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Notes from the nursery - The role of botanic gardens in fighting the extinction battle
Matthew Nicholson, volunteer editor, Notes from the Nursery
I am a member of the nursery team in a botanic garden and also work as a bush restorer. Please get in touch if you would like to contribute to this section in the future by emailing me at nicholson20@hotmail.com.au.
As the world grapples with an unprecedented biodiversity crisis, the role of botanic gardens in shaping conservation policy, preserving genetic material through seed banking, and educating the public in this area has become increasingly important. This article delves into these crucial functions of botanic gardens, elucidating how their work transcends traditional boundaries to impact conservation in profound and lasting ways. Botanic gardens are often seen as quiet repositories of plant knowledge, but they provide a valuable resource from which aspects of public policy concerning conservation are derived. This knowledge base consists of data collected from seed collection and conservation sites. It provides snapshots of species’ increase or decline and makes the botanic garden ‘a driving force’ behind plant conservation (Westwood et al., 2020).
According to a 2017 study conducted by the University of Cambridge, 41% of plants classified as ‘threatened’ are contained within the world’s botanic gardens. Botanic gardens are thus ‘on the front lines of biodiversity conservation’ (Ren & Antonelli, 2023). The development of botanic gardens was ‘driven by the basic needs of human society’ up until the present stage of their development (Li et al., 2023). Li and colleagues discovered a strong correlation between the establishment of the world’s first botanic garden in Germany in 1593 and global social and economic progress ever since. The initial ‘exploration’ stage of botanic gardens served to establish collections of medicinal and edible plants. The ‘classic’ stage was precipitated by the invention of the binomial system of nomenclature, devised by Carl Linnaeus in 1753, which facilitated the categorisation of plant species in botanic gardens. Li and colleagues charted the subsequent development of the ‘colonial tropical’ botanic garden in the modern era (1765–1945), up to and including the ‘gardening and specialised’ botanic garden stage, and finally the rapid post war development of the ‘scientific and conservation’ stage of botanic gardens. They show how botanic gardens have evolved from collections of medicinal plants to multipurpose institutions, involved in ‘scientific research, plant diversity conservation, education, and dissemination of knowledge’ (Li et al., 2023).
Experts from botanic gardens often work with government or other bodies on a consultative, volunteer, or advisory basis.
Their involvement is evident in the activities and aims of organisations such as BGANZ and Botanic Gardens Conservation International (BGCI). Botanic gardens, such as Botanic Gardens of Sydney (BGoS), which are part of the NSW State Government’s Saving our Species program, provide a valuable resource for the preservation of the species in question.
The many Friends groups in Australia, New Zealand and worldwide also make an important contribution to threatened species conservation; for example, the Friends of the Australian National Botanic Gardens (FANBG) in Canberra offer student scholarships that support honours, masters, or PhD candidates who ‘engage in collaborative research projects that bring direct benefits to the ANBG’ and align with its objectives (FANBG, 2023). The FANBG scholarships aim to ‘enhance knowledge of and the conservation’ of Australian plants. The Friends of the Royal Botanic Gardens Melbourne has a trust fund, which supports a research grant and staff scholarships. Some botanic garden Friends groups, such as the Friends of Auckland Botanic Gardens, the Friends of Wollongong Botanic Garden, and further afield, the Friends of Edinburgh Botanic Gardens, Friends of the Royal Botanic Gardens, Kew, and Friends of the Botanic Gardens at the University of California, Berkeley, offer internal scholarships that enable staff to visit other botanic gardens to further their career prospects and gather information pertinent to their home botanic garden. This information and networking may be aimed at caring for or extending a collection of rare and threatened species or creating a section dedicated to rare and threatened genera. Aspects such as specific habitat requirements, genetic diversity, propagation techniques, pest and disease management, or ideas about public education surrounding these rare and threatened species may be gleaned from these trips and visits.
