EUROPEAN POSTGLACIAL FORESTS - COMPOSITIONAL CHANGES IN RESPONSE TO CLIMATIC-CHANGE

Abstract. Multivariate analysis of an extensive palyno‐logical database for Europe has enabled reconstruction of broad‐scale vegetation history. Whereas many major features of present vegetation patterns were established early in the Holocene, floristic composition of the forests has changed continuously up to the present day. For example, although ‘mixed deciduous forests’ had reached approximately their present extent in northwest Europe by 8000 B.P., Tilia peaked in abundance in these forests during the middle post glacial, whereas Pinus was most abundant in these forests during the early post‐glacial and Fagus increased in abundance only in recent millennia. Pollen‐climate response surfaces for major pollen taxa show how their distribution and abundance patterns relate to contemporary climate. Past forest‐compositional changes were responses to climatic changes, the nature of which can be inferred from pollen‐climate response surfaces. Post‐glacial climate changes have been different in magnitude and direction in different regions of Europe. For example, in recent millennia the vegetation changes indicate decreasing summer temperatures in northern Europe but increasing summer temperatures in the Mediterranean region. The way in which vegetation responded to past climatic changes gives insight into the likely response of vegetation to future climate changes induced by the ‘greenhouse effect’. 1990 IAVS ‐ the International Association of Vegetation Science