Combining limnology and palaeolimnology to investigate recent regime shifts in a shallow, eutrophic lake

Linda Randsalu-Wendrup, Daniel J. Conley, Jacob Carstensen, Lars Anders Hansson, Christer Brönmark, Sherilyn C. Fritz, Preetam Choudhary, Joyanto Routh, Dan Hammarlund

Research output: Contribution to journalArticlepeer-review

Abstract

In this study, we demonstrate that an integrated approach, combining palaeolimnological records and limnological monitoring data, can increase our understanding of changing ecological patterns and processes in shallow lakes. We focused on recent regime shifts in shallow Lake Krankesjön, southern Sweden, including the collapse of the clear-water state in 1975 and its subsequent recovery in the late 1980s. We used diatom, hydrocarbon and biogenic silica sediment records, in concert with limnological data sets on nutrient concentrations, water clarity, chlorophyll-a and water depth, to investigate the shifts. The shift from clear to turbid conditions was abrupt and occurred over 1 to 2 years, whereas recovery of the clear-water state was more gradual, taking 4-5 years. In 1978, shortly after the first regime shift in water clarity, the diatom community underwent a significant shift. It became less diverse, with decreased abundance of epiphytic and planktonic taxa. Despite rising phosphorus concentrations and lower abundance of submerged macrophytes, Lake Krankesjön has remained in the clear-water state over the past 20 years, although this state seems to be increasingly unstable and susceptible to collapse. The complex reactions of the entire lake ecosystem to major changes in lake-water clarity, as shown by the palaeolimnological variables investigated in this study, emphasize the importance of careful lake and catchment management if a stable, clear-water state is desired.

Original languageEnglish (US)
Pages (from-to)437-448
Number of pages12
JournalJournal of Paleolimnology
Volume51
Issue number3
DOIs
StatePublished - Mar 2014

Keywords

  • Alternative stable state
  • Diatoms
  • Ecosystem
  • Hydrocarbons
  • Monitoring
  • Regime shift

ASJC Scopus subject areas

  • Aquatic Science
  • Earth-Surface Processes

Fingerprint

Dive into the research topics of 'Combining limnology and palaeolimnology to investigate recent regime shifts in a shallow, eutrophic lake'. Together they form a unique fingerprint.

Cite this