A high-resolution spectroscopic study of pore-water dissolved organic matter in annually laminated lake sediments: a new tool for reconstructing eutrophication history

摘要

Spectroscopic methods have been used widely in studies of dissolved organic matter (DOM) in a large variety of water bodies (Zumstein Buffle 1989, Kowalczuk et al. 2003) and marine sediments (De-flandre Gagne 2001, Sierra et al. 2001). These methods allow predicting quantities as well as revealing qualitative properties of DOM. The main merits of the methods are (1) simplicity, (2) small sample volume required for analyses and (3) no need for chemical pretreatment of samples. In the present research, spectroscopic methods were employed to detect changes in characteristics of pore-water DOM (pwDOM) in lake sediments. Fluorescence and absorption spectra were analysed to examine conformity of spectral indicators with the pa-leolimnological proxies. A lake with annually laminated sediments was chosen, which allowed dating sediments with high accuracy and tracking temporal variations of paleoindicators in high-resolution scale.