Patterns of dissolved organic matter across the Patagonian landscape: a broad scale survey of Chilean and Argentine lakes

ZAGARESE, HE; FERRARO, M; QUEIMALIÑOS, C; DIÉGUEZ, MC; AÑÓN SUÁREZ, DA; LLAMES, M

MARINE AND FRESHWATER RESEARCH

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2017

1323-1650

Dissolved organic matter (DOM) is a complex mixture of carbon compounds from autochthonous and allochthonous sources. Dissolved organic carbon concentration (DOC) and optical metrics of DOM provide clues on the sources and processes affecting the DOM pool. Here, we provide the first broad-scale characterization of DOM from Patagonian lakes across a strong west-east precipitation gradient. Fifty-eight lakes from Northern Patagonia (Argentina and Chile) plus 6 lakes from the Antarctic Peninsula were sampled during summer 2000-2001. Our analysis is based on 6 DOM metrics: DOC, absorbance at 254 nm (a254) and 350 nm (a350), DOC-specific absorbance at 254 nm (a254:DOC) and 350 nm (a350:DOC), and spectral slope between 275-295 nm (S275-295). The DOM of Chilean maritime lakes and shallow (15 m) Andean lakes, which is consistent with their longer water retention time. Steppe lakes, mostly from endorheic basins, made up the most heterogeneous group as regards to DOM characteristics.