The trampling associated with grazing is an important driver for below ground impacts.

A very high-resolution false color Ikonos-2 satellite image of Jauristunturit in the border zone shared by Norway and Finland. Image acquired 28 June 2001. The main vegetation type is lichen dominated tundra heath with dwarf shrubs. The difference in whiteness is due to lichen coverage, and the national border with reindeer fence visibly divides the area. The northern portion is Norway, where fruticose lichen coverage is higher. This is a consequence of different pasture management. The Norwegian side is used only in late winter when there is snow cover and no grazing or trampling occurs in summer. The Finnish area is used in early summer, when vulnerable lichen mats have been progressively trampled over several decades

Conservation of Arctic Flora and Fauna (CAFF)

www.caff.is 

The data can be downloaded freely.

Users are requested to reference it source.

i.e. Arctic Biodiversity Trends 2010.