2000 years of forest dynamics in southern Sweden: suggestions for forest management

Maps of forest types in southern Sweden covering the last 2000 years reveal a rapid and widespread transformation from rich, mixed deciduous forest types to species-poor coniferous-dominated forest types. The maps are presented at 500-year intervals and are based on syntheses of fossil pollen data. Fagus sylvatica replaced deciduous mixtures in southerly regions, and during the last 500 years Picea abies became a widespread dominant. We interpret this transformation as being partially a consequence of the climate-driven, continental-scale migrations of Fagus and Picea, but the major controlling factor appears to have been former land-use. This conclusion has significant consequences for 'nature-based' silviculture and conservation of biodiversity. Many threatened species are associated with deciduous forest mixtures, and these forest types have experienced recent. rapid decline. We state that a biologically sustainable silviculture in southern Sweden should be based on a larger range of tree species than at present, thus mimicking natural conditions and providing a greater diversity of product and biological value for the future. (C) 1998 Elsevier Science B.V.