Johannes Iversen (, 12 December 1904 – 17 October 1971) was a Danish palaeoecologist and plant ecologist.

Biography

He was born in

Sønderborg (; ) is a Denmark, Danish town in the Region of Southern Denmark. It is the main town and the administrative seat of Sønderborg Municipality (Kommune). The town has a population of 28,333 (1 January 2025),University of Copenhagen The University of Copenhagen (, KU) is a public university, public research university in Copenhagen, Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in Scandinavia, after Uppsala University. ...

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'', commonly called ivy (plural ivies), is a genus of 12–15 species of evergreen climbing or ground-creeping woody plants in the family Araliaceae, native to Western Europe, Central Europe, Southern Europe, Macaronesia, northwestern ...

(Hedera) and

holly ''Ilex'' () or holly is a genus of over 570 species of flowering plants in the family Aquifoliaceae, and the only living genus in that family. ''Ilex'' has the most species of any woody dioecious angiosperm genus. The species are evergreen o ...

(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 Slash-and-burn agriculture is a form of shifting cultivation that involves the cutting and burning of plants in a forest or woodland to create a Field (agriculture), field called a swidden. The method begins by cutting down the trees and woody p ...

agriculture in a primeval forest to study the forest regeneration. In 1931, Iversen was first appointed assistant at the Geological Survey of Denmark and Greenland. In 1938, Iversen became a Sectional geologist and in 1942 he became State Geologist, an appointment he kept until his death. In 1955, he became a lecturer in

pollen analysis Palynology is the study of microorganisms and microscopic fragments of mega-organisms that are composed of acid-resistant organic material and occur in sediments, sedimentary rocks, and even some metasedimentary rocks. Palynomorphs are the mic ...

at the

University of Copenhagen The University of Copenhagen (, KU) is a public university, public research university in Copenhagen, Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in Scandinavia, after Uppsala University. ...

. In 1953, he was made a member of the Royal Danish Academy of Sciences and Letters. He was awarded honorary doctorates at

Uppsala University Uppsala University (UU) () is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in operation. Initially fou ...

and

Cambridge University The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the List of oldest universities in continuous operation, wo ...

Textbook of modern pollen analysis

* Fægri, Knut & Iversen, J. (1950) Textbook of modern pollen analysis. Ejnar Munksgaard, Copenhagen. 168 p. * Fægri, Knut & Iversen, J. (1964) Textbook of pollen analysis, 2nd edn. Scandinavian University Books, Copenhagen. 237 p. * Fægri, K. & Iversen, J. (1975) Textbook of pollen analysis, 3rd ed. by Knut Fægri, Scandinavian University Books, Copenhagen. 294 p. * Fægri, K. & Iversen, J. (1989) Textbook of pollen analysis. 4th ed. by K. Fægri, P.E. Kaland & K. Krzywinski. John Wiley & Sons, Chichester. 328 p.

Scientific works by Johs. Iversen

* Iversen, J. (1928) Über Isoëtes in

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

und

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. Dansk Botanisk Arkiv, 5 (23), 1–4. * Iversen, J. (1928) Über die Spezies-Umgrenzung und Variation der Isoëtes echinospora Durieu. Botanisk Tidsskrift, 40 (2), 126–131. * Iversen, J. (1929) Studien über die pH-Verhältnisse dänischer Gewässer und ihren Einfluss auf die Hydrophyten-Vegetation. Botanisk Tidsskrift, 40 (4), 277–333. **Keywords: plant

ecology Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...

* Iversen, J. (1930) Isoëtes, In: Christensen, C., The pteridophytes of

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

. Dansk Botanisk Arkiv, 7, 200–201. * Gabrielsen, E.K. & Iversen, J. (1933) Die Vegetation der Halbinsel Skallingen. Botanisk Tidsskrift, 42 (4), 355–383. **Keywords: plant

* 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. **Keywords: plant

* Iversen, J. (1934) Fund af Vildhest ( Equus caballus) fra Overgangen mellem Sen- og Postglacialtid i Danmark. (Meddelelser fra Dansk Geologisk Forening, 8, 327-34

. 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

**Keywords: History of Greenland#Norse abandonment, Demise of Greenland Norse settlements * 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. **Keywords: plant

* Iversen, J. (1936) Sekundäres Pollen als Fehlerquelle. Eine Korrektionsmethode zur Pollenanalyse minerogener Sedimente. Danmarks Geologiske Undersøgelse IV.række, 2 (15), 1-24. **Keywords:

* 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 Litorina transgressioner 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

Vinland Vinland, Vineland, or Winland () was an area of coastal North America explored by Vikings. Leif Erikson landed there around 1000 AD, nearly five centuries before the voyages of Christopher Columbus and John Cabot. The name appears in the V ...

srejser. 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. **Keywords: plant macrofossils,

Bronze Age The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of ...

tumuli A tumulus (: tumuli) is a mound of Soil, earth and Rock (geology), stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds, mounds, howes, or in Siberia and Central Asia as ''kurgans'', and may be found through ...

