The combined effects of herbivory and warming on subarctic ecosystem carbon stocks / Laidunnuksen ja ilmastonmuutoksen yhteisvaikutukset subarktisen ekosysteemin hiilivarastoihin

Contact person: Dr Sari Stark
Research group: Global change

Start of the project : 1st January 2013
End of the project : 31st December 2015


The effects of the ongoing climate warming in the Arctic raises the question how vegetation and ecosystem carbon stocks will respond to warming. So far, the important role of herbivores in ecosystem responses at long timescales has not been considered. In this project, we combine data from long-term field experiments using experimental simulation of warming with old datasets of plant and soil properties in subarctic tundra and mountain birch ecosystems.

We have used two field experiments that simulate effects of global change with specifically designed warming chambers (ITEX standard open top chambers) combined with herbivory: one in Kilpisjärvi (running since 1994, making it one of the longest running warming experiments in the Arctic) and one in Reisa (running since 2010).

We have also monitored long-term changes in vegetation and ecosystem carbon stocks at different levels of grazing intensity and timing via field inventories combined with comparisons with data collected in 2000-2003. These studies bring insights into the ongoing changes in sub-arctic vegetation, soil processes and ecosystem carbon sink.

This project lasts for three years (2013-2015) and is funded by Maj and Tor Nessling Foundation.


Ylänne, H., Stark, S., Tolvanen, A. (2015) Vegetation shift from deciduous to evergreen dwarf shrubs in response to selective herbivory offsets carbon losses: evidence from 19 years of warming and simulated herbivory in the sub-arctic tundra. Global Change Biology, 21:3696-3711. DOI: 10.1111/gcb.12964

Participants and collaboration

  • Henni Ylänne (MSc) (graduate student), Arctic Centre, University of Lapland/Department of Biology, University of Oulu
  • Dr Sari Stark, Arctic Centre, University of Lapland
  • Prof. Anne Tolvanen, Natural Resources Institute Finland, Oulu
  • Dr Jouko Kumpula, Natural Resources Institute Finland, Kaamanen Reindeer Research Station
  • Prof. Johan Olofsson, Department of Environmental Sciences, University of Umeå, Sweden