Moose management and browsing dynamics in boreal forest

The foraging patterns of large herbivores will affect their impact on structures and functions of ecosystems and on human use of natural resources. The foraging patterns are affected by a multitude of factors, e.g. forage availability, environmental conditions and herbivore density. Furthermore, the importance of these factors has been suggested to vary over temporal and spatial scales. The impact from large herbivores will affect the management actions to fulfil socio-political policies (e.g. regarding damage to forests) and the harvest quotas could be decided from monitoring of animal numbers and damage. However, wildlife managers are often faced with a choice of several available monitoring methods, at varying cost and precision. The aim of this thesis was to improve our understanding of: 1) factors governing the foraging patterns of large herbivores and thereby also the impact on the ecosystem; and 2) performance of survey methods in relation to monitoring cost. The study was performed in south-central Sweden, and moose (Alces alces) in boreal forest was used as a model system. The results suggest that herbivore foraging decisions are scale-dependent. The significance of moose density effects, site productivity and diversity among forage species on the foraging pattern varied from feeding patch to landscape level. On the plant level, browsing pressure and moose preference for groups of certain species varied significantly. On the stand level, moose preference for certain habitats varied according to variation in snow conditions. Furthermore, the distribution of forage types (e.g. field and shrub layer) differed between the habitats and the browsing on the different layers of forage will therefore vary according to environmental conditions. The browsing pressure was also dependent on forage availability and herbivore density. Moose density in Sweden is mainly regulated by hunting. The hunting quotas rely on more or less accurate monitoring methods. The ability to reach management goals generally increased with monitoring effort, but a combination of two relatively inexpensive monitoring methods also produced successful management outcomes