This data set provides the environmental measurements collected during the implementation of operational methods to achieve both deep soil heating (0-3 m) and whole-ecosystem warming (WEW) appropriate to the scale of tall-stature, high-carbon, boreal forest peatlands. The methods were developed to allow scientists to provide a plausible set of ecosystem warming scenarios within which immediate and longer term (one decade) responses of organisms (microbes to trees) and ecosystem functions (carbon, water and nutrient cycles) could be measured. Elevated CO2 was also incorporated to test how temperature responses may be modified by atmospheric CO2 effects on carbon cycle processes.
Data Products List
These data are provided in support of the Commentary, Advanced molecular techniques provide a rigorous method for characterizing organic matter quality in complex systems, Wilson and Tfaily (2018).
Measurement results demonstrate that optical characterization of peatland dissolved organic matter (DOM) may not fully capture classically identified chemical characteristics and may, therefore, not be the best measure of organic matter quality.
Results of analyses of a representative sample by FTICRMS and additional analytical techniques provide a broader picture of the compounds occurring in peatland DOM.
This data set provides annual biomass growth rates of epiphytic lichen transplants in the SPRUCE experimental plots at the S1 Bog of the Marcell Experimental Forest. Epiphytic lichens (Evernia mesomorpha, a boreal forest indicator species) were collected at S1 Bog outside the experimental enclosures and mounted on Picea mariana branches inside the 10 experimental enclosures and the 2 ambient plots without enclosures using transplant techniques. Lichen transplants were weighed annually, in August of 2013-2016, to measure biomass growth rates as a function of experimental temperature and CO2 treatments.
This study investigated the potential for methylotrophic methanogenesis in three Sphagnum-dominated peatland soils in northern Minnesota. Collected soils were amended with 13C-labeled traditional substrates (acetate and sodium bicarbonate/ H2) and methylated substrates (methanol, monomethylamine (“MMA”), dimethylsulfide (“DMS”)) and monitored for δ13C-CH4, δ 13C-CO2, and net CH4 and CO2 production in laboratory incubations.
This data set reports the results of the analysis of dissolved organic matter (DOM) in porewater samples collected from multiple depths in northern peatlands and during laboratory peat incubations to characterize the gain or loss of specific chemical moieties (e.g. CH2, H2, CH2O, etc.) that may be attributed to microbial degradation. During incubations, CO2 and CH4 concentrations and stable isotopes were determined by isotope ratio mass spectrometry.
This data set reports measurements of CO2 and CH4 fluxes and d13C-CO2 and d13C-CH4 values associated with each flux measurement for the SPRUCE experimental study plots located in the S1-Bog. Flux measurements started in 2014 and are continuing.
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This data set contains the results of a microcosm incubation study on deep peat collected from the SPRUCE experimental site in the S1 Bog in September 2014. Microcosms were monitored for CO2 and CH4 production, and microbial community dynamics were assessed using qPCR and amplicon sequencing.
The experiment was designed with a full factorial design with elevated temperature, nitrogen (N), (P), and pH treatments was used with samples from each transect serving replicates. In all, 96 microcosms were constructed to account for the 16 treatment combinations (N x P x pH x temperature), 2 time points, and 3 replicates. Temperature treatments were 6 °C, to mimic the SPRUCE ambient plot temperatures, and 15 °C to mimic the SPRUCE +9 °C treatment.
Study developed a data-informed process-based model using methane chamber measurement data from the SPRUCE project experiment in a northern peatland in northern Minnesota.
Study used existing manual CH4 flux measurements collected from the ambient environment from 2011-2014 and developed a data-informed process-based methane module. The module was incorporated into the Terrestrial ECOsystem (TECO) model before its parameters were constrained with multiple years of methane flux data for forecasting CH4 emission under five warming and two elevated CO2 experimental treatments at SPRUCE.
Included in this model archive are the (1) source code of the TECO model used in the study (2) the posterior distribution of parameters values, and (3) model simulated results of methane emission for different pathways under different environmental conditions.
This data set provides (1) the results of in-situ Sphagnum-peat hourly net ecosystem exchange (NEE) measured using a LICOR 8100 gas exchange system and (2) the component fluxes -- gross primary production (GPP) and ecosystem respiration (Re), derived using empirical regressions.
NEE measurements were made from 6 June to 6 November 2014 and 20 March to 10 May 2015. Three 8100 chambers per dominant species (S. magellanicum or S. fallax) were placed in the S1 Bog in relatively open ground where there was no obvious hummock-hollow microtopography. The 8100 chambers were not located in the SPRUCE experimental enclosures.
