The Green Infrastructure Project, hosted by the Botanic Gardens of South Australia (BGSA) within the Department of Environment, Water and Natural Resources (DEWNR), worked with Dr. Martin Ely to develop an Evidence Base for Green Infrastructure in South Australia. This report summarizes and provides an overview of the relevant literature in the field and outlines key findings by specific research topics. The report also identifies areas of research requiring further investigation.
1.2 Study background
The Green Infrastructure Project has a vision of ‘South Australians living in healthy, resilient and beautiful landscapes that sustain and connect people with plants and places’. Green Infrastructure includes the ‘green’ (plants) and ‘blue’ (water) components of the environment that can provide a wide range of social, economic and environmental benefits to cities.
The ultimate success of Green Infrastructure as a new ‘paradigm’ requires:
- Recognition of its values and benefits by the whole community and at the highest strategic levels
- Capacity building in the institutions and organisations involved in implementing Green Infrastructure in its different forms
- Incorporation of Green Infrastructure as an essential, rather than optional, component in the urban development process.
One of the key strategy areas of the Green Infrastructure Project has been the development of a sound and credible 'evidence base' which ‘makes the case’ for investment in Green Infrastructure. The 'evidence base' underpins our advocacy and awareness activities, organisational capacity building, resource development, and development of design principles for Green Infrastructure.
1.3 Study scope
Green Infrastructure (also referred to in this report as GI) is by definition a multi-disciplinary topic. GI has its origins in a number of different research fields, and has evolved over time under a number of names. It has also been applied at a range of scales from the global to the local. Owing to its ‘multifunctionality’, there is no single science or discipline responsible for GI (Benedict and McMahon, 2002). According to some authors, the nearest integrative scientific discipline responsible for the evolution of GI is ‘landscape planning’, which developed as a separate discipline in the 1970s, (European Commission, 2012). GI is also founded on the theories and practices of a wide range of scientific and land planning professions, such as conservation biology, landscape ecology, urban forestry, urban ecology, urban and regional planning, geographic analysis, information systems and economics (European Commission, 2012). Research into GI also occurs at a range of scales, from individual buildings to neighbourhoods, cities and entire regions (Naumann et al., 2011a). A current emphasis is on the role of GI in addressing global issues of climate change, sustainable development, and human health and well-being, as well as more local issues such as the effects of prolonged drought on Australian cities and the adoption of more sustainable water management practices.
1.4 Report structure
The literature review is presented in the following sections:
- Study background, scope and methodology
- GI concepts and definitions, including concepts of ecosystem services, biodiversity and their links to human health and well-being
- A literature review of key GI benefits categorized as follows:
- Human health and well-being
- Community liveability
- Economic benefits
- Climatic modification
- Water management
- Urban ecology
- Food production
- Study conclusions and recommendations
- A list of references cited in the text is also provided at the end of each chapter of the report
1.5 Green Infrastructure research
Figure 1:Scope of Green Infrastructure benefits. Source: M. Ely.
In the last decade, extensive research has been undertaken documenting the ‘triple bottom line’ (social, economic and environmental) benefits of Green Infrastructure as shown in Figure 1 (McPherson, 1995; Staley, 2004; McPherson, 2005; Nowak and Dwyer, 2007; Macdonald and Supawanich, 2008; Clark and Matheny, 2009). Being a multi-disciplinary topic, this research is spread over a very wide field.
Much of the research has taken place in the United States and Europe, however significant recent research and literature reviews have also been undertaken in Australia (Moore, 2000b; Killicoat et al., 2002; Plant, 2006; Tarran, 2006; Fam et al., 2008; Tarran, 2009; Townend and Weerasuriya, 2010). A significant body of local research has been undertaken recently as part of the City of Melbourne Urban Forest Strategy (City of Melbourne, 2011; GHD, 2011b; Townend and Sick, 2011; GHD, 2011a). Recent research has also been commissioned by the Nursery and Garden Industry Australia (NGIA) into the benefits of urban trees and green-spaces (Holbrook, 2009; NGIA, 2011).
