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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 through 2019 now available.

This data set provides a record of the half-hourly automated water table depth data collected for 12 SPRUCE plots (4, 6, 7, 8, 10, 11, 13, 14, 16, 17, 19, 20, and 21) beginning during deep peat heating (DPH) in 2015 and continuing throughout the whole ecosystem warming (WEW) manipulations for the SPRUCE Project (Hanson et al. 2017). Also provided are plot normalized data for water table depths with respect to mean hollow locations within each plot. The hollow referenced data provide the basis for the intercomparison of peat saturation or aeration across treatment plots. A limited data set for manual water table observations in 2019 is also provided as a reference to the plot center automated observations

This dataset consists of PhenoCam data from the SPRUCE experiment from the beginning of whole ecosystem warming (Hanson et al. 2017) in August 2015 through March-31 of 2020, with start- and end-of-season phenological transition dates derived through the end of autumn 2019. Digital cameras, or phenocams, installed in each SPRUCE enclosure track seasonal variation in vegetation “greenness”, a proxy for vegetation phenology and associated physiological activity. Three separate regions of interest (ROIs) were defined for each camera field of view, corresponding to different vegetation types and demarcating: Picea trees (vegetation type EN, for evergreen needleleaf); Larix trees (vegetation type DN, for deciduous needleleaf); and the mixed shrub layer (vegetation type SH).

This data set consists of phenological transition dates, as derived from direct observations of vegetative and reproductive phenology recorded by a human observer, from the SPRUCE experiment during 2019, the fourth full year of whole-ecosystem warming (Hanson et al. 2017). Both spring and autumn phenological events are included. Since April 2016, human observers have been directly tracking the phenology of both woody and herbaceous species on a weekly schedule within the SPRUCE experimental chambers. The observed date reported here is the first survey date on which an event/phenophase was definitively observed.

This data set reports the chemistry of precipitation water that was collected at the SPRUCE site located in the S1 bog and calculated values of bulk atmospheric deposition of solutes in precipitation. Sample collection and analyses started during December 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.

This dataset provides leaf area index (LAI) data collected across vegetation community plots within the 10 chambered treatment plots (6, 19, 11, 20, 4, 13, 8, 16, 10, 17) and 3 unchambered ambient plots (7, 14, 21) of the SPRUCE experiment project in 2017, 2018, and 2019. The vegetation community plots were established in 2014 and designated to be undisturbed and reserved for long-term sampling. LAI measurements were collected using a LICOR-LAI 2200 instrument over a standard 1x2 meter rectangular sampling frame with 50 20x20 cm grid cells. LAI was measured above the canopy and below the vegetation at the surface of the peat (living sphagnum) in the same grid cells each year.

This data set reports the concentrations of carbon (C), nitrogen (N), and phosphorus (P) in capitula, current year stems, and one-year old stem tissue of Sphagnum from 2016-2018. Measurements are continuing and new data will be appended as they become available.
Three types of Sphagnum were sampled -- S. angustifolium/fallax from hummocks, S. angustifolium/fallax from hollows, and S. magellanicum from hummocks from SPRUCE experimental study plots. Measurements were made in 10 enclosures comprising five levels of temperature elevation in ambient CO2 and five levels in elevated CO2. Measurements also were made in two ambient (no enclosure) plots. Nutrient concentrations were analyzed in conjunction with assessment of Sphagnum growth, which was measured in 3.79-cm diameter mesh columns collected every October and are described in the related dataset (https://doi.org/10.25581/spruce.049/1426474).

Images were collected using first of their kind, non-destructive, high-resolution automated minirhizotrons (RhizoSystems, LLC) to assess the response of plant fine-root and fungal mycelium dynamics to elevated temperatures after 4-6 years of whole-ecosystem warming and exposure to elevated carbon dioxide concentrations (e[CO2]) in a peat bog where the SPRUCE experiment is located. We focused on two SPRUCE experimental plots: Plot 10 has elevated temperature (+9°C) and plot 19 is a control (+0°C). Both have elevated CO2 (e[CO2]). Changes in root and fungal abundance with warming were estimated from a timeseries of landscape-level mosaiced images for each plot by measuring the proportional abundance of five belowground classes: fine roots of vascular plants, ectomycorrhizas, fungal hyphae, fungal rhizomorphs, and fungal sporocarps. To examine root and fungal phenology responses to warming, the length per individual root or fungal structure areal coverage were measured per image area of a set of timeseries patch-level mosaiced images for each plot. These data are provided in support of the publication: High-Resolution Minirhizotrons in an Experimentally-Warmed Peatland Provide an Unprecedented Glimpse at Fine Roots and their Fungal Partners (Defrenne et al., In review)

This dataset reports growth and chemistry of newly-grown fine roots from root ingrowth cores in the SPRUCE experimental enclosures. There is one comma separated file (.csv) that provides fine-root growth and chemistry data for the ten SPRUCE experimental enclosures from years 2014 to 2017. These data were used to assess the warming and elevated CO2 response of fine roots and also capture responses across microtopographical features and plant types.

