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Variation in carbon and nitrogen concentrations among peatland categories at the global scale

November 23, 2022

Peatlands account for 15 to 30% of the world’s soil carbon (C) stock and are important controls over global nitrogen (N) cycles. However, C and N concentrations are known to vary among peatlands contributing to the uncertainty of global C inventories, but there are few global studies that relate peatland classification to peat chemistry. We analyzed 436 peat cores sampled in 24 countries across six continents and measured C, N, and organic matter (OM) content at three depths down to 70 cm. Sites were distinguished between northern (387) and tropical (49) peatlands and assigned to one of six distinct broadly recognized peatland categories that vary primarily along a pH gradient. Peat C and N concentrations, OM content, and C:N ratios differed significantly among peatland categories, but few differences in chemistry with depth were found within each category. Across all peatlands C and N concentrations in the 10–20 cm layer, were 440 ± 85.1 g kg-1 and 13.9 ± 7.4 g kg-1, with an average C:N ratio of 30.1 ± 20.8. Among peatland categories, median C concentrations were highest in bogs, poor fens and tropical swamps (446–532 g kg-1) and lowest in intermediate and extremely rich fens (375–414 g kg-1). The C:OM ratio in peat was similar across most peatland categories, except in deeper samples from ombrotrophic tropical peat swamps that were higher than other peatlands categories. Peat N concentrations and C:N ratios varied approximately two-fold among peatland categories and N concentrations tended to be higher (and C:N lower) in intermediate fens compared with other peatland types. This study reports on a unique data set and demonstrates that differences in peat C and OM concentrations among broadly classified peatland categories are predictable, which can aid future studies that use land cover assessments to refine global peatland C and N stocks.

Publication Year 2022
Title Variation in carbon and nitrogen concentrations among peatland categories at the global scale
DOI 10.1371/journal.pone.0275149
Authors Shaun A. Watmough, Spencer Gilbert-Parkes, Nathan Basiliko, Louis J. Lamit, Erik A. Lilleskov, Roxanne Andersen, Jhon del Aguila-Pasquel, Rebekka E. Artz, Brian W. Benscoter, Werner Borken, Luca Bragazza, Stefani M. Brandt, Suzanna L. Bräuer, Michael A. Carson, Xin Chen, Rodney A. Chimner, Bev R. Clarkson, Alexander R. Cobb, Andrea S. Enriquez, Jenny Farmer, Samantha P. Grover, Charles F. Harvey, Lorna I. Harris, Christina Hazard, Alison M. Hoyt, John Hribljan, Jyrki Jauhiainen, Sari Juutinen, Evan S. Kane, Klaus-Holger Knorr, Randy Kolka, Mari Könönen, Anna M. Laine, Tuula Larmola, Patrick A. Levasseur, Carmody K. McCalley, Jim McLaughlin, Tim R. Moore, Nadia Mykytczuk, Anna E. Normand, Virginia Rich, Bryce Robinson, Danielle L. Rupp, Jasmine Rutherford, Christopher W. Schadt, Dave S. Smith, Graeme Spiers, Leho Tedersoo, Pham Q. Thu, Carl C. Trettin, Eeva-Stiina Tuittila, Merritt Turetsky, Zuzana Urbanová, Ruth K. Varner, Mark Waldrop, Meng Wang, Zheng Wang, Matt Warren, Magdalena M. Wiedermann, Shanay T. Williams, Joseph B. Yavitt, Zhi-Guo Yu, Geoff Zahn
Publication Type Article
Publication Subtype Journal Article
Series Title PLoS ONE
Index ID 70261202
Record Source USGS Publications Warehouse
USGS Organization Geology, Minerals, Energy, and Geophysics Science Center
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