Effect of primary producers on microbial degradation of organic matter mobilized by permafrost thawing in small arctic and subarctic lakes

Samples are being collected at the two study sites in order to account for different states of permafrost degradation and colonization by plants. At both sites, vertical profiles of dissolved greenhouse gas (GHG) concentrations are obtained with the headspace equilibration technique, together with temperature and oxygen profiles. GHG fluxes are estimated using gas transfer models. Ebullition fluxes are also measured using submerged funnels. Lake water samples are collected to quantify dissolved organic carbon (DOC), total nitrogen and phosphorus, soluble reactive phosphorus, chlorophyll-a, and major cations and anions. The Chromophoric fraction of dissolved organic matter (DOM) is characterized with absorbance scans and fluorescence matrices (PARAFAC), and a subset of DOM samples is analyzed with high-resolution mass spectrometry (FT-ICR-MS). Bacterial abundance is estimated by flow cytometry. Lake water collected during field work is brought back to the laboratory for further experiments. Three-week incubations are conducted using microcosms with the microbial food web exposed to varying conditions. As a preliminary set of experiments carried out in June 2016, water collected in March from a thermokarst lake located in the Sasapimakwananisikw River valley near Kuujjuarapik was incubated with algal lysates and glucose. During the incubation, dissolved oxygen concentration was measured along with DOC concentration and DOM optical characteristics. Heterotrophic bacterial abundance and bacterial production (leucine incorporation) were also determined.

Identifier
Source https://www.polardata.ca/pdcsearch/PDCSearchDOI.jsp?doi_id=12726
Metadata Access http://www.polardata.ca/oai/provider?verb=GetRecord&metadataPrefix=fgdc&identifier=12726_fgdc
Provenance
Creator LAURION, Isabelle; PACOUREAU, Thomas; GUILLEMETTE, François; MAZOYER, Flora; PRESKIENIS, Vilmantas; RAUTIO , Milla
Publisher Canadian Cryospheric Information Network
Contributor Polar Data Catalogue
Publication Year 2017
Rights Research programs, CCIN, or ArcticNet take no liability for the use or transmission of this data
OpenAccess true
Contact isabelle.laurion(at)ete.inrs.ca; pdc(at)uwaterloo.ca
Representation
Language English
Format Computer file
Discipline Environmental Research
Spatial Coverage (-83.000W, 54.000S, -74.000E, 75.000N)
Temporal Coverage Begin 2016-03-18T00:00:00Z
Temporal Coverage End 2019-12-30T00:00:00Z