Title: Decomposition of peat and plant material from a thawing palsa
Citation: Roulet, N., & Zheng, W. (2015). Decomposition of peat and plant material from a thawing palsa. NWT Discovery Portal. https://nwtdiscoveryportal.enr.gov.nt.ca/geoportal/catalog/search/resource/details.page?uuid=%7BDE4E8445-AF42-4E8B-B280-32BDE0B14F60%7D
Study Site: Kuujjuarapik-Whapmagoostui, Québec
Purpose: Ample evidence shows that dissolved organic carbon (DOC) would be the major or even the only direct contributor to the respired carbon fluxes in temperate forest, peatland, even permafrost peatland. And DOC pool is composed by different DOC fractions with a continuum of biodegradability ranging from labile fractions to recalcitrant fractions. The goal of this research was to provide the litter continuous-recalcitrance (decomposition status) DOC production/mineralization functions for each litter type in permafrost peatland for my model to simulate DOC production /mineralization along peat profile. This study will also provide a constant anaerobic moisture modifier for DOC production/mineralization, test and modify the unsaturated moisture modifier that is used in the Holocene Peat Model (HPM), and modify decomposition temperature dependency that is used in the McGill Wetland Model.
Abstract: Vegetation samples of shrub, sedges and moss were collected from permafrost peatland in the eastern shore of Hudson Bay, near the hamlet of Kuujjuarapik-Whapmagoostui in subarctic Quebec in summer 2012. Each litter type was incubated under two moist conditions (Anoxic and oxic treatments), and adjusted to 2 different temperatures (~4ºC and ~22ºC). I have set several time interval (caused different mass remaining, i.e. different decomposition degrees) to repeat this measurement three to five times along the incubation for each peatland litter type. At each time interval, the samples were drained, rewashed with distilled water, and the water was replaced in order to remove the DOC produced by previous degradation status organic matter. DOC concentration plus CO2 and CH4 concentrations at each time interval were measured, as well as DOC biodegradability (determined by its spectroscopic properties by UV radiation absorbance). The DOC, CH4 and CO2 concentration were expressed as g-1 oven-dry plant tissue.
Supplemental Information Summary:
Research:
Further Info:
Status: Complete
Keywords:
methane,
vegetation,
carbon dioxide,
dissolved organic carbon,
Biogeochemistry,
decomposition,
Geographical coordinates: North: 55.21, South: 55.2 East: -77.3 West: -77.31
Bounding Temporal Extent: Start Date: 2012-06-01, End
Date: 2012-08-31
