Australian National Botanic Gardens
This document sets out the policy and implementation plans for the development of the living collection at the Australian National Botanic Gardens (ANBG) as required by Section 3.1 of the Plan of Management 2002-2008 (PoM). The overall aim is to provide recreational and learning experiences for visitors, and opportunities for scientific study, through the development of interpreted thematic plant displays.
The ANBG has a mandate to exhibit and interpret the Australian flora from its designation in the Burley Griffin plan and its role as the botanic garden of the national capital, receiving visitors from diverse localities from both within the nation and internationally.
The ANBG was the original Australian botanic garden specialising in the Australian flora and has developed within its general charter, and now maintains a living collection of almost 6,000 Australian species that includes a broad taxonomic representation of the flora.
The origins of the thematic charter of the ANBG are in the Burley Griffin report and are reflected in the seminal report by Dr B T Dickson to the Department of the Interior in 1935. Dickson stressed the importance of incorporating Australian plants as well as the scientific and educative potential of the proposed gardens.
The ANBGs foundation plantings were established in the 1950s and early 60s; among the earliest were the taxonomic plantings of Callitris and representatives of the families Myrtaceae and Proteaceae. In 1968 the development of the rainforest gully began. At this time also, in recognition of the central role of education in botanic gardens, the first interpretive signage was installed and facilities for indoor interpretive displays and for teaching propagation methods were developed.
The scientific and educational resources of the Gardens were further expanded during the late 1960s and early 1970s with the development of the herbarium, library, nursery (including glasshouses), and the research laboratory. Close data linkage between the living collections, the herbarium and research was also established. The ANBGs' particular research interest in the families Fabaceae and Orchidaceae began in the mid 1970s; the living collection of Australian orchids is now perhaps the most comprehensive in cultivation.
During the 1980s and 1990s a conservation collection of threatened plants was developed in cooperation with nature conservation authorities. The purpose of these collections is to secure genetic stock for species' recovery programs and for use in interpreted thematic displays. The Conservation Policy has been articulated and has emphasised the importance of education and public awareness of biodiversity and sustainable development.
The living collections of the Gardens have been developed to encourage public enjoyment, appreciation and use of the Australian indigenous plant life and for the conservation and study of Australias plant heritage. The whole collection has conservation significance, particularly for plants and plant communities known to be at risk in the wild.
A master list of all garden sections, their current or proposed thematic development, and their development priority ranking is presented in Appendix 1.
The existing planting themes have been developed in three broad areas as described below:
Plant displays that illustrate the scientific classification of plants are a traditional and highly effective way to provide opportunities to compare the similarities and differences within taxonomic groupings. Many of the early plantings in the Gardens are organised in this way. Taxonomic themes are in place that cover the monocots and gymnosperms, families Asteraceae, Casuarinaceae, Fabaceae, Lamiaceae, Myoporaceae, Myrtaceae, Proteaceae, Rutaceae, Sterculiaceae, and the genera Acacia, Callistemon, Correa, Eucalyptus and Hibbertia
Ecological and Geographic
Plant displays that group species from similar ecological or geographic areas provide opportunities for visitors to readily relate to and understand natural communities. These displays have a rich educational and interpretive potential. The best existing examples of these displays at the ANBG are the rainforest gully, which represents rainforest communities from Tasmania to north Queensland, the mallee sections, the Sydney basin display and the Tasmanian gardens.
Grouping species that originate from similar environments also facilitates management of their horticultural needs. Some displays, such as the Tasmanian garden, have been slow and difficult to establish and will need to be improved over time as additional collections of plants are made and better understanding of their specific horticulture needs is developed. Other ecological or geographic themes include Southern Tablelands grassland/woodland, Pacific islands flora and arid plant displays. The Rock Garden plantings represents a partly ecological theme in that plants of rocky, exposed habitats and alpine plants are important features.
Plant displays promoting an appreciation of the horticultural values of the native flora are used throughout the Gardens, both in display beds and as a complementary backdrop to more scientifically structured themes. There are a number of plantings where aesthetic qualities, such as flower or foliage colour, or plant form and texture are exemplified; for example the colourful and diverse displays alongside the visitor concourse. The eucalypt lawn is another fine example of a horticultural theme regarding the lawns and tree plantings, the latter at the same time forming a specific taxonomic theme.
As well as the three major themes, there are a number of other themes, including plants used by aboriginal people for food, fibre and medicine and the conservation theme that focuses on threatened plant species and plant communities. While plants with a significant conservation status are scattered throughout the Gardens there is a concentration of them around the Visitors Centre. In addition, educational themed walks are developed through the Gardens living landscape.
Themes for plant displays will continue to feature Australian plants in a broad scientific, cultural and horticultural context, based on scientifically authenticated information.
Physical environmental constraints impinging on theme selection
The climate and soils of the Black Mountain site can be said to be relatively inhospitable in regard to cultivating a wide range of plants.
The Canberra climate is typified by warm to hot summers with cold winters and generally high evaporative potential. Mean annual rainfall is about 640 mm, distributed more or less evenly throughout the year but with a tendency to a slight winter maximum. Droughts are not uncommon with occasional severe examples. The effects of rainfall on plants that have other requirements such as a greater or a lesser rainfall or a different yearly distribution, can be modified using irrigation to supplement the natural precipitation or by using shelters for those arid zone plants that require less precipitation. The most imposing climatic factor for plants grown outdoors at the Gardens is frost.
