News

On Tuesday, 19 April 2011, at 14.15 Minna-Maarit Kytöviita  from  Jyväskylä University in  Finland
gives a lecture on Ecosystem effects of reindeer grazing. The lecture is held in Tartu, at 40-218 Lai Street.  

ECOSYSTEM EFFECTS OF REINDEER GRAZING

Modern intensive reindeer herding has caused large scale vegetation changes that can be observed from the satellite images and is by far the most important anthropogenic factor influencing the arctic
ecosystems today.  Reindeer grazing enhances nutrient cycling and increases the abundance of grasses in productive areas. Terrestrial lichens are consumed during winter and trampled during summer and thus only fragmentary lichen grounds remain today. Intensive reindeer grazing has variable effects on ecosystem productivity and diversity depending on the natural level of system productivity. Soil microbes are relatively resistant, at least in the short-term, to reindeer grazing and, for example moderate levels of reindeer grazing do not have strong adverse effects on arbuscular mycorrhizal fungi in plant roots. Arbuscular mycorrhizas are important as they are believed to be the main mode of
nutrient acquisition in plants.  Also soil animal community shows little response to reindeer grazing.  In conclusion, intensive grazing by reindeer has strong effects on vegetation, but the soil communities are relatively resistant to environmental changes. When reindeer grazing is stopped, vegetation recovers very slowly.

 Manninen, O. H., Stark, S., Kytöviita, M.-M., Tolvanen, A. (2011) Individual and combined effects of disturbance and N additions
on understorey vegetation in a subarctic mountain birch forest. Journal of Vegetation Science, 22: 262?272

Kytöviita, M.-M. & Stark S. (2009) No allelopathic effect of the dominant forest-floor lichen Cladonia stellaris on pine seedlings.
Functional Ecology 23: 435-441.

 Sørensen, L., Mikola, J. Kytöviita, M.-M. & Olofsson, J.  (2009) Trampling and spatial heterogeneity explain decomposer abundances
in a sub-arctic grassland subjected to simulated reindeer grazing. Ecosystems 12: 830-842.

Stark S, Kytöviita, M-M, Männistö, M.K., & Neumann, A.B. (2008) Microbial and microfaunal communities and organic matter quality in
Finnish subarctic mountain birch forests used as reindeer ranges. Applied Soil Ecology, 40: 456-464.

 Sørensen L, Kytöviita M-M, Mikola J, Olofsson  J (2008): Soil feedback on plant growth in a subarctic grassland as a result of
repeated defoliation. Soil Biology and Biochemistry, 40: 2891-2897.

Additional information:

Maarja Öpik / maarja.opik@ut.ee
Tiit Teder / tiit.teder@ut.ee