Danish palaeoecologist and plant ecologist From Wikipedia, the free encyclopedia
Johannes Iversen (Danish pronunciation:[ˈiˀvɐsn̩], 12 December 1904 – 17 October 1971) was a Danish palaeoecologist and plant ecologist.[1]
Iversen c. 1955
He was born in Sønderborg and began studies in botany at the University of Copenhagen in 1923 under professor C.H. Ostenfeld, and with considerable inspiration from prof.em. Christen Raunkiær. At first he worked with macrophyte vegetation of lakes in relation to water pH. 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. In addition, halobio-types (salt tolerance) were described. 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. Iversen conducted a practical experiment with stone axe clear-cutting and slash-and-burn agriculture in a primeval forest to study the forest regeneration.[2][3]
Iversen, J. (1929) Studien über die pH-Verhältnisse dänischer Gewässer und ihren Einfluss auf die Hydrophyten-Vegetation. Botanisk Tidsskrift, 40 (4), 277–333.
Iversen, J. (1933) Studier over Vegetationen i Ringkøbing Fjord før Hvide Sande-Kanalens genåbning 1931 (with English summary). In: Johansen, A.C. & Blegvad, H. (eds) Ringkøbing Fjords Naturhistorie i Brakvandsperioden 1915–1931.
Iversen, J. (1934) Fund af Vildhest (Equus caballus) fra Overgangen mellem Sen- og Postglacialtid i Danmark. (Meddelelser fra Dansk Geologisk Forening, 8, 327-340 ). Danmarks Geologiske Undersøgelse IV.række, 2 (13), 1-16.
Iversen, J. (1934) Moorgeologische Untersuchungen auf Grönland. Ein Beitrag zur Beleuchtung der Ursachen des Unterganges der mittelalterlichen Nordmännerkultur. Meddelelser fra Dansk Geologisk Forening, 8, 341–358.
Iversen, J. (1936) Biologische Pflanzentypen als Hilfsmittel in der Vegetationsforschung. Ein Beitrag zur ökologischer Charakterisierung und Anordnung der Pflanzengesellshaften. Doctoral dissertation, University of Copenhagen. Levin & Munksgaard, København.
Iversen, J. (1936) Sekundäres Pollen als Fehlerquelle. Eine Korrektionsmethode zur Pollenanalyse minerogener Sedimente. Danmarks Geologiske Undersøgelse IV.række, 2 (15), 1-24.
Iversen, J. (1937) Pollenalalytiske Tidsbestemmelser af midtjydske mesolitiske Bopladser (Appendix til Th. Mathiassen: Gudenaa-Kulturen). Aarbøger for nordisk Oldkyndighed og Historie 1937, 182–186.
Iversen, J. (1937) Undersøgelser over Litorinatransgressioner i Danmark. Meddelelser fra Dansk Geologisk Forening, 9, 223–232.
Nominated as one of the most significant 20th Century publications in Danish geology. It is one of the most cited publications on short-term, low-amplitude sea-level changes and their causes.
Iversen, J. (1938) Et botanisk Vidne om Nordboernes Vinlandsrejser. Naturhistorisk Tidende, 2, 113–116.
Iversen, J. (1939) Planterester fremdragne i tre Høje i Haderslev Amt. In: Broholm, H.C. & Hald, M. Skrydstrupfundet: en sønderjysk Kvindegrav fra den ældre Bronzealder. Nordiske Fortidsminder, 3, 18–21.
Iversen, J. (1940) Blütenbiologische Studien. I. Dimorphie und Monomorphie bei Armeria (English summary) Biologiske Meddelelser / Kongelige Danske Videnskabernes Selskab, 15 (8), 1-40.
Iversen, J. (1941) Landnam i Danmarks Stenalder: En pollenanalytisk Undersøgelse over det første Landbrugs Indvirkning paa Vegetationsudviklingen (Dansk tekst 7-59, Engl. text 60–65). Danmarks Geologiske Undersøgelse II.række, 66, 1-68. (reprinted 1964)
Degerbøl, M. & Iversen, J. (1942) On a find of Sheat-fish (Silurus glanis L.) from the Ancylos period in Denmark. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening, 105, 435–446.
