title: Bioturbation enhances the aerobic respiration of lake sediments in warming lakes.
abstract: While lakes occupy less than 2% of the total surface of the Earth, they play a substantial role in global biogeochemical cycles. For instance, shallow lakes are important sites of carbon metabolism. Aerobic respiration is one of the important drivers of the carbon metabolism in lakes. In this context, bioturbation impacts of benthic animals (biological reworking of sediment matrix and ventilation of the sediment) on sediment aerobic respiration have previously been underestimated. Biological activity is likely to change over the course of a year due to seasonal changes of water temperatures. This study uses microcosm experiments to investigate how the impact of bioturbation (by Diptera, Chironomidae larvae) on lake sediment respiration changes when temperatures increase. While at 5°C, respiration in sediments with and without chironomids did not differ, at 30°C sediment respiration in microcosms with 2000 chironomids per m(2) was 4.9 times higher than in uninhabited sediments. Our results indicate that lake water temperature increases could significantly enhance lake sediment respiration, which allows us to better understand seasonal changes in lake respiration and carbon metabolism as well as the potential impacts of global warming.
authors.affiliation: Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587 Berlin, Germany Faculty of Mathematics and Natural Sciences, Geography Department, Humboldt University of Berlin, Rudower Chaussee 16, 12489 Berlin, Germany baranov@igb-berlin.de.
authors.forename: Viktor
authors.identifier: 0000-0003-1893-3215
authors.initials: V
authors.lastname: Baranov
authors.affiliation: Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587 Berlin, Germany Faculty of Mathematics and Natural Sciences, Geography Department, Humboldt University of Berlin, Rudower Chaussee 16, 12489 Berlin, Germany.
authors.forename: Jörg
authors.identifier: 0000-0001-5278-129X
authors.initials: J
authors.lastname: Lewandowski
authors.affiliation: School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: Stefan
authors.initials: S
authors.lastname: Krause
mesh_terms: D000818:Animals; D002244:Carbon; D002683:Chironomidae; D019015:Geologic Sediments; D060106:Lakes; D007814:Larva
chemical_list: D002244:Carbon
keywords: Chironomidae; bioturbation; carbon metabolism; lakes; respiration; temperature