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Optical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation
Author(s) -
Hansen Angela M.,
Kraus Tamara E. C.,
Pellerin Brian A.,
Fleck Jacob A.,
Downing Bryan D.,
Bergamaschi Brian A.
Publication year - 2016
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.1002/lno.10270
Subject(s) - dissolved organic carbon , degradation (telecommunications) , absorbance , photodegradation , environmental chemistry , organic matter , environmental science , biodegradation , algae , light source , biological system , chemistry , optics , photocatalysis , chromatography , ecology , computer science , biology , telecommunications , biochemistry , organic chemistry , catalysis , physics
Advances in spectroscopic techniques have led to an increase in the use of optical properties (absorbance and fluorescence) to assess dissolved organic matter (DOM) composition and infer sources and processing. However, little information is available to assess the impact of biological and photolytic processing on the optical properties of original DOM source materials. Over a 3.5 month laboratory study, we measured changes in commonly used optical properties and indices in DOM leached from peat soil, plants, and algae following biological and photochemical degradation to determine whether they provide unique signatures that can be linked to original DOM source. Changes in individual optical parameters varied by source material and process, with biodegradation and photodegradation often causing values to shift in opposite directions. Although values for different source materials frequently overlapped, multivariate statistical analyses showed that unique optical signatures could be linked to original DOM source material, with 17 optical properties determined by discriminant analysis to be significant ( p < 0.05) in distinguishing between DOM source and environmental processing. These results demonstrate that inferring source material from optical properties is possible when parameters are evaluated in combination even after extensive biological and photochemical alteration.