In this thesis, we focused on woodland regeneration in the presence of large herbivores. We performed field surveys, experiments and elementary modelling to gain insight into the patterns of woody species regeneration, the mechanisms at work and the natural processes that influence woodland regeneration on former agricultural land that is grazed by large herbivores. In general, we aimed to contribute to the understanding of the changing temporal and spatial patterns of the grassland-forest matrix in grazed conditions. We approached the issue of conservation management strategies and landscape openness at the scale of present day, controlled grazing management in fenced nature reserves, but results may also gain insights into mechanisms and processes that are/were active in traditional wooded pastures and wilderness landscapes. The key processes to be understood in grazed ecosystems that include woodland are plant strategies in coping with herbivory, herbivore selectivity, light and nutrient requirements, dispersal and natural disturbances.