Published by the Victorian Government
Department of Sustainability and Environment
Melbourne, September 2011
© The State of Victoria Department of Sustainability and Environment 2011
This publication is copyright. No part may be reproduced by any process except in accordance with the
provisions of the Copyright Act 1968.
Authorised by the Victorian Government,
8 Nicholson Street, East Melbourne.
Print managed by Finsbury Green
Printed on recycled paper
ISBN 978-1-74287-207-0 (online)
For more information contact the
DSE Customer Service Centre 136 186
Disclaimer
This publication may be of assistance to you but the State of Victoria and its employees do not
guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular
purposes and therefore disclaims all liability for any error, loss or other consequence which may arise
from you relying on any information in this publication.
This publication reflects the views of the local governments interviewed and should not be taken to
represent the views of the State of Victoria or its employees.
Accessibility
If you would like to receive this publication in an accessible format, such as large print or audio, please
telephone 136 186, or through the National Relay Service (NRS) using a modem or
textphone/teletypewriter (TTY) by dialling 1800 555 677, or email customer.service@dse.vic.gov.au
This document is also available in PDF format on the internet at www.dse.vic.gov.au
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
2.
Table of Contents
1. Introduction ..................................................................................................................4
Background ............................................................................................................. 4
The Accord and its advisory committee ................................................................................ 4
The urban trees issue............................................................................................................ 4
VLSAC Urban Trees project and this paper .......................................................................... 4
Policy Context ....................................................................................................................... 5
Acknowledgments ................................................................................................................. 5
Scope and methodology ......................................................................................... 6
2. Understanding why urban tree canopy is important –
literature review* ............................................................................................................7
Air pollution ............................................................................................................. 7
Urban climate, temperature and energy use ......................................................... 8
Carbon sequestration and storage ........................................................................ 9
Water run-off and quality ........................................................................................ 9
Social, aesthetic and property values.................................................................. 10
Summary of urban forestry benefits .................................................................... 10
History of tree species in urban Melbourne ........................................................ 11
Understanding the trends in urban tree canopy in Melbourne .......................... 11
Approach to trend analysis .................................................................................................. 11
Tree planting and removal records ..................................................................................... 12
Aerial image analysis .......................................................................................................... 14
Key trends ............................................................................................................. 17
4. Drivers of urban tree canopy trends .......................................................... 18
Trees on council land and private land ............................................................... 18
Council managed land......................................................................................................... 18
Private managed land ......................................................................................................... 19
Key urban forestry barriers .................................................................................. 20
Establishing trees on the western plains ............................................................................. 20
Built environment................................................................................................................. 20
Community perceptions....................................................................................................... 21
Action councils are taking .................................................................................... 21
The bigger picture – the role for state government ............................................ 22
Agreed position on the value of urban trees ....................................................................... 22
State planning ..................................................................................................................... 22
Line clearing regulations ..................................................................................................... 22
5. Conclusion and next steps................................................................................ 23
Summary of findings............................................................................................. 23
Future opportunities ............................................................................................. 23
6. References .................................................................................................................. 24
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
3.
1. Introduction
Background
The Accord and its advisory committee
The Accord is a partnership agreement between local governments and the state government. It has
been successful in gaining the commitment of all 79 councils in Victoria, raising the profile of
sustainability issues across local government and building the capacity of smaller regional councils to
address environmental sustainability within their communities.
The Victorian Local Sustainability Advisory Committee (VLSAC) oversees the implementation of the
Accord. The VLSAC was appointed by the Minister for Environment and Climate Change to provide
advice to the Minister about local government issues for input into policy making and to act as a forum
for strategic discussion and resolution of cross-jurisdictional sustainability and climate change issues
between state and local government.
To focus its efforts, the VLSAC identified five key issues for priority action. The priority issues were
based on input from the Accord partners and extensive consultation with local governments across
Victoria. These complex, cross-jurisdictional issues require action by both state and local government to
improve sustainability outcomes for local communities, and Victoria as a whole. The VLSAC Urban
Trees project looks at the implications for Melbourne’s liveability through changes to public and private
urban tree canopy and what steps can be taken to further recognise and take advantage of the benefits
urban trees provide.
The urban trees issue
Trees and urban landscapes emerged as an issue for local governments through consultation
processes undertaken by VLSAC. In particular:

