title: Increases in terrestrially derived carbon stimulate organic carbon processing and CO₂ emissions in boreal aquatic ecosystems.
abstract: The concentrations of terrestrially derived dissolved organic carbon have been increasing throughout northern aquatic ecosystems in recent decades, but whether these shifts have an impact on aquatic carbon emissions at the continental scale depends on the potential for this terrestrial carbon to be converted into carbon dioxide. Here, via the analysis of hundreds of boreal lakes, rivers and wetlands in Canada, we show that, contrary to conventional assumptions, the proportion of biologically degradable dissolved organic carbon remains constant and the photochemical degradability increases with terrestrial influence. Thus, degradation potential increases with increasing amounts of terrestrial carbon. Our results provide empirical evidence of a strong causal link between dissolved organic carbon concentrations and aquatic fluxes of carbon dioxide, mediated by the degradation of land-derived organic carbon in aquatic ecosystems. Future shifts in the patterns of terrestrial dissolved organic carbon in inland waters thus have the potential to significantly increase aquatic carbon emissions across northern landscapes.
authors: Groupe de Recherche Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, Quebec, Canada H3C 3P8.
authors: Jean-François
authors: JF
authors: Lapierre
authors: 1] Groupe de Recherche Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, Quebec, Canada H3C 3P8 [2] Department of Ecology and Genetics/Limnology, Uppsala University, SE-752 36 Uppsala, Sweden.
authors: François
authors: F
authors: Guillemette
authors: 1] Groupe de Recherche Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, Quebec, Canada H3C 3P8 [2] Department of Physical Geography and Ecosystem Science, Lund University, SE-223 62 Lund, Sweden.
authors: Martin
authors: M
authors: Berggren
authors: Groupe de Recherche Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, Quebec, Canada H3C 3P8.
authors: Paul A
authors: PA
authors: del Giorgio
mesh_terms: D001673:Biodegradation, Environmental; D002170:Canada; D002244:Carbon / Q000737:chemistry*; D057486:Carbon Cycle; D002245:Carbon Dioxide / Q000032:analysis*; D003247:Conservation of Natural Resources; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D005618:Fresh Water; D060106:Lakes; D009930:Organic Chemicals; D012044:Regression Analysis; D045483:Rivers; D053833:Wetlands
chemical_list: D009930:Organic Chemicals; D002245:Carbon Dioxide; D002244:Carbon