This data set includes the chemistry of porewater in the SPRUCE experiment plots located in the S1 bog of the USDA Forest Service Marcell Experimental Forest (MEF) in northern Minnesota, 40 km north of Grand Rapids. Sample collection and analyses started in August of 2013 and will continue for the duration of the experiment. The current release contains data through 2020.
These data are the pre- and post-treatment data from the warming and elevated carbon dioxide (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.
Samples were analyzed for pH, specific conductivity, nutrient concentrations (ammonium, nitrate, soluble reactive phosphorus, total nitrogen, total phosphorus), cation concentrations (calcium, potassium, magnesium, sodium, aluminum, iron, manganese, silicon, strontium), anion concentrations (chloride, sulfate), and total organic carbon (TOC) concentrations. Subsets of the samples have been analyzed for natural-abundance stable isotopes of water (δ18O-H2O and δD-H2O) and total mercury (THg) and methylmercury (MeHg) concentrations. While the THg and MeHg are described and provided in another data publication (Pierce et al. 2019), the values are included here for the convenience of comparison to and use with other porewater chemistry.
User note: Results will be added to this data set and released to the public periodically as quality assurance and publication of results are accomplished. This February 2022 release (Version 3) is an updated and expanded version that supersedes and replaces the previous release. See the Data Release History table in the user guide for additional release notes.
Griffiths, N. A., S.D. Sebestyen, K.C. Oleheiser, J.M. Stelling, C.E. Pierce, E.A. Nater, B.M. Toner, & R.K. Kolka. 2016. SPRUCE Porewater Chemistry Data for Experimental Plots, Beginning in 2013. Oak Ridge National Laboratory, TES SFA, US Department of Energy, Oak Ridge, Tennessee, USA. Version 3. https://doi.org/10.3334/CDIAC/spruce.028.
Wednesday, August 3, 2016