Find research datasets worth reusing

opencc-by-4.0May 2024View details →

Tropical Peatland Drainage Canal Methane Concentrations, Fluxes, and Isotopic Composition

This dataset contains methane (CH4) concentration and 13C isotope composition (δ13C-CH4) and environmental variables (canal dimensions, water quality, etc.) from canals draining peatlands in West Kalimantan, Indonesia. The data also contains CH4 emissions measured using floating chambers and potential CH4 oxidation rates and associated isotopic fractionation from a subset of studied canals, as well as porewater data from peat soils in the study region. Each data file contains a "README" tab with a guide for variable units and descriptions.  File contents:  <ul> <li>Canal_CH4_Survey_Perryman.xlsx = canal water CH4 concentration and δ13C-CH4 from a synpotic survey of canals in Kubu Raya Regency and Mempawah Regency, West Kalimantan, Indonesia. Data also includes canal properties, water chemistry, and estimates of the fraction of CH4 oxidized and diffusive emissions for each canal</li> <li>Canal_Water_Incubations_Perryman.xlsx = measurements of dissolved CH4 concentration and δ13C-CH4 from canal water incubations</li> <li>Floating_Chamber_Flux_Perryman.xlsx = CH4 emissions and source δ13C-CH4 determined from floating chamber deployments on canals</li> <li>Porewater_CH4_Perryman.xlsx = peatland  porewater CH4 concentration and δ13C-CH4 from 6 profiles collected in the study area</li> </ul>

opencc-by-4.0Aug 2024View details →

Dataset for sea ice modulates air–sea methane flux in the Southern Ocean

Air-sea methane (CH4) flux in marginal ice zone in the East Antarctic seas measurements on the icebreaker R/V Xuelong2 from December 2020 to January 2021

opencc-by-4.0Mar 2022View details →

Meteorological responses of carbon dioxide and methane fluxes in the terrestrial and aquatic ecosystems of a subarctic landscape [Data set]

The data set contains carbon dioxide (CO2) and methane (CH4) fluxes of boreal subarctic landscape and its ecosystems and ecotones, and ancillary meteorological and environmental data, measured at Kaamanen, northern Finland (69°8’ N, 27°16’ E; 155 m a.s.l.), during June 2017 - June 2019. The studied ecosystems and ecotones include: upland pine forest, fen, treed pine bog, sparsely treed pine bog, lakes and string top fen plant community. C_fluxes1b_Heiskanen_et_al_2022.csv includes quality screened, u* filtered and gap-filled eddy covariance ecosystem flux data and modelled pine bog and string top time series utilising eddy covariance and manual flux chamber measurements. C_fluxes2_Heiskanen_et_al_2022.csv includes quality screened daily average lake fluxes from mineral and organic sediment lakes. environmental_data_Heiskanen_et_al_2022.xlsx includes ancillary meteorological and environmental data.

opencc-by-4.0Feb 2023View details →

Rates of greenhouse gas (carbon dioxide, methane and nitrous oxide) fluxes, denitrification-derived N2O and N2 fluxes and nitrification-derived N2O fluxes from salt marsh soils in Quebec, Canada and Louisiana, U.S. under ambient and elevated temperature and nutrient loading.

