Johannes Iversen

[1] He was born in Sønderborg and began studies in botany at the University of Copenhagen in 1923 under professor C.H.

The influence from Raunkiær is particularly evident in Iversen's doctoral thesis, in which he divided herbaceous plants into hydrotypes based on experiments and morphological studies: xerophytes, mesophytes, hygrophytes, telmatophytes, amphiphytes and limnophytes.

He brilliantly used modern equivalents in the interpretation of pollen diagrams, e.g. his now classic studies on frost damage to ivy (Hedera) and holly (Ilex) during the severe winters of the early 1940s led to their fossil pollen being used as climate indicators.

Iversen demonstrated the steppe and tundra components of the late glacial flora.

In 1953, he was made a member of the Royal Danish Academy of Sciences and Letters.