* Iversen, J. (1940) Blütenbiologische Studien. I. Dimorphie und Monomorphie bei

Armeria ''Armeria'' is a genus of flowering plants. These plants are sometimes known as "lady's cushion", "thrift", or "sea pink" (the latter because as they are often found on coastlines). The genus counts over a hundred species, mostly native to the ...

(English summary) Biologiske Meddelelser / Kongelige Danske Videnskabernes Selskab, 15 (8), 1-40. **Keywords:

palynology Palynology is the study of microorganisms and microscopic fragments of mega-organisms that are composed of acid-resistant organic material and occur in sediments, sedimentary rocks, and even some metasedimentary rocks. Palynomorphs are the mic ...

* 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) **Keywords: palaeoecology,

history of agriculture Agriculture began independently in different parts of the globe, and included a diverse range of Taxon, taxa. At least eleven separate regions of the Old World, Old and New World were involved as independent centers of origin. The developmen ...

* 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. **Keywords: plant

* Iversen, J. (1943) En pollenanalytisk Tidsfæstelse af Ferskvandlagene ved Nørre Lyngby. Meddelelser fra Dansk Geologisk Forening, 10, 130–151

**Keywords: Last glacial period, Late Weichselian * Iversen, J. (1943) Et Litorinaprofil ved Dybvad i Vendsyssel. Meddelelser fra Dansk Geologisk Forening, 10, 324–328

* Iversen, J. (1944) Viscum,

Hedera ''Hedera'', commonly called ivy (plural ivies), is a genus of 12–15 species of evergreen climbing or ground-creeping woody plants in the family Araliaceae, native to Western Europe, Central Europe, Southern Europe, Macaronesia, northwestern ...

and

Ilex ''Ilex'' () or holly is a genus of over 570 species of flowering plants in the family Aquifoliaceae, and the only living genus in that family. ''Ilex'' has the most species of any woody dioecious angiosperm genus. The species are evergreen or ...

as climatic indicators. A contribution to the study of the Post-Glacial temperature climate. Geologiska Föreningen i Stockholm Förhandlingar, 66, 463–483. **Keywords: palaeoecology, plant

* Iversen, J. (1944)

Helianthemum ''Helianthemum'' (), known as rock rose, sunrose, rushrose, or frostweed,

som fossil Glacialplante i Danmark. Geologiska Föreningen i Stockholm Förhandlingar, 66, 774–776. **Keywords: Last glacial period, Late Weichselian * Degerbøl, M. & Iversen, J. (1945) The

bison A bison (: bison) is a large bovine in the genus ''Bison'' (from Greek, meaning 'wild ox') within the tribe Bovini. Two extant taxon, extant and numerous extinction, extinct species are recognised. Of the two surviving species, the American ...

in Denmark. A zoological and geological investigation of the finds in Danish

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

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. **Keywords: Last glacial period, Late Weichselian * Iversen, J. (1947) Plantevækst, Dyreliv og Klima i det senglaciale Danmark. Geologiska Föreningen i Stockholm Förhandlingar, 69, 67–78. **Keywords: Last glacial period, Late Weichselian * Iversen, J. (1947) Centaurea cyanus-pollen in Danish late-glacial deposits. Meddelelser fra Dansk Geologisk Forening, 11, 197–200

**Keywords: Last glacial period, Late Weichselian * Iversen, J. (1947) Senglacialens nivåförändingar och klimatutveckling (contribution to discussion). In: Geologklubben vid Stockholms Högskola. Nordiskt kvartärgeologisk möte den 5–9 November 1945 p. 215–217, 252 Geologiska Föreningen i Stockholm Förhandlingar, 69, 215–217. **Keywords: Last glacial period, Late Weichselian * 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

. In: The humanities and the Sciences in Denmark during the Second World War. Ejnar Munksgaard, Copenhagen, pp 313–315. * Iversen, J. (1949) The influence of prehistoric man on vegetation. Danmarks Geologiske Undersøgelse IV.række, 3 (6), 1-25. **Keywords: palaeoecology,

* Iversen, J. (1949) Determinations of the specific gravity of the roots of swamp, meadow and dry-soil plants.