Dataset used in <a href="https://link.springer.com/article/10.1007/s10533-023-01104-0?utm_source=rct_congratemailt&utm_medium=email&utm_campaign=oa_20231214&utm_content=10.1007/s10533-023-01104-0#citeas">Elevated temperature and nutrients lead to increased N2O emissions from salt marsh soils from cold and warm climates</a>. The dataset contains fluxes calculated from headspace gas samples taken over a 24 hour period from intact soil cores, as well as corresponding environmental data. Intact soil cores (0-15 cm depth, 2.5 cm diameter) were taken at five sampling locations along a 20 m transect using a soil auger or piston corer. Samples were collected along a transect in four marsh sites in Quebec, Canada (La Pocatière: 47°22'24.7"N 70°03'26.3"W) and Louisiana, U.S. (Barataria Basin: 29°33'47.3"N 90°04'22.8"W and 29°29'52.2"N 89°55'00.2"W) from two vegetation types (Sporobolus alterniflorus formerly known as Spartina alterniflora and Sporobolus pumilus formerly known as Spartina patens). In Quebec, the two vegetation zones were in the same marsh whereas in Louisiana two separate marshes, dominated by the relevant vegetation, were chosen. Soil samples were collected on the 20-21st July 2021 from Louisiana and the 9-10th August 2021 from Quebec. Environmental data was collected including in-situ soil temperature and salinity, and gravimetric soil moisture, extractable soil dissolved organic carbon (DOC), extractable soil total dissolved nitrogen (TDN), extractable soil nitrate, extractable soil ammonium, extractable soil soluble reactive phosphate, soil total carbon, soil total nitrogen, soil carbon to nitrogen ratio, soil d13C and soil d15N determined from additional 0-15 cm core samples. This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement no. 838296, a NSERC Discovery Grant and a Natural Environment Research Council grant number (NE/T012323/1). Stable 15N tracers were added to the intact soil cores so that at each location, at each treatment level (ambient and elevated, described below), there was one core receiving no tracer for greenhouse gas fluxes, one core receiving 15N-NO3‑ for denitrification rates and one core receiving 15N-NH4+ for nitrification rates. The cores were incubated at ambient temperature (16 ℃ and 28.1 ℃ for Quebec and Louisiana, respectively) and nutrient concentrations (3.2 NO3-, 2.0 NH4+; 2.9 NO3-, 2.5 NH4+; 0.5 NO3-, 7.3 NH4+ and 5.7 NO3-, 2.8 NH4+ mg g wet soil-1 for Quebec S. alterniflorus, Quebec S. pumilus, Louisiana S. alterniflorus and Louisiana S. pumilus, respectively), and elevated temperature (ambient temperature +5 ℃) and nutrient concentration (double ambient concentration). Gas samples were collected from the headspace of 0-15 cm intact cores in a 20 cm high PVC pipe, capped at the top and bottom to create a 5 cm headspace. Gas samples were analysed for greenhouse gases (GHGs: N2O, CH4, CO2) and 15N in denitrification-derived N2O, denitrification-derived N2 and nitrification-derived N2O. Soil temperature (YSI 30, Baton Rouge, USA or DeltaTrak 11050, Pleasanton, USA) and porewater salinity (YSI 30, Baton Rouge, USA or portable ATC refractometer) were measured in-situ or in the laboratory using the portable refactometer. Additional soil samples were used for multiple analyses; one subsample was extracted with ultrapure water (18.2 MΩ) for DOC and TDN analysis, one subsample was extracted with 2M KCl for NO3- and NH4+, one subsample was extracted with Olsen-P solution (0.5 M NaHCO3, pH 8.5), for soluble reactive phosphate analysis and one subsample was weighed and dried for soil moisture and then finely ground and analysed for total carbon, total nitrogen, d13C and d15N. N2O, CH4 and CO2 concentrations were measured in the gas samples using a gas chromatograph interfaced with a PAL3 autosampler (Agilent 7890A, Agilent Technologies Ltd, USA) fitted with a flame ionisation detector (FID) for CH4 analysis and a micro electron capture detector (mECD) for N2O analysis. CO2 was methanised to CH4 before analysis on the FID. The instrument precision as the relative standard deviation was < 5 % for all of the gases, while the minimum detectable concentration difference (MDCD) was 9 ppb N2O, 72 ppb CH4 and 31 ppm CO2. Potential GHG fluxes were calculated from the linear portion or where the highest production was observed in the concentration-time series ( https://doi.org/10.2134/jeq2003.2436). If fluxes were below the MDCD they were set to zero see (https://doi.org/10.1002/2017JG003783). The 15N content of the N2 and N2O was determined using a continuous flow isotope ratio mass spectrometer (Elementar Isoprime PrecisION; Elementar Analysensysteme GmbH, Hanau, Germany) coupled with a trace-gas pre-concentrator inlet with autosampler (isoFLOW GHG; Elementar Analysensysteme GmbH, Hanau, Germany), with a standard deviation of d15N < 0.05 %. Extractable dissolved organic carbon and total dissolved nitrogen were analysed in soil extractant (ultrapure water 18.2 MΩ, 7:1 of extractant to soil) on a TOC/TDN analyser (TOC VCSn + TMN-1, Shimadzu, Kyoto, Japan), with 50 mg C l-1 and 10 mg l-1 standards resulting in accuracy and precision of 0.3 and ±0.3 mg C l-1, and 0.5 and ±0.3 mg N l-1, respectively. Extractable nitrate+nitrite (assumed to be nitrate) and ammonium were analysed in soil extractant (2M KCl, 5:1 of extractant to soil) using a microplate reader and methods in Sims et al., 1995 (<a href="https://doi.org/10.1080/00103629509369298">https://doi.org/10.1080/00103629509369298</a>) with a limit of detection of 0.1 ppm and accuracy of ±5 %. Extractable phosphate was analysed in soil extractant (Olsen-P solution 0.5M NaHCO3, pH 8.5, 10:1 of extractant to dry soil) using a microplate reader and methods in Jeannotte et al., 2004 (https://doi.org/10.1007/s00374-004-0760-4) with a limit of detection of 1 mg P l-1 and accuracy of ±6 %. Soil total carbon, total nitrogen, d13C and d15N analysis was performed using a continuous flow isotope ratio mass spectrometer (Elementar Isoprime PrecisION; Elementar Analysensysteme GmbH, Hanau, Germany) coupled with an elemental analyser (EA) inlet (vario PYRO cube; Elementar Analysensysteme GmbH, Hanau, Germany). The precision was < 5 % for both C and N and the precision as a standard deviation was < 0.06 % for both d13C and d15N. Results from the experiments were entered into an Excel spreadsheet for ingestion into the Zenodo data repository.