Urban densification and some water saving initiatives (e.g. the increased use of artificial turf) have
lead to a reduction in the amount of vegetation in Melbourne. Fewer trees can increase local
temperatures on hot days, leading to increased use of air-conditioning and associated water loss

The benefits provided by urban trees and urban landscapes – reduction in runoff, air filtration, shade
provision and local biodiversity and habitat – are not being recognised in urban planning and land
use decisions

The need for better metrics and understanding of the economic value of these services provided by
urban trees and landscapes.
An Accord funded project ‘Valuing Urban Trees’ is currently underway. The project aims to put a
financial value on the environmental, health and amenity benefits of urban trees to provide future
guidance for urban decision makers such as urban designers, planners and policy makers. This project
includes customising an American methodology and software (I-tree) to Australian species for creating a
value (price) on the amenity attributed to urban trees such as shade/cooling effects, UV protection and
carbon sequestration.
VLSAC Urban Trees project and this paper
The purpose of the VLSAC Urban Trees project is to:

Understand the degree to which Melbourne’s urban tree canopy has changed over the last 10 years

Investigate the drivers of changes in urban tree canopy through council interviews
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
4.

Engage with, and bring together, local governments and subject matter experts to tap into their first
hand experience
of the impacts of changes in urban tree canopy on their
local communities

Provide evidence for key decisions makers in local (and state) governments about the extent of the
changes in urban tree canopy and the impacts of these changes, to inspire effective action.

The urban trees project will have two outcomes:

An issues paper addressing the trends, drivers benefits
and barriers in urban trees across Melbourne

An event aimed at senior decision makers across local and state government to explore possible
solutions and opportunities to the barriers and issues identified in the research for the paper.
Policy Context
The VLSAC Urban Trees project is consistent with a number of the Victorian Government’s policy
commitments, in particular:

Living Melbourne, Living Victoria Roadmap which aims to establish Melbourne as a world leader in
liveable cities and integrated water cycle management and provide a vision for a liveable,
sustainable and productive Melbourne that supports green landscapes that significantly enhance
urban amenity and help combat the impacts of the urban heat island effect

Whole-of-government liveability audit of metropolitan Melbourne to identify gaps in physical and
community infrastructure

The $5m Living Victoria green roof plan to reduce energy use and cool city buildings and offices

The planting plan to build a green future across Victoria (1.5million trees to be planted across
metropolitan Melbourne) – restoring urban spaces; better utilising trees effectiveness in reducing
pollution and cooling our towns and cities (heat island effect); preservation of biodiversity.
Local governments have a clear role to play in these policy areas. Reductions in urban tree canopy
(and related permeable surfaces) impact on Melbourne’s liveability and ‘greeness’ by way of increasing
heat island effect, less carbon emissions being absorbed, greater pressure on storm water management
facilities and infrastructure and loss of biodiversity.
Acknowledgments
In the Accord spirit of connecting across and between levels of government, many people and
organisations need to be acknowledged for their contribution to this project as reference and working
group members, interview subjects and subject matter experts. In alphabetical order, the VLSAC would
like to acknowledge:

Brimbank City Council

City of Bayside

City of Boroondara

City West Water

DPCD

DSE

Hobsons Bay City Council

Hume City Council

Judy Bush

Maribyrnong City Council

Maroondah City Council

Municipal Association of Victoria

Melbourne City Council
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
5.

Melbourne University School of Land and Environment

Moonee Valley City Council

Rob Gell

Yarra Ranges Council
Scope and methodology
This discussion paper is focused on the trends in urban tree canopy across metropolitan Melbourne. It is
acknowledged that some issues (benefits and barriers) addressed in this paper are relevant to a wider
audience, in particular regional centres such as Geelong, Ballarat and Bendigo.
A combination of sources were utilised in undertaking the research for this discussion paper. Nine
councils were interviewed across Melbourne. Council staff interviewed included arborists, open space
managers, tree managers, landscape architects, biodiversity officers, environmental planning managers
and sustainability officers and managers. Each council was asked what trends it saw in its municipality on
both council-managed and private land; the drivers of those trends; activities council were undertaking
around trees; barriers faced; and what role, if any, councils saw for the state government to take around
urban trees.
The paper also includes a literature review, based on the work of Thomas Fairman in his 2010 Master’s
paper ‘Using STRATUM to Estimate the Benefits of Street Trees in Melbourne, Victoria’.
To determine the trends in urban tree canopy across metropolitan Melbourne, two methods were
employed. The first involved using council-sourced data to interpret the changes in trees planted and
removed, in addition to the total size of the urban tree asset. Using this information it was possible to
estimate if there has been a net increase (or decrease) in trees within metropolitan Melbourne.
The second method was more directly tied to analysing the trends in the presence of tree cover. Aerial
photos owned by the Department of Sustainability & Environment were analysed for change in tree
canopy cover over time using spatial software (ArcMap 9.3.1) over a variety of different suburbs within
different councils. These suburbs were:

