A1 Journal article (refereed)
Ecosystem responses to increased organic carbon concentration : comparing results based on long-term monitoring and whole-lake experimentation (2019)

Kankaala, P., Arvola, L., Hiltunen, M., Huotari, J., Jones, R. I., Nykänen, H., Ojala, A., Olin, M., Peltomaa, E., Peura, S., Rask, M., Tulonen, T., & Vesala, S. (2019). Ecosystem responses to increased organic carbon concentration : comparing results based on long-term monitoring and whole-lake experimentation. Inland Waters, 9(4), 489-502. https://doi.org/10.1080/20442041.2019.1600938

JYU authors or editors

Publication details

All authors or editors: Kankaala, Paula; Arvola, Lauri; Hiltunen, Minna; Huotari, Jussi; Jones, Roger I.; Nykänen, Hannu; Ojala, Anne; Olin, Mikko; Peltomaa, Elina; Peura, Sari; et al.

Journal or series: Inland Waters

ISSN: 2044-2041

eISSN: 2044-205X

Publication year: 2019

Volume: 9

Issue number: 4

Pages range: 489-502

Publisher: Taylor & Francis

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1080/20442041.2019.1600938

Publication open access: Not open

Publication channel open access:

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/66467

Publication is parallel published: https://erepo.uef.fi/handle/123456789/7784


Recent increases in terrestrial dissolved organic carbon (DOC) concentrations in northern inland waters have many ecological consequences. We examined available data on carbon cycles and food webs of 2 boreal headwater lakes in southern Finland. Basic limnology and catchment characteristics of a pristine lake, Valkea-Kotinen (VK), were monitored over the past 25 years while the lake has undergone browning and DOC increased from ∼11 to 13 mg L−1. Pronounced changes in the early 2000s represent a regime shift in DOC concentration and color. Lake Alinen Mustajärvi (AM) was manipulated for 2 years by additions of labile DOC (cane sugar), raising the DOC concentration from ∼10 to 12 mg L−1, but not changing light conditions. The 2 different approaches both revealed increased concentrations and efflux of carbon dioxide (CO2) from the lakes and thus net heterotrophy and changes in the pelagic community structure following an increase in DOC concentration. Long-term monitoring of VK revealed a decline in phytoplankton primary production (PP) along with browning, which was reflected in retarded growth of young (1–2-year-old) perch. In the experimentally manipulated lake (AM), PP was not affected, and the growth of young perch was more variable. The results suggested the importance of a pathway from labile DOC via benthic invertebrates to perch. Although provided with this extra resource, the food chain based on DOC proved inefficient. Long-term monitoring and whole-lake experimentation are complementary approaches for revealing how freshwater ecosystems respond to climate and/or atmospheric deposition-induced changes, such as browning.

Keywords: ecosystems (ecology); lakes; organic substances; carbon

Free keywords: ecosystem responses; organic carbon concentration

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2019

JUFO rating: 1

Last updated on 2023-10-01 at 15:00