Iversen, J. & Olsen, Sigurd (1943) Die Verbreitung der Wasserpflanzen in Relation zur Chemie des Wassers. Botanisk Tidsskrift, 46, 136–145.
Iversen, J. (1943) Et Litorinaprofil ved Dybvad i Vendsyssel. Meddelelser fra Dansk Geologisk Forening, 10, 324–328.
Iversen, J. (1944) Viscum, Hedera and Ilex as climatic indicators. A contribution to the study of the Post-Glacial temperature climate. Geologiska Föreningen i Stockholm Förhandlingar, 66, 463–483.
Degerbøl, M. & Iversen, J. (1945) The bison in Denmark. A zoological and geological investigation of the finds in Danish Pleistocene deposits. Danmarks Geologiske Undersøgelse II.række, 73, 1-62.
Iversen, J. (1946) Datering af en senglacial Boplads ved Bromme (Datation Géologique de la station glaciaire postérieure de Bromme). Aarbøger for nordisk Oldkyndighed og Historie 1946: 197–231.
Iversen, J. (1947) Senglacialens nivåförändingar och klimatutveckling (contribution to discussion). In: Geologklubben vid Stockholms Högskola. Nordiskt kvartärgeologisk möte den 5–9 November 1945 [pp.215–217, 252]. Geologiska Föreningen i Stockholm Förhandlingar, 69, 215–217.
Iversen, J. (1947) Pollenanalysens principer och tillämpning (contribution to discussion). In: Geologklubben vid Stockholms Högskola. Nordiskt kvartärgeologisk möte den 5–9 November 1945. Geologiska Föreningen i Stockholm Förhandlingar, 69, 241–242.
Iversen, J. (1948) Palaeobotany and pollen analysis. In: The humanities and the Sciences in Denmark during the Second World War. Ejnar Munksgaard, Copenhagen, pp 313–315.
Iversen, J. (1953) Radiocarbon dating of the Alleröd period. Science, 118 (3053), 4–6.
Iversen, J. (1953) Origin and postglacial development of the flora of West Greenland in the light of pollen analysis. Proceedings of the Seventh International Botanical Congress Stockholm, July 12–20, 1950 (eds H. Osvald & E. Åberg), pp.634–636.
Iversen, J. (1953) Identification of difficult pollen types by means of structural characters. Proceedings of the Seventh International Botanical Congress Stockholm, July 12–20, 1950 (eds H. Osvald & E. Åberg), pp.873–874.
Iversen, J. (1954) The late-glacial flora of South-Scandinavia and its recent relics. Huitième Congrès International de Botanique, Paris 1954, Comptes rendus des séances et rapports et communications déposés lors du congrès dans les sections 3,4,5 et 6 pp.241–242.
German translation (1956) Neolitische Waldrodungen beleuchtet durch Pollenanalyse und Experiment. Mitteilungen der Naturforschender Gesellschaft Bern N.F., 13, 30–32.
French translation (1960) Le défrichement da la forêt pendant l’age de pierre. Les Naturalistes Belges, 41, 53–64.
Iversen, J. (1954) Pollenanalytischer Nachweis des Reliktencharakters eines jütischen Linden-Mischwaldes. Veröffentlichungen des Geobotanischen Institutes Rübel in Zürich, 33, 137–144.
Iversen, J. (1958) The bearing of glacial and interglacial epochs on the formation and extinction of plant taxa. In: Hedberg, O. (ed.): Systematics of to-day. Proceedings of a symposium held at the University of Uppsala in commemoration of the 250th anniversary of Carolus Linnaeus. Acta Universitatis Upsaliensis/Uppsala Universitets Årsskrift, 1958 (6), 210–215.
Iversen, J. (1964) Plant indicators of climate, soil and other factors during the Quaternary. INQUA VIth international Congress on the Quaternary, Warszawa 1961, 2, 421–428.
Iversen, J. & Fægri, Knut (1965) Field techniques. In: Handbook of Paleontological Techniques, p.482-494. San Francisco.
Iversen, J. & Fægri, Knut (1966) terminology in palynology. Pollen et Spores, 8, 345–445.
Iversen, J. (1969) Retrogressive development of a forest ecosystem demonstrated by pollen diagrams from a fossil mor. Oikos, 12S, 35–49.