Disturbance by large herbivores in boreal forests with special reference to moose

Moose and reindeer occur in large populations in the Fennoscandian boreal forests, and also roe deer occurs in dense populations in Sweden and Norway. These large herbivores affect the structure and function of the forest ecosystems. During periods of high densities discussions arise about the impact of these herbivores on e.g. economic forest trees and preservation of biodiversity. The aim of this study is to review the present knowledge of the disturbance caused by moose in the boreal forest. First, we give a quantitative estimate of the different disturbance factors (feeding, trampling, defecation and urination). Second, we discuss the ecological impact of the different disturbances.