The majority of the living collections, about 83 000 specimens representing some 5900 taxa, is maintained in open-ground plantings in the developed sections of the Gardens in Canberra and at Jervis Bay. The component of the collection that for climatic and other reasons cannot be readily cultivated in open-ground plantings is kept in a permanent pot collection in the Nursery (5000 specimens representing 1800 taxa) and in glasshouses (14 500 specimens representing 1350 taxa).
The open-ground plantings have traditionally been developed following three broad themes: taxonomic, ecological and horticultural. The original garden beds at the Gardens in Canberra were arranged taxonomically by family (for example, Proteaceae) or genus (for example, Eucalyptus) and this arrangement has proved to be a useful teaching and research tool. In addition, to promote an appreciation of the horticultural values of the native flora in landscaping, there have always been beds planted for their aesthetic appeal, often involving the use of cultivars.
Over the past 25 years there has been an increasing use of ecological groupings of plants, the best developed examples being the Rainforest Gullies in Canberra and at Jervis Bay and the Sydney Basin flora display in Canberra. Ecological groupings are preferable to taxonomic groupings on horticultural grounds and are of greater educational and interpretive value. For these reasons it is the Gardens' policy to give priority to ecological themes in future developments.
Two other themes have recently become important: conservation and ethnobotany. The Gardens' involvement in conservation has increased considerably in the last 10 years and many plantings are now used to assist in the conservation of rare and threatened species, providing a secure source of material to assist in the rehabilitation and reintroduction of species into their natural habitats. Ethnobotanical plantings, which display the wide range of species that have been and still are used by people, are valuable educationally and culturally and require further development. The conservation and ethnobotanical themes are also reflected in the plants held in the Nursery and glasshouses, although in these collections taxonomic, ecological and conservation themes predominate.
In furthering the development of these themes in Canberra the Development Planning Guide (see Section 1.4) recommended that future development of the living collections focus on three broad ecological groupings of plants: those of grassland and woodland communities (a xeric zone); a cool climate zone; and additional ecosystem types from the temperate zone. During the currency of this Plan of Management effort will be concentrated on development of further ecological displays of the temperate and, to a lesser degree, the xeric and cool climate floras. Planning and initial collecting for developments foreshadowed in the Development Planning Guide for the subsequent five-year period may also begin.
A similar development planning guide now being prepared for Jervis Bay will recommend thematic developments appropriate for that site.