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Hagbard Jonassen

April 16, 2024

Hagbard Jonassen (24 May 1903 – 1 March 1977) was a Danish botanist, quaternary geologist, war resister and nuclear disarmament proponent. He made a lasting impact on the interpretation of pollen diagrams, including the use of modern pollen deposition in moss polsters to aid interpretation and the consideration of pollen productivity in different types of vegetation.

Career edit

He studied natural history at the University of Copenhagen and obtained his M.Sc. (cand. mag.) in 1931. He then became an assistant to Knud Jessen, who was the professor of botany at the University of Copenhagen and director of the Copenhagen Botanical Garden and one of the pioneers of pollen analysis in quaternary geology. He assisted Jessen in his work on Irish vegetation history.[1]

Jonassen’s list of papers is short.[2][3][4] Nevertheless, his doctoral dissertation[5] from 1950 had a lasting impact on its field in two respects. Jonassen pioneered the use pollen collected from moss polsters to assess the modern pollen rain and, by comparison with the species composition of surrounding vegetation, he was able to infer past vegetation from fossil pollen spectra much more accurately than before. Hence, he concluded that 1) cultivated crops such as cereals (except rye), beet, clover and lucerne had very low pollen production and the pollen signal from such areas would have a much higher detection limit than more productive types of land. Similarly, the pollen signal from un-wooded terrain like heathland and grassland could be completely swamped in pollen production from wind-pollinated trees. 2) Pollen dispersal in forest very limited local due to restricted wind speed, which was later confirmed by detailed investigations by Henrik Tauber.[6] Jonassen’s work on the Holocene history of heathlands in Jutland showed that forest had preceded heathland. He hypothesized that climate change had led to abandonment of agriculture and heathland expansion. More recent investigations in Denmark and Norway have shown that heathland expansion was metachronous, i.e. occurring at multiple separate locations to different times, suggesting an overriding impact of humans and less of importance for climate change.[7][8]

Peace activism edit

As a young student and army conscript, he was a co-founder of the Danish branch of War Resisters' International in 1926. He served as its president 1936-1942 and again from 1964.[9][10] He also co-founded the humanitarian non-governmental organisation Mellemfolkeligt Samvirke in 1944. In the 1960s, Jonassen engaged himself in the popular struggle against nuclear weapons.[11]

See also edit

References edit

  1. ^ Herries Davies, Gordon L. (1997). "Frank Mitchell (1912-1997): some memories in appreciation". Irish Geography. 30 (2): 106–112. doi:10.1080/00750779709478638.
  2. ^ Jonassen, H. (1935). "Et Pollendiagram fra Karupfladen [A pollen diagram from the Karup Plain]". Botanisk Tidsskrift. 43: 187–196.
  3. ^ Jonassen, H. (1954). "Dating of sand-drift east of Ulfborg". Botanisk Tidsskrift. 51: 134–140.
  4. ^ Jonassen, H. (1957). "Bidrag til Filsøegnens naturhistorie (English abstract)" (PDF). Bulletin of the Geological Society of Denmark. 13 (4): 192–205.
  5. ^ Jonassen, H. (1950). Recent pollen sedimentation and Jutland heath diagrams (Doctoral dissertation). Dansk Botanisk Arkiv 13:7. Copenhagen: Munksgaard. p. 168.
  6. ^ Tauber, H. (1965). "Differential pollen dispersal and the interpretation of pollendiagrams (Doctoral dissertation)". Danmarks Geologiske Undersøgelse, IV Række. 4: 1–69.
  7. ^ Odgaard, B. V. (1994). "The Holocene vegetation history of northern West Jutland, Denmark (Doctoral dissertation)". Opera Botanica. 123: 1–171.
  8. ^ Prøsch-Danielsen, L.; Simonsen, A. (2000). "Palaeoecological investigations towards the reconstruction of the history of forest clearances and coastal heathlands in south-western Norway". Journal Vegetation History and Archaeobotany. 9 (4): 189–204. doi:10.1007/BF01294634.
  9. ^ Aldrig mere Krig
  10. ^ War Resisters' International
  11. ^ Wittner, Lawrence S. (1993). Resisting the bomb: a history of the world nuclear disarmament movement. Stanford University Press. ISBN 0-8047-2141-6. Chapter 10

