THE INFLUENCE OF PLANT COLONIZATION ON THE VERTICAL PROFILE OF FLUORESCENT ORGANIC MATTER IN PORE WATERS FROM SALT MARSH SEDIMENTS

摘要

Studies on the characterization of dissolved organic matter(DOM)in natural waters by excitation-emission matrix(EEM)fluorescence spectroscopy usually reveal the existence of two types of fluorophoric groups.One of these groups is characterized by fluorescence emission at 420-450 nm from excitation at 230-240 and 310-350 nm and is attributed to humic substances(Mopper and Schultz,1993).The other group gives rise to a maximum at lambda_(exc)=265-285 nm-lambda_(em)=300-370 nm and has been related to amino acid and protein fluorophores(Mopper and Schultz,1993;Coble et al.,1990;Komada et al.2002;Mayer et al.1999).This DOM with protein-type fluorescence has been associated to relatively young organic substances released into water by recent biological activity(Mopper and Schultz,1993).