CENTURION - Cumulative effects of climate change and eutrophication on Swedish lakes

Last changed: 15 October 2021
A lake. Photo.

The CENTURION-project focuses on two major threats, climate change and eutrophication, to ecological status of Swedish lakes.

Aquatic ecosystems face tremendous changes due to a multitude of stressors, among which ongoing climate change and cultural eutrophication are major large-scale drivers of ecological change, resulting in degraded ecological states and potential loss of ecological services. Stressors are expected to exert complex interactive effects, but interactions among multiple stressors cannot be easily modelled because they often generate impacts that either exceed (i.e. synergism) or fall below (i.e. antagonism) their expected additive effects. Further, the number and types of combinations of stressors affecting aquatic ecosystems has dramatically increased during the last two centuries, but few studies have empirically tested for their cumulative effects on lakes.

Aims

CENTURION addresses knowledge gaps on the cumulative effects of climate change and eutrophication on freshwater lakes.

Specific objectives

  • Evaluate temporal patterns in aquatic biodiversity and ecological status since ca. 1850 and identify ecological hot-spots and extreme events in freshwater lakes across a latitudinal gradient in Sweden.
  • Quantify ecological resilience to environmental drivers through paleolimnological reconstructions that help to understand the cumulative effects of nutrient enrichment and climate warming on ecological status of lakes across a latitudinal gradient in Sweden.
  • Develop a novel assessment method for the EU´s Water Framework Directive that better quantifies ecological changes in lakes and provides relevant estimates of internal reference conditions for individual lakes and lake types.
  • Inform policy makers, NGOs, the public, and scientists about changes in Swedish freshwater ecosystems.
A sediment core. Photo.
A sediment core collected from Väster-Rännöbodsjön.

Implementation

We will address these objectives by using an innovative paleolimnological approach to reconstruct past ecological trajectories (i.e. from reference conditions to current states) over the last 200 years in 30 lakes. To do so, CENTURION will use multi-proxies paleolimnogical reconstructions to assess the resilience of lake ecosystems to climate change and anthropogenic eutrophication, and link changes in ecological status to knowledge of past environmental drivers (i.e. climate change and eutrophication). A modelling approach will also be used to disentangle the respective influences of climate and eutrophication on past ecological trajectories and quantify their cumulative effects on lake ecosystems.

Collaborations

A reference group will be established, consisting of relevant persons from each of the participating counties, representatives from both local and national (e.g. Swedish Agency for Marine and Water Management) decision-makers and other relevant stakeholders.

Participants from the department

Facts:

CENTURION is funded by the Swedish EPA during 2020–2022.