External links edit

  • Portrait on the front cover of The War Resister 1952

April 16, 2024
hagbard, jonassen, 1903, march, 1977, danish, botanist, quaternary, geologist, resister, nuclear, disarmament, proponent, made, lasting, impact, interpretation, pollen, diagrams, including, modern, pollen, deposition, moss, polsters, interpretation, considerat. Hagbard Jonassen 24 May 1903 1 March 1977 was a Danish botanist quaternary geologist war resister and nuclear disarmament proponent He made a lasting impact on the interpretation of pollen diagrams including the use of modern pollen deposition in moss polsters to aid interpretation and the consideration of pollen productivity in different types of vegetation Contents 1 Career 2 Peace activism 3 See also 4 References 5 External linksCareer editHe studied natural history at the University of Copenhagen and obtained his M Sc cand mag in 1931 He then became an assistant to Knud Jessen who was the professor of botany at the University of Copenhagen and director of the Copenhagen Botanical Garden and one of the pioneers of pollen analysis in quaternary geology He assisted Jessen in his work on Irish vegetation history 1 Jonassen s list of papers is short 2 3 4 Nevertheless his doctoral dissertation 5 from 1950 had a lasting impact on its field in two respects Jonassen pioneered the use pollen collected from moss polsters to assess the modern pollen rain and by comparison with the species composition of surrounding vegetation he was able to infer past vegetation from fossil pollen spectra much more accurately than before Hence he concluded that 1 cultivated crops such as cereals except rye beet clover and lucerne had very low pollen production and the pollen signal from such areas would have a much higher detection limit than more productive types of land Similarly the pollen signal from un wooded terrain like heathland and grassland could be completely swamped in pollen production from wind pollinated trees 2 Pollen dispersal in forest very limited local due to restricted wind speed which was later confirmed by detailed investigations by Henrik Tauber 6 Jonassen s work on the Holocene history of heathlands in Jutland showed that forest had preceded heathland He hypothesized that climate change had led to abandonment of agriculture and heathland expansion More recent investigations in Denmark and Norway have shown that heathland expansion was metachronous i e occurring at multiple separate locations to different times suggesting an overriding impact of humans and less of importance for climate change 7 8 Peace activism editAs a young student and army conscript he was a co founder of the Danish branch of War Resisters International in 1926 He served as its president 1936 1942 and again from 1964 9 10 He also co founded the humanitarian non governmental organisation Mellemfolkeligt Samvirke in 1944 In the 1960s Jonassen engaged himself in the popular struggle against nuclear weapons 11 See also editList of peace activistsReferences edit Herries Davies Gordon L 1997 Frank Mitchell 1912 1997 some memories in appreciation Irish Geography 30 2 106 112 doi 10 1080 00750779709478638 Jonassen H 1935 Et Pollendiagram fra Karupfladen A pollen diagram from the Karup Plain Botanisk Tidsskrift 43 187 196 Jonassen H 1954 Dating of sand drift east of Ulfborg Botanisk Tidsskrift 51 134 140 Jonassen H 1957 Bidrag til Filsoegnens naturhistorie English abstract PDF Bulletin of the Geological Society of Denmark 13 4 192 205 Jonassen H 1950 Recent pollen sedimentation and Jutland heath diagrams Doctoral dissertation Dansk Botanisk Arkiv 13 7 Copenhagen Munksgaard p 168 Tauber H 1965 Differential pollen dispersal and the interpretation of pollendiagrams Doctoral dissertation Danmarks Geologiske Undersogelse IV Raekke 4 1 69 Odgaard B V 1994 The Holocene vegetation history of northern West Jutland Denmark Doctoral dissertation Opera Botanica 123 1 171 Prosch Danielsen L Simonsen A 2000 Palaeoecological investigations towards the reconstruction of the history of forest clearances and coastal heathlands in south western Norway Journal Vegetation History and Archaeobotany 9 4 189 204 doi 10 1007 BF01294634 Aldrig mere Krig War Resisters International Wittner Lawrence S 1993 Resisting the bomb a history of the world nuclear disarmament movement Stanford University Press ISBN 0 8047 2141 6 Chapter 10External links editPortrait on the front cover of The War Resister 1952 Retrieved from https en wikipedia org w index php title Hagbard Jonassen amp oldid 1188148289, wikipedia, wiki, book, books, library,

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