers and consequently the increase in sea and ocean levels. This phenomenon threatens the existence of some of the island states. The warming casing all this was brought on by the economic activity of humans, with the greatest responsibility being attributed to the ever-increasing production of greenhouse gases. Transport generates large portion of these gases. When means of transport are in motion, they are affected by certain driving resistances which try to keep vehicle from moving. In order to overcome them, it is necessary to produce certain useful work equivalent to the measurement of driving resistances. An internal combustion motor is the most frequent source of such energy. It generates energy by oxygenating hydrocarbon fuels, and in addition to the useful work, it produces also unfavourable emission. The amount of such emissions equals to the amount of burnt fuel. Thus, levels of emissions can drop by reducing fuel consumption. The most commonly mentioned gas is the CO2. Reduction of CO2 production is essential to affect the high level of CO2. The article focuses on the possibilities of reducing CO2 from road transport. The possibilities of reducing CO2 from road transport are quantified in the form of mathematical model calculations.

Greenhouse gas cycling by the plastisphere: The sleeper issue of plastic pollution.

Plastic is an allochthonous material to marine ecosystems but is rapidly colonized by marine microbial communities, with an as yet unclear contribution to biogeochemical cycles. In this study, we investigated the influence of an active microbial community grown on microplastic particles (the plastisphere) on CO2 and N2O recycling and its potential role in greenhouse gas inventories and air-sea exchange. Microplastics were collected during two cruises (Cimar 21 and FIP Montes Submarinos) from the surface layer (5m depth) from several contrasting trophic regions of the South Pacific Ocean, i.e., from a transition zone off the eutrophic coastal upwelling of Chile, to a mesotrophic transition area of oceanic seamounts and, finally, to an oligotrophic zone in the South Pacific Subtropical Gyre. . Experiments were carried out onboard to evaluate CO2 and N2O production/consumption by the plastisphere. The active microbial community and its specific quantification were determined for Cimar 21 using iTag 16S rRNA. The experiments showed that the plastisphere generally contributed to CO2 and N2O production/consumption, with rates ranging from-20.5 (consumption) to+4.5 (production) μmol/m2/d. The seamounts and the transition zone presented the highest production/consumption rates. The experiments performed in the two seamount stations showed that production and consumption of CO2 were related to the environmental nutrient concentration. Both stations presented N2O consumption that was associated with the high nitrogen deficit of the subantarctic water mass. The transition zone presented CO2 and N2O production in a plastisphere dominated by heterotrophic communities. The plastisphere in oligotrophic waters was diverse and active. The experiments, however, presented low or no production of greenhouse gases. Our results show a contribution of CO2 and N2O to the global gas surface inventories and air-sea exchange is lower than 1% of the global sources. These results highlight different critical impacts of plastic pollution on the environment that have, until now, not been considered.

Charging coordination and load balancing of plug‐in electric vehicles in unbalanced low‐voltage distribution systems

Plug-in electric vehicles (PEVs) are gaining popularity as a solution to reduce greenhouse gas production. On the other hand, uncoordinated charging of PEVs is a reason for grid stress and increasing congestion, total power consumption (TPC) and distribution lines and transformers losses. Moreover, single-phase connection of electric vehicles in residential buildings causes line current imbalance and it has more negative effects on TPC and power losses. Thus, they are characterised as unbalanced loads with random locations, plug-in times, charging rates, and durations. Hence, a charging coordination algorithm is proposed to utilise the integration of PEVs in both operational modes (grid-to-vehicle, vehicle-to-grid) to guarantee power loss reduction, voltage profile maintaining and load current balancing. The introduced algorithm can perform an optimal calculation to determine proper phase for PEVs in distribution feeders and decline the unbalancing by deploying a new device called phase switcher which is in series with chargers in residential buildings. The phase switcher is connected to the smart load management centre which uses the proposed algorithm to determine the proper phase for connection or disconnection of PEVs and finding the appropriate numbers of PEVs. To show the effectiveness of the proposed algorithm, simulation results are provided.

Saltwater reduces potential CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; and CH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt; production in peat soils from a coastal freshwater forested wetland

Abstract. A major concern for coastal freshwater wetland function and health is the effects of saltwater intrusion on greenhouse gas production from peat soils. Coastal freshwater forested wetlands are likely to experience increased hydroperiod with rising sea level, as well as saltwater intrusion. These potential changes to wetland hydrology may also alter forested wetland structure and lead to a transition from forest to shrub/marsh wetland ecosystems. Loss of forested wetlands is already evident by dying trees and dead standing trees (“ghost” forests) along the Atlantic coast of the US, which will result in significant alterations to plant carbon (C) inputs, particularly that of coarse woody debris, to soils. We investigated the effects of salinity and wood C inputs on soils collected from a coastal freshwater forested wetland in North Carolina, USA, and incubated in the laboratory with either freshwater or saltwater (2.5 or 5.0 ppt) and with or without the additions of wood. Saltwater additions at 2.5 and 5.0 ppt reduced CO2 production by 41 % and 37 %, respectively, compared to freshwater. Methane production was reduced by 98 % (wood-free incubations) and by 75 %–87 % (wood-amended incubations) in saltwater treatments compared to the freshwater plus wood treatment. Additions of wood also resulted in lower CH4 production from the freshwater treatment and higher CH4 production from saltwater treatments compared to wood-free incubations. The δ13CH4-C isotopic signature suggested that, in wood-free incubations, CH4 produced from the freshwater treatment originated primarily from the acetoclastic pathway, while CH4 produced from the saltwater treatments originated primarily from the hydrogenotrophic pathway. These results suggest that saltwater intrusion into coastal freshwater forested wetlands will reduce CH4 production, but long-term changes in C dynamics will likely depend on how changes in wetland vegetation and microbial function influence C cycling in peat soils.

Net greenhouse gas fluxes from three High Arctic plant communities along a moisture gradient

Climate in high latitude environments is predicted to undergo a pronounced warming and increase in precipitation, which may influence the terrestrial moisture gradients that affect vegetation distribution. Vegetation cover can influence rates of greenhouse gas production through differences in microbial communities, plant carbon uptake potential, and root transport of gases out of the soil into the atmosphere. To predict future changes in greenhouse gas production from High Arctic ecosystems in response to climate change, it is important to understand the interaction between trace gas fluxes and vegetation cover. During the growing seasons of 2008 and 2009, we used dark static chambers to measure CH4 and N2O fluxes and CO2 emissions at Cape Bounty, Melville Island, NU, across a soil moisture gradient, as reflected by their vegetation cover. In both years, wet sedge had the highest rates of emission for all trace gases, followed by the mesic tundra ecosystem. CH4 consumption was highest in the polar semi-desert, correlating positively with temperature and negatively with moisture. Our findings demonstrate that net CH4 uptake may be largely underestimated across the Arctic due to sampling bias towards wetlands. Overall, greenhouse gas flux responses vary depending on different environmental drivers, and the role of vegetation cover needs to be considered in predicting the trajectory of greenhouse gas uptake and release in response to a changing climate.