Stable isotopic composition of sedimentary organic carbon and nitrogen as indicator of trophic state changes in high-mountain lakes in the Julian Alps

Abstract

In the present study we explore the applicability of carbon and nitrogen stable isotope signatures in sedimentary organic matter to trace changes in lake trophic state in four highmountain lakes in Triglav National Park (NW Slovenia). Results show higher δ13Corg values associated with lower (δ15N values that are characteristic of oligotrophic lakes, while lower δ13Corg values are associated with higher δ15N values that are characteristic of eutrophic lakes.