Ostenfeld, C.H.; Phyto-geographical studies based upon observations of "Phanerogamae and Pteridiphyta".
His work consisted of studies in the fields of floristics, phytogeography and plant systematics, of which he conducted systematic investigations of ferns and also plants from the genera Verbascum, Rubus, Salix, Rumex, Mentha, Rosa, Carex and Epilobium.
However, following the publication of John Stanley Beard's phytogeographic regionalisation of Western Australia in 1980, it was recognised that Hopper's zones could be defined as aggregates of Beard's botanic districts.
Jaan Eilart (24 June 1933 in Pala, Kirna Parish, Järva County – 18 May 2006 in Tartu) was an Estonian phytogeographer, landscape ecologist, cultural historian and conservationist.
The American ecologist H. A. Gleason praised the hypothesis for being testable in the field of phytogeography but came to the conclusion that it could not account for migration data.