openCC (other)Apr 2022View details →

Methane concentrations and fluxes in agricultural and preserved tropical headwater streams

Tropical streams have been intensively impacted by agricultural activities. Among the most important agricultural activities in Brazil, sugarcane production represents a large impact for economic development and for environmental conditions. Permeating sugarcane fields, several headwater streams can be affected by sugarcane cultivation, in special, aquatic biogeochemical cycles because of the deforestation, fertilization, crop residues and higher temperatures in the tropics. In this study, we analyzed the effects of sugarcane cultivation on methane fluxes and concentrations, assuming that carbon cycles are influenced by agricultural activities in headwater streams. Our study aimed to (1) measure methane fluxes and concentrations in tropical streams located in Southeastern Brazil, (2) Analyze whether seasonal cycles influence methane fluxes and concentrations, (3) Evaluate the influence of sugarcane cultivation on methane fluxes and (4) Analyze the association between water chemistry in the methane concentrations in tropical streams. We found mean fluxes of CH4 of 0.280 mmol m-2 d-1, with higher fluxes during the summer and in streams draining preserved catchments. The average CH4 concentrations were 0.695 µmol L-1, with higher values during the summer and in streams draining preserved catchments. Methane concentrations in the studied streams was influenced by dissolved oxygen (negatively), dissolved organic carbon (negatively), water velocity (positively) and conductivity (negatively). Methane concentrations were significantly higher than concentrations found in Temperate Grasslands, Savannas & Shrublands and similar to concentrations found in other tropical biomes (excluding Tropical & Subtropical Moist Broadleaf Forests which receives large amounts of organic inputs). We conclude that sugarcane influence methane concentrations and fluxes in tropical streams by reducing the organic matter availability provided by the native vegetation in soil and water.

