One of Australia’s treasures is Rhododendron lochiae – Australia’s native Rhododendron.
The presence of Rhododendron in the mountains of Queensland was predicted by Ferdinand von Mueller and subsequently confirmed by plant hunters. There remains some contention around the definition of a second species from the same region. In partnership with the Australian Rhododendron Society and with support from the Stanley Smith Horticultural Trust, the Botanic Gardens of Adelaide have agreed that Mount Lofty Botanic Garden will host the ex situ conservation collection for this species. Mount Lofty is a long way from Queensland but is better suited for maintaining such a collection than Brisbane’s Mount Cooth-tha or Cairns’ Flecker Botanic Gardens. As an endangered species, the journey to obtaining approval to collect living material from the field from both the Queensland National Parks & Wildlife Service and the Aboriginal Traditional Owners will take some time.
One of the many spectacular plants that the Adelaide Botanic Gardens should be growing with the signature Giant Amazon Waterlily has been in the pipeline for acquisition for six or seven years. The plant, Brocchinia micrantha is a tank bromeliad – the bases of the leaves form water tanks with an ecology of their own that includes providing home to the Golden Poison Arrow frog. Failing to source the plant in Australia the Gardens began the challenge of running the gauntlet of approvals to bring the plant into Australia. The Gardens has had to satisfy a biosecurity risk assessment for approval to import, obtain permits to satisfy the Convention on Trade in Endangered Species (CITES), meet quarantine requirements for import to Australia (and export from, in this case, the US) and ensure the plants survived quarantine procedures. Marvellously the Brocchinia is finally here and seems to be establishing itself in quarantine.
Even sending plant material out of Australia is challenging. In partnership with the Dahlia Society of South Australia the Gardens recently sent dahlia tubers to the Parc Floral in Paris at their request. The dahlias will be entered in an international dahlia exhibition in Paris in 2013 and shown in the Parc Floral – part of Paris’s botanic gardens network. This exercise required pre-export inspections during the growing season as well as export and import permits dependent on the issue of a phytosanitory certificate.
The development of plant collections in putative ancient ‘botanic gardens’ can be interpreted as being as critical to the development of modern civilisation as food surpluses, writing and the formation of cities. The relatively recent beginnings of Australia’s botanic gardens are rooted in economic and social agendas. For example, the first director of Adelaide’s Botanic Gardens saw the Gardens as a conduit ‘(through) which flows the vegetable riches of other countries to be distributed in our own.’ and as, ‘… a place of rational amusement for the public, and of instruction to the young.’ George Francis’ successor, Richard Schomburgk can take credit for introductions such as DuToit’s wheat, the foundation for the success of South Australia’s economic development through the wheat-rush from the 1860s to the 1880s and even today’s wheat industry.
While there is considerable merit in the introduction of, in Francis’ words, ‘useful, harmless, interesting and ornamental plants’ and in understanding the opportunities and threats posed by introduced and native plants there are significant risks in such introductions. Plants established for utility, such as the prickly pear or the blackberry, may turn out to have a Jekyll and Hyde personality as Australians have found to their cost. Such plant introductions have directly impacted the conservation and primary production estate, or in the case of ornamental Berberis (barberry) species provide an alternate host for the devastating wheat rust (Puccinia graminis). With a changing climate, efforts to control trade in endangered species, requirements for benefit-sharing of biodiversity with countries of origin and the potential impact of breaches of biosecurity the legal importation of plant material into Australia is now more challenging than ever before.
The current devastation of Britain’s ash (Fraxinus excelsior) woodlands reinforces the potential of biosecurity breaches to change our landscapes. The pathogen, ash dieback (Chalara fraxinea), reached Britain with imported nursery stock. The deadly disease has highlighted the debate about the countervailing demand for free trade that can dilute efforts to tighten biosecurity. The head of forest pathology at the British Forestry Commission has observed that more than twice as many diseases have arrived in Britain in the first 10 years of this century than in the whole of past century despite advances in understanding biosecurity.
Prior to the tightening of biosecurity botanic gardens could freely exchange plant materials. The great diaspora of plant material that accompanied the Age of Empire through to the 20th century was unparalleled in history. Botanic gardens accumulated staggering living plant collections with holdings worldwide of over four million living plant collections representing more than 80,000 species – perhaps a third of the known flora worldwide.
The reasons for the tightening are all too apparent but the flow of plant material has now stemmed from a flood to a trickle. In many ways this isn’t a bad thing. Botanic gardens need to focus on better understanding the values of their existing living collections and the significance of gaps in those collections. The effort of interrogating the provenance and purpose of living collections will ensure that significant living plant material is more effectively stewarded. The effort of obtaining new material might ensure that only material that presents high value for the living collections (in terms of conservation, education, research values, or of course, beauty or charisma) and has low risk in terms of breaching biosecurity, ownership or conservation protocols is chased down rather than an eclectic ad hoc approach to collections development. The analogy with Pandora’s Box has merit – but if the contents represent the Earth’s botanical diversity the threats to be assessed on a case by case basis – a difficult task.
Originally published in The Adelaide Review on 21 December 2012.