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Research of the CAUL Hub: Urban Greening for Liveability and Biodiversity from CAUL on Vimeo.

Photo: City of Melbourne

Tree canopy coverage for Perth's South-East region (19%). Photo : Kath Phelan

CAUL Hub Project 3 – Urban Greening for Liveability and Biodiversity

Project Leader – Dr Nicholas Williams, The University of Melbourne

Project Summary

Green cities are healthier and more pleasant places to live, for people and other organisms. Despite a growing enthusiasm for urban greening in cities around the world there are a number of technical and social barriers to increasing the quantity and quality of urban green space. These include urban climates and environmental conditions difficult for plant growth, community attitudes and perceptions that policy makers may not understand, lack of data to inform urban greening extent, quality and distribution targets and the absence of a mechanism or tool to achieve these.

This project will map the current state of Australia's urban green spaces, setting realistic goals for increasing various types of urban greening in the future and developing the methods to meet and assess these goals.

See here for a project update.

Research

Research activities will be focussed around seven main subprojects:

  1. 3.1 Quantifying urban green space and tree cover
  2. 3.2 Review of the knowledge base
  3. 3.3 Understanding the psycho-social dimensions of urban greening
  4. 3.4 Assessing the vulnerability of Australian cities’ green infrastructure to climate change
  5. 3.5 Developing an audit tool to quantify the multiple benefits of urban greening
  6. 3.6 Quantifying the co-benefits of urban greening to develop an optimisation framework for urban planners and policymakers
  7. 3.7 Development of an Integrated Sampling and Experimental Framework

3.1 Quantifying urban green space and tree cover

In collaboration with industry partners, we will develop a standardised urban greenery typology and user friendly mapping protocol that we will evaluate for its accuracy and cost effectiveness. We will map the current urban green space and urban forest cover, its composition and distribution in three or four cities (Melbourne, Sydney, Perth, Canberra) using a variety of different methods and data and assess how it has changed over time through reference to historical imagery. The production of a user guide to the implementation of this protocol will enable local and state governments across Australia to map urban vegetation in and enable policy-makers to establish realistic, evidenced based targets that Green Cities Blueprints can aim for.

3.2 Review of the knowledge base

A well-established body of research demonstrates that visual and physical access to vegetated environments is associated with a range of social and psychological benefits including improved aesthetic enjoyment, improved mood, attention and self-reported well-being. There is also some evidence that increased urban greening may be linked with broader improvements in health and physical activity, connectedness and concern for nature, as well as reduced social isolation, crime and aggression. We will review the national and international published and grey literature to determine evidence based relationships between urban greening and a range of ecosystem service, human mental and physical health and psycho-social metrics. This will assist in the setting of evidenced-based urban greening targets.

3.3 Understanding the psycho-social dimensions of urban greening

Little is known about how effectively different kinds of urban green space support psycho-social benefits. Furthermore, different human communities in different urban locations (i.e., inner, middle and outer areas of a city) may prefer and benefit differentially from different forms of urban greening, yet there is little understanding of the nature of these relationships. Currently, decision makers must act in the absence of guidance on how different attributes, quality or types of urban greening impact on communities for whom they plan across different urban environments. A key priority for this project is to better understand how urban green spaces, and the different vegetation types within them (e.g. trees, understorey, groundcovers) provide these psycho-social benefits, how different qualities, characteristics or types of urban green spaces influence psycho-social benefits and how different social groups experience these benefits.

3.4 Assessing the vulnerability of Australian cities’ green infrastructure to climate change

The vulnerability of Australian cities’ green infrastructure networks to climate change will be investigated by assessing the risk of extended drought and rising temperatures to urban green space and tree populations and by exploring innovative ways to use and manage water in urban landscapes to mitigate climate change impacts. This will produce tangible improvement in the efficient use of water and the better management of climate risk to urban green infrastructure. The subproject will inform a review of urban planting and revegetation protocols to determine how climate change is incorporated into species selection and green space planning guidelines that will contribute to the green cities blueprint

3.5 Developing an audit tool to quantify the multiple benefits of urban greening

CAUL researchers have previously developed a Public Open Space Desktop Auditing Tool (POSDAT), to assess the quality of parks as it relates to human physical health outcomes. We aim to extend POSDAT so that it also assesses the ecosystem service and psycho-social benefits of all urban green infrastructure. This will be done by developing evidenced-based indices that reflect the different characteristics of green infrastructure and the various benefits it provides. This Urban Greening Benefit Audit Tool (UGBAT) is a critical step in developing the Green Cities.

3.6 Quantifying the co-benefits of urban greening to develop an optimisation framework for urban planners and policymakers

Effective implementation and evaluation of successful urban green infrastructure is an inherently transdisciplinary pursuit requiring expertise from disciplines as diverse as landscape architecture and design, horticulture, ecology, engineering, health and social sciences. However, to date studies of the impact of urban greening initiatives have been largely restricted to discipline silos. Consequently studies quantifying the co-benefits of urban greening are lacking. In this sub-project we will seek to elucidate the best strategies to increase, and spatially and temporally optimise the co-benefits of urban greening.

3.7 Development of an Integrated Sampling and Experimental Framework

This sub-project provides the opportunity to coordinate experimental frameworks across a number of sub-projects across Project 3 and CAUL’s research projects more generally. These will include:

  1. Integrated sampling at shared study sites
  2. Measuring the social, environmental and biodiversity impact of urban greening intervention experiments, and compare them to closely matched control sites so as to fairly assess true impact from inter-annual variability and increased community awareness

We aim to establish networks of three experimental sites across urbanisation gradients in Melbourne, Sydney and Perth, ideally in inner, middle and urban fringe suburbs and corresponding closely matched control sites where no additional urban greening takes place. Assessing the impact of urban greening activities in rapidly developing, low socio economic, culturally diverse outer suburbs will be particularly important.

Expected Outcomes

Outcomes

The project will deliver multiple outcomes, including benchmark data on urban green infrastructure; an innovative, evidenced based tool to quantify the multiple benefits of urban greening that can be used to assess urban greening targets and progress the Green Cities Blueprints at an individual site scale; identification of the benefits and concerns that urban residents associate with urban greening; a comprehensive strategy to increase the social and ecological co-benefits of greening Australian urban landscapes; and optimised strategies for water use and climate resilience of urban trees.

Specific management or policy outcomes

This project will improve the ecosystem function, liveability and biodiversity benefits of Australian urban landscapes by developing targeted, evidence-based strategies to maximise the effectiveness of current and new urban greening approaches; providing information that could be incorporated into activities undertaken by the 20 Million Trees Program and Green Army; and informing urban greening policies and programs undertaken by state and local governments.

Value

This project will provide more effective use of funding and resources targeted for urban greening projects, and ecological and social gains through new urban greening opportunities measured by the positive outcomes for liveability and biodiversity.

Further details can be read in the public version of the CAUL Hub Research Plan. Return to the overview of CAUL Hub research projects.