07 May 2021

07 May 2021

Review status: this preprint is currently under review for the journal ESSD.

The Boreal-Arctic Wetland and Lake Dataset (BAWLD)

David Olefeldt1, Mikael Hovemyr2, McKenzie A. Kuhn1, David Bastviken3, Theodore J. Bohn4, John Connolly5, Patrick Crill6, Eugénie S. Euskirchen7,8, Sarah A. Finkelstein9, Hélène Genet8, Guido Grosse10,11, Lorna I. Harris1, Liam Heffernan12, Manuel Helbig13, Gustaf Hugelius2,14, Ryan Hutchins15, Sari Juutinen16, Mark J. Lara17,18, Avni Malhotra19, Kristen Manies20, A. David McGuire8, Susan M. Natali21, Jonathan A. O'Donnell22, Frans-Jan W. Parmentier23,24, Aleksi Räsänen25, Christina Schädel26, Oliver Sonnentag27, Maria Strack28, Suzanne Tank29, Claire Treat10, Ruth K. Varner2,30, Tarmo Virtanen25, Rebecca K. Warren31, and Jennifer D. Watts21 David Olefeldt et al.
  • 1Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2G7, Canada
  • 2Department of Physical Geography, Stockholm University, 10691 Stockholm, Sweden
  • 3Department of Thematic Studies – Environmental Change, Linköping University, 58183 Linköping, Sweden
  • 4WattIQ, 400 Oyster Point Blvd. Suite 414, South San Francisco, CA, 94080, USA
  • 5Department of Geography, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
  • 6Department of Geological Sciences, Stockholm University, 10691 Stockholm, Sweden
  • 7Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
  • 8Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
  • 9Department of Earth Sciences, University of Toronto, Toronto, ON, M5S 3B1, Canada
  • 10Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Permafrost Research Section, 14473 Potsdam, Germany
  • 11Institute of Geosciences, University of Potsdam, 14476 Potsdam, Germany
  • 12Department of Ecology and Genetics, Uppsala University, 752 36 Uppsala, Sweden
  • 13Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, B3H 4R2, Canada
  • 14Bolin Centre for Climate Research, Stockholm University, 10691 Stockholm, Sweden
  • 15Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
  • 16Ecosystems and Environment Research Program, University of Helsinki, FI-00014 Helsinki, Finland
  • 17Department of Plant Biology, University of Illinois, Urbana, IL 61801, USA
  • 18Department of Geography, University of Illinois, Urbana, IL 61801, USA
  • 19Department of Earth System Science, Stanford University, Stanford, CA 94305, USA
  • 20U.S. Geological Survey, Menlo Park, CA, USA
  • 21Woodwell Climate Research Center, Falmouth, MA 02540, USA
  • 22Arctic Network, National Park Service, Anchorage, AK 99501 USA
  • 23Centre for Biogeochemistry in the Anthropocene, Department of Geosciences, University of Oslo, 0315 Oslo, Norway
  • 24Department of Physical Geography and Ecosystem Science, Lund University, 223 62 Lund, Sweden
  • 25Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, 00014 University of Helsinki, Finland
  • 26Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ 86011, USA
  • 27Département de Géographie, Université de Montréal, Montréal, QC, Canada
  • 28Department of Geography and Environmental Management, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
  • 29Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
  • 30Department of Earth Sciences and Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durhan, NH 03824, USA
  • 31National Boreal Program, Ducks Unlimited Canada, Edmonton, AB, T5S 0A2, Canada

