Factors Governing Biodegradability of Dissolved Natural Organic Matter in Lake Water

Dissolved Natural Organic Matter (DNOM) is a heterogeneous mixture of partly degraded, oxidised and resynthesised organic compounds terrestrial or aquatic origin. In the boreal biome, it plays central role in element cycling practically all biogeochemical processes governing physico-chemistry surface waters. Because multiple processes, especially microbial respiration, an improved understanding biodegradability DNOM water needed. Here current study, we used relatively cheap non-laborious analytical method to determine DNOM, based on rate time lapse at which decomposed. This was achieved by monitoring oxygen consumption during incubation with addition nutrients. A synoptic using set lake samples from southeast Norway, showed that maximum respiration (RR) normalised RR (respiration per unit carbon) lakes varied significantly. conceived as proxy for DNOM. The sUVa C:N ratio were main predictors RR. implies these predominantly oligotrophic dystrophic waters mainly governed their molecular size aromaticity, its same manner found soil matter. (independently overall concentration DOC) predicted weight origin duration first phase rapid biodegradation (BdgT) be higher autochthonous allochthonous amount biodegradable