St. Albans (Brimbank)

Balwyn (Boroondara)

Carlton (Melbourne)

North Melbourne (Melbourne)
 Broadmeadows (Hume).
The suburbs used in this analysis are broadly representative of different parts of Melbourne. The selection
of these five suburbs allows a broad west-to-east, north-to-central selection of suburbs within metropolitan
Melbourne. They are also characterised by differing establishment histories, as well as land uses and
suburb characteristics.
A series of fixed points was overlaid across aerial photographs of the different suburbs. For a given
year, each of these points was then assessed by eye as to whether it intersected a tree or its canopy or
not (identified as ‘Tree’ or ‘Non-tree’ accordingly). Aerial photographs dated 2000 and 2009 were
analysed for all suburbs except St Albans where data was available for 1989 and 2009. It is
acknowledged that this analysis is relatively coarse, however it does provide indication in the trends in
tree canopy cover in the urban landscape.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
6.
2. Understanding why urban tree canopy is
important – literature review*
Australia is a highly urbanised nation, with an estimated 75% - 82% of the population (compared to 55%
of the American population) living in urban areas (ABS, 2006a; Sutton et al, 2010). In Victoria, greater
Melbourne has absorbed 80% of the increase in the State’s total population since 2001, with the
population percentage residing in urban Melbourne slowly, but steadily, increasing in the same period
(ABS, 2010) (Figure 1.)
Figure 1. Change in Melbourne population
Accordingly, the ecology of ecosystems within urban areas is increasingly being examined (Cooke et al,
2002; Garden et al, 2006) and valued (Bolund & Hunhammar, 1999). It is generally considered that the
proper management of cities, including their ecological management, will ensure that they are
reasonable places to live in the future (Pickett et al, 2001) through the provision of a healthy and
resilient environment. For scientists, councils, resource managers and the general public, the roles of
trees in an urban landscape are increasingly being scrutinised, with a keen eye on any potential
benefits.
The numerous benefits of urban forests, and in particular street trees, have been frequently cited in
numerous reports over the past few decades, including: reduced particulate air pollution; reduced
energy use through increased shade, reduced air conditioner use and subsequent mitigation of urban
heat island effects; the storage/sequestration of carbon; improved water quality and retention (Brack,
2002; Donovan & Butry, 2009). Street trees have also been observed to provide more ‘intangible’
benefits such as aesthetic/visual amenity and psychological benefits to the community, including stress
reduction, improved work attitudes, reduced domestic violence, and ‘consumer-friendly’ retail
environments (Treiman & Gartner, 2006). Despite these benefits being identified in academia, little
quantitative data exists to demonstrate the full benefits provided by urban trees.
Air pollution
It is generally accepted that there are four ways that urban trees affect the levels of air pollution in a city
(Nowak, 2000a):

