Impacts of semi-domesticated reindeer on structure of tundra and forest communities in Fennoscandia: a review

Grazing and trampling by semi-domesticated reindeer are important factors c ontrolling vegetation in northern Fennoscandia. In this article we review N ordic studies on the effects of reindeer on vegetation and animal communiti es. The studies have shown clear effects on vegetation, especially on Cladi na lichen dominated sites. Cladina is the main forage of reindeer during wi nter and dominates climax vegetation in dry site types in the absence of re indeer. Reindeer can even affect galling and ground-dwelling invertebrates. Due to the special relationship between reindeer and Cladina majority of t he research has concentrated on winter grazing on Cladina, but there are so me studies of summer grazing which have also shown substantial changes in v egetation. Reindeer grazing increases richness and diversity of vegetation and invertebrate assemblages in most cases, but this influence depends on s ite type and grazing intensity. The enriching effect seems to be strongest at moderate grazing intensity.