• Home
  1. Home
  2. Recent human-induced trophic change in the large and deep perialpine Lake Lucerne (Switzerland) compared to historical geochemical variations
Scientific article
English

Recent human-induced trophic change in the large and deep perialpine Lake Lucerne (Switzerland) compared to historical geochemical variations

Contributors

Thevenon, Florian; Adatte, Thierry; Pote-Wembonyama, John; Spangenberg, Jorge E.

Published in

Palaeogeography, palaeoclimatology, palaeoecology, vol. 363-364, p. 37-47

Publication date

2012

Abstract

This study investigates the sedimentological and geochemical changes that occurred during the last 2200 years in the meromictic Lake Lucerne (Switzerland), one of the largest freshwater lakes of Central Europe. The stable isotope composition (δ13C and δ18O values) of bulk carbonates is compared to changes in grain-size distribution (clay and silt fraction), natural trace element input (titanium and thorium concentrations), and organic material abundance (Corg, nitrogen and phosphorus) and composition (C/N ratios and hydrogen and oxygen indexes). A drop in carbonate accumulation and in the δ18O values of sediments between ca. AD 500 and 700 followed a large and consistent rise in chemical weathering, marked by increases in the silicate-clay fraction and in crustal element concentrations. During the following millennium, there was a long-term decreasing trend in the lithogenic trace element input and in the phosphorus loading, suggesting decreasing terrigeneous input from runoff water. The major sedimentological change over the studied period occurred after ca. AD 1800 with a significant increase in the erosion-driven silt-fraction and in the sedimentation rate. During the last century, human-induced increase in nutrient input to the lake highly enhanced the accumulation of organic matter in sediment. Changes in nutrients and oxygen conditions in the hypolimnion of Lake Lucerne during the eutrophication period (i.e., the last 40 years) highly modified the geochemical fluxes compared to the relatively stable oligotrophic conditions that prevailed during the previous 2000 years. Before the 19th century, climate driven meromixis had a limited impact on the organic matter flux to the sediments, but the accumulation of carbonate considerably decreased during periods of lower mechanical erosion rates and high chemical weathering rates.

Keywords

  • Trace elements
  • Paleolimnology
  • Paleohydrology
  • Eutrophication

UNIGE affiliation entities

UNIGE research groups

Citation (ISO format)

THEVENON, Florian et al. Recent human-induced trophic change in the large and deep perialpine Lake Lucerne (Switzerland) compared to historical geochemical variations. In: Palaeogeography, palaeoclimatology, palaeoecology, 2012, vol. 363-364, p. 37–47. doi: 10.1016/j.palaeo.2012.08.010

Main files (1)

Article (Published version)

Identifiers

Additional URL for this publication

http://linkinghub.elsevier.com/retrieve/pii/S0031018212004622

Journal ISSN

0031-0182
811views
10downloads

Technical informations

Creation

26/09/2012 16:45:00

First validation

26/09/2012 16:45:00

Update

14/03/2023 17:42:16

Status update

14/03/2023 17:42:16

Last indexation

29/10/2024 20:44:15
All rights reserved by Archive ouverte UNIGE and the University of Geneva
OpenAIRE Indexed & Validated