Soils are predominantly poorly drained fine sandy to clay loams, often with gravel included and of low, though not extremely low fertility. In early years of the Gardens development little soil modification was practised, but this has increased, particularly with increased plantings of ecological themes.
The climate and soils at the Gardens restricts the number of species that can be grown with minimal site manipulation and has strong resource implications when considering growing a fully representative collection of the Australian flora. This is particularly so for frost tender plants and those demanding warm, humid conditions which will inevitably be under-represented in the collection.
The costs of growing plants in containers and maintaining protected growing environments are high, so a priority has been placed on species and microclimatic site selection as well as on acclimatisation so that as much of the living collection as possible can be grown and displayed in the outdoor gardens
Theme planning and implementation
Existing themes need to be regularly assessed for their relevance to the thematic plan, their in-ground-plant content and their potential to be meaningfully organised into the public landscape of the Gardens using the system of Main Path, secondary loops off this path and the network of other pathways.
The development of a comprehensive thematic structure and plan for the ANBG must also take into account the practicalities of horticultural maintenance and meaningful landscaping. From the thematic plan an interpretation plan can be developed which will consider the fundamentally important requirements for interpretation, education, recreation and aesthetics.
Science based organisation
From the beginning the ANBG has developed its various living collections on the basis of them being wild sourced and scientifically documented. This includes the taking of pressed herbarium voucher specimens for all living material collected for propagation. The collections are authentically identified in the herbarium and the collection data with verified identity are held on a computerised database linked by a common accession identifier to the living and herbarium specimens.
These integrated living, herbarium and data collections, including many photographs, are maintained as a resource for the scientific study of the Australian flora. Research organisations are able to request material from the living collections in the knowledge that the names reflect the most up to date and accepted taxonomic treatments. Local and overseas botanists frequently request material for study, or visit to the Gardens to view the voucher collections as part of taxonomic reviews. Living cultivated plants in the Gardens support research at the Centre for Plant Biodiversity Research.
Education and Visitors
The fundamental functions and outcomes in education in its broad sense of increasing peoples knowledge, understanding and appreciation of plants, and thence conservation via influencing of opinion and behaviour, are classically delivered in botanic gardens by the agency of a relaxing, amenable, meaningful and attractive garden environment for the visitor. This given must be a basic consideration in the development of thematic plans. In addition to these passive education and amenity purposes, teaching institutions have a valuable resource for both botanical and horticultural classes through visit to the Gardens living collections.
1. Plant conservation
Plant displays illustrating plants at risk in the wild will be rationalised and extended where necessary to form a dispersed and interpreted theme. The threatened species beds around the Visitor Centre will continue to be enhanced and, where available and appropriate, threatened species will be included into ecological themes. Many threatened taxa will be planted into the new bed above the Rock Garden lawn, section 14. A greater emphasis will be placed on interpreting threatened communities, represented by the rainforest gully, Sydney sandstone, grasslands/woodlands and Tasmanian ecological displays.
2. Economic botany
Interpretive programs based on plants used by indigenous people have been popular with visitors. The Aboriginal Plant Use Walk was first developed in the 1970s and features plants used by Australias indigenous people for food, fibre and medicine. Options for extending this walk, through consultation with representatives of local Aboriginal communities will be investigated. This walk needs realigning with other developments in the Gardens, such as the Main Path and secondary loops, and the Rock Garden. Themes based on plants used by the broader community for timber, grazing, horticulture, floral emblems will be developed and interpreted.
3. Evolutionary Origins and Relations of Australian plants
The origins and relations theme will be developed as a logical broadening of the interpretation of the present Australian flora. A display featuring plants that have origins in the ancient super continent of Gondwana is currently under development. (See also 4.3 of PoM). Taxa to be included are cycads, Asteraceae, Ericaceae, conifers, and orchids.
4. Tablelands grassy woodlands
The current expression of this theme, in section 175, below the Visitor Centre and just inside of the entrance to the Gardens, will be enhanced with supplementary plantings (particularly of liliacous species), and interpreted.
Rainforest vegetation elements such as epiphytes, lithophytes, ground herbs and palms, will be added to the rainforest displays, taking advantage of the new boardwalks, the general advancement of the vegetation canopy layer and the existence of warm protected microclimates on the northern edge. The removal of shading lianas, trees and shrubs will continue as needed. There will be additional sourcing and planting of advanced palms, ferns, cycads, trees and shrubs into the rainforest display. Field collection of windfall epiphytes will continue. Major epiphyte displays, using trees nearby the kiosk terrace and the Tasmanian rainforest gully bridge will be created.
6. Secondary thematic loops from the primary walk
A series of secondary thematic loops from the primary walk will be developed and interpreted. These may include Tasmanian flora, Sydney region flora, Myrtaceae (paperbarks, tea trees, lilly pillies) and Proteaceae (banksias, grevilleas, waratahs).
7. Arid plants display
The site currently occupied by the nursery will be redeveloped during the period covered by the PoM. It is planned to create a display of arid zone plants that currently are not accessible to the public. Preliminary concept plans were completed in summer 2002 Further planning will be contingent on the vacation of the site and subsequent funding levels.
Appendix 1 - Themes for each Section - Note this is a large table (278 K)