Trees in Adelaide

The tragic death of 20-year-old Rebecca Jolly in 2010 resulting from a falling Grey Box branch on Greenhill Road was likely one factor in the Local Government Association commissioning an Independent Inquiry into Management of Trees on Public Land. The inquiry was chaired by Brian Cunningham and resulted in a number of recommendations aimed at improving tree management on public land. Last year Coroner Mark Johns presented his findings into this tragedy underscoring the inherent challenges of working with trees. Both inquiries provided a balanced view of the difficulties of ensuring tree safety in public areas and endeavoured to ensure that the lessons that could be learned from Rebecca Jolly’s death would be applied to tree management in South Australia. As director of a botanic garden such issues are top of mind. Last September a visitor to the Royal Botanic Gardens, Kew died after being hit by a falling tree branch, and earlier this year a five-year-old girl had a narrow escape from a massive branch that fell from a Casuarina in the Adelaide Botanic Gardens. None of this is supposed to be a criticism of trees. Visitors to botanic gardens come in search of beauty, peace and tranquillity and it’s the trees that are the star attraction. I’ve worked in botanic gardens in Melbourne, Perth, Sydney and Adelaide, each with between 1.5 and five million visitors each year (with visits in the order of two to three hours), for over three decades and while there have been a couple of near-misses such as the one mentioned here, fortunately such incidents remain extremely rare. Nevertheless the public debate on tree selection rarely strays beyond exaggerated exposition of tree hazards – a largely one-dimensional and one-sided analysis. The selection of trees in public and private landscapes remains driven by preoccupations with risk and cost rather than being balanced by an examination of the benefits and opportunities trees provide in an urban environment. It’s a depressive outlook that would be anathema to the founders of Adelaide. Early South Australian plant nurseries and directors of the Adelaide Botanic Gardens began with some appreciation of climate and soils but no data on tree performance in this place (beyond observations of the indigenous flora and even here the landscape character was confounded by the systematic management of the landscape by the Kaurna people). While some knowledge was transferable from experiences elsewhere, trial and error was likely the basis of early tree planting in Adelaide. The 3500 trees that dominate the landscape of Adelaide Botanic Gardens represent the richest tree collection in South Australia, and to a significant measure, are the result of trial and error. Adelaide Botanic Gardens’ trees were planted for their botanical interest and beauty as much as for their performance and sound structure. Of course the trees that remain are the successful ones – the unsuccessful ones having died or removed along the way. Over the past 175 years there has been a great deal learned about tree performance in Adelaide and so why is the quality of the debate around the use of trees so derisory? Tree selections in public open space seem to be considerably less imaginative that those of the 19th century. This isn’t to say that there aren’t informed proponents of a wider palette of trees and a clear understanding of the values that trees offer the community. The recent decision to plant Plane Trees and Spotted Gums in Victoria Square illustrate the challenges for plant professionals working in an environment where their professionalism is often cursorily dismissed by amateurs. Gifted garden designer and landscape architect Kate Cullity from TCL landscape architects and David Lawry OAM, the founder of TREENET, a non-profit group dedicated to improving our urban forests, promoted Lemon-scented Gums as beautiful trees with a distinctly Australian appearance. Lemon-scented Gums line the main boulevard of Kings Park in Perth where they have provided great service but were derided by opponents on the City Council as too dangerous for Adelaide. As the Lord Mayor observed, lowering speed limits in the city would have a greater benefit for public safety. Leadership, respect for professionals working with trees and respect for professional advice underpin the effective use of trees. Paris and Singapore illustrate what’s possible. The City of Paris is the most densely wooded capital in Europe – a visit to Paris is likely to be more fun but an analysis of the statistics might do – Paris’s 10,539 hectares include 478,000 trees comprised of 120 main species, two woods (the Bois de Boulogne and the Bois de Vincennes of 852 and 995 hectares respectively), four city botanic gardens as well as the national Jardin des Plantes, over 400 parks and gardens and, of course, the famed tree-lined boulevards. In Singapore Lee Kuan Yew has provided leadership with a vision of Singapore as a city in garden since independence in 1959 – there’s more green space in Singapore per person today than at independence. LKY delivered his vision through an unwavering commitment to a tree cover for Singapore that required a significant shift and reconciliation in government and urban development cultures, substantial innovation and a major investment in capacity building for the landscape industry (including the construction of a horticulture school in the Singapore Botanic Gardens). Formally retired for two years and now close to 90, LKY continues to share his passion for trees and their effective management with calls expressing concerns with individual tree performance! The benefits to people in terms of environment, well-being, innovation and livelihoods of the effective use of trees is apparent in great cities such as Singapore and Paris – why not Adelaide? Stephen Forbes is the Director of the Botanic Gardens of Adelaide