Temperature reduction and other microclimate effects

Removal of air pollutants

Emission of volatile organic compounds and emissions
from tree maintenance programs
 Energy effect on buildings.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
7.
In terms of the actual removal of air pollutants, trees can use two methods: gaseous pollution can be
absorbed via leaf uptake and diffusion; trees can also intercept airborne particles, which can then either
be absorbed into the tree or retained on the tree surface (Nowak et al, 2006). For this latter case, the
tree only serves as a temporary retention site for airborne particles. Ultimately, the ‘success’ of urban
trees in removing pollution depends on the amount of air pollution, the length of the ‘in-leaf’ season,
precipitation and other meteorological variables. Furthermore, it has been suggested large, healthy
trees – generally those with a diameter at breast height (DBH) of >77cm – remove approximately 70
times more air pollution annually than small, healthy trees (<8cm DBH) (Nowak, 2002). With this in
mind, it is of little surprise that studies based in the United States assessing the extent of pollution
reduction by urban forests have found a large degree of variability – for example, the urban forests of
New York City annually remove an estimated 1,821 tons of air pollution citywide, where as those in
Baltimore remove 499 tons (Nowak, 2000a).
However, the benefits of trees in reducing air pollution are not always necessarily clear cut. For
example, in certain urban environments, street trees can create a ‘blockage effect’ on the escape of air
pollution, potentially lowering local air quality (Salim et al, 2009). Certain tree species also emit chemical
compounds known as “biogenic volatile organic compounds” (BVOCs), which play a role in the
formation of photochemical smog, especially in the presence of other urban pollutants (Penuelas &
Staudt, 2010). The genus Eucalyptus is a particularly high emitter of BVOCs (Nowak, 2000a), which
could therefore potentially alter local air quality. However, there is a current lack of research into this
area of urban air pollution (Penuelas & Staudt, 2010).
* Based on ‘Using STRATUM to Estimate the Benefits of Street Trees in Melbourne, Victoria’ by Thomas Fairman, 2010
Urban climate, temperature and energy use
With increased urban density and extreme heat events, parks and other trees areas such as nature
strips and roadsides will help counter increased temperatures resulting from heat absorbed by roads,
buildings and footpaths (VEAC 2011).
The shade of a tree can provide energy savings and cuts in carbon dioxide emissions. The shade from
a street tree cast on a house with a street frontage can reduce the local ambient temperature, through
evapotranspiration and shading of the house, paved street and sidewalks, which in turn reduces the
need for energy expenditure through air conditioning use.
The reductions in energy use are discernible – for example, in the city of Adelaide, South Australia, it
has been estimated that all street trees city wide are responsible for a 0.5°C - 2°C reduction in summer
temperatures, and an estimated per year saving of $AU20 per household, equivalent to 57 million kWh
(Stringer, 2007).
In Sacramento, California, trees located within 20m of houses were found to provide reductions in summer
time electricity use equivalent to household savings of $US25.16 and a per household power-use
reduction of 185kWh (Donovan & Butry, 2009).
Furthermore, the decrease in power consumption correlates to a reduction in carbon dioxide emissions
from power plants that supply households with their energy. This reduction in emissions occurs
alongside localised uptake of carbon dioxide through tree growth, via the process of photosynthesis. In
the case of Sacramento, it was found that a single London Plane Tree (Platanus x acerifolia) correctly
placed near a house and well-maintained for 100 years, could reduce annual summertime carbon
emissions from electricity use by 31% – equal to roughly 298kg of carbon dioxide per year (Donovan &
Butry, 2009) through avoided carbon dioxide release and sequestration.
This is very much location and species specific, however. In the case of Australia, it has been observed
that the sequestration of street trees in Adelaide is matched by the trees respiration, and therefore there
is no net change in this regard – aside from the indirect avoided carbon emissions due to lowered power
consumption (Stringer, 2007). The need for greater detailed measurement in Australia is acknowledged.
However, a significant finding of the Victorian Environmental Assessment Council’s (VEAC) Melbourne
Metropolitan Investigation was the importance of treed areas for ameliorating the urban heat island
effect (VCEC 2011).
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
8.
Carbon sequestration and storage
The sequestration of carbon in trees and forests (carbon sinks) has frequently been cited as one way of
assisting in the reduction of carbon dioxide emissions. Urban vegetation is not currently considered
under the framework of the Kyoto protocol for carbon sink or sequestration purposes, primarily due to
issues regarding the verification of data, in addition to the relatively small scale of urban plantings
