The Potential of Yellow Gum (Eucalyptus leucoxylon F. Muell.) as an Urban Street Tree: An Assessment of Species Performance in the City of Greater Melbourne, Australia
G.M. Moore and A. Chandler
Abstract: Background: In contrast to trees from northern hemisphere genera, there has been little research into the selection and vegetative propagation of Australian native tree species for use as street trees. Eucalyptus leucoxylon F. Muell. is one of a few eucalypts occurring in south-eastern Australia with bright coloured fl owers and is highly regarded as an ornamental tree that fl owers readily. It is propagated from seed, but progeny typically show seedling variability and diversity. Eucalyptus leucoxylon was identifi ed as the most widely planted eucalypt
in the streets of the city of greater Melbourne, Australia. Methods: This research assessed 300 E. leucoxylon street trees growing across the city of greater Melbourne for their performance against arboricultural criteria relating to canopy structure and density, straightness of the trunk, health (assessed on canopy, trunk, and branch condition, production of exudates, and presence of fungal fruiting bodies), fl ower colour, and root systems. Results: The results showed that E. leucoxylon was a suitable street tree species with most specimens showing good habit, vigour, and health. Discussion: The trees had traits such as live crown ratio, height, fl ower colour, and capacity to cope with pruning that are considered appropriate for a street tree. Their dense canopies and high live crown ratios provide shade that can reduce the urban heat island (UHI) effect. Conclusion: This suggests the species has the potential to be a successful street tree not only in Australia, but in other parts of the world where it has been grown successfully in forestry plantations.
Keywords: Arboricultural Criteria; Eucalyptus; Flower Colour; Live Crown Ratio; Street Tree Performance; Urban Forest