Comparison of plant litter and peat decomposition changes with permafrost thaw in a subarctic peatland
- 475 Downloads
Background and aims
Organic matter decomposition in response to thawing permafrost has critical implications for carbon release. This study examined how thaw induced plant community and environmental changes influenced litter and peat decomposition in a subarctic peatland.
We conducted laboratory incubations under current site pre-thaw (dry and large oxic peat layer) and thawed (wet and small oxic peat layer) conditions, and mimiced pond thaw conditions (water saturated and anoxic) at 4 and 22 °C. Carbon dioxide (CO2) and methane (CH4) releases from ground surface plant litter and top 1 m peat samples at permafrost area (Palsa) and wet thawed lawn (WL) were quantified under current site conditions. Dissolved organic carbon (DOC) released from litter was additionally quantified under pond thaw conditions.
Plant litter mass significantly increased from Palsa to WL. Under current site conditions, litter in WL had significantly higher CO2 and CH4 production rates than litter in Palsa. Pond thaw conditions changed litter carbon loss partitioning into lower CO2 but higher DOC and CH4 production, and increased total carbon release. Whole peat decomposition was restricted from Palsa to WL with thaw. Estimated growing season gas carbon loss (CO2 and CH4) in WL was greater than that in Palsa due to significantly increased litter carbon loss after thaw.
Changes in organic matter decomposition, especially litter decomposition, enlarged carbon losses from this subarctic peatland with permafrost thaw.
KeywordsDecomposition CO2 CH4 DOC production Litter Peat Permafrost thaw Subarctic peatland
We thank Claude Tremblay, Warwick F. Vincent, Najat Bhiry and Denis Sarrazin and the Centre des e’etudes norique for field support and site access. Mike Dalva provded laboratory and technical assistances, particularly in the preparation of equipment for use in the field. Kristina Disney and Paul Wilson helped to prepare field instruments and assisted with field research. Youngil Kim provided advices of laboratory incubations. Tim Moore made numerous suggestions on data analysis, and interpretations of results. Alexandre Lamarre and Michelle Garneau kindly shared their peat carbon density data in palsa and permafrost thaw areas. ZW received financial assistance from a Ph.D. fellowship by Chinese Scholarship Council, and recruitment and foreign student differential fee scholarships from Department of Geography, McGill University. This research was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Frontiers grant for ADAPT project (411351), and a NSERC DG grant (RGPIN 153450-12) to NTR.
- Bhiry N, Delwaide A, Allard M, Bégin Y, Filion L, Lavoie M, Nozais C, Payette S, Pienitz R, Saulnier-Talbot É, Vincent WF (2011) Environmental change in the great Whale River region, Hudson Bay: five decades of multidisciplinary research by Centre d'études Nordiques (CEN). Ecoscience 18:182–203CrossRefGoogle Scholar
- Bracho R, Natali S, Pegoraro E, Crummer KG, Schädel C, Celis G, Hale L, Wu L, Yin H, Tiedje JM, Konstantinidis KT, Luo Y, Zhou J, Schuur EAG (2016) Temperature sensitivity of organic matter decomposition of permafrost-region soils during laboratory incubations. Soil Biol Biochem 97:1–14CrossRefGoogle Scholar
- Euskirchen ES, Edgar CW, Turetsky MR, Waldrop MP, Harden JW (2014) Differential response of carbon fluxes to climate in three peatland ecosystems that vary in the presence and stability of permafrost. Journal of Geophysical Research: Biogeosciences 119:1576–1595Google Scholar
- Frolking S, Roulet NT, Moore TR, Lafleur PM, Bubier JL, Crill PM (2002) Modeling seasonal to annual carbon balance of Mer Bleue Bog, Ontario. Canada Global Biogeochem Cycles 16:1030Google Scholar
- Grosse G, Harden J, Turetsky M, McGuire AD, Camill P, Tarnocai C, Frolking S, Schuur EAG, Jorgenson T, Marchenko S, Romanovsky V, Wickland KP, French N, Waldrop M, Bourgeau-Chavez L, Striegl RG (2011) Vulnerability of high-latitude soil organic carbon in North America to disturbance. J Geophys Res 116. doi: 10.1029/2010JG001507