This data set reports selected ambient environmental monitoring data (public) from the S1 bog for the period June 2010 through 2016. Measurements of the environmental conditions at these stations will serve as a pre-treatment baseline for experimental treatments and provide driver data for future modeling activities.
This data set provides the peat water content and peat temperature at time of sampling for peat cores collected before and during the SPRUCE Whole Ecosystem Warming (WEW) study.
Cores for the current data set were collected during the following bulk peat sampling events: 13 June 2016 and 23 August 2016. Over time, this dataset will be updated with each new major bulk peat sampling event, and dates/methods will be updated accordingly.
This data set reports fungal hyphal carbon and nitrogen concentrations and δ13C, and δ15N data for samples obtained from in-growth cores in the S1 Bog. Hyphae were collected using 40 μm in-growth bags (10 cm × 10 cm) filled with sterile sand. Bags were incubated in the field in paired hummock and hollows at six locations in the bog. In hummocks, bags were inserted at +10 to 0 cm above the adjacent hollow and in both locations from 0 to -10 cm and -10 to -20 cm below the hollow surface.
This data set reports the results of elemental analyses of foliar and stem/woody twig plant tissues collected at the SPRUCE site in 2009, 2012, and 2013. Samples were obtained at various locations around the S1 Bog and from within the developing experimental treatment plots. These are pretreatment vegetation samples, collected prior to initiation of the SPRUCE experiment heating and elevated CO2 treatments.
This data set consists of observations of plant-available nutrients assessed using ion-exchange resin capsules incubated serially in aerobic and anaerobic peat layers beginning in 2013 in the SPRUCE experimental plots at four depths in hummock microtopography and two depths in hollow microtopography. Data will be periodically added to until the conclusion of the SPRUCE experiment.
This data set consists of observations of plant-available nutrients assessed using ion-exchange resin capsules incubated serially in aerobic and anaerobic peat layers beginning in 2011. Data were collected from 2011 to 2012 (prior to the construction of the SPRUCE experimental plots) at the southern end of the S1 Bog at three depths in hollow microtopography only.
The composition and cover of woody and understory species, along with the timing of stem growth, were characterized near minirhizotron installations at the south and north ends of the S1 bog in order to understand the relationship between root dynamics and the surrounding plant communities.
There are three data streams:
(1) Woody species basal area -- the number, basal area, and distance from the center point of all trees within a 5-m radius of each minirhizotron pair, which were quantified in 2011,
(2) Understory cover -- the understory vascular plant community composition and percent cover, which were surveyed in 1 m2 areas at four cardinal directions adjacent to each pair of minirhizotrons in June 2011, and
(3) Stem growth -- the basal area increment (stem growth) of nearby trees, which was quantified using automated or manual dendrobands in 2011 and 2012, respectively.
Aerial coverage of hummocks and hollows was estimated in July 2012 in ten 4 m × 4 m plots each along three 60-m t transects (30 plots total) in the S1-Bog. Hollows were defined as the lowest elevation within plots and were typically at or near the height of the water table, hummocks included area above hollows, including the sides of the hummocks.
This data set reports fine-root peak growth and standing crop measurements from a forested, ombrotrophic bog as determined using non-destructive minirhizotron technology. Minirhizotron images were collected throughout the growing seasons of 2011 and 2012 at the southern and northern ends of the S1 bog across gradients of tree density in paired hummock and hollow microtopography. The dominant woody species in the bog, and focus of the investigation, were trees Picea mariana and Larix laricina, and ericaceous shrubs Rhododendron groenlandicum and Chamaedaphne calyculata.
This data set provides hollow elevation data for the 17 SPRUCE experimental plots in the S1 bog on the Marcell Experimental Forest.
Hollows were selected for measurement by walking along each octagonal boardwalk segment in a plot and identifying where a hollow intersected the boardwalk. The vertical distance between the surface of the boardwalk (with a known elevation) and the surface of the hollow was measured and the absolute elevation (in meters amsl) of the hollow surface was calculated.
The hollow elevation measurements were carried out in October 2015, May 2016, and October 2016. These measurements will be repeated annually or more frequently.
EcoPAD is an interactive Model-Experiment (ModEx) system that assimilates various data streams into models in a rigorous way to constrain model parameters and system states, improve ecological prediction, and quantify associated uncertainty. The system provides feedback to experimenters on which data sets are needed to further improve model predictions and to modelers on which parts of a model need to be improved.
