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PAST AND PRES ENTThe Late-Quaternary Vegetation of SwedenBy MAGNUS FRIESIntroductionIn 1966 fifty years have passed since LENNARTvoN PosT worked out the first pollen diagrams.They were presented in 1916 at the Scandinavianscientists' meeting in Kristiania (now Oslo) in theform of a very large coloured drawing now kept inthe Institute of Quaternary Geology of the Universityof Stockholm. It was, however, neverpublished. This series of diagrams from Sjrelland(Zealand) in Denmark through Skane (Scania),Smaland, Vastergotland, and Ostergotland toNarke in south-central Sweden (Fig. 2, map /)opened new possibilities of investigation into thehistory_ of late-Quaternary vegetation. The paperread by voN PosT at the meeting was publishedas a short account in 1916, and fully in 1918.Although pollen grains and spores were consideredeven earlier in local stratigraphic studies (seeFJEGRI & IvERSEN 1964, pp. 11-12) the pollenstatisticalmethod of voN PosT turned out to bean extremely valuable complement to the investigationsbased on macrofossils. In fact the research inthis field soon became more and more dependenton pollen analysis. The consequence, at least inSweden, was that the macrofossils were undeservedlypushed into the background as objects ofstudy.However, the outlines of the late-Quaternaryvegetational and climatic history of Sweden havebeen drawn on the basis of studies of macrofossilsand "macrostratigraphy". Thus interglacial layerswere discovered in central Sweden (Jamtland,Angermanland, Halsingland); see a survey of theinterglacial deposits in Sweden by G. LUNDQVIST(1964). The occurrence of an arctic flora (Dryas,Betula nana, Salix polaris, and S. reticulata) insouthernmost Sweden shortly after the retreatof the ice was reported as early as 1871 by A. G.NATHORST. A period of warmer climate than thatof today was discovered, although there was somecontroversy regarding its character and duration(G. ANDERSSON 1909,· 1910; SERNANDER 1910). Thecourse of immigration of the main forest treesbecame known through early stratigraphic studiesin Denmark (STEENSTRUP 1841, etc.), which couldalso be applied to southernmost Sweden. The resultsof these early studies in the vegetational and climatichistory of Sweden were summarized in somepublications by G. ANDERSSON (1896, 1906, 1909,1910) and SERNANDER ( 1895, 1899-1900, 1910,1916).The Late-glacialFor an account of the present knowledge of theLate-glacial and Post-glacial vegetational historywithin the area, which corresponds to Sweden oftoday, it is necessary to take several investigationsin our neighbouring countries into consideration.For the understanding of the Late-glacial landscapeof southern Sweden, not yet separated fromthe Continent by the Sounds (cf. map a, Fig. 2),modern Danish studies are especially instructive;cf. the survey by IvERSEN (1954) and KROG (1954).The Late-glacial of Skane (Scania) and other partsof southern Sweden has been illustrated in thepioneer work by T. Nrr..ssoN ( 1935), followed bylater pollen-analytical studies (MOHREN 1942;ERDTMAN 1946, 1949; BRORSON 0HRISTENSEN 1949;DoNNER 1951, p. 59; M. FRIES 1951, pp. 110-120;TERASMAE 1951; MAGNUSSON 1962; BERGLUND1963 b).Obviously the Scanian course of vegetationalActa Phytogeogr. Suec. 50