Dust inputs and bacteria influence dissolved organic matter in clear alpine lakes

• Published in: Nature Communications
• Main Authors: Mladenov, N., Camarero, L., Delgado, A., Reche, Isabel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2011
• Subjects: Biological Sciences; Biogeochemistry; Ecology; Canada; Antarc*; Antarctica; ArcticNet; International Polar Year; Polar Continental Shelf Project
• Online Access: http://hdl.handle.net/10261/39282; https://doi.org/10.1038/ncomms1411

N. Mladenov et al. Remote lakes are usually unaffected by direct human influence, yet they receive inputs of atmospheric pollutants, dust, and other aerosols, both inorganic and organic. In remote, alpine lakes, these atmospheric inputs may influence the pool of dissolved organic matter, a critical constituent for the biogeochemical functioning of aquatic ecosystems. Here, to assess this influence, we evaluate factors related to aerosol deposition, climate, catchment properties, and microbial constituents in a global dataset of 86 alpine and polar lakes. We show significant latitudinal trends in dissolved organic matter quantity and quality, and uncover new evidence that this geographic pattern is influenced by dust deposition, flux of incident ultraviolet radiation, and bacterial processing. Our results suggest that changes in land use and climate that result in increasing dust flux, ultraviolet radiation, and air temperature may act to shift the optical quality of dissolved organic matter in clear, alpine lakes. Funding was provided by Fundación BBVA- ECOSENSOR, Junta de Andalucia AEROGLOBAL, and Ministerio de Medio Ambiente MICROBIOGEOGRAPHY (080/2007) projects; Natural Sciences and Engineering Research Council of Canada, ArcticNet, Polar Continental Shelf Project, Parks Canada, International Polar Year, Centre d'études nordiques. Work in Antarctica was supported by the projects CGL2005-06549-C02-02/ANT and CGL2005-06549-C02-01/ANT from the Spanish Ministry of Education and Science, the former co-financed by European FEDER funds. Work in the Pyrenees was partially funded by the Ministerio de Medio Ambiente ACOPLA (011/2008) project and the GRACCIE project (CSD2007-00067). The Austrian Science Fund (FWF) Project role of lake‐catchment‐atmosphere linkages for bacteria (P19245-BO3) supported work in the Alps and funded open access fees. This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ Peer reviewed