Specifically, the system will (read more)
- Predict what ecosystems may respond to treatments once you selected a site and decide your experimental plan.
- Assimilate data you are collecting along your experiment to constrain model prediction.
- Project what ecosystem responses may likely be in the rest of your experiment.
- Tell you what are those important datasets you may want to collect in order to understand the system.
- Periodically update the projections.
- Improve the models, the data assimilation system, and your experiments during the process.
EcoLAB assimilates multiple streams of data from the SPRUCE experiment to the TECO model using MCMC algorithm, and then makes forecasts of ecosystem dynamics. Effects of warming and elevated [CO2] on carbon fluxes and pool sizes are forecast.
These data are provided in support of the SPRUCE publication, Stability of peatland carbon to rising temperatures, Wilson et al., (2016).
This data set reports the results of extensive field measurements and laboratory analyses of samples from the SPRUCE experiment. Results indicate that ecosystem-scale warming of over 2 m of peat exponentially increased CH4 emissions —but not ecosystem respiration of CO2. Multiple lines of evidence, including incubations and in situ analyses of 14C, dissolved gases, and microbial community metabolic potential, indicate that CH4 emissions increased due to surface processes and not degradation of deeper buried carbon.
The supporting data provided include the summarized and aggregated data used to generate the six figures in the main text of the paper and the 12 supplementary figures.
This data set reports the chemistry of porewater in the SPRUCE plots located in the S1 bog. Sample collection and analyses started in August of 2013 and will continue for the duration of the experiment. Results will be added to this data set and released to the public periodically as quality assurance and publication of results are accomplished.
These data are the pre- and post-treatment data from the warming and elevated CO2 treatments associated with the SPRUCE experiment. There are 10 experimental plots in SPRUCE: 5 temperature treatments (+0, +2.25, +4.5, +6.75, +9°C) at ambient CO2, and the same 5 temperature treatments at elevated CO2 (+500 ppm). There are 7 additional ambient plots without experimental enclosures, and thus a total of 17 plots.
This data set reports the results of physical and chemical analyses of peat core samples from the SPRUCE experimental study plots located in the S1-Bog.
On August 13-15, 2012, a team of SPRUCE investigators and collaborators collected core samples of peat in the SPRUCE experimental plots. The goal was to characterize the biological, physical, and chemical characteristics of peat, and how those characteristics changed throughout the depth profile of the bog, prior to the initialization of the SPRUCE experimental warming and CO2 treatments.
Cores were collected from 16 experimental plots; samples were collected from the hummock and hollow surfaces to depths of 200-300 cm in defined increments. Three replicate cores were collected from both hummock and hollow locations in each plot. The coring locations within each plot were mapped.
This data set reports the chemistry of S1 Bog porewater, outlet stream water, and groundwater from upland wells from 2011 through 2013. These data provide information for studies of the biogeochemical status of the bog and surrounding groundwater aquifer.
The data have been analyzed and reported on in the following paper: Griffiths, N.A. and S.D. Sebestyen. 2016. Dynamic vertical profiles of peat porewater chemistry in a northern peatland. Wetlands, 36:1119–1130, DOI 10.1007/s13157-016-0829-5
This data set provides the peat water content and peat temperature at time of sampling for peat cores collected before and during the SPRUCE Deep Peat Heating (DPH) study. Cores were collected during three sampling events: 03 June 2014, 09 September 2014, and 16 June 2015.
Two cores were extracted from hollow locations in each of the 10 experimental plots (4, 6, 8, 10, 11, 13, 16, 17, 19, and 20). Cores were partitioned into samples at 11 depth increments: 0-10, 10-20, 20-30, 30-40, 40-50, 50-75, 75-100, 100-125, 125-150, 150-175, and 175-200 cm below surface of the hollow.
This data set provides links to the results of metagenomic analyses of 38 peat core samples collected on 16 June 2015 from SPRUCE experiment treatment plots after approximately one year of belowground heating. These metagenomes are archived in the U.S. Department of Energy Joint Genome Institute (DOE JGI) Integrated Microbial Genomes (IMG) system and are available at the accession numbers provided in the accompanying inventory file.