- Herndon EM, Mann BF, Roy Chowdhury T, Yang Z, Wullschleger SD, Graham D, Liang L, Gu B (2015) Pathways of anaerobic organic matter decomposition in tundra soils from Barrow, Alaska. Journal of Geophysical Research: Biogeosciences 120:2345–2359Google Scholar
- Hicks Pries CE, van Logtestijn RSP, Schuur EAG, Natali SM, Cornelissen JHC, Aerts R, Dorrepaal E (2015) Decadal warming causes a consistent and persistent shift from heterotrophic to autotrophic respiration in contrasting permafrost ecosystems. Glob Chang Biol 21:4508–4519CrossRefPubMedGoogle Scholar
- Hodgkins, S. B., M. M. Tfaily, C. K. McCalley, T. A. Logan, P. M. Crill, S. R. Saleska, V. I. Rich, and J. P. Chanton (2014) Changes in peat chemistry associated with permafrost thaw increase greenhouse gas production. Proceedings of the National Academy of Sciences:doi: 10.1073/pnas.1314641111
- Hugelius G, Strauss J, Zubrzycki S, Harden JW, Schuur EAG, Ping CL, Schirrmeister L, Grosse G, Michaelson GJ, Koven CD, O'Donnell JA, Elberling B, Mishra U, Camill P, Yu Z, Palmtag J, Kuhry P (2014) Estimated stocks of circumpolar permafrost carbon with quantified uncertainty ranges and identified data gaps. Biogeosciences 11:6573–6593CrossRefGoogle Scholar
- IPCC (2013) Near-term climate change: projections and predictability. In: Climate change 2013: the physical science basis. Cambridge University Press, Cambridge and New York, pp 953–1028Google Scholar
- Loisel J, Yu Z (2013) Recent acceleration of carbon accumulation in a boreal peatland, south central Alaska. Journal of Geophysical Research: Biogeosciences 118:41–53Google Scholar
- Malhotra A. 2016. Relating Self-regulation with Ecosystem Structure and Function in Northern Peatlands. Pages: 43–52. Biogeosciences. McGill University. Montreal. Quebec. CanadaGoogle Scholar
- Malmer N, Johansson T, Olsrud M, Christensen TR (2005) Vegetation, climatic changes and net carbon sequestration in a north-Scandinavian subarctic mire over 30 years. Glob Chang Biol 11:1895–1909Google Scholar
- Nykanen, H., J. E. P. Heikkinen, L. Pirinen, K. Tiilikainen, and P. J. Martikainen. 2003. Annual CO2 exchange and CH4 fluxes on a subarctic palsa mire during climatically different years. Global Biogeochemical Cycles 17:doi: 10.1029/2002GB001861
- Olefeldt D, Roulet NT (2012) Effects of permafrost and hydrology on the composition and transport of dissolved organic carbon in a subarctic peatland complex. J Geophys Res Biogeosci 117. doi: 10.1029/2011JG001819
- Payette S (2004) Accelerated thawing of subarctic peatland permafrost over the last 50 years. Geophys Res Lett 31. doi: 10.1029/2004GL020358
- Prokushkin AS, Gleixner G, McDowell WH, Ruehlow S, Schulze ED (2007) Source- and substrate-specific export of dissolved organic matter from permafrost-dominated forested watershed in central Siberia. Glob Biogeochem Cycles 21. doi: 10.1029/2007GB002938
- Roy Chowdhury T, Herndon EM, Phelps TJ, Elias DA, Gu B, Liang L, Wullschleger SD, Graham DE (2014) Stoichiometry and temperature sensitivity of methanogenesis and CO2 production from saturated polygonal tundra in Barrow, Alaska. Glob Chang Biol 21. doi: 10.1111/gcb.12762
- Schuur EAG, Bockheim J, Canadell JG, Euskirchen E, Field CB, Goryachkin SV, Hagemann S, Kuhry P, Lafleur PM, Lee H, Mazhitova G, Nelson FE, Rinke A, Romanovsky VE, Shiklomanov N, Tarnocai C, Venevsky S, Vogel JG, Zimov SA (2008) Vulnerability of permafrost carbon to climate change: implications for the global carbon cycle. Bioscience 58:701–714CrossRefGoogle Scholar
- Tarnocai C, Canadell JG, Schuur EAG, Kuhry P, Mazhitova G, Zimov S (2009) Soil organic carbon pools in the northern circumpolar permafrost region. Glob Biogeochem Cycles 23. doi: 10.1029/2008GB003327
- Treat CC, Frolking S (2013) Carbon storage: a permafrost carbon bomb? Nature Clim. Change 3:865–867Google Scholar
- Waldrop MP, Wickland KP, White R, Berhe AA, Harden JW, Romanovsky VE (2010) Molecular investigations into a globally important carbon pool: permafrost-protected carbon in Alaskan soils. Glob Chang Biol 16:2543–2554Google Scholar