caa a22 4500 445383437 CHVBK 20180317143024.0 cr unu---uuuuu 170323e20110101xx s 000 0 eng 10.1007/s10021-010-9393-7 doi (NATIONALLICENCE)springer-10.1007/s10021-010-9393-7 Spatial Heterogeneity of Surface CO2 Fluxes in a Newly Created Eastmain-1 Reservoir in Northern Quebec, Canada [Elektronische Daten] [Cristian Teodoru, Yves Prairie, Paul del Giorgio] We assessed the spatial variability in both, surface carbon dioxide (CO2) fluxes and in pelagic respiration rates in a newly created 600-km2 boreal reservoir, located in Northern Quebec. We show that total CO2 emission to the atmosphere was highest in the first year after flooding, and that surface fluxes were spatially heterogeneous. This spatial heterogeneity was not random, but was linked to the pre-flood landscapes: reservoir areas overlying former peatbogs and mature forests had the highest average emissions, whereas areas overlying former non-forest and burned soils had the lowest emissions. Total reservoir emissions appeared to decline exponentially in the next 2years, and so did the degree of spatial heterogeneity in surface fluxes, suggesting a progressive weakening of the link to the pre-flood landscapes, and a homogenization of reservoir processes. We show that pelagic respiration rates were also initially high and spatially heterogeneous, the latter linked to the pre-flood landscapes. A simple, first-order mass balance for the first 3years after flooding was used to derive potential benthic CO2 production rates, and thus to apportion the total reservoir emissions between its pelagic and benthic components. Extrapolation of the observed declines (normal exponential) in total emission, as well as of the underlying pelagic and benthic fluxes, results in a large underestimation of the fluxes for the fourth year, relative to the measured emissions. We postulate that the initial exponential decline in total emissions is driven primarily by the patterns of decomposition of surface plant biomass, whereas at later stages emission is increasingly dominated by sediment and pelagic respiration, which decline in time at a slower rate. Springer Science+Business Media, LLC, 2010 carbon stock nationallicence CO2 flux nationallicence GHG emission nationallicence hydropower reservoir nationallicence pre-flood ecosystem nationallicence soil respiration nationallicence water column respiration nationallicence Teodoru Cristian Département des Sciences Biologiques, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, H3C 3P8, Montréal, Quebec, Canada aut Prairie Yves Département des Sciences Biologiques, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, H3C 3P8, Montréal, Quebec, Canada aut del Giorgio Paul Département des Sciences Biologiques, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, H3C 3P8, Montréal, Quebec, Canada aut Ecosystems Springer-Verlag 14/1(2011-01-01), 28-46 1432-9840 14:1<28 2011 14 10021 https://doi.org/10.1007/s10021-010-9393-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10021-010-9393-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Teodoru Cristian Département des Sciences Biologiques, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, H3C 3P8, Montréal, Quebec, Canada aut NATIONALLICENCE 700 1- Prairie Yves Département des Sciences Biologiques, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, H3C 3P8, Montréal, Quebec, Canada aut NATIONALLICENCE 700 1- del Giorgio Paul Département des Sciences Biologiques, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, H3C 3P8, Montréal, Quebec, Canada aut NATIONALLICENCE 773 0- Ecosystems Springer-Verlag 14/1(2011-01-01), 28-46 1432-9840 14:1<28 2011 14 10021 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer