The natural distribution of Eucalyptus species in Tasmania.
A summary is provided of the natural geographical distributions of the 29 Tasmanian Eucalyptus species. The work is based on over 60 000 observations from numerous data sources. After an introductory section, the distribution of each species is described separately with a map on a 10×10 km grid-cell scale, which is accompanied by graphs of the altitudinal range and flowering times, as well as descriptive notes on distribution and ecology, and a list of key references. The remaining part of the paper examines the geographical pattern of species richness at generic, subgeneric and series levels. Total species richness is greater in the drier, eastern regions than in the wet, western regions of Tasmania, with highest concentrations of species occurring mainly in the central east coast and south-eastern regions. Monocalyptus species occur in 8% more grid cells than Symphyomyrtus species but are absent from King Island. At the series level, greatest species richness is reached by the Obliquae in the north-east, the Piperitae in the south-east, the Ovatae on the central east coast, and the Viminales in highland areas of the south-east and Central Plateau. Series Obliquae species are absent from Flinders Island and are poorly represented in the south-west. The general patterns of eucalypt distribution and ecology are reviewed. Species are classified into nine categories based on the grid cells they occupy within their geographical range. The most widespread species are E. delegatensis, E. obliqua, E. ovata, E. viminalis and the endemic E. amygdalina. Most species with localized distributions have been nationally recognized as rare (i.e. E. barberi, E. morrisbyi, E. perriniana and E. risdonii). Rare species with regional distributions have either dispersed (E. cordata) or disjunct (E. archeri) occurrences. Most species that are rare in Tasmania are endemics, with the exception of E. perriniana and E. aff. radiata, although the taxonomic status of the latter requires investigation. Unresolved issues relating to the natural distribution and taxonomic affinities of the Tasmanian eucalypt species are summarized.