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

Biography

He was born in

Sønderborg (; german: Sonderburg ) is a 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 27,766 (1 January 2022),University of Copenhagen The University of Copenhagen ( da, Københavns Universitet, KU) is a prestigious public research university in Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in Scandinavia after Uppsala Unive ...

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, central and southern Europe, Macaronesia, northwestern Africa and ...

(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 farming method that involves the cutting and burning of plants in a forest or woodland to create a field called a swidden. The method begins by cutting down the trees and woody plants in an area. The downed veget ...

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 The Geological Survey of Denmark and Greenland ( da, Danmarks og Grønlands Geologiske Undersøgelse, GEUS) is the independent sector research institute under the Danish Ministry of Climate and Energy. GEUS is an advisory, research and survey i ...

. 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 dust" (from grc-gre, παλύνω, palynō, "strew, sprinkle" and ''-logy'') or of "particles that are strewn". A classic palynologist analyses particulate samples collected from the air, from water, or from deposits ...

at the

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

. In 1953, he was made a member of the

Royal Danish Academy of Sciences and Letters {{Infobox organization , name = The Royal Danish Academy of Sciences and Letters , full_name = , native_name = Det Kongelige Danske Videnskabernes Selskab , native_name_lang = , logo = Royal ...

. He was awarded honorary doctorates at

Uppsala University Uppsala University ( sv, Uppsala universitet) is a public research university in Uppsala, Sweden. Founded in 1477, it is the oldest university in Sweden and the Nordic countries still in operation. The university rose to significance during ...

and

Cambridge University The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209 and granted a royal charter by Henry III of England, Henry III in 1231, Cambridge is the world' ...

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 ''Isoetes'', commonly known as the quillworts, is the only extant genus of plants in the family Isoetaceae, which is in the class of lycopods. There are currently 192 recognized species, with a cosmopolitan distribution but with the individual s ...

in China und Japan. Dansk Botanisk Arkiv, 5 (23), 1–4. * Iversen, J. (1928) Über die Spezies-Umgrenzung und Variation der

Isoëtes echinospora ''Isoetes echinospora'', also known as spiny quillwort, spiny-spored quillwort or spring quillwort is a species of quillwort in the Isoetaceae family, and is the most abundant species in Canada. It can be found in shallow aquatic environments fro ...

Durieu.

Botanisk Tidsskrift ''Botanisk Tidsskrift'' (standard abbreviation ''Bot. Tidsskr.'') was a Danish mixed scientific and amateur journal concerning botany, issued in Copenhagen by the Danish Botanical Society. It was published from 1866 to 1980, when it fused with Bot ...

, 40 (2), 126–131. * Iversen, J. (1929) Studien über die pH-Verhältnisse dänischer Gewässer und ihren Einfluss auf die

Hydrophyte Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that g ...

n-Vegetation.

, 40 (4), 277–333. **Keywords: plant

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overl ...

* Iversen, J. (1930)

, In: Christensen, C., The pteridophytes of

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

. Dansk Botanisk Arkiv, 7, 200–201. * Gabrielsen, E.K. & Iversen, J. (1933) Die Vegetation der Halbinsel Skallingen.

, 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 The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million y ...

) 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#The demise of the Greenland Norse settlements, 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 ( non, Vínland ᚠᛁᚾᛚᛅᚾᛏ) 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 ...

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

macrofossil Macrofossils, also known as megafossils, are preserved organic remains large enough to be visible without a microscope. The term ''macrofossil'' stands in opposition to the term microfossil. Microfossils, by contrast, require substantial magnifica ...

Bronze Age The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second prin ...

tumuli A tumulus (plural tumuli) is a mound of earth and stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds or ''kurgans'', and may be found throughout much of the world. A cairn, which is a mound of stones built ...

* Iversen, J. (1940) Blütenbiologische Studien. I. Dimorphie und Monomorphie bei Armeria (English summary) Biologiske Meddelelser / Kongelige Danske Videnskabernes Selskab, 15 (8), 1-40. **Keywords:

palynology Palynology is the "study of dust" (from grc-gre, παλύνω, palynō, "strew, sprinkle" and ''-logy'') or of "particles that are strewn". A classic palynologist analyses particulate samples collected from the air, from water, or from deposit ...

* 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 taxa. At least eleven separate regions of the Old and New World were involved as independent centers of origin. The development of agriculture a ...

* Degerbøl, M. & Iversen, J. (1942) On a find of

Sheat-fish Siluridae is the nominate family of catfishes in the order Siluriformes. About 105 living species of silurids are placed in 12 or 14 genera. Although silurids occur across much of Europe and Asia, they are most diverse in Southeast Asia, beyon ...

(''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.

, 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 ''Viscum'' is a genus of about 70–100 species of mistletoes, native to temperate and tropical regions of Europe, Africa, Asia and Australasia. Traditionally, the genus has been placed in its own family Viscaceae, but recent genetic research by ...

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, central and southern Europe, Macaronesia, northwestern Africa an ...

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 o ...

as climatic indicators. A contribution to the study of the

Post-Glacial The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

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

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

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 The ancient Greek word ''oikos'' (ancient Greek: , plural: ; English prefix: eco- for ecology and economics) refers to three related but distinct concepts: the family, the family's property, and the house. Its meaning shifts even within texts. The ...

, 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 ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland i ...

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. ''

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it ...

'', 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 Bornholms 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 change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

* Iversen, J. (1960) Problems of the early

post-glacial The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

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 The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

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. 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 ''

'' 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 was founded in 1902 by botanist Arthur Tansley, who served as editor until 1931. Topics covered ''New Phytolo ...

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

Harry Godwin Sir Harry Godwin, FRS (9 May 1901 – 12 August 1985) was a prominent English botanist and ecologist of the 20th century. He is considered to be an influential peatland scientist, who coined the phrase "peat archives" in 1981. He had a long ass ...

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