Johannes Eugenius Bülow Warming (born Nov. 3, 1841, Manø, Den.—died April 2, 1924, Copenhagen) was a Danish botanist whose work on the relations between living plants and their surroundings made him a founder of plant ecology.
Warming was educated at the University of Copenhagen (Ph.D., 1871). From 1882 to 1885 he was professor of botany at the Royal Institute of Technology in Stockholm. He traveled to western Greenland in 1884 as part of the Fylla Expedition to study the ecological adaptations of native plants.
Warming returned to the University of Copenhagen in 1885 as professor of botany and director of the botanical garden there (1885–1911). The result of his trip to Greenland was his first book on ecological plant distribution, Om Grønlands Vegetation (1888; “On the Vegetation of Greenland”), in which he described the structural adaptations of plants to their surroundings. Warming extended this type of study to several other countries, including Denmark, Venezuela, and some islands of the West Indies. His famous work, Lagoa Santa . . . (1892; “Lagoa Santa, a Contribution to Biological Phytogeography”), together with his other books, provided a thorough survey of the vegetation of temperate, tropical, and arctic zones. This work prepared him for his most significant contribution to plant ecology, Plantesamfund (1895; Oecology of Plants). The book was an attempt to group and characterize plant communities (by which Warming meant a group of species growing in the same locality) that are subject to the same external conditions arising from the interaction of ecological factors.