openCC (other)Jul 2024View details →

Dataset for: The influence of mixing on seasonal carbon dioxide and methane fluxes in ponds

Inland waters are important sources of the greenhouse gases carbon dioxide (CO2) and methane (CH4). Ponds have amongst the highest CO2 and CH4 fluxes of all aquatic ecosystems, yet seasonal variation in fluxes remain poorly characterized, creating challenges for accurately estimating annual emissions. Further, ponds can exhibit a range of mixing regimes, yet the impact of mixing regimes on gas emissions remains unclear. Here, we assessed annual dynamics of CO2 and CH4 in four temperate ponds (Minnesota, USA) that varied in mixing regimes. This dataset includes high frequency temperature data for each pond to asses mixing, and CO2 and CH4 emissions and concentrations taken by-weekly from 2021-2022.

openCC (other)Jan 2021View details →

A dataset for methane concentrations and fluxes for alpine permafrost streams and rivers on the East Qinghai-Tibet Plateau

This dataset is a collation of 3-year direct measurement values of CH4 concentrations and fluxes for EQTP streams and rivers, along with information on location, hydrological, physical, and chemical conditions of the study sites. Given the rarity and high value of this EQTP data set, it will be very valuable for the next update to global C flux estimates.

openOpenDec 2015View details →

Methane flux from experiemental plots near Toolik Lake, AK from 2001

The methane fluxes from tussock tundra and wet sedge plots near Toolik Lake, AK during the summer of 2001.

openOpenJan 2019View details →

Warming effects of spring rainfall increase methane emissions from thawing permafrost: Site-level data from bog complex III - Methene Flux 2014-2016

Methane emissions regulate the near-term global warming potential of permafrost thaw, particularly where loss of ice-rich permafrost converts forest and tundra into wetlands. Northern latitudes are expected to get warmer and wetter, and while there is consensus that warming will increase thaw and methane emissions, effects of increased precipitation are uncertain. At a thawing wetland complex in Interior Alaska, we found that interactions between rain and deep soil temperatures controlled methane emissions. In rainy years, recharge from the watershed rapidly altered wetland soil temperatures, warming the top ~80 cm of soil in spring and summer, and cooling it in autumn. When soils were warmed by spring rainfall, methane emissions increased by ~30%. The warm, deep soils early in the growing season likely supported both microbial and plant processes that enhanced emissions. Our study identifies an important and unconsidered role of rain in governing the radiative forcing of thawing permafrost landscapes. All site-level data from the studied bog, eddy covariance and micrometeorological data referenced in the published manuscript are available in the LTER data repository. These data are related to the following data package: Surface carbon, water and energy fluxes measured by eddy covariance at 3 sites within the Alaska Peatlands Experiment and Bonanza Creek Experimental Forest 2013-2016 (http://dx.doi.org/10.6073/pasta/4fabab3846113a1866b06f1b3d6d52a3).

openOpenOct 2019View details →

Eight Mile Lake Research Watershed, Carbon in Permafrost Experimental Heating Research (CiPEHR): Methane chamber flux data, 2016 - 2018

The Carbon in Permafrost Experimental Heating Research (CiPEHR) project addresses the following questions: 1) Does ecosystem warming cause a net release of C from the ecosystem to the atmosphere?, 2) Does the decomposition of old C, that comprises the bulk of the soil C pool, influence ecosystem C loss?, and 3) How do winter and summer warming alone, and in combination, affect ecosystem C exchange? We are answering these questions using a combination of field and laboratory experiments to measure ecosystem carbon balance and radiocarbon isotope ratios at a warming experiment located in an upland tundra field site near Healy, Alaska in the foothills of the Alaska Range. This dataset includes methane flux data from winter warming, summer, warming, and control treatment plots.

openOpenOct 2019View details →

Eight Mile Lake Research Watershed,Carbon in Permafrost Experimental Heating and Drying Research (DryPEHR): Methane chamber flux data, 2016 - 2018

