title: A comparison of the carbon balances of a natural lake (L. Orträsket) and a hydroelectric reservoir (L. Skinnmuddselet) in northern Sweden.
abstract: Carbon balances were calculated for the summer stratification period of 2001 for the hydroelectric reservoir L. Skinnmuddselet (created in 1989) and the natural L. Orträsket, and estimated on annual basis for both lakes. The reservoir and the lake have similar chemical characteristics and are located in adjacent catchments in the northern part of Sweden. Our main hypothesis was that the CO(2) production and emissions from the reservoir, L. Skinnmuddselet, would be greater than in the natural L. Orträsket, due to the decomposition of flooded vegetation and peat. The carbon balances showed that the total production of CO(2) per unit lake surface area during the summer was very similar in the natural lake and the reservoir (31.3 g Cm(-2) in L. Orträsket and 25.3 g Cm(-2) in L. Skinnmuddselet). The sediments were the major CO(2) source in the reservoir, while most of the mineralization in the natural lake occurred in the water column. On annual basis the natural L. Orträsket produced and emitted more CO(2) per unit of lake surface area than the reservoir L. Skinnmuddselet since mineralization proceeded during winter when L. Skinnmuddselet was emptied for electricity production. Therefore, the potential for CO(2) emission was not greater in the reservoir than in the natural lake.
authors.affiliation: Department of Ecology and Environmental Science, Umea University, Umea SE-901 87, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Aberg
authors.forename: Ann-Kristin
authors.initials: AK
authors.lastname: Bergström
authors.forename: Grete
authors.initials: G
authors.lastname: Algesten
authors.forename: Kenneth
authors.initials: K
authors.lastname: Söderback
authors.forename: Mats
authors.initials: M
authors.lastname: Jansson
mesh_terms: D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000032:analysis*; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D012621:Seasons; D013548:Sweden; D014881:Water Supply
chemical_list: D002245:Carbon Dioxide; D002244:Carbon