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 August 2019 of the Whole-Ecosystem-Warming (WEW) phase of the experiment.

This data set reports plot-specific bog surface elevation measurements collected with the SPRUCE Elevation Transect (SET) instrument. Measurements are reported as absolute elevation in meters above mean sea level for two locations in each of the SPRUCE experimental treatment plots and additional ambient boardwalk plots -- 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 19, 20 and 21.

This data set reports measurements collected from June 2013 through August 2020, but it will be appended annually as new data are collected.

This data set reports shrub layer growth assessments for the S1-Bog on the Marcell Experimental Forest in Minnesota from 2010 through 2018. Data were obtained by destructively harvesting two 0.25 m2 plots within defined plot areas of the S1-Bog or SPRUCE experimental plots. In 2015, SPRUCE plots 4, 6, 8, 10, 11, 13, 16, 17, 19 and 20 were enclosed in the SPRUCE enclosures. 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.

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. New 2019-2020 photos collected from UAV have been added.

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. This December 2019 release is an updated and expanded version and replaces the previous release.

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 dataset consists of maps and summaries of very high resolution (1 cm2) spatial data derived from terrestrial laser scans (TLS) characterizing the microtopography (hummocks and hollows) in 12 SPRUCE experimental plots from 2016-2018. The SPRUCE experiment is located in the S1-Bog of the Marcell Experimental Forest (MEF) near Grand Rapids, Minnesota. Additional data will be added through Summer 2021.

In the spring of each year, four TLS scans were taken per plot/enclosure and registered together to produce a single point cloud for each plot. Digital surface models (DSMs) were generated from the point clouds and clipped to the inside boundary of the boardwalk in each plot resulting in an approximately 9 x 9 m study area.

All other characterization data types were derived from plot DSMs (elevation), including: slope, concavity, index used for microform classification (Hollow Index), and microforms (hummocks and hollows) classified using three methodologies.

This data set contains biochemical and physiological data collected between June 2016 and May 2017 on two ericaceous shrub species, Chamadaphne calyculata and Rhododendron groenlandicum, at the SPRUCE (Spruce and Peatland Responses under Changing Environments) experiment to assess the response of peatland ecosystems to increases in whole ecosystem temperatures and elevated atmospheric CO2 concentrations.The SPRUCE experiment is located 40 km north of Grand Rapids, MN, in the USDA Forest Service Marcell Experimental Forest.

This data set consists of phenological transition dates, as derived from direct observations of vegetative and reproductive phenology recorded by a human observer, from the SPRUCE experiment during 2018, the third full year of whole-ecosystem warming (Hanson et al. 2017). Both spring and autumn phenological events are included.

Since April 2016, human observers have been directly tracking the phenology of both woody and herbaceous species on a weekly schedule within the SPRUCE experimental chambers. The observed date report here is the first survey date on which an event/phenophase was definitively observed.

This data set comprises terrestrial laser scanning (TLS) point clouds from the SPRUCE experimental plots located in the S1-Bog of the Marcell Experimental Forest (MEF) near Grand Rapids, Minnesota. In 2015 the 12 experimental SPRUCE plots were scanned near peak foliage. In 2016, 2017, and 2018 the 12 plots were scanned prior to green up and once near peak foliage. Additional data will be added through Summer 2021.

This dataset consists of PhenoCam data from the SPRUCE experiment from the beginning of whole ecosystem warming (Hanson et al. 2017) in August 2015 through March-31 of 2019, with start- and end-of-season phenological transition dates derived through the end of autumn 2018.

Digital cameras, or phenocams, installed in each SPRUCE enclosure track seasonal variation in vegetation “greenness”, a proxy for vegetation phenology and associated physiological activity. Three separate regions of interest (ROIs) were defined for each camera field of view, corresponding to different vegetation types and demarcating: Picea trees (vegetation type EN, for evergreen needleleaf); Larix trees (vegetation type DN, for deciduous needleleaf); and the mixed shrub layer (vegetation type SH).

