2.1.1 Ecological Theme


Plantings with an ecological theme are a relatively recent development in botanic gardens, reflecting increasing public interest in the natural environment. Such plantings display a wide taxonomic range of species from the same or similar habitats, providing an excellent basis for interpretive and educational programs. They are easier to manage because the same environmental conditions and horticultural management are appropriate to the entire planting. The problems of pests and diseases are also reduced in that a pest or disease specific to a certain taxonomic group of plants does not devastate the entire planting.

The first major ecological planting to be established in the Gardens was the Rainforest Gully in Canberra in 1968. This planting displays the rainforest flora of eastern Australia, from the cool temperate rainforests of Tasmania to the montane rainforest of northern Queensland. It has been very successful: the survival of plants and the development of the vegetation structure have exceeded expectations and the display receives a very high level of patronage. A rainforest display has also been developed at Jervis Bay, where it is one of the major attractions.

Since the development of the Rainforest Gully there have been several other similarly successful developments at the Canberra site, among them displays of Sydney Basin flora, the mallee shrubland and the Rock Garden. The most recent development with an ecological theme is the Tasmanian flora display.

In addition to the outdoor plantings several specialised collections in the Nursery have been developed to represent the flora of particular ecosystems or habitat types. Among these are plants from the subantarctic Macquarie and Heard Islands and plants from the arid and semi-arid regions of Australia.

Management prescriptions


The objectives are to maintain and refurbish existing ecological displays and to develop additional displays to represent the flora of temperate regions.


Figures 2.1 and 2.2 show the existing ecological plantings and those being developed in Canberra and at Jervis Bay. Priority will be given to completing those displays already under construction before work commences on proposed new developments. The following projects are to be carried out during the life of this Plan of Management; they are listed in priority order.

1. Tasmanian Garden. A large proportion of the Tasmanian flora has been successfully cultivated and displayed in various parts of the Gardens and in 1990 a decision was made to develop a display of these plants in their natural ecological associations. Many of the plants for this display had already been collected and propagated and planting commenced in the spring of 1992. The majority of the remaining landscape development was completed in late 1993. Further plant material will be collected by Gardens staff and by associates working in Tasmania; this will be added to the display during the next two years.

2. Rock Garden. The Rock Garden display includes a range of habitat types and associated plant communities. Many of the plants in the Rock Garden are of high horticultural appeal and this is a popular and successful display in the Gardens in Canberra. The display is currently in need of refurbishment and some rationalisation and this will be accomplished in a section-by-section upgrade, involving soil removal, some rock repositioning, installation of micro-irrigation, and the addition of new improved soil. A limestone reef with calcicole plantings is planned, as are rock reef extensions into the adjacent lawn and a partial extension of the lawn into the Rock Garden. Many of the plants that are suitable for the planting are already available in the Gardens' collections, but new plants suitable for the Rock Garden will be sought in future collecting trips.

3. Sydney Basin. The Sydney region is botanically diverse and contains many plants that are well-known representatives of the Australian flora and are an important part of a nationally representative collection. The Sydney Basin display will contain a range of plant communities characteristic of the region, including heathland and forest types. Much of the landscape development for the display has been completed; the only major work remaining to be completed is the path system. Several sections of this display have already been planted and field work will be carried out annually to collect the material required to plant the remaining sections.

4. Mallee. The mallee is another significant and well-known component of Australia's vegetation. The mallee eucalypt and mallee shrubland sections have been developed in recent years to display elements of this flora. The majority of landscape development and much of the planting has been completed, although some soil modification is still required for the shrubland display. Further development, to include additional plant communities from the mallee areas of New South Wales and Victoria, is planned to complete these displays.

5. Coastal Heath. Coastal heath communities are familiar to a large proportion of Australia's population and a display of these communities will provide opportunities to interpret aspects of the development of the Australian flora in soils of low fertility. The Jervis Bay site is the most ecologically appropriate site for display and interpretation. Very little landscape development is required for this project and much of the material for the display has already been collected or is readily available in the local area.

6. Rainforest. The rainforest flora of Australia is of considerable conservation significance and of increasing interest to the Australian public. The rainforest displays at the Gardens are very successful examples of ecological displays. Most areas of the Rainforest Gully in Canberra are now almost fully planted, although they may need further underplantings as the display matures. There are also elements of the rainforest flora that are not well represented in the display and an assessment will be undertaken to determine whether the display can be enhanced to more effectively represent the range of rainforest communities. The collection at Jervis Bay will also be further developed, with a strong emphasis on the rare and poorly conserved coastal rainforest flora of south-eastern Australia.

The development of further ecological displays will be dependent on provision of the resources necessary for their construction and maintenance. The following projects are proposed during the life of this Plan of Management; they are listed in priority order.

1. Australian Capital Territory regional flora. A large proportion of the visitors to the Gardens in Canberra are from the surrounding region. The Gardens' responsibility to cultivate, display and interpret the regional flora is not being adequately met at present. The plant material for such a display is already part of the collection or is readily available locally. Detailed planning for the display has not yet been undertaken but it is proposed that it be developed around the existing Brindabella Gully section.

2. Woodland and grassland. Although grassland and woodland floras cover a very large proportion of Australia, they are often poorly conserved and poorly represented in botanic gardens. The proposed redevelopment at the entrance to the Gardens in Canberra makes it likely that the current temporary display of these plants will need to be relocated. The development of a permanent display for grassland and woodland plants will require detailed planning, but a large amount of the material for such a display is already being grown at the Gardens.

3. Subantarctic and alpine plants. The Gardens' collection of plants from Australia's subantarctic territories has aroused great interest. The flora of these areas is an unusual component of the Australian flora and is of value to researchers as well as of interest to the public. Construction of a cool conservatory is proposed to provide an appropriate place for a permanent display of this collection. Such a facility would also be appropriate for the display of Australia's alpine flora. Material has already been collected from about 60 per cent of the Macquarie Island flora and has been cultivated successfully for the past two years. Further collecting from both Macquarie and Heard Islands was undertaken in 1993. The Australian alpine plants already in the Gardens collection are mostly Tasmanian and further collecting from New South Wales and Victoria will be required to create a comprehensive display.

4. Arid and semi-arid region flora. Since so much of the Australian continent is arid or semi-arid the representation of plants from these regions is an important part of a national collection. Some of this flora is already displayed in the mallee section and a collection is also held in the Nursery in a structure that provides protection from rain and frost. It may be feasible to develop this collection further to provide a public display.

5. Rainforest. The current rainforest display in Canberra lacks communities representative of the tropical regions of northern Australia. A tropical conservatory has been proposed as a major visitor attraction at the head of the Rainforest Gully to display this component of Australia's rainforest flora. Initial planning and collecting for this display will begin when funding for its development is approved.

6. Aquatic plants. At the Jervis Bay site there is potential to cooperate with the National Park to provide displays of marine and freshwater algae, another major plant group that cannot be effectively displayed in Canberra.