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Dry, boreal, forest ecosystems have been shown to alternate due to reindeer presence by changing the field layer. This affects the temperature of the soil, changes the microclimate and the nutrients of soil and field layer. By removal of biomass and trampling stress the ground lichen mats reduce in cover and thickness. In this thesis two dry, boreal pine forests in Northern Finland were studied, to see how the nutrient stocks in the field layer are impacted by reindeer presence. A comparison of the same site, with >20 years in between was studied to see how year-round grazing affect the carbon storage in the field layer compared to winter grazing.

 I found that reindeer grazing reduces the vegetation carbon storage, however, the impact on the vegetation nitrogen storage differs with site. Furthermore, the lichens and shrubs had lower C:N ratios because of increased nitrogen content in the plant tissue and unaffected carbon content. These results show that reindeer actively changes the vegetation quantity and quality which will have implications for the soil carbon storage.