caa a22 4500 605516510 CHVBK 20210128100714.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s10533-015-0098-z doi (NATIONALLICENCE)springer-10.1007/s10533-015-0098-z Effect of open water pools on ecosystem scale surface-atmosphere carbon dioxide exchange in a boreal peatland [Elektronische Daten] [Luc Pelletier, Ian Strachan, Nigel Roulet, Michelle Garneau, Karoline Wischnewski] Peatland carbon dioxide (CO2) exchange can vary spatially over a few meters because of the heterogeneity in plant communities, differing responses to environmental conditions, and the presence of pools in patterned peatlands. In contrast to the plant communities comprising a peatland's vegetated surface, permanent pools that are characteristic of peatlands in temperate to subarctic regions are net sources of CO2 to the atmosphere. Measurements of net ecosystem CO2 exchange using the eddy covariance (EC) technique over peatlands without permanent pools do not show the smaller plant scale spatial heterogeneity in fluxes because the atmosphere mixes the variations in fluxes over the EC tower source area. However, if different vegetation communities and pools approach the spatial scale that they form a significant proportion of an EC tower's source area, such as might be the case in peatlands with pools, they should be able to be discriminated if the surface fluxes by cover type are significantly different. In the present study, we evaluate if the observed variability in peatland surface CO2 exchange can be identified from 30-min net ecosystem CO2 exchange measurements using the proportion of the different plant communities or pools within the eddy covariance tower source area. Our results show that the variability in CO2 exchange at the local scale across the peatland surface has a measureable impact on the ecosystem level measurement, primarily when open water pools are present within the tower source area. Our results also suggest that large CO2 exchange rates measured above Sphagnum spp. hummocks with Picea mariana, combined with their large fractional contribution to the source area, counterbalanced the CO2 loss from the open water pools, explaining why the ecosystem as a whole was a net CO2 sink during the measurement period. Springer International Publishing Switzerland, 2015 Peatland nationallicence Open water pools nationallicence Carbon dioxide nationallicence Eddy covariance nationallicence Source area nationallicence Pelletier Luc Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, Canada aut Strachan Ian Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, Canada aut Roulet Nigel Global Environmental and Climate Change Centre, McGill University, Montréal, QC, Canada aut Garneau Michelle GEOTOP Research Center, Université du Québec à Montréal, Montréal, QC, Canada aut Wischnewski Karoline Département de Géographie, Université de Montréal, Montréal, QC, Canada aut Biogeochemistry Springer International Publishing 124/1-3(2015-05-01), 291-304 0168-2563 124:1-3<291 2015 124 10533 https://doi.org/10.1007/s10533-015-0098-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10533-015-0098-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Pelletier Luc Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, Canada aut NATIONALLICENCE 700 1- Strachan Ian Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, Canada aut NATIONALLICENCE 700 1- Roulet Nigel Global Environmental and Climate Change Centre, McGill University, Montréal, QC, Canada aut NATIONALLICENCE 700 1- Garneau Michelle GEOTOP Research Center, Université du Québec à Montréal, Montréal, QC, Canada aut NATIONALLICENCE 700 1- Wischnewski Karoline Département de Géographie, Université de Montréal, Montréal, QC, Canada aut NATIONALLICENCE 773 0- Biogeochemistry Springer International Publishing 124/1-3(2015-05-01), 291-304 0168-2563 124:1-3<291 2015 124 10533