In Canberra the natural vegetation on the eastern slopes of Black Mountain is primarily dry open eucalypt forest with some remnant woodland on the lower slopes. The dominant tree species in the open forest are Eucalyptus mannifera, E. rossii and E. macrorhyncha. The understorey is a relatively sparse mixture of shrubs and tufted grasses. At the Jervis Bay site the natural vegetation is coastal heath dominated by Banksia ericifolia and Hakea teretifolia in the north and tall open forest dominated by Eucalyptus pilularis to the south. There are also small patches of remnant coastal rainforest.
At both sites this vegetation provides a buffer zone for fire and weed control between the developed gardens and surrounding national park or reserve. In Canberra a fire-control irrigation system has been installed within this buffer zone along the western and southern boundaries. A weed eradication program to prevent the spread of exotic and non-local native plants is also conducted in these areas. At Jervis Bay controlled burning of the heath is conducted to protect the gardens and stimulate growth within the heath plant community. Some control of exotic species has also been undertaken.
Within the developed areas some naturally occurring remnant plants, particularly `habitat' trees, have been retained for the benefit of wildlife and for aesthetic reasons. Old, large trees, particularly those with hollows, are retained even when dead if they do not pose a safety threat.
One taxonomic group that is becoming increasingly important in the Gardens is the cryptogams (non-vascular plants). This major group is poorly represented in botanic garden living collections the world over. There is a reasonable diversity of naturally occurring bryophytes, lichens and fungi, particularly in the undeveloped southern part of the Gardens in Canberra and at Jervis Bay. These provide scope for developing interpretive displays of these groups.
The nature trail at Jervis Bay will be maintained and its interpretation enhanced, particularly in relation to the fire ecology in the heaths. The nature trail in Canberra will be reviewed and refurbished as resources allow. The naturally occurring cryptogams, both in Canberra and at Jervis Bay, will be made accessible, carefully exposed and interpreted to the public. Plans for development of the southern part of the Gardens in Canberra include a cryptogam and orchid walk. This is planned for the central ridge and the two adjacent gullies, where mosses, liverworts, lichens, fungi and terrestrial orchids occur in abundance. At Jervis Bay work is underway to provide interpretation of the cryptogams occurring on rock outcrops. These groups relate well to research being conducted in the Gardens and they will be useful in the exposition and interpretation of this research.
At the boundary between the developed gardens and the neighbouring bushland sharp contrasts in foliage texture and height will be minimised by the selection of new plantings to create a gradual transition.
In Canberra the southern and western boundaries of the Gardens will continue to be managed as a fire buffer zone between the higher forested slopes of Black Mountain and the developed landscape zones. Any development outside the present fenceline will adopt a similar policy. Weed control programs to prevent the spread of non-local native species from the developed sections of the Gardens into the undeveloped areas and adjacent conservation areas will be continued.