The literature review indicates current research focus on three key topics, being funded by the Australian government and pursued within local research institutions.
- Recognition of global climate change has led to an emerging body of research into the potential role of Green Infrastructure in climate change mitigation and adaptation (Moore, 2006; McPherson et al., 2009; Thom et al., 2009). Important research into mitigating the ‘urban heat island’ effect is currently taking place in Australia (Coutts et al., 2007; Loughnan et al., 2008; Livesley, 2010; Loughnan et al., 2010).
- The related topic of sustainable water management has also become a significant research focus, driven by issues of prolonged drought and water restrictions in Australian cities (Wong, 2011).
- Current concerns with the health costs of modern sedentary lifestyles have led to a significant body of research into the human health and well-being benefits of urban nature and Green Infrastructure, including recent Australian based research (Kent et al., 2011; Planet Ark, 2011; Planet Ark, 2012).
A project at the University of Washington provides access to a green infrastructure knowledge base. The website Green Cities: Good Health represents a collection of more than 2,800 scholarly works, most of which are peer reviewed(University of Washington 2014). The papers are sorted into key themes, each represented by a summary with citations. Support for the Green Cities: Good Health project is provided by the U.S. Department of Agriculture Forest Service, Urban and Community Forestry Program.
USEFUL GREEN INFRASTRUCTURE RESEARCH SITES
Landscape and Human Health Laboratory
A science team at the University of Illinois studies the connection between urban greenery and human health. The research has produced landmark findings concerning people and nearby nature.
Human Dimensions of Urban Greening and Urban Forestry
This web site features research at the University of Washington (Seattle) on people’s perceptions and behaviors regarding nature in cities. The site addresses the following topics: nature and consumer environments, trees and transportation, civic ecology, and policy and planning.
American Planning Association, How Cities Use Parks
This web site features a series of briefing papers. Topics include: community revitalization, community engagement, economic development, safer neighbourhoods, green infrastructure, children and learning, improve public health, arts and cultural programs, promoting tourism, smart growth, and climate change management.
The Trust for Public Land, Center for City Park Excellence
The Trust is a national non-profit that conserves built and natural places for people to enjoy, ensuring livable communities for generations to come. TPL shares white papers about why city parks are necessary assets.
Local Government Commission
The web site lists multiple benefits of city trees. A fact sheet about livable communities reports on a range of community benefits, from economic development to public health and safety.
Casey Tree Foundation, The Case for Trees & Growing a Healthier D.C.
The non-profit Foundation works to restore tree canopy in Washington, D.C. A Tree Benefits page highlights why trees are important for green infrastructure and urban livability. A second web page shares documents on the importance of green assets for city life: neighborhoods, streets, parks, schools, business districts, parking lots, residences, and jobs.
Home Depot Foundation, Green Cities Institute
The nonprofit Foundation is dedicated to affordable housing for working families, and to sustainable community development (promoted by Neighborwoods programs and the Green Cities Institute). A Green Infrastructure "classroom" includes information about the role of trees in healthy communities, including economics, community, education, and health.
Sacramento Tree Foundation
This community-based nonprofit works to build the Sacramento's urban forest, and improve regional programs using a collaborative GreenPrint approach. Web page summaries report research on the social, psychological and community benefits of urban greening: girls and greenery, canopy and crime, vegetation and violence, kids and concentration, neighbors and nature, and plants and poverty.
Urban Forestry South Expo
This USDA Forest Service site provides support to urban and community forestry programs in the southeastern U.S., but the materials are relevant to other regions.
Children & Nature Network
The nonprofit Network supports those who work to reconnect children with nature. One web page tracks recent research on the influence of nature on children, including social benefits.
Evergreen, Learning Grounds
This nonprofit organization is working to make Canada’s cities more livable by deepening the connection between people and nature. One program, Learning Grounds, is dedicated to transforming the outdoor landscape of Canada's schools. Links share studies about the effects of urban greening on children in Canada.
United Nations Food and Agriculture Organization, Urban Forestry Community
The FAO is a neutral forum for international food security issues. One project is an informational program on Forests and Trees for Healthy Cities, which brings together people from across the globe to promote urban greening. The website tracks international research on the social benefits of trees in cities, and shares files.
