Articles | Volume 17, issue 24
Research article
15 Dec 2020
Research article |  | 15 Dec 2020

The relative importance of photodegradation and biodegradation of terrestrially derived dissolved organic carbon across four lakes of differing trophic status

Christopher M. Dempsey, Jennifer A. Brentrup, Sarah Magyan, Lesley B. Knoll, Hilary M. Swain, Evelyn E. Gaiser, Donald P. Morris, Michael T. Ganger, and Craig E. Williamson

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Cited articles

Allesson, L., Ström, L., and Berggren, M.: Impact of photochemical processing of DOC on the bacterioplankton respiratory quotient in aquatic ecosystems, Geophys. Res. Lett., 43, 7538–7545, 2016. 
Amado, A. M., Farjalla, V. F., Esteves, F. A., and Bozelli, R. L.: DOC photo-oxidation in clear water Amazonian aquatic ecosystems, Amazonia, 17, 513–523, 2003. 
Bertilsson, S. and Tranvik, L. J.: Photochemical transformation of dissolved organic matter in lakes, Limnol. Oceanogr., 45, 753–762,, 2000. 
Biddanda, B. A. and Cotner, J. B.: Enhancement of Dissolved Organic Matter Bioavailability by Sunlight and Its Role in the Carbon Cycle of Lakes Superior and Michigan, J. Great Lakes Res., 29, 228–241, 2003. 
Catalan, N., Marcé, R., Kothawala, D. N., and Tranvik, L. J.: Organic carbon decomposition rates controlled by water retention time across inland waters, Nat. Geosci., 9, 501–504,, 2016. 
Short summary
We looked at how terrestrial dissolved organic carbon (DOC) from the watersheds of four different lakes responded to both biodegradation (i.e., microbes) and photodegradation (i.e., sunlight). The traditional paradigm is that biodegradation is more important than photodegradation. Our research shows that, on short timescales (i.e., 7 d), sunlight is more important than microbes in degrading DOC. Interestingly, the lakes had different responses to sunlight based on their trophic status.
Final-revised paper