This data set consists of reflectance observations from hyperspectral remote sensing of the vegetation communities in SPRUCE experimental study plots located in the S1-Bog. Community vegetation plots in ten chambered treatment plots (6, 19, 11, 20, 4, 13, 8, 16, 10, 17) and 3 unchambered ambient plots (7, 14, 21) were scanned. Spectral data were collected on 22 September 2016 under clear sky conditions beginning at 1:00 p.m. local time. Although it was past peak growing season, senescence had only just begun at the site, and experimentally warmed plots were still near peak growing conditions.

This data set reports the tritium concentrations in (1) porewater from selected SPRUCE experimental plots located in the S1 bog and in (2) groundwater, streamwater, and precipitation in the S1 bog watershed, and (3) in porewater from the S2 bog, S3 fen, and Bog Lake fen. All sites are located at the USDA Forest Service, Marcell Experimental Forest (MEF) near Grand Rapids, MN. Samples were collected between June of 2014 and August of 2016.

These data include samples collected pre- and post- belowground warming 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).

Porewater samples in this dataset were collected from three of the warming treatment plots (+0, +4.5, +9°C) at ambient CO2.

This data set contains the empirical biochemical, morphological, and physiological data collected between 2010 and 2015 on an herb (Maianthemum trifolium), understory shrubs (Rhododendron groenlandicum, Chamaedaphne calyculata, Kalmia polifolia and Vaccinium angustifolium) and  overstory trees (Picea mariana and Larix laricina) in the S1-Bog at the USDA Forest Service Marcell Experimental Forest (MEF) in northern Minnesota, USA. Data reported include the measurements of photosynthetic light and CO2 response curves, and dark respiration, as applied to standardized curve-fitting programs to estimate biochemical parameters.

Hopple et al. (2019) investigated whether, as a primary substrate – dissolved organic matter (DOM) or solid peat – was driving anaerobic respiration at surface and at deep depth increments within two bogs and a poor fen in northern Minnesota. To address this question, they used a combination of soil laboratory incubations, as well as in-situ analyses of porewater dissolved organic carbon (DOC) concentrations and specific UV absorbance (SUVA) measurements. Soil samples were collected in June 2013 and July 2014, while porewater samples were taken in July 2013. Data provided include: porewater DOC concentration and SUVA values, soil CH4 and CO2 potential production rates from peat samples exposed to varying DOM concentrations, and soil CH4 and CO2 potential production rates.These data are provided in support of the publication: Does dissolved organic matter or solid peat fuel anerobic respiration in peatlands? (Hopple et al., 2019)

This data set reports the results of total gaseous mercury (TGM) flux monitoring conducted in a sub-set of the SPRUCE experimental study enclosures (Plots 4, 6, 10, 13, 17 and 19) located in the S1 Bog. These plots were selected to represent duplicates of the +0, +4.5 and +9°C experimental temperature treatments.  Monitoring of TGM fluxes was conducted in May-June 2014, August 2014 and June 2015 to capture the influence of the deep (2 m below the ground surface) peat warming experiment. These sampling events were conducted prior to the initiation of deep peat warming (May-June 2014), once target peat temperatures were achieved at depth (August 2014) and at the conclusion of the deep warming experiment prior to the initiation of whole ecosystem warming (June 2015).

This data set also presents the total mercury (Hg) concentration for peat samples collected during the group sampling campaigns, involving a team of SPRUCE investigators and collaborators, in June 2014 (prior to deep peat warming experiment), September 2014 (target temperatures achieved at depth) and June 2015 (end of deep warming experiment and prior to whole ecosystem warming).  Peat samples for total mercury analysis were collected from Enclosures 4, 6, 8, 10, 11, 13, 16, 17, 19, 20.

This data set reports the results of total mercury and methylmercury analyses of the chemical analyses of outflow samples from the SPRUCE experimental study plots located in the S1-Bog. Sample collection and analyses started in April of 2017 and will continue for the duration of the experiment. Data will be added to this data set and released to the public periodically as quality assurance and publication of results are accomplished.

This data set reports the results of total mercury and methylmercury analyses of porewater samples from the SPRUCE experimental study plots located in the S1-Bog. Sample collection and analyses started in June of 2016 and will continue for the duration of the experiment. Data will be added to this data set and released to the public periodically as quality assurance and publication of results are accomplished.