UK Forest Research
Forest Research is the science division of the U.K. Forestry Commission, and informs policy on woodlands and forests, from wildland to urban settings. One web page features social science, including decision making. A second page outlines current research (with publications) on the role of trees in human health and well being..
Northwest Public Health, Health and the Built Environment
Links to research studies are provided, along with summaries. Topics include the precautionary principle, the role of the natural environment in healing, daylighting in schools and other settings, building healthy communities, transportation, and urban density, sprawl and land use planning. Many, but not all, of the studies are based in the Pacific Northwest.
Source: University of Washington 2014)
1.6 Study methodology
This study comprises a comprehensive review of literature on the benefits of Green Infrastructure. Key informants in academic and government organisations in all Australian states were initially contacted to identify the most recent literature in different fields of research. A ‘snowball method’ of literature review was conducted, starting with the reference lists of key articles and documents (Babbie, 2001; Sustainable Development Commission, 2008). Where key documents cited other literature, the original source of information was acquired and reviewed.
In deciding which studies to use the following were given preference:
- Peer-reviewed, published literature
- Evidence from other reputable sources (such as reports conducted or commissioned by government bodies or non-government agencies)
- The most recent (post 2000) evidence was preferred, although on occasion older studies which are seminal in nature or where more recent research is limited have been included
- Studies from across the world have been referenced, however local Australian studies have been sourced and reviewed where possible to reflect local climatic and other conditions
1.7 Study limitations
Due to limits on time and resources, and the wide scope of the topic, individual studies have not been assessed on methodology or sample size. Where other research has undertaken these assessments, this has been noted in the text. Areas where evidence is considered weak or in need of further exploration have also been identified.
1.8 Target audience
This 'evidence base' is intended to bring together evidence supporting the concept of Green Infrastructure. It is designed to be used as a resource by policy makers, planners, designers and others who are interested in developing and promoting Green Infrastructure in urban environments.
1.9 How to use this document
Users of this document are advised to:
- Read Chapter 1 for an understanding of the study scope and methodology
- Read Chapter 2 for an overview of the main concepts underlying the study and definition of key terms
- Read Chapters 2-8 for a summary and review of Green Infrastructure benefits relating to specific topic areas
- Read Chapter 9 for a summary of key study conclusions and recommendations
- Use the Reference list to source the original articles and other documents referenced in each body of the report
Green Infrastructure is a continually developing field with a growing body of research. Readers should also refer to additional literature produced since publication of this report.
Coutts, A. M., J. Beringer, et al. (2007). "Impact of increasing urban density on local climate: Spatial and temporal variations in the surface energy balance in Melbourne, Australia." Journal of Applied Meteorology and Climatology46(4): 477-493.
Fam, D., E. Mosley, et al. (2008). Irrigation of urban green spaces: A review of environmental, social and economic benefits. Technical Report No. 04/08. Darling Heights, Qld., Cooperative Research Centre for Irrigation Futures: 35pp.
GHD (2011a). City of Melbourne: Report for Urban Heat Island Effect, Literature Review. Melbourne, Vic.
Holbrook, A. (2009). The Green We Need: An investigation of the benefits of green life and green spaces for urban-dwellers’ physical, mental and social health. Epping, NSW, Nursery and Garden Industry Australia: 175pp.
Kent, J., S. M. Thompson, et al. (2011). Healthy Built Environments: A review of the literature. Sydney, Healthy Built Environments Program, City Futures Research Centre, UNSW.
Killicoat, P., E. Puzio, et al. (2002). The Economic Value of Trees in Urban Areas: Estimating the Benefits of Adelaide's Street Trees. TREENET Proceedings of the 3rd National Tree Symposium:5th and 6th September 2002. Adelaide, TREENET Inc.
Livesley, S. (2010). Energy saving benefits of shade trees in relation to water use., TREENET Proceedings of the 10th National Street Tree Symposium September 2010.