This data set reports community-level CO2 and CH4 flux measurements for the SPRUCE experimental study plots located in the S1-Bog. Surface flux measurements of CO2 and CH4 were made using open-path analyzers over an area of 1.13 m2 within each of 16 plots. A custom-designed chamber encloses the hummock-hollow topography and allows point in time measurements of the shrub, forb, Sphagnum spp. and the complex microbial community. These observations were made with ambient light and imposed dark conditions to allow estimates of community daytime and night respiratory processes. Measurements were collected seasonally starting in 2011 and have continued through 2016. Data collection will continue and the new data will be added periodically.
Here we provide model code, inputs, outputs and evaluation datasets for a new configuration of the Community Land Model (CLM) for SPRUCE, which includes a fully prognostic water table calculation for SPRUCE.
Our structural and process changes to CLM focus on modifications needed to represent the hydrologic cycle of bogs environment with perched water tables, as well as distinct hydrologic dynamics and vegetation communities of the raised hummock and sunken hollow microtopography characteristic of SPRUCE and other peatland bogs. The modified model was parameterized and independently evaluated against observations from an ombrotrophic raised-dome bog in northern Minnesota (S1-Bog), the site for the Spruce and Peatland Responses Under Climatic and Environmental Change experiment (SPRUCE).
This data set provides annual movies created from daily and twice daily images of vegetation stands in the S1 Bog showing the seasonal changes of vegetation and appearance and disappearance of snow for the period June 2010 through December 2015. Compiled movies are useful for examining the phenology of the bog and the changes to the landscape as experimental facilities have been constructed.
This data set provides a record of the half-hourly automated environmental data collected for 14 SPRUCE plots (4, 5, 6, 7, 8, 10, 11, 13, 14, 16, 17, 19, 20, and 21) during the Deep Peat Heating (DPH) study. In June 2014, deep soil heating was initiated at 5 warming levels (+0, +2.25, +4.5, +6.75 and +9 °C) with 2 replicate plots per level. Measurements were underway before the initiation of heating treatments and continued through July 27 of 2015 at the transition to whole-ecosystem warming manipulations.
This data set provides a record of the aerial photographs taken of the S1-Bog on the Marcell Experimental Forest and the SPRUCE experimental site within the S1-Bog.
This data set provides a record of the horizontal and vertical survey results of SPRUCE experimental infrastructure and measurement locations on the S1-Bog on the Marcell Experimental Forest and the SPRUCE experimental site within the S1-Bog.
This data set contains biochemical, morphological, and physiological data collected between 2010 and 2013 on mature black spruce (Picea mariana) trees at the S1 bog site in northern Minnesota, located 40 km north of Grand Rapids in the USDA Forest Service Marcell Experimental Forest (MEF). These data were collected prior to the initiating of heating and elevation of CO2 for the SPRUCE experiment to assess the response of northern peatland ecosystems to increases in temperature and exposures to elevated atmospheric CO2 concentrations. Note that file SPRUCE_4_cohort_Rd_data_20151119.csv was replaced on November 19, 2015.
Microbial Metabolic Potential for Carbon Degradation and Nutrient (Nitrogen and Phosphorus) Acquisition in an Ombrotrophic Peatland
Xueju Lin, Malak M. Tfaily, Stefan J. Green, J. Megan Steinweg, Patrick Chanton, Aopeau Imvittaya, Jeffrey P. Chanton, William Cooper, Christopher Schadt and Joel E. Kostka
Appl. Environ. Microbiol. 2014, 80(11):3531. DOI: 10.1128/AEM.00206-14.
Metagenomic analyses revealed that genes encoding laccases and dioxygenases, involved in aromatic compound degradation, declined in relative abundance with depth, while the relative abundance of genes encoding metabolism of amino sugars and all four saccharide groups increased with depth in parallel with a 50% reduction in carbohydrate content.
This data set reports the thickness of peat for the S1 Bog measured directly with manual push probes on September 21 and 22, 2009, and measured by ground penetrating radar (GPR) across transects from January 26 to February 2, 2010 and June 2 to June 9, 2010. Also included are interpolated values of peat depth from both probe and GPR data for the S1 Bog at 1 meter square horizontal resolution.
This data set reports the results of measurements on sampled aboveground tissues of trees (Picea mariana and Larix laricina), shrubs (Ledum, Chamaedaphne, and Vaccinium), and ground layer vegetation (all species) of the S1 Bog located in areas adjacent to planned experimental study plots. Ground layer vegetation was sampled from both hummocks and hollows, within a 0.25 m2 plot, to evaluate total standing biomass of bog vegetation at or near the peak of annual production. Vegetation was harvested, processed, and measured in July of 2010 and again in June of 2011.
