The fact that large herbivores, such as Rangifer tarandus, play a part in shaping its environment through grazing and trampling of the ground is widely acknowledged today, as well as that these factors have the potential of affecting regional patterns and even global climate. This study investigated whether a considerable increase in grazing by R. tarandus for 25 years resulted in any measurable effects on the diversity of plant species in tundra vegetation. We evaluated if any differences in species composition could be found, based on differences in grazing pressure and productivity of the soil. The effect of difference in grazing pressure was studied through analysis of vegetation at 30 sites, each site comparing two different classes of grazing pressure separated by a fence, and pellets from R. tarandus were counted along transects. We did not find any evidence that the difference in grazing pressure affected the species composition on either side of the fence, depending on the site. The lack of difference in plant species composition may be explained by insufficient differences in abundance of R. tarandus, insufficient time passed since the change in grazing pressure, or varying grazing seasons at the sites on either side of the fence.

vegetation and soil carbon-and nitrogen cycles in a grazing area through food selection, consumption, fertilization, and trampling. There have been discussions on how reindeer grazing, plant communities, and different ecosystems relate to each other and how the management of protected areas should proceed based on various laws, recommendations, and perspectives. The purpose of this study is to examine the impact of reindeer grazing on biodiversity in northern Scandinavia and thus be able to support these discussions. Inventory data was collected in 1995 on both sides of the fence that demarcates Norway from Malla National Park in Finland. At the time of the inventory, reindeer husbandry had been prohibited on the Finnish side of the fence for several decades, creating a difference in grazing pressure between the inventory areas. A statistical comparison was made between the number of plant species for six different functional plant groups divided into four different soil moisture types between the two countries, as well as a comparison of the number of reindeer droppings per study area in each country to quantify the difference in grazing pressure. The results show that there were more grass species in meadow areas and more reindeer droppings on the Norwegian side. I found no significant difference for the other functional plant groups or for the grasses in the other soil moisture types. Based on these results, I conclude that reindeer may increase the number of grass species in meadow areas.