Abstract. Methane emissions from boreal and arctic wetlands, lakes, and rivers are expected to increase in response to warming and associated permafrost thaw. However, the lack of appropriate land cover datasets for scaling field-measured methane emissions to circumpolar scales has contributed to a large uncertainty for our understanding of present-day and future methane emissions. Here we present the Boreal-Arctic Wetland and Lake Dataset (BAWLD), a land cover dataset based on an expert assessment, extrapolated using random forest modelling from available spatial datasets of climate, topography, soils, permafrost conditions, vegetation, wetlands, and surface water extents and dynamics. In BAWLD, we estimate the fractional coverage of five wetland, seven lake, and three river classes within 0.5 × 0.5° grid cells that cover the northern boreal and tundra biomes (17 % of the global land surface). Land cover classes were defined using criteria that ensured distinct methane emissions among classes, as indicated by a co-developed comprehensive dataset of methane flux observations. In BAWLD, wetlands occupied 3.2 × 106 km2 (14 % of domain) with a 95 % confidence interval between 2.8 and 3.8 × 106 km2. Bog, fen, and permafrost bog were the most abundant wetland classes, covering ~28 % each of the total wetland area, while the highest methane emitting marsh and tundra wetland classes occupied 5 and 12 %, respectively. Lakes, defined to include all lentic open-water ecosystems regardless of size, covered 1.4 × 106 km2 (6 % of domain). Low methane-emitting large lakes (> 10 km2) and glacial lakes jointly represented 78 % of the total lake area, while high-emitting peatland and yedoma lakes covered 18 and 4 %, respectively. Small (< 0.1 km2) glacial, peatland, and yedoma lakes combined covered 17 % of the total lake area, but contributed disproportionally to the overall spatial uncertainty of lake area with a 95 % confidence interval between 0.15 and 0.38 × 106 km2. Rivers and streams were estimated to cover 0.12 × 106 km2 (0.5 % of domain) of which 8 % was associated with high-methane emitting headwaters that drain organic-rich landscapes. Distinct combinations of spatially co-occurring wetland and lake classes were identified across the BAWLD domain, allowing for the mapping of “wetscapes” that will have characteristic methane emission magnitudes and sensitivities to climate change at regional scales. With BAWLD, we provide a dataset which avoids double-accounting of wetland, lake and river extents, and which includes confidence intervals for each land cover class. As such, BAWLD will be suitable for many hydrological and biogeochemical modelling and upscaling efforts for the northern Boreal and Arctic region, in particular those aimed at improving assessments of current and future methane emissions. Data is freely available at (Olefeldt et al., 2021).  

David Olefeldt et al.

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on essd-2021-140', Anonymous Referee #1, 09 Jul 2021
    • AC1: 'Author response to reviewer comments', David Olefeldt, 31 Aug 2021
  • RC2: 'Comment on essd-2021-140', Anonymous Referee #2, 21 Jul 2021
    • AC1: 'Author response to reviewer comments', David Olefeldt, 31 Aug 2021
  • RC3: 'Comment on essd-2021-140', Anonymous Referee #3, 28 Jul 2021
    • AC1: 'Author response to reviewer comments', David Olefeldt, 31 Aug 2021
  • AC1: 'Author response to reviewer comments', David Olefeldt, 31 Aug 2021

David Olefeldt et al.

Data sets

The fractional land cover estimates from the Boreal-Arctic Wetland and Lake Dataset (BAWLD) Olefeldt, D., Hovemyr, M., Kuhn, M. A., Bastviken, D., Bohn, T. J., Connolly, J., Crill, P., Euskirchen, E. S., Finkelstein, S. A., Genet, H., Grosse, G., Harris, L. I., Heffernan, L., Helbig, M., Hugelius, G., Hutchins, R., Juutinen, S., Lara, M. J., Malhotra, A., Manies, K., McGuire, A .D., Natali, S. M., O’Donnell, J. A., Parmentier, F.-J. W., Räsänen, A., Schädel, C., Sonnentag, O., Strack, M., Tank, S. E., Treat, C., Varner, R. K., Virtanen, T., Warren, R. K., and Watts, J. D.

David Olefeldt et al.


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Short summary
Wetlands, lakes and rivers are important sources of the greenhouse gas methane to the atmosphere. To understand current and future methane emissions from northern regions, we need maps that show the extent and distribution of specific types of wetlands, lakes, and rivers. The Boreal-Arctic Wetland and Lake Dataset (BAWLD) provides maps of five wetland types, seven lake types, and three river types for northern regions, and will improve our ability to predict future methane emissions.