Stratification strength and light climate explain variation in chlorophyll α at the continental scale in a European multilake survey in a heatwave summer.

Donis, Daphne; Mantzouki, Evanthia; McGinnis, Daniel F.; Edwards, Christine

Abstract

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4°C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature.

Citation

DONIS, D., MANTZOUKI, E., MCGINNIS, D.F. et al. 2021. Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer. Limnology and oceanography [online], 66(12), pages 4314-4333. Available from: https://doi.org/10.1002/lno.11963

• Journal Article Type: Article
• Acceptance Date: Oct 8, 2021
• Online Publication Date: Oct 30, 2021
• Publication Date: Dec 31, 2021
• Deposit Date: Nov 16, 2021
• Publicly Available Date: Nov 16, 2021
• Journal: Limnology and Oceanography
• Print ISSN: 0024-3590
• Electronic ISSN: 1939-5590
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 66
• Issue: 12
• Pages: 4314-4333
• DOI: https://doi.org/10.1002/lno.11963
• Keywords: Phytoplankton blooms; Thermal stratification; Nutrients; Light; Pigment; Lakes
• Public URL: https://rgu-repository.worktribe.com/output/1529239
• Additional Information: The accompanying file for this output contains supplementary figures and tables, located at the end of the main article text (pages 22-38).