This drying and warming experiment addresses the following questions: 1) Does ecosystem drying, warming and permafrost thaw cause a net release or uptake of C from the ecosystem to the atmosphere?, 2) Does the decomposition of old C that comprises the bulk of the soil C pool influence ecosystem C loss? 3) How do drying and warming affect plant communities and ecosystem properties? We are answering these questions using a combined warming and drying experiment (DryPEHR), which is situated with the Carbon in Permafrost Experimental Heating Research (CiPEHR) project and located in an upland tundra field site near Healy, Alaska in the foothills of the Alaska Range. Warming treatment here refers to growing season air temperature warming (~1C) using open top chambers (OTC) combined with soil 'warming' using snow fences during the snow covered months. Drying is achieved using an automated pumping system that lowers the water table in the dry plots. Soil warming began in 2008; OTCs and drying in 2011. *** ADD YOUR OWN DATA SPECIFIC DETAILS HERE

Plant-mediated root methane emissions and oxidation in a thermokarst bog complex in the Bonanza Creek LTER Experimental Forest I - Standard Oxic Methane Fluxes 2015

Vascular plants are important in the wetland methane cycle but their effect on production, oxidation, and transport has high uncertainty, limiting our ability to predict emissions. Vegetation operated on top of baseline methane emissions, which varied with proximity to the thawing permafrost margin. Emissions from vegetated plots increased over the season, resulting in cumulative seasonal methane emissions that were 4.1-5.2 g m-2 season-1 greater than unvegetated plots. Mass balance calculations signify these greater emissions were due to increased methane production (3.0-3.5 g m-2 season-1) and decreased methane oxidation (1.1-1.6 g m-2 season-1). Minimal oxidation occurred along the plant-transport pathway and oxidation was suppressed outside the plant pathway. Our data indicate suppression of methane oxidation was stimulated by root exudates fueling competition among microbes for electron acceptors. Root exudates are known to fuel methane production and our work provides evidence they also decrease methane oxidation. This dataset contains the 2015 weekly oxic methane flux from treatment plots within a bog complex in the Bonanza Creek LTER. Treatments include natural-vegetation, simulated-aerenchyma, and sphagnum-only. No updates are planned.

Plant-mediated root methane emissions and oxidation in a thermokarst bog complex in the Bonanza Creek LTER Experimental Forest II - Non-standard Anoxic Methane Fluxes and Associated Standard Oxic Fluxes 2015

Vascular plants are important in the wetland methane cycle but their effect on production, oxidation, and transport has high uncertainty, limiting our ability to predict emissions. Vegetation operated on top of baseline methane emissions, which varied with proximity to the thawing permafrost margin. Emissions from vegetated plots increased over the season, resulting in cumulative seasonal methane emissions that were 4.1-5.2 g m-2 season-1 greater than unvegetated plots. Mass balance calculations signify these greater emissions were due to increased methane production (3.0-3.5 g m-2 season-1) and decreased methane oxidation (1.1-1.6 g m-2 season-1). Minimal oxidation occurred along the plant-transport pathway and oxidation was suppressed outside the plant pathway. Our data indicate suppression of methane oxidation was stimulated by root exudates fueling competition among microbes for electron acceptors. Root exudates are known to fuel methane production and our work provides evidence they also decrease methane oxidation. This dataset contains the 2015 weekly anoxic methane flux from treatment plots within a bog complex in the Bonanza Creek LTER. Anoxic measurements used with oxic measurements to calculate the fraction of methane oxidized. Treatments include natural-vegetation, simulated-aerenchyma, and sphagnum-only. No updates are planned.

