Paper I.indd

Vegetation composition and reproduction of vascular plants were studied in relation to seven spatial structures: Betula pendula, Pinus sylvestris, Juniperus communis, Rosa dumalis, dung pats, grazing rejects and grazed patches. Th e study was performed in 14 unfertilized semi-natural pastures, with diff erent grazing intensities, in southcentral Sweden. Vegetation height diff ered between sites and between structures and signifi cantly infl uenced plant reproduction. Intensive grazing decreased the amount of grazing reject and increased the area of grazed patches. Vegetation height and number of fertile shoots were higher in grazing rejects, dung pats and near shrubs than in grazed patches and under trees, indicating that shrubs, but not trees, can function as partial grazing refugees. Th e results were used to simulate the eff ects of three diff erent grazing intensities and three diff erent shrub covers on plant reproduction. Th e simulation showed that grazing intensity was more important for plant reproduction than shrub cover due to the strong eff ect on the quantity of grazing rejects. Study site was the factor that best explained the variance for plant composition, accounting for 39% of the variation; spatial structurs accounted for 16% of the variation. Trees, shrubs, vegetation height and grazed patches signifi cantly aff ected plant composition but not dung pats and grazing rejects.