Traditional management of forests: plant and bird community responses to alternative restoration of oak–hazel woodland in Sweden

Species richness of vascular plants and birds were examined in relation to five types of management (including abandonment) of oak-hazel woodland in south-central Sweden. The biodiversity of this type of woodland is affected by lengthy management in contrast to present emphasis on the fragmentation of more or less pristine forests. The woodlands derive from old deciduous forests but were a source of agricultural commodities from medieval time to end of the 19th century. Vascular plants and birds were censused during spring–summer for four years. Total number of plant species, species of field layer forbs, breeding birds and migrant birds were more numerous at simulated original management with mowing of small interior grasslands than at mechanical clearing or abandonment. Summer grazing led to intermediate numbers. Exotic plants were more common at long-time abandonment. Species richness of trees and shrubs, graminoids, all spring birds, resident birds and non-passerine birds did not exhibit any difference between treatments. Inter-site variation in species richness was usually smaller at abandonment than at true management. Species richness of plants and birds showed positive correlation in the particularly large sites examined. The general findings were in accordance with the intermediate disturbance hypothesis. Original management would secure most potential plant and bird species but extensive cattle grazing would also retain many species.