Reindeer grazing and tundra soil carbon storage under changing climate
Porolaidunnus ja tundramaan hiilivarastot muuttuvassa ilmastossa
Contact person: Dr Sari Stark
Research group: Global change
Start of the project : 1st May 2012
End of the project : 31st July 2014
Research
At present, tundra ecosystems store large quantities of soil carbon that
has been accumulating to the soil over centuries and millennia. It is
currently predicted that increasing temperatures by global change will
enhance decomposition of these large soil carbon stocks. As a result,
tundra soils may start contributing to the increase in atmospheric
carbon dioxide. In this project, we experimentally simulate effects of
global change with specifically designed warming chambers (ITEX standard
open top chambers) in a sub-oceanic tundra ecosystem. Similar
treatments are conducted in two cases, tundra that is either ungrazed or
grazed by reindeer (Rangifer tarandus). In ungrazed tundra, vegetation
is dominated by slow-growing dwarf shrubs (e.g. Betula nana, Empetrum
hermaphroditum, Vaccinium vitis-idaea, Vaccinium uliginosum), and in
grazed tundra, by different sedges and grasses. We investigate changes
in vegetation, soil microbial activity and community composition,
ecosystem carbon balance and phenolic secondary metabolites of evergreen
and deciduous dwarf shrubs.
When our project is finished, we will be able to make more accurate
predictions on ecosystem responses to global change that take into
account the importance of reindeer grazing as a factor that shapes
vegetation and soil processes in tundra ecosystems. This project lasts
for five years (2009-2014) and it is funded by the Academy of Finland.
Participants and collaboration
- Dr Sari Stark, Arctic Centre, University of Lapland
- MSc Maria Väisänen (graduate student), Arctic Centre, University of Lapland
- Ms. Henni Ylänne (undergraduate student), Department of Biology, University of Oulu
- Dr. Minna Männistö and Dr. Francoise Martz, Finnish Forest Research Institute, Rovaniemi Research Unit
- Prof. Johan Olofsson and MSc Elina Kaarlejärvi, Department of Environmental Sciences, University of Umeå, Sweden
- Dr. Sofie Sjögersten-Turner, Dr. Trevor Drage and Dr. David Large, University of Nottingham, UK
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Analyzing net ecosystem carbon exchange in the field. Photo: Sari Stark.
Experimental plot with warming treatment by open top chamber. Photo: Sari Stark.
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