Dissolved organic matter and associated light and temperature conditions in degradation experiments with water from tundra ponds on Bylot Island, Nunavut, Canada.

Permafrost thawing mobilizes large quantities of organic carbon that was sequestered in Arctic regions over the last glacial cycle. Processes involved in the oxidation and mineralization of this carbon need to be further assessed to estimate the fraction to be released into the atmosphere as greenhouse gases. This archive contains data from an experiment assessing the short term (12 days) degradation of dissolved organic matter (DOM) collected from four tundra ponds sampled early July on Bylot Island, Nunavut, Canada. Four treatments were applied in situ: 1- Control (C) obtained by filtering water onto 0.2 µm filters incubated in the dark; 2- Sunlight (S) obtained using the same filtered water but incubated under natural sunlight conditions; 3- Bacteria (B) obtained on unfiltered water incubated in the dark; 4- Sunlight and Bacteria (SB) obtained on unfiltered water incubated under natural light conditions. DOM was characterized by absorption scans, matrices of fluorescence (with PARAFAC extraction), and DOC quantification. Bacterial abundance was also followed. Associated environmental data are also included in this archive, specifically thermal profiles during sunny and cloudy days in two ponds, and light (PAR), air temperature and bottle temperatures during the incubations.

We are grateful to L. Boutet and P. N. Bégin for their help in the field, M. Lionard and W. F. Vincent for the flow cytometer analyses, V. Preskienis for insightful discussions and his comprehensive view of the landscape, S. Prémont for his assistance at the lab, G. Gauthier, D. Sarrazin and the Centre for Northern Studies for their precious help with the logistics, and Parks Canada for the access to this National park. Comments and suggestions provided by two anonymous reviewers and the associate editor were substantial and greatly helped to improve the manuscript. The research was funded by the Polar Continental Shelf Program of Natural Resources Canada, the Natural Sciences and Engineering Research Council of Canada (NSERC), and Network of Centres of Excellence ArcticNet.

Published

Version 1.0 (2010-2010) - Updated March 16, 2020