Oikos ''Oikos'' ( ; : ) was, in Ancient Greece, two related but distinct concepts: the family and the family's house. Its meaning shifted even within texts. The ''oikos'' was the basic unit of society in most Greek city-states. For regular Attic_G ...

, 1, 1–5

**Keywords: plant

* Iversen, J. & Troels-Smith, J. (1950) Pollenmorfologiske definitioner og typer. Danmarks Geologiske Undersøgelse IV.række, 3 (8), 1-54. **Keywords:

* Iversen, J. (1951) Steppeelementer i den senglaciale flora og fauna (English summary) Meddelelser fra Dansk Geologisk Forening, 12, 174–175

**Keywords: Last glacial period, Late Weichselian * Iversen, J. (1952/53) Origin of the flora of Western

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

in the light of

, 4, 85-103

* Iversen, J. (1953) Radiocarbon dating of the Allerød Oscillation, Alleröd period. ''Science'', 118 (3053), 4–6

* Iversen, J. (1953) Origin and postglacial development of the flora of West

in the light of

. 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. **Keywords:

* Iversen, J. (1953) The zonation of the salt marsh vegetation of Skallingen in 1931-34 and in 1952. Danish Journal of Geography, Geografisk Tidsskrift, 52, 113–118. * Iversen, J. (1954) The Late-Glacial flora of Denmark and its relation to climate and soil. Danmarks Geologiske Undersøgelse II.række, 80, 87-119. **Keywords: Last glacial period, Late Weichselian * 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. **Keywords: Last glacial period, Late Weichselian * Iversen, J. (1954) Über die Korrelationen zwischen den Pflanzenarten in einem grönländischen Talgebiet. Vegetatio, 5–6, 238–246. * Iversen, J. (1956) Forest clearance in the

Stone Age The Stone Age was a broad prehistory, prehistoric period during which Rock (geology), stone was widely used to make stone tools with an edge, a point, or a percussion surface. The period lasted for roughly 3.4 million years and ended b ...

. ''

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it, with more than 150 Nobel Pri ...

'', 194, 36–41. ** 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. **Keywords: palaeoecology,

* Iversen, J. (1957) Istidsrelikter i

Bornholm Bornholm () is a List of islands of Denmark, Danish island in the Baltic Sea, to the east of the rest of Denmark, south of Sweden, northeast of Germany and north of Poland. Strategically located, Bornholm has been fought over for centuries. I ...

s flora. In: Bornholms naturhistoriske Forening, udgivet i anledning af 25 års jubilæet pp. 35–37. **Keywords: Last glacial period, Late Weichselian * 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. **Keywords:

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

* Iversen, J. (1960) Problems of the early post-glacial forest development in Denmark. Danmarks Geologiske Undersøgelse IV.række, 4 (3), 1-32. **Keywords: palaeoecology * Iversen, J. (1964) Retrogressive vegetational succession in the Post-glacial.

Journal of Ecology The ''Journal of Ecology'' is a bimonthly peer-reviewed scientific journal covering all aspects of the ecology of plants. It was established in 1913 and is published by Wiley-Blackwell on behalf of the British Ecological Society. The journal pub ...

, 52S, 59–70. **Keywords: palaeoecology * Iversen, J. (1964) Plant indicators of climate, soil and other factors during the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

. 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

. Pollen et Spores, 8, 345–445. * Iversen, J. (1969) Retrogressive development of a forest ecosystem demonstrated by pollen diagrams from a fossil mor.

, 12S, 35–49. **Keywords: palaeoecology * Iversen, J. (1973) The development of Denmark's nature since the last glacial. Danmarks Geologiske Undersøgelse V.række, 7C, 1–126. **Keywords: palaeoecology

References

Other sources

* Obituary in '' Botanisk Tidsskrift'' 67 (3): 275-277 (1972) by Svend Th. Andersen. * Obituary in the ''

New Phytologist ''New Phytologist'' is a peer-reviewed scientific journal published on behalf of the New Phytologist Foundation by Wiley-Blackwell. It covers all aspects of botany and was established in 1902 by Arthur Tansley, who served as editor until 1931. M ...

'' 72 (5): 1245-1250 (1973) by

Harry Godwin Sir Harry Godwin, FRS (9 May 1901 – 12 August 1985) was a prominent English botanist Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxon ...

External links

Virtual International AuthorityInternational Plant Names Index
{{DEFAULTSORT:Iversen, Johannes 1904 births 1971 deaths People from Sønderborg Municipality University of Copenhagen alumni Academic staff of the University of Copenhagen Danish ecologists Danish science writers Palynologists Plant ecologists 20th-century Danish botanists Members of the Royal Danish Academy of Sciences and Letters