A1 Journal article (refereed)
Increasing air temperature relative to water temperature makes the mixed layer shallower, reducing phytoplankton biomass in a stratified lake (2023)
Ahonen, S. A., Seppälä, J., Karjalainen, J. S., Kuha, J., & Vähätalo, A. V. (2023). Increasing air temperature relative to water temperature makes the mixed layer shallower, reducing phytoplankton biomass in a stratified lake. Freshwater Biology, 68(4), 577-587. https://doi.org/10.1111/fwb.14048
JYU authors or editors
Publication details
All authors or editors: Ahonen, Salla A.; Seppälä, Jukka; Karjalainen, Juha S.; Kuha, Jonna; Vähätalo, Anssi V.
Journal or series: Freshwater Biology
ISSN: 0046-5070
eISSN: 1365-2427
Publication year: 2023
Publication date: 13/01/2023
Volume: 68
Issue number: 4
Pages range: 577-587
Publisher: Wiley-Blackwell
Publication country: United Kingdom
Publication language: English
DOI: https://doi.org/10.1111/fwb.14048
Publication open access: Openly available
Publication channel open access: Partially open access channel
Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/85183
Abstract
To determine the responses of phytoplankton biomass to the depth of the mixed layer, light availability and associated meteorological forcing, we followed daily changes in weather and water column properties in a boreal lake over the first half of a summer stratification period.
Phytoplankton biomass increased with the deepening of the mixed layer associated with high wind speeds and low air temperature relative to the temperature of the mixed layer (Tair−Tmix < 0), whereas heatwave conditions—shallow mixed layer driven by high Tair−Tmix value and low wind speed—reduced the biomass.
Improving light availability from low to moderate light conditions increased the phytoplankton biomass, while the highest light availability was associated with low phytoplankton biomass.
Our study demonstrates that the climatic impact-drivers wind speed and Tair−Tmix are major drivers of mixed layer depth, which controlled phytoplankton biomass during the early summer stratification period. Our study suggests that increasing air temperature relative to water temperature and declining wind speeds have potential to lead to reduced phytoplankton biomass due to a shallower mixed layer during the first half of the stratification period in non-eutrophic lakes with sufficient light availability.
Keywords: biomass (ecology); climate changes; water systems; lakes; water quality
Free keywords: algal biomass; climate warming; heatwave; lake mixing; thermal stratification
Contributing organizations
Related projects
- Integrated Atmospheric and Earth System Science Research Infrastructure - Ecosystems (INAR RI Ecosystems)
- Karjalainen, Juha
- Research Council of Finland
Ministry reporting: Yes
VIRTA submission year: 2023
JUFO rating: 2