This data set provided the results of a 2-year fungal necromass litter bag decomposition study at the Spruce and Peatland Responses Under Changing Environments (SPRUCE) experiment in the Marcell Experimental Forest in northern Minnesota, USA. Necromass from four mycorrhizal fungal species that naturally occur and associate with either the ectomycorrhizal (EM) tree hosts or ericoid mycorrhizal (ERM) shrubs in the S1 Bog site and vary in melanin content (Cenococcum geophilum Fr., Suillus grisellus, Meliniomyces bicolor, and Oideodendron griseum) were incubated in situ in SPRUCE experimental treatment chambers for 3, 12, and 24 months duration beginning in June of 2016 and ending in June of 2018. Analyses of the necromass included pre-incubation chemistry and post-incubation mass loss and Fourier transform infrared (FTIR) spectroscopy of remaining fungal necromass.

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 consists of observations of Normalized Difference Vegetation Index (NDVI) collected via stationary sensors positioned 1.5 meter above unobstructed areas of the ground layer. Sensors were installed above undisturbed community composition plots, that are not instrumented or destructively sampled in any way, in six of the ten chambered SPRUCE experimental study plots located in the S1-Bog. Spectral data (630 and 800 nanometers) were collected at 10-minute intervals over a field of view of ~53 cm in diameter beginning May 6, 2016.  Data collection ended at a different time for each sensor as batteries discharged – ranging from January 1, 2018 to April 1, 2018.

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 on 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, 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. Samples were collected from June of 2013 to June of 2014.

This dataset reports the results of nonstructural carbohydrate (NSC) analyses of foliage/twig/root tissues collected at the SPRUCE site in 2013. Samples were obtained at various locations around the S1 Bog. These are pretreatment vegetation samples, collected prior to initiation of the SPRUCE experiment heating and elevated CO2 treatments.

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 2016-2018 (October 2015 to October 2018). Additional data will be appended as they become available.

This data set consists of PhenoCam data from the SPRUCE experiment from the beginning of whole ecosystem warming in August 2015 through the end of 2017. Digital cameras, or phenocams, installed in each SPRUCE enclosure track seasonal variation in vegetation “greenness”, a proxy for vegetation phenology and associated physiological activity. Regions of interest (ROIs) were defined for vegetation types (1) Picea trees (EN, evergreen needleleaf); (2) Larix trees (DN, deciduous needleleaf); and (3) the mixed shrub layer (SH, shrubs). Users please note that this dataset has been superseded by a later version. See Schädel et al., 2019. https://doi.org/10.25581/spruce.071/1556082

This data set consists of phenological transition dates, as derived from direct observations of vegetative and reproductive phenology recorded by a human observer, from the SPRUCE experiment during the 2+ years (August 2015 through December 2017) of whole-ecosystem warming. For 2016, only springtime (April - June) phenological events are included. For 2017 (April - December), spring and autumn events are included.

Beginning in April 2016, human observers have been directly tracking the phenology of both woody and herbaceous species on a weekly schedule within the SPRUCE experimental chambers. The observed date report here is the first survey date on which an event/phenophase was definitively observed.

This data set provides links to the results of metagenomic analyses of 44 peat samples collected on 13 June 2016 from SPRUCE experiment treatment and ambient plots. Experimental plots had received approximately 24 months of belowground warming (deep peat heating (DPH), Hanson et al. 2015) with the last 9 of those months including air warming for implementation of whole ecosystems warming (WEW – Hanson et al. 2016). Data from these metagenomes are archived in the U.S. Department of Energy Joint Genome Institute (DOE JGI) Integrated Microbial Genomes (IMG) system. Link: https://img.jgi.doe.gov/cgi-bin/m/main.cgi. Quick Genome Search: June2016WEW.

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.

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.

The experimental work was conducted in a Picea mariana [black spruce] – Sphagnum spp. bog forest in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF).

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 experimental work was conducted in a Picea mariana [black spruce] – Sphagnum spp. bog forest in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF).

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.

The experimental work was conducted in a Picea mariana [black spruce] – Sphagnum spp. bog forest in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF).

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. The measurements were made in the S1 Bog, a Picea mariana [black spruce] – Sphagnum spp. bog forest in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF).

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, October 2016, April 2017, and August 2018. 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 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 results from two horizontal and vertical surveys (2015, 2020) 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.

In Process

data set contains empirical physiological, morphological, and chemical data collected on two dominant conifer species, Picea mariana and Larix laricina, between May 2016 and August 2017 at the SPRUCE (Spruce and Peatland Responses Under Changing Environments) experiment that assesses the response of peatland ecosystems to whole-ecosystem warming and elevated atmospheric CO2 concentrations. The SPRUCE experiment is located 40 km north of Grand Rapids, MN, in the USDA Forest Service Marcell Experimental Forest.

SPRUCE Diurnal and Seasonal Patterns of Water Potential in S1 Bog and SPRUCE Experimental Plot Vegetation beginning in 2011.

