A1 Journal article (refereed)
Increasing temperature and productivity change biomass, trophic pyramids and community‐level omega‐3 fatty acid content in subarctic lake food webs (2021)

Keva, O., Taipale, S. J., Hayden, B., Thomas, S. M., Vesterinen, J., Kankaala, P., & Kahilainen, K. K. (2021). Increasing temperature and productivity change biomass, trophic pyramids and community‐level omega‐3 fatty acid content in subarctic lake food webs. Global Change Biology, 27(2), 282-296. https://doi.org/10.1111/gcb.15387

JYU authors or editors

Publication details

All authors or editorsKeva, Ossi; Taipale, Sami J.; Hayden, Brian; Thomas, Stephen M.; Vesterinen, Jussi; Kankaala, Paula; Kahilainen, Kimmo K.

Journal or seriesGlobal Change Biology



Publication year2021

Publication date30/10/2020


Issue number2

Pages range282-296


Publication countryUnited Kingdom

Publication languageEnglish


Publication open accessNot open

Publication channel open access

Publication is parallel published (JYX)https://jyx.jyu.fi/handle/123456789/72447


Climate change in the Arctic is outpacing the global average and land‐use is intensifying due to exploitation of previously inaccessible or unprofitable natural resources. A comprehensive understanding of how the joint effects of changing climate and productivity modify lake food web structure, biomass, trophic pyramid shape and abundance of physiologically essential biomolecules (omega‐3 fatty acids) in the biotic community is lacking. We conducted a space‐for‐time study in 20 subarctic lakes spanning a climatic (+3.2°C and precipitation: +30%) and chemical (dissolved organic carbon: +10 mg/L, total phosphorus: +45 µg/L and total nitrogen: +1,000 µg/L) gradient to test how temperature and productivity jointly affect the structure, biomass and community fatty acid content (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) of whole food webs. Increasing temperature and productivity shifted lake communities towards dominance of warmer, murky‐water‐adapted taxa, with a general increase in the biomass of primary producers, and secondary and tertiary consumers, while primary invertebrate consumers did not show equally clear trends. This process altered various trophic pyramid structures towards an hour glass shape in the warmest and most productive lakes. Increasing temperature and productivity had negative fatty acid content trends (mg EPA + DHA/g dry weight) in primary producers and primary consumers, but not in secondary nor tertiary fish consumers. The massive biomass increment of fish led to increasing areal fatty acid content (kg EPA + DHA/ha) towards increasingly warmer, more productive lakes, but there were no significant trends in other trophic levels. Increasing temperature and productivity are shifting subarctic lake communities towards systems characterized by increasing dominance of cyanobacteria and cyprinid fish, although decreasing quality in terms of EPA + DHA content was observed only in phytoplankton, zooplankton and profundal benthos.

Keywordsaquatic ecosystemsfood websnutrients (animals and humans)omega fatty acidsclimate changesland usesilviculturedissolved organic carbon

Free keywordsDOC; food web structure; forestry; land‐use; nutrients; omega‐3 HUFA; trophic level; trophic pyramid

Contributing organizations

Ministry reportingYes

Reporting Year2021

JUFO rating3

Last updated on 2024-03-04 at 20:47