compared to forest stands or plantations (Moore, 2006).
However, given the close proximity of urban vegetation to emission sources, the carbon storage
potential of urban forests, and street trees, should not be disregarded (Nowak, 2000b). Studies in the
US and UK suggest that urban forests are able to hold an average 25.1 to 31.6 tonnes of carbon per
hectare (tC/ha) - a relatively significant amount compared to the average of 53.5 tC/ha in US traditional
forests (Nowak & Crane, 2002; Davies et al, 2011). A similar UK study found 31.6 tC/ha in the urban
vegetation of Leicester. However, this value of tons per hectare of urban vegetation has a fair degree of
variability – in the US the figure can vary between 3.3 tC/ha to 51.2 tC/ha (Nowak & Crane, 2002).
Below-ground organic carbon stored in urban soils (typically with a large sequestration potential due to
general lack of disturbance), estimated at roughly 5-8 kg/m2 in certain US cities (Pouyat et al, 2006) can
also be considered.
Given that urban areas are generally increasing in size, the carbon stock of urban vegetation will
become larger and more relevant. However, the vegetation being cleared at the expense of urban
expansion will ultimately determine whether there is a net-gain, or loss, in carbon stocks per hectare of
urban land
Water run-off and quality
The large impermeable surface associated with urban areas allows a great magnitude and volume of
run-off after rainfall events efficiently – however, it also efficiently transports many pollutants generated
from urban activities (Wettenhall, 2006). Traditionally, the management of stormwater in cities such as
Melbourne has focused on rapid collection and rapid discharge into nearby waterways (Denham, 2006).
However, the aquatic ecosystems of these waterways can be negatively affected by the quality and
quantity of the water discharge from urban areas. This effect, in terms of all human impacts on stream
ecosystems, is considered one of the most damaging and long lasting - changing channel flow regimes,
channel stability, impairing water quality and reducing biological diversity (Miller & Boulton, 2005).
Water sensitive urban design (WSUD) attempts to integrate urban design into the treatment of run-off
on-site, in an effort to reduce contaminant load, the volume of run-off and the resulting negative impacts
on ecosystems (Wong, 2006). Urban trees are an important element of WSUD as they capture water
through their canopy and in the permeable soil layer that surrounds their root zone, allowing a reduction
in the quantity of water that would otherwise be discharged into waterways.
The quality of urban water run-off is also important. Reducing nutrients such as nitrogen in run-off is
important given the role these nutrients play in algal blooms and eutrophication in waterways. It has
been observed that certain species in Australia (Eucalyptus polyanthemos, Lophostemon confertus and
Platanus orientalis) can assist in the bioretention of nitrogen through uptake from their soil root zones
(Denham, 2006). Furthermore, it was also shown that increased growth rates prevail under stormwater
treatment compared to regular water treatment. In terms of the value this benefit represents, in Adelaide
the storm water savings per tree is estimated at $AUS6.50 (Stringer, 2007), while in studies of street
tree benefits citywide in Berkeley, which has a climate zone somewhat similar to Melbourne, the total
value of stormwater benefits was USD $215,648 – which equates to about USD $7 per tree (McPherson
et al, 2005).
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
9.
Social, aesthetic and property values
Trees close to a house increases the price of the house by an average of seven percent, though this
varies depending on the age of the trees (mature tree >23cm dbh, house price rise of 2%), the location
of the tree (front of house/yard, 3-5%), the amount of tree cover in the neighbourhood (good tree cover,
6-9%), or the economic status of the neighbourhood (mature tree in high-income neighbourhood, 1015%) (Wolf, 2007). There are also a variety of other intangible benefits offered by street trees – the
creation of an appealing consumer environment and positive consumer behaviour (Wolf, 2003; Wolf
2009); positive social, psychological and spiritual benefits in terms of community health (Maller, 2005;
Tarran, 2006); and even increased driver awareness and safety (Naderi et al, 2008).
In their investigation into the contribution of public land (including council owned land) to Melbourne’s
liveability the Victorian Environmental Assessment Council (VEAC) identified open space as contributing
to physical and mental health by providing opportunities for physical and social activities (VEAC 2011).
A key finding of the VEAC investigation was a projected decrease in public open space per capita,
exacerbated in established municipalities where limited scope to create additional open space exists. To
combat this, the report recommends the government consider a review of the open space contribution
policy and provisions in the Victorian Planning Provisions and Subdivision Act 1988 and that a new
metropolitan open space strategy be developed (VEAC 2011).
Summary of urban forestry benefits
In summary, the literature on urban forestry has identified a range of benefits attributed to urban trees:

