Thorvald Sørensen

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Thorvald Julius Sørensen
Soerensen Th.jpg
Born(1902-07-04)4 July 1902
Sækbæk, Denmark
Died21 June 1973(1973-06-21) (aged 70)
Nationality Danish
Alma mater University of Copenhagen
Known for Flora of the Arctic, Sørensen similarity index
Scientific career
Fields Botany
Institutions University of Copenhagen

Thorvald (Thorwald) Julius Sørensen (4 July 1902 – 21 June 1973) was a Danish botanist and evolutionary biologist. [1]



Sørensen was professor at the Royal Veterinary and Agricultural University 1953–1955 and at the University of Copenhagen 1955–1972. He was director of the Copenhagen Botanical Garden and Botanical Museum during the same period. [1]

Thorvald Sørensen spent the years 1931–1935, based on Ella Island, studying plants in the then little known North-East Greenland. He published the botanical research of the Three-year Expedition to East Greenland. [2] He also published a doctoral thesis on the annual phenological rhythm of the High Arctic plant species, including the pollination of their flowers (1941).

He critically revised the Greenland flora and sorted out taxonomy of a number of difficult taxa, most notably Puccinellia .

He carried out a number of studies in the evolutionary biology of plants, such as Taraxacum , Capsella bursa-pastoris and Ranunculus .

He developed a quotient of similarity in species composition between plant communities—the still much-used Sørensen similarity index. He illustrated its use on a data set collected in Danish grassland by Johannes Grøntved (1882-1956), who used the quantitative method to sample vegetation developed by Christen C. Raunkiær (1860–1938). [3] [4]

Selected plant names he published


The Arctic campion species Silene sorensenis and Th. Sørensen Land in Greenland were named in his honour.

Selected publications

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  1. 1 2 "Thorvald Sørensen". Dansk Biografisk Leksikon. Retrieved May 1, 2020.
  2. "Catalogue of place names in northern East Greenland". Geological Survey of Denmark. Retrieved 7 July 2019.
  3. "Grøntved, Johannes (1882-1956)". Retrieved May 1, 2020.
  4. "Raunkiær, Christen Christiansen (Denmark 1860-1938)". Retrieved May 1, 2020.
  5. IPNI.  T.J.Sørensen.

Other sources