The recent expansion of erect woody plants in the arctic threatens to create a positive feed back loop which speeds up global warming. Increasing shrub cover speeds up snow-melt, thus reducing the surface albedo in June, when the influx of solar energy to the tundra is maximal. Surfaces covered by prostrate vegetation have also higher albedo in summer, as compared to scrublands and woodlands.

If autumnal warming continues, northern communities with much woody vegetation may also become net sources of CO2. The abundance of shrubs and trees at high latitudes has thus significant impact on global energy balance, both via changing surface albedo and via impact on emission of greenhouse gasses.

Our recent results indicate that food limited herbivorous mammals can prevent the expansion of woody vegetation. This top down perspective has recently been corroborated by several lines of evidence.


Social aspects

The preservation of open arctic alpine habitats is also crucial for the indigenous cultures of the reindeer herding Sámi and many other northern peoples, whose livelihood is dependent on the seasonal movements between lichen rich and largely forest-covered inland areas and the open tundra, which offers optimal summer grazing conditions for the reindeer. Also the aesthetic values of the vast, open northern landscapes are at stake. This has even economical consequences, because tourism plays an increasingly important role in the economy of the North Calotte.

The impacts of arctic food web dynamics on global biodiversity and climatic feedbacks provide an example of ecosystem services, where different states of an ecosystem have different impacts on desired utilities. To obtain the services desired in the context of the arctic - preservation of its biota and its reflective properties - we must also consider the actions of the human component: the people owning and managing the larger grazers. In the present project, we will approach this complex of ecological, climatologic, and socio-economic issues by means of an integrated, co-Nordic CoE project, gathering specialists already working on different aspects of the above problem into an integrated Co-Nordic team.


Study area

We will focus on the summer ranges of the Nordic area of Sámi reindeer husbandry, extending from the mountains of Central Scandinavia to the Varanger Peninsula, encompassing about 150 000 km2 of land which currently lies above or north of the coniferous forest limit but below the altitudinal limit of willow scrublands. Adjacent winter ranges will be considered, too, because optimal grazing units should consist of arctic-alpine summer ranges and continental heaths with lichen dominated vegetation, but these are very unequally divided between different countries. Optimal land use in this area is thus a co-Nordic problem, probably requiring co-Nordic solutions. To obtain the goals outlined above, we have organized the project to eight work packages. The WP-teams are not national but defined by the competence profiles of involved scientists.



Training of PhD students and post docs will have a central role in the activities of the NCoE, as it is the case in the national projects led by the contributing scientists. Within the framework of the NCoE, these activities can be coordinated and strengthened in several ways. We will use shared field sites as much as possible, which will provide possibilities for interaction between students and researchers involved in different WPs, and recruitment of PhD students and post docs will be based on the principle of Nordic mobility. PhD students will also be sent to courses arranged by graduate schools in various Nordic countries. Moreover, we will organize at least one open graduate course within the framework of the NCoE.

Newest Publications

     Content Editor

    Keskitalo, E.C.H, Horstkotte, T., Kivinen, S., Forbes, B., and Käyhkö, J. (2015). "Generality of mis-fit"? The real-life difficulty of matching scales in an interconnected world. Accepted for publication in Ambio.

    Saccone P. and Virtanen R. (2015). Extrapolating multi-decadal plant community changes based on medium-term experiments can be risky: evidence from high-latitude tundra. Oikos. DOI: 10.1111/oik.02399.

    Stark, S. and Ylänne H. (2015). Grazing in Arctic peatlands – an unknown agent in the global carbon budget. Environmental Research Letters, 10: 051002. DOI: 10.1088/1748-9326/10/5/051002.

    Ylänne, H., Stark, S., and 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.

    Ruffino, L., Oksanen, T., Hoset, K.S., Tuomi, M., Oksanen, L., Korpimäki, E., Bugli, A., Hobson, K.A., Johansen, B., and Mäkynen A. (2015). Predator-rodent-plant interactions along a coast-inland gradient in Fennoscandian tundra. Ecography. DOI: 10.1111/ecog.01758.

    Björkman, C. and Niemelä, P., eds. (2015). Climate Change and Insect Pests. CABI Climate Change Series 7. 279 pp.

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