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Title: SPRUCE Geochemical Changes in Porewater from Northern Peatlands at Multiple Depths in Field Samples and over Time in Peat Incubations

Dataset ·

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. Porewater samples were collected from the S1 Bog (April 2015), a Sphagnum-dominated site at northern Minnesota peatland in the Marcell Experimental Forest, using permanently-installed piezometers, which provided profiles from the watertable surface to 200 cm depth. This is the site of the SPRUCE experiment. Porewater and peat samples were collected in July 2015 from an additional Sphagnum-dominated site within Stordalen Mire, Sweden, a palsa mire underlain by thawing permafrost, using perforated stainless steel tubes that were inserted into the peat to the desired depths (13 cm and 32 cm). Porewater samples were analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) followed by Kendrick mass transform analysis. The Kendrick mass (i.e., Kendrick 1963) transform analysis identifies the gain or loss of specific chemical moieties (e.g. CH2, H2, CH2O, etc.) via mass differences, and was used to infer potential microbial degradation pathways by which compounds were consumed in these samples. Increasing depth would suggest more degradation of DOM with the greater length of time for peat accumulation and similarly, with increasing length of peat incubation. During incubations, CO2 and CH4 concentrations and stable isotopes were determined by isotope ratio mass spectrometry.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER). Earth and Environmental Systems Science Division
DOE Contract Number:
AC05-00OR22725
OSTI ID:
1673623
Resource Relation:
Related Information: Rachel M. Wilson, Malak M. Tfaily, Virginia I. Rich, Jason K. Keller, Scott D. Bridgham, Cassandra Medvedeff Zalman, Laura Meredith, Paul J. Hanson, Mark Hines, Laurel Pfeifer-Meister, Scott R. Saleska, Patrick Crill, William T. Cooper, Jeff P. Chanton, and Joel E. Kostka. 2017. Hydrogenation of organic matter as a terminal electron sink sustains high CO2:CH4 production ratios during anaerobic decomposition. Organic Geochemistry, Volume 112, 2017, Pages 22-32, ISSN 0146-6380, https://doi.org/10.1016/j.orggeochem.2017.06.011
Country of Publication:
United States
Language:
English