Abstract

We re-examined the effects of acidification on Scandinavian freshwater lakes using paleolimnological reconstructions focused on subfossil chironomids. Our study showed a widespread shift in chironomid community composition occurring at around 1960 and corresponding with the maximum fallout of anthropogenic SO42- deposition. Results also showed that taxonomic turn-over was higher in chironomid records from nitrogen-limited lakes, likely due to the cumulative effects of acidification and eutrophication driven by atmospheric nitrogen deposition. Despite strong evidence of chemical recovery from acidification, all lake records failed to show a return to pre-acidified community compositions and most chironomid communities instead continue to follow the trajectories triggered by acidification. We hypothesized that when SO42- deposition started to decrease after 1980, a period also marked by rapid environmental and climatic changes, the influence of pH and/or other acidification-related variables in structuring chironomid community became less important, thus, giving more relative importance to other drivers, such as brownification and climatic processes. Results, therefore, suggest the key role of acidification in shaping the response of chironomid communities to future environmental changes. Future paleolimnological studies will contribute to better manage aquatic ecosystems recovering from acidification worldwide by allowing managers to quantify the efficacy of different management actions taken to mitigate acidification as well as to redefine appropriate restoration targets.

Keywords

Biodiversity; Resilience; Climate change; Acid rain; Nutrient limitations; Paleolimnology

Published in

Hydrobiologia
2024, Volume: 851, number: 3, pages: 585-600
Publisher: SPRINGER

SLU Authors

• Belle, Simon

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Johnson, Richard

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss
Take urgent action to combat climate change and its impacts
Ensure availability and sustainable management of water and sanitation for all


UKÄ Subject classification

Ecology
Environmental Sciences


Publication identifier

DOI: https://doi.org/10.1007/s10750-023-05346-9

Permanent link to this page (URI)

https://res.slu.se/id/publ/126581