(a) Species of conservation concern are those that have been listed nationally as being endangered, vulnerable, rare or poorly known and may occur in more than one growth area.
(b) The geographical extent of growth areas was based on boundaries used to agglomerate information on biodiversity distribution at the State and national levels. Agglomerations of biodiversity regions were selected that included the city itself, satellite towns and the hinterland and adjacent agricultural regions over which the population disperses, travels, builds roads, dams and holiday homes.
Source: Australians and the Environment (Cat. No. 4601.0 p 339). (http://www.abs.gov.au/Websitedbs/c311215.nsf/20564c23f3183fdaca25672100813ef1/bc7dc08a640751f8ca2569e70003c7f6!OpenDocument) In Victoria there are 815 species of plants under threat (more than 10 percent of these in Melbourne) and 30 species of birds (more than half of these in Melbourne). The figures are not insignificant.
The following table looks at the causes of extinction and past and present threats to endangered plant species.