This dataset reports a suite of complementary environmental geochemical analyses of peat and pore water samples from SPRUCE experimental plots across a range of whole ecosystem warming (WEW) temperature treatments collected in August of 2016. Results of analyses of peat extracts include NMR and GC-MS analyses of central metabolites, liquid chromatography mass spectra (LC-MS) analyses of lipids, and quantitative proteomics. Pore water was analyzed by FTICR-MS for secondary metabolites and for carbon dioxide (CO2), methane (CH4) concentrations, stable isotope composition, and the differential solubility corrected CO2:CH4 ratio.
Analyses show that WEW stimulated primary production in warmer treatment enclosures resulting in increased fresh, labile organic matter inputs to the surface peat, thereby enhancing microbial activity and greenhouse gas production.
Investigations leveraged the Spruce and Peatland Responses Under Changing Environments (SPRUCE) experiment where air and peat warming were combined in WEW treatments. SPRUCE is located at the 8.1-ha S1 Bog forest site in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF).

Project Only

This data set provides a record of the aerial photographs of the SPRUCE experimental plots obtained using an unmanned aerial vehicle (UAV) with attached camera beginning in June of 2019. New photographs of the plots will be added periodically.

The UAV is a YUNEEC Typhoon Hexacopter with GCO3+ 4K Camera. Photographs were collected for the 10 plots with enclosures, the 7 unchambered plots, and the environmental monitoring instrument cluster area.  Images are slightly off-plot center at 12 to 15 meters above ground level or approximately 2 meters above the top of an experimental chamber.

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 in northern Minnesota, 40 km north of Grand Rapids in the USDA Forest Service Marcell Experimental Forest (MEF). Sample collection and analyses started in June of 2014 and will continue for the duration of the 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 an additional two plots without experimental enclosures, and thus a total of 12 plots. Core samples are collected annually from all 12 plots to a depth of 200cm in 10cm and 25cm increments. Samples are analyzed for total mercury concentration, methylmercury concentration, percent carbon, percent nitrogen, and percent sulfur.

This dataset provides vegetation survey data collected across vegetation community plots within the 10 chambered treatment plots (6, 19, 11, 20, 4, 13, 8, 16, 10, 17) and 3 unchambered ambient plots (7, 14, 21) of the SPRUCE experiment project in 2014-2020. The vegetation community plots, three in each experimental plot, were established in 2014 and designated to be undisturbed and reserved for long-term sampling. Vegetation survey data were collected at the peak of each growing season by placing a 1x2 meter rectangular grid over each community plot. The 1x2 meter grid is subset into 50 20x20 cm grid cells. Observations are of the presence of each species in each grid cell for each subplot. In 2018 and 2019, shrub stem density was counted and percent shrub cover was estimated in five selected grid cells in each vegetation community plot. Also included are photographs of each community plot taken at the time of data collection for each measurement year.

Periodic observations of the phenology of vegetation bud swell, leaf out, leaf off, flowering, fruiting and the nature of snow cover and ice presence have been assessed by SPRUCE project personnel since 2010. These observations are supplemented by the collection of images from periodic photographs. Annual summaries of vegetation phenology and snow and ice presence are also provided.

Early observations were conducted throughout the S1-Bog with an emphasis on the southern end of the bog. Observations collected since the spring of 2013 have focused on the southern end of the S1-Bog and the plots 2 through 21 of the SPRUCE experiment.  Beginning in 2015 those observations included assessments within the enclosure space surrounding plots 4, 6, 8, 10, 11, 13, 16, 17, 19 and 20.  Newly collected data will be appended annually.  2018 observations are now available.

This data set consists of images of fine-root birth, growth, and death collected using non-destructive minirhizotron technology from a warming × CO2 enrichment experiment in a forested, ombrotrophic bog. Minirhizotron images were collected ~ weekly or bi-weekly beginning in 2013 in the 12 SPRUCE experimental plots in paired hummock and hollow microtopography.

The dominant woody species in the bog, and the focus of our investigation, were trees Picea mariana (spruce) and Larix laricina (larch), and ericaceous shrubs Rhododendron groenlandicum and Chamaedaphne calyculata. In each of the 12 SPRUCE experimental plots, one pair of tubes was installed within a 1.5 m radius of spruce or larch trees (treed) and one pair was installed in areas dominated by ericaceous shrubs (non-treed), for a total of 48 tubes.

Each ~ weekly or bi-weekly imaging session resulted in ~4500 image files in JPEG (.jpg) format. To date (through the end of 2018) there are 291 sessions (including treed and non- treed sessions) and a total of ~625,000 images.

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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