This data set reports the results of a field survey of the S1 Bog to characterize the vegetation and to determine peat depth. The survey was conducted on September 21 and 22, 2009. The initial survey of vegetation and peat depth characteristics of the target bog was conducted to evaluate the logical locations for installing replicated experimental blocks for SPRUCE. The goal was to identify multiple locations of uniform aboveground vegetation and belowground peat depth for positioning experimental units within the bog.
This data set reports annual dry matter production of Sphagnum in replicated growth columns, the composition of the moss community, and plot-average Sphagnum productivity in the SPRUCE experimental study plots located in the S1-Bog. Data are reported for 2016 (October 2015 to October 2016) and 2017 (October 2016 to October 2017).
This data set reports community-level CO2 and CH4 flux measurements for the SPRUCE experimental study plots located in the S1-Bog.
Surface flux measurements of CO2 and CH4 were made using open-path analyzers over an area of 1.13 m2 within each of 16 plots. A custom-designed chamber encloses the hummock-hollow topography and allows point in time measurements of the shrub, forb, Sphagnum spp. and the complex microbial community. These observations were made with ambient light and imposed dark conditions to allow estimates of community daytime and night respiratory processes.
This data set is all inclusive – beginning in 2011 and continuing through the Whole-Ecosystem-Warming (WEW) phase of the experiment.
In support of: Furman, Olha S., M. M. Tfaily, S. L. Nicholas, J. C. Wasik, S. D. Sebestyen, R. K. Kolka, E. A. Nater, and B. M. Toner (in progress). Co-cycling of sulfur and mercury within the zone of water-table fluctuations in organic soils. Environmental Science & Technology.
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This data set reports selected ambient environmental monitoring data from the S1bog. There are three monitoring sites located in the bog: Stations 1 and 2 are co-located at the southern end of the bog and Station 3 is located north central and adjacent to an existing U.S. Forest Service monitoring well.
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These data are provided in support of the SPRUCE publication: Small Differences in Ombrotrophy Control Regional-Scale Variation in Methane Cycling among Sphagnum-Dominated Peatlands (Zalman et al., 2018) Reports the examination of the mechanisms controlling C cycling rates and greenhouse gas emissions using a combination of biogeochemical and microbial approaches in three low pH, Sphagnum-dominated peatlands in northern Minnesota. In particular, we investigated biogeochemical parameters (CH4 and CO2 production potentials, porewater and gas CH4 and CO2 concentrations and associated isotopic signatures), soil chemistry (organic acids and phenolics), and microbial community characteristics (quantification of methanogen and methanotroph abundance and activity) over a 1-year period in these three peatlands.
This data set reports shrub layer growth assessments for the S1-Bog on the Marcell Experimental Forest in Minnesota from 2010 through 2017. Data were obtained by destructively harvesting two 0.25 m2 plots within defined plot areas of the S1-Bog or SPRUCE experimental plots 2, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 19, 20 and 21.
In 2015, SPRUCE plots 4, 6, 8, 10, 11, 13, 16, 17, 19 and 20 were enclosed in the SPRUCE enclosures. SPRUCE treatments were applied to the enclosed plots beginning in 2016. Prior to 2015 all data are for open ambient conditions. In early years a distinct hummock and a hollow sampling square were both collected, but in later years unsampled hollow areas became unavailable due to prior sampling or instrument installations.
All vegetation material above the Sphagnum surface of the bog was clipped and transferred to plastic storage bags which were then frozen until the samples could be sorted. Sorting was done by species, tissue type (leaves vs. stems) and tissue age (current-year vs. older tissues).
This data set reports tree growth measurements of mature Picea mariana and Larix laricina located in the S1-Bog permanent plots and the SPRUCE experimental study plots,
Annual data collections were initiated in February of 2011and have been continued on an annual basis during mid-winter observation periods at the end of February or early March. Data collections are anticipated to continue through February of 2025 and this data set will be appended annually.
Initial observations in 2011 included measurements of circumference at 1.3 m (diameter at breast height assessments; DBH) above the nominal bog hollow surface, tree heights and crown diameters. Subsequent annual measurements have focused on the measures of circumference at DBH. Circumference measurements to the nearest 0.1 cm are converted to DBH in cm and basal area at DBH in (cm2). Tree height and crown diameter are measured to the nearest 0.1 m.
Note that the current data set is sequestered as project-only access pending publication of data in peer reviewed publications.