Trees affect levels of pollution. Large, healthy trees remove approximately 70 times more air
pollution annually than small, healthy trees (Nowak, 2002)

Shade provided by trees can reduce building energy use and carbon emissions

Carbon sequestration and storage by urban trees is a potentially significant opportunity for urban
areas

Urban forests play an important role in managing storm water nutrient run-off into our waterways
 Trees have aesthetic, social and health benefits.
Despite these benefits being identified in academia little quantitative data exists to demonstrate the full
benefits provided by urban trees. Worth noting are a number of models that have been developed by
research bodies that try to provide encompassing assessments of the benefits of urban forests, aimed
for use not by scientists, but by councils and community resource managers. These models have been
primarily developed in the USA, and include titles such as CITYgreen (from the American Forests
group), the Urban Forest Effects Model and the iTree program, both of which are developed by the
United States Department of Agriculture Forest Service). These programs can assist in understanding
the complete range of benefits provided by urban trees to assist in placing a comprehensive monetary
value on them.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
10.
3. Trends in urban tree canopy across
metropolitan Melbourne
History of tree species in urban Melbourne
The species selected for planting in Melbourne’s long established suburbs and street scapes (and
regional centres) usually date back to the late 19th century, largely from the 1870s onwards. In this era
(until around 1910), street planting sought to mimic those found in Europe and North America, and
consequently species from those regions were selected – the most common being the London plane
tree (Platanus x acerifolia) and elms (Ulmus sp.) (Spenneman & Marcar, 1999). Evergreens, and
consequently the majority of native Australian species, were derided as a choice for street tree use – in
the late 1800s it was observed that evergreens were “too gloomy, dirty and dense,” and the generic
eucalypt was “too towering and ragged, their leaves being narrow and verticle [sic], giving little shade”
(Spencer, 1986).
The evolution of tree planting has resulted in differing regimes being adopted. Since World War II, there
has been a general acceptance of native species, mainly due to the rise of ecological consciousness
and the sentiment to maintain native ecosystems, preserve the Australian flora and attract native birdlife
(Spencer, 1986). As a consequence, ‘newer’ suburbs tend to have
a greater prevalence of native species, such as eucalypts - Eucalyptus nicholii, E. Leucoxylon, E.
sideroxylon, E. Citriodora and the former Eucalyptus maculata (now Corymbia maculata)
all being popular – callistemons, and melaleucas (Spencer, 1986). This chronological change in species
selection can be observed as one travels outwards from the city centre of Melbourne to the more
recently established outer suburbs.
Understanding the trends in urban tree canopy in
Melbourne
Approach to trend analysis
The question of the changes in urban tree canopy in metropolitan Melbourne seems at first a simple
question, however accurate answers are not readily accessible. Some councils have investigated the
extent of canopy cover of certain components of their urban tree assets (such as Brimbank City Council,
Figure 2.). While this information is informative – Brimbank clearly having a tree canopy skewed towards
smaller canopy rather than larger – single point-in-time analysis does not allow us to infer trends.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
11.
Figure 2. Brimbank City Council’s 2009 assessment of the number of trees that fall within certain
intervals for canopy extent. More than 80% of both street and open space trees have a canopy extent
between 0 - 6m.
To therefore ascertain trends in the canopy cover over urban Melbourne, this paper makes use of a
variety of available datasets. Two types of data were interrogated, and each represented a different
‘scale’ of analysis – local government
area scale, and suburb scale.
The first dataset analysed was sourced from council records (where available) of the number of trees
the council removes and plants over a wide as possible timescale, across their municipality. This
information was used given the understanding that the trends in tree planting can be considered broadly
analogous to potential changes in tree canopy cover.
The second source of information around the change in tree canopy entailed the use of a sequence of
aerial images from a cross-section of suburbs across metropolitan Melbourne. A grid of points at fixed
intervals was laid over the photographs. Each point was then assessed if it intersected a ‘tree’ or ‘nontree’ on the aerial image.
Nine councils across Melbourne were interviewed to gain
a better understanding of what might be driving the canopy trends identified in the two sets of data. A
summary of the key findings from the interviews completes the high-level trend analysis in this paper.
Tree planting and removal records
The recording of tree planting and removal of council managed trees is a fairly recent phenomena for
most councils and as such, obtaining accurate and historic records (beyond the last few years) proved
to be quite challenging. Data was available for
a selection of councils across metropolitan Melbourne, including the number, type and health of the
trees that they manage.
Table 1 shows the average number of trees planted per year
for a variety of different councils.
Table 1. A variety of local government areas and their characteristics compared to the