One prominent threatened species success story is that of the Wollemi Pine Wollemia nobilis, a coniferous species discovered in Wollemi National Park in 1994. It was subsequently bred by tissue culture and brought back from the brink of extinction despite its low population size and high susceptibility to pathogens such as Phytophthora cinnamoni. In 1994, it was cultivated by the Adelaide Botanic Garden, South Australia, the Royal Botanic Garden, Sydney, Mt Annan Botanic Gardens, and Mt Tomah Botanic Gardens. In 2001, a comprehensive paleoenvironmental reconstruction of the distribution of Wollemia was conducted by Kershaw and Wagstaff (2001), with particular attention paid to how Araucariaceae responded to Australian continental drift, the evolution of angiosperms and the associated changes in fire regimes. It has been challenging to study the breeding system of W. nobilis due to a lack of reproductive material, but ‘recent female cone production in cultivated plants has enabled some manipulations’ and provided access for ‘repeated preliminary observations’ (Australian Government, n.d.). However, as the challenge of global warming increases, it poses yet another threat to the wild population. Izzard’s article (2023) about conservation efforts surrounding W. nobilis recounts the Black Summer fires of 2019–2020 when the stand was saved just in time by firefighters and airborne water tankers.
A new metacollection of this species comprises a global collaborative effort and involved an initial citizen science survey in 2019. Then, shipments of ‘210 young Wollemi Pines representing the full diversity of the wild population’ were sent to botanic gardens in the United Kingdom, Ireland, Europe, Australia, and North America – places selected to provide ‘the best possible long‑term conditions for a resilient and global metacollection’ (Izzard, 2023). The BGoS sent each botanic garden a micro‑population of six plants, ensuring ‘plenty of genetic diversity’ (Izzard, 2023).
In a recent article, Ostgaard (2024), the Director of Botanical Solutions for Species360, comments that the reason behind the huge gap in knowledge of the content of one‑third of the world’s botanic gardens is ‘due to the poor adoption of computerised plant record systems’, and advocates for the use of plant collections platforms, specifically Hortis (which he founded), to address this issue. He also advances the case for collaboration between different botanic gardens, which can ‘help increase genetic diversity…[and create] a valuable source of material’, as a single plant in one garden lacks the genetic diversity ‘required for practical conservation purposes’.
Research conducted by botanic gardens and systematic botanists can be controversial, as evidenced by papers such as the one by Wilson et al. (2022) on the conservation of the Critically Endangered Hairpin Banksia Banksia vincentia. They write that the number of species of Hairpin Banksia has been overestimated, and suggest that incorrectly applied taxonomy can gradually erode species resilience by an over‑emphasis of genetically poor populations. This has the knock‑on effect of ‘masking others that are more genetically diverse’ – poorly applied taxonomy can cost time and money in the misdirection of conservation resources, thereby concentrating on genetically poor populations, while more genetically diverse populations remain neglected. This is a lesson for conservationists worldwide to get the taxonomy right before launching into a conservation program. The article and its conclusions are certainly worth reading in full.
In addition to germplasm conservation and seed banking, botanic gardens play a vital role in habitat restoration and reintroduction programs by partnering with groups such as Landcare and Bushcare, which rely on armies of volunteers, as well as working with environmental contractors and subcontractors who maintain natural areas. Through this intimate knowledge of endemic species, botanic gardens can, directly and indirectly, influence public environmental management policy through collaborative processes. Their expertise in biodiversity and conservation positions staff at botanic gardens to influence and inform decision makers in areas of public policy. There is currently a collaborative project around the restoration of key ‘Big Scrub’ tree species to prevent inbreeding and protect them from emergent threats (Big Scrub Rainforest Conservancy, n.d.). This project is being conducted by Big Scrub Rainforest Conservancy in collaboration with the BGoS’s Research Centre for Ecosystem Resilience.
It involves genome analysis of 10,000 leaf samples from 60 tree species across 30 populations to ensure the best possible genetic diversity for the Big Scrub region, as well as planting of a seed bank plantation, and harvesting of genetically optimal seed. This seed will be propagated into planting stock for rainforest restoration contractors. As of 2022, the project has planted 250,000 individual trees over 80ha in the Big Scrub, located in north‑eastern NSW.
