Isopollen map

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An isopollen map is a map that shows the frequency of certain pollen in a certain layer of the earth.

application

A certain epoch can be assigned to a certain layer of the earth. A certain growth of the corresponding plant species can be assigned to a certain pollen frequency. In this way one can reconstruct past ecosystems . These findings are used by archaeologists. That is why an isopolis map is an archaeological aid.

Application example Linde

If one looks at the distribution of the linden tree since the end of the last ice age with the help of a set of isopole maps , the following findings emerge. The times refer to the year 2000.

  • The linden tree survived the last ice age only on the Balkan Peninsula and in northern Italy.
  • It reached the Paris Basin and the Baltic Sea 9,000 years ago .
  • It reached the south of Scandinavia 8,000 years ago .
  • It reached Britain 7,000 years ago.
  • 6,000 years ago it reached its greatest distribution in western Europe.
  • 5,000 years ago it retreated far north in Italy.
  • The lime tree never reached southern Italy, Spain and the Mediterranean islands with an almost constant southern border.
  • The linden tree never reached the island of Ireland.

literature

Władysław Szafer: The significance of isopollen lines for the investigation of the geographical distribution of trees in the post-glacial period . In: Bulletin de l'Academie Polonaise des Sciences and Letters, Series B, et . tape 1 , 1935, p. 235-239 (English).