Ian has 33 years of experience in the design, construction and management of local government public open space, including five years as Manager Recreation and Open Space at Dubbo Regional Council. As part of his portfolio Ian oversees the strategic management and development of the urban forest on council’s streets, park and reserves. An advocate for interconnected parks and green space for improved health and well-being of residents, Ian has led the discussion on long-term planning to integrate green and grey Infrastructure and deliver intergenerational community and environmental benefit. This has included the application of a modified Stockholm Tree Planting methodology – a structural soil system which is transforming how trees are planted in the urban road network. Ian has qualifications in Amenity Horticulture, Parks, Recreation and Heritage and Natural Resource Management and has taken additional study through the University of Melbourne in the area of Green Infrastructure.
Treenet Symposium Speaker
Ian McAlister
Biography
Session Abstract
Engineered spaces for trees in Dubbo Regional Council
As Australia’s climate warms we face increasing challenges in our cities and towns including the urban heat island effect and its impact on our communities. Many local government areas are under pressure from their communities to increase canopy cover to mitigate the effects of increasing temperature. While councils understand the need for more trees increasing densification of urban centres through smaller lot sizes, infill development and associated utilities reduce planting opportunities. Large homes on smaller lots also reduce opportunities to plant trees on private property. Combined with narrower carriageways and verges, these changes are increasingly forcing councils to reconsider their planting palette and use smaller and narrower tree species. Reduced shading and cooling from these smaller trees means more heat is absorbed and retained which raises night-time temperatures. Not only does this reduce resident comfort and wellbeing but it has a financial impact on councils through reduced life cycles of the asphaltic road seal and it impacts biodiversity conservation. To address these challenges, since 2012 Dubbo Regional Council has trialled different methods for establishing trees in paved areas, including a modified Stockholm Method for creating a structural root vault under the road pavement. This method has been shown to improve growing conditions and to enable trees to develop more fully. This method was developed from a case study which compared three different methods. Thirty years on this early experiment now helps to reinforce the case for improving growing conditions for urban trees.