Plant conservation can aid sustainability by protecting ecosystems, maintaining biodiversity and safeguarding clean air and water, climate regulation and pollination. Botanic gardens not only provide spaces for biodiversity as far as providing habitat, food and shelter for native fauna, but also provide excellent learning spaces for children and adults who have a vested interest in absorbing the benefits these spaces provide and the training programs botanic gardens education centres offer in the conservation area, among others.
Botanic gardens provide valuable data for conservation-related public policy.
Policy and decision makers can see the concrete effects that botanic gardens have on endangered species, such as the Wollemi Pine. Botanic gardens promote research and conservation by, for example, offering workshops, lectures and guided tours to educate the wider public about their collections and conservation efforts regarding threatened species, collaborating with universities and research institutions on studies that advance knowledge in plant conservation, and maintaining seed banks and living collections of rare, threatened, and endangered plant species in the effort to preserve genetic diversity. They also collaborate with other gardens and stakeholders in the propagation and reintroduction of threatened species into their natural habitats. Indeed, as Blackmore argues, their future role should be ‘nothing less than shaping and contributing to a sustainable future for humanity’ (Blackmore, 2017).
Further reading
Australian Government. (n.d.). Department of Climate Change, Energy, the Environment and Water: Species profile and threats database. Wollemia nobilis — Wollemi Pine. http://www.environment. gov.au/cgi bin/sprat/public/publicspecies.pl?taxon_id=64545
Big Scrub Rainforest Conservancy. (n.d.) Science saving rainforests https://bigscrubrainforest.org/ science saving rainforests/
Blackmore, S. (2017). The future role of botanical gardens. The Royal Danish Academy of Sciences and Letters, 6:287–299. http://publ.royalacademy.dk/backend/web/uploads/2020 11 25/AFL%20X/ SDB_6_00_00_2017_6005/SDB_6_24_00_2017_6028.pdf
Friends of the Australian National Botanic Gardens. (2023). Friends of the ANBG Student Scholarships. https://www.friendsanbg.org.au/node/1890
Izzard, H. (2023). The global endeavour to save Australia’s iconic ‘dinosaur tree’. https://www. botanicgardens.org.au/discover and learn/watch listen read/global endeavour save australias iconic dinosaur tree
Kershaw, P and Wagstaff, B. (2001). The southern conifer family Araucariaceae: history, status, and value for paleoenvironmental reconstruction. Annual Review of Ecology and Systematics, 32:397–414.
Li, Y, Li, S, and Zhao, G. (2023). Spatiotemporal development of national botanic gardens worldwide and their contributions to plant diversity conservation from 1593 to 2023. Front. For. Glob. Change, 6. https://www.frontiersin.org/articles/10.3389/ffgc.2023.1310381/full
Ostgaard, H. (2024). How botanic gardens are preserving biodiversity. https://www.hortis.com/ blog/how botanic gardens are preserving biodiversity
Ren, H, and Antonelli, A. (2023). National botanical gardens at the forefront of global plant conservation. Innovation (Camb), 4(5):100478. https://www.ncbi.nlm.nih.gov/pmc/articles/ PMC10407540/
University of Cambridge. (2017). World’s botanic gardens contain a third of all known plant species, and help protect the most threatened. https://www.cam.ac.uk/research/news/worlds botanic gardens contain a third of all known plant species and help protect the most Westwood, M, Cavender, N, Meyer, A, et al. (2021). Botanic garden solutions to the plant extinction crisis. Plants People Planet, 3(1):22–32. https://nph.onlinelibrary.wiley.com/doi/full/10.1002/ ppp3.10134
Wilson, T, Rossetto, M, Bain, D et al. (2022). A turn in species conservation for hairpin banksias: demonstration of oversplitting leads to better management of diversity. American Journal of Botany, 109(10):1652–1671. https://doi.org/10.1002/ajb2.16074