Loughnan, M. E., N. Nicholls, et al. (2008). "Demographic, seasonal, and spatial differences in acute myocardial infarction admissions to hospital in Melbourne Australia." International Journal of Health Geographics7(42).
Loughnan, M. E., N. Nicholls, et al. (2010). "When the heat is on: Threshold temperatures for AMI admissions to hospital in Melbourne Australia " Applied Geography30: 63-69.
Macdonald, E. S., R. and P. Supawanich (2008). The effects of transportation corridors' roadside design features on user behaviour and safety, and their contribution to health, environmental quality, and community economic vitality : A literature review, University of California Transportation Center: 185pp.
McPherson, E. G. (1995). Net benefits of healthy and productive urban forests. Urban Forest Landscapes:Integrating Multidisciplinary Perspectives. G. A. Bradley, University of Washington Press.
McPherson, E. G. (2005). "Trees with benefits." American Nurseryman201(7).
McPherson, E. G., J. Simpson, et al. (2009). "Urban Forests and Climate Change." Retrieved 20 July 2011, from http://www.fed.us/ccrc/topics/urban-forests.
Moore, G. M. (2000). Treenet:A Management System and Choices for Australia. TREENET Proceedings of the Inaugral Street Tree Symposium:7th and 8th September 2000, Adelaide, TREENET Inc.
Moore, G. M. (2006). Urban trees and the global greenhouse. TREENET Proceedings of the 7th National Street Tree Symposium: 7th and 8th September 2006, Adelaide.
Naumann, S., D. McKenna, et al. (2011a). Design, implementation and cost elements of Green Infrastructure projects. Final report Brussels, European Commission.
NGIA (2011). Estimating the benefits of Australian Street Trees using i-Tree Stratum - A Pilot Study. Nursery Papers 8, Nursery and Garden Industry Australia.
Nowak, D. J. and J. F. Dwyer (2007). Understanding the benefits and costs of urban forest ecosystems. Urban and Community Forestry in the Northeast. J. Kruser. Newtown Square, PA., U.S.D.A. Forest Service, North Eastern Research Station,: 25-46.
Planet Ark (2011). "Climbing Trees: Getting Aussie Kids Back Outdoors." Retrieved 20 April 2012, from http://treeday.planetark.org/about/2011-research.cfm.
Planet Ark (2012). "Planting Trees: Just What The Doctor Ordered." Retrieved 20 April 2012, from http://treeday.planetark.org/about/health-benefits.cfm.
Plant, L. (2006). Brisbane: Beautiful one day, perfect the next-Is there room for improvement? TREENET Proceedings of the 7th National Street Tree Symposium:7th and 8th September 2006, Adelaide,S.A.
Staley, D. (2004). Casey Trees White Paper: Benefits of the Urban Forest Literature Review. Washington, DC, Casey Trees Endowment Fund 73pp.
Sustainable Development Commission (2008). "Health, Place and Nature: How outdoor environments influence health and well-being : a knowledge base." S.D.C.UK
Tarran, J. (2006). Trees, Urban Ecology and Community Health. TREENET Proceedings of the 7th National Street Tree Symposium: 7th and 8th September 2006, Adelaide, TREENET Inc.
Tarran, J. (2009). People and trees: providing benefits, onercoming impediments. TREENET Proceedings of the 10th National Street Tree Symposium 3rd and 4th September 2009.
Thom, B., J. Cane, et al. (2009). National Climate Change Adaptation Research Plan: Settlements and Infrastructure. Gold Coast, National Climate Change Adaptation Research Facility: 60pp.
Townend, M. and L. Sick (2011). Report on the City of Melbourne Urban Forest Strategy Health Indicators Project. Melbourne, Deakin University: 27pp.
Townend, M. and R. Weerasuriya (2010). Beyond Blue to Green: The benefits of contact with nature for mental health and well-being, A Literature Review from the School of Health and Social Development, Deakin University, prepared for beyondblue: the national depression initiative.
Wong, T. H. F. (2011). Blueprint 2011. Stormwater Management in a Water Sensitive City. Melbourne, The Centre for Water Sensitive Cities, Monash University.