Plant-mediated root methane emissions and oxidation in a thermokarst bog complex in the Bonanza Creek LTER Experimental Forest III - Non-standard Dark Methane Fluxes and Associated Standard Oxic Fluxes 2015

Vascular plants are important in the wetland methane cycle but their effect on production, oxidation, and transport has high uncertainty, limiting our ability to predict emissions. Vegetation operated on top of baseline methane emissions, which varied with proximity to the thawing permafrost margin. Emissions from vegetated plots increased over the season, resulting in cumulative seasonal methane emissions that were 4.1-5.2 g m-2 season-1 greater than unvegetated plots. Mass balance calculations signify these greater emissions were due to increased methane production (3.0-3.5 g m-2 season-1) and decreased methane oxidation (1.1-1.6 g m-2 season-1). Minimal oxidation occurred along the plant-transport pathway and oxidation was suppressed outside the plant pathway. Our data indicate suppression of methane oxidation was stimulated by root exudates fueling competition among microbes for electron acceptors. Root exudates are known to fuel methane production and our work provides evidence they also decrease methane oxidation. This dataset contains the 2015 weekly anoxic control methane flux from treatment plots within a bog complex in the Bonanza Creek LTER. Anoxic control measurements used to assess the effect of the anoxic fluxes on results. Treatments include natural-vegetation, simulated-aerenchyma, and sphagnum-only. No updates are planned.

Plant-mediated root methane emissions and oxidation in a thermokarst bog complex in the Bonanza Creek LTER Experimental Forest IV - Oxic and Anoxic Methane Fluxes on Isolated Carex Plants 2015

Vascular plants are important in the wetland methane cycle but their effect on production, oxidation, and transport has high uncertainty, limiting our ability to predict emissions. Vegetation operated on top of baseline methane emissions, which varied with proximity to the thawing permafrost margin. Emissions from vegetated plots increased over the season, resulting in cumulative seasonal methane emissions that were 4.1-5.2 g m-2 season-1 greater than unvegetated plots. Mass balance calculations signify these greater emissions were due to increased methane production (3.0-3.5 g m-2 season-1) and decreased methane oxidation (1.1-1.6 g m-2 season-1). Minimal oxidation occurred along the plant-transport pathway and oxidation was suppressed outside the plant pathway. Our data indicate suppression of methane oxidation was stimulated by root exudates fueling competition among microbes for electron acceptors. Root exudates are known to fuel methane production and our work provides evidence they also decrease methane oxidation. This dataset contains 2015 monthly methane fluxes from isolated Carex plants in a bog complex in the Bonanza Creek LTER. Isolated plant fluxes were used to partition the flux from the plant mediated pathway.

openCC (other)Sep 2021View details →

Hubbard Brook Experimental Forest: Soil-atmosphere fluxes of carbon dioxide, nitrous oxide and methane on snow removal plots

Soil atmosphere fluxes of the trace gases; carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) have been measured at several locations at the Hubbard Brook Experimental Forest (HBEF) including 1) the “freeze” study reference plots that provide contrast between stands dominated (80%) by sugar maple versus yellow birch and low and high elevation areas, 2) the Bear Brook Watershed where trace gas sampling is coordinated with long-term monitoring of microbial biomass and activity and 3) watershed 1 where trace gas sampling locations were co-located with long-term microbial biomass and activity monitoring sites that are located near a subset of the lysimeter sites established for the calcium addition study on this watershed. This dataset contains the Freeze study data. Watershed 1 and Bear Brook trace gas data can be found in: https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-hbr&identifier=116. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station. These data have been published in: Groffman, P. M., Hardy, J. P., Driscoll, C. T., & Fahey, T. J. (2006). Snow depth, soil freezing, and fluxes of carbon dioxide, nitrous oxide and methane in a northern hardwood forest. Global Change Biology, 12, 1748–1760.

openCC (other)Nov 2018View details →

Soil methane flux, temperature, moisture, C, and N data for South of saddle, 1991.

Methane emissions were measured from dry and wet meadow plots established by W. Bowman in the Boulder watershed south of the Saddle. The effects of N and P fertilization were evaluated.