Tim Johnson

This session is about identifying where the real investment is when it comes to managing trees in an ‘asset management’ portfolio. About treating trees as part of an asset inventory in much the same way we consider power and water supply, communication infrastructure, drains, roads, footpaths buildings and structures, as assets  …… Recognising also that at many points within our common city spaces, part of a tree will interface with these other assets in some way.

We all know that trees are one of the most cost-effective and essential civil infrastructure components available to help sustain healthy communities and cities. Their above ground parts provide us with many attributes that have been well recorded in TREENET Symposiums.

Their below ground parts also provide us with proven attributes in the management of stormwater and reduced spending on conventional drainage infrastructure. The space that tree roots occupy provides connectivity with soil and water resources that form an integral part of the urban ecology, while reducing heat-related illness and morbidity and a raft of benefits that we are continuing to research and bring to TREENET‘s library of resources.

We also know that trees are relatively inexpensive to install and establish, and returns on investment in trees can be massive, but many investments fail to deliver.

Achieving good return on investment in trees requires more than expertise and planning. Success in this regard requires a paradigm shift in what it is that we think we are investing in and why we would consider change.

Unlike other assets, trees are living assets. They grow and change in size and stature above and below ground. Without applying the right knowledge at the right time – well before the trees are planted – tree failures will continue. Resulting in asset management budgets continuing to be robbed of their real value, ratepayers will continue to be duped and professions whose role it is to the manage their assets, continue to be confused about what is ‘investment’ in trees and how to measure ‘return on investment’.

This paper summarises some of the costs of investing in trees, the returns that communities can realise from wise investment, and how future investment should be targeted to grow community wealth.

The challenge for our asset managers will be to re-assess how they can progressively re-purpose funds within their existing budgets.

The challenge for Arboricultural technicians and Urban Foresters will be in securing the right expertise at the right time, throughout the planning, establishment, growth and maturity stages of the tree’s asset life cycle……

This session will demonstrate why going for this kind of change is a ‘NO BRAINER’ in maximising returns.

Presentation by Rob Bodenstaff and Dr Tim Johnson

Tim Johnson

Dr Tim Johnson is an arborist, green engineer, conservationist and researcher who works to better connect urban communities with nature in their gardens, streets and parks. Tim’s interests focus on green engineering design to support trees and urban vegetation so interactions between plants, infrastructure, water and soil can deliver maximum community and environmental benefit. His experience ‘on the tools’, in technical, strategic and research roles in the private and public sectors underpins his practical approach to applied interdisciplinary research.

Through his role as Sustainable Infrastructure Engineer working for the City of Mitcham in South Australia, Tim leads research based on experiments designed into working infrastructure in the public realm. These studies serve as demonstrations of nature-based solutions to challenges associated with urbanisation and climate change. The effectiveness of this approach saw Tim named amongst the top 20 most influential people in local government in South Australia by the state’s media in 2020.

Current research projects include investigating the effects of stormwater harvesting on transpiration rates in urban trees, the capacity of urban soil to retain stormwater, and the effects of stormwater infiltration on reactive soil. Tim is currently supervising two PhD students who are researching the stormwater management benefits of dispersed, small-scale infiltration devices and the climate moderation impacts of stormwater infiltration into tree root zones.

Tim serves on the Advisory Board and Management Committee of TREENET Incorporated and is a member of several industry groups including the Institute of Public Works Engineering Australasia, Arboriculture Australia, the International Society of Arboriculture and the South Australian Local Government Urban Forest Alliance. He is an Industry Adjunct at the University of South Australia-STEM and an Adjunct Lecturer at Flinders University. He has served on the Significant Tree Committee of the National Trust of South Australia (2002 – 2012) and the South Australian Urban Forest Biodiversity Program (1997–2006).