ABSTRACT
THEREHAVEBEENanumberofimportantchangesin climatesincetheLastGlaciation,andthesehavebeenreflected inalterationsincompositionanddistributionofvegetation. Thesevegetationalchangeswerefirstrecognizedinthelast centurybyBlyttin1881andbySernander(1910)asaresultof studyingassemblagesofmacroscopicplantremainsinsuccessive Post-GlacialdepositsinNorwayandSweden.Theirsubdivisions ofHolocenetimehavesincebeenconfirmedandmoreclosely studiedbypollen-analysis(p.70),mainlyinDenmark.When ProfessorH.Godwin(1940,1941,1956)workedoutthePostGlacialforesthistoryinBritainbythismethod(Fig.15),he foundthatthesuccessivetreeassociationswerealmostidentical withthoseinDenmark,andaccordinglyheadopted,with slightmodifications,thesystemofnumberingthepollen-zones whichhadbeendevisedtherebyJessen.
