Lake browning counteracts cyanobacteria responses to nutrients Evidence from phytoplankton dynamics in large enclosure experiments and comprehensive observational data

Lake browning counteracts cyanobacteria responses to nutrients : Evidence from phytoplankton dynamics in large enclosure experiments and comprehensive observational data

© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd.

Bibliographische Detailangaben
Veröffentlicht in:Global change biology. - 1999. - 30(2024), 1 vom: 27. Jan., Seite e17013
1. Verfasser: Lyche Solheim, Anne (VerfasserIn)
Weitere Verfasser: Gundersen, Hege, Mischke, Ute, Skjelbred, Birger, Nejstgaard, Jens C, Guislain, Alexis L N, Sperfeld, Erik, Giling, Darren P, Haande, Sigrid, Ballot, Andreas, Moe, S Jannicke, Stephan, Susanne, Walles, Tim J W, Jechow, Andreas, Minguez, Laetitia, Ganzert, Lars, Hornick, Thomas, Hansson, Truls Hveem, Stratmann, Cleo N, Järvinen, Marko, Drakare, Stina, Carvalho, Laurence, Grossart, Hans-Peter, Gessner, Mark O, Berger, Stella A
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2024
Zugriff auf das übergeordnete Werk:Global change biology
Schlagworte:Journal Article climate change deep-mixing harmful algal blooms lake browning large-scale lake survey long-term monitoring mesocosm multiple stressors nutrient gradient mehr... Humic Substances Phosphorus 27YLU75U4W
Beschreibung
Zusammenfassung:© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd.
Lakes worldwide are affected by multiple stressors, including climate change. This includes massive loading of both nutrients and humic substances to lakes during extreme weather events, which also may disrupt thermal stratification. Since multi-stressor effects vary widely in space and time, their combined ecological impacts remain difficult to predict. Therefore, we combined two consecutive large enclosure experiments with a comprehensive time-series and a broad-scale field survey to unravel the combined effects of storm-induced lake browning, nutrient enrichment and deep mixing on phytoplankton communities, focusing particularly on potentially toxic cyanobacterial blooms. The experimental results revealed that browning counteracted the stimulating effect of nutrients on phytoplankton and caused a shift from phototrophic cyanobacteria and chlorophytes to mixotrophic cryptophytes. Light limitation by browning was identified as the likely mechanism underlying this response. Deep-mixing increased microcystin concentrations in clear nutrient-enriched enclosures, caused by upwelling of a metalimnetic Planktothrix rubescens population. Monitoring data from a 25-year time-series of a eutrophic lake and from 588 northern European lakes corroborate the experimental results: Browning suppresses cyanobacteria in terms of both biovolume and proportion of the total phytoplankton biovolume. Both the experimental and observational results indicated a lower total phosphorus threshold for cyanobacterial bloom development in clearwater lakes (10-20 μg P L-1 ) than in humic lakes (20-30 μg P L-1 ). This finding provides management guidance for lakes receiving more nutrients and humic substances due to more frequent extreme weather events
Beschreibung:Date Completed 29.01.2024
Date Revised 29.01.2024
published: Print-Electronic
Citation Status MEDLINE
ISSN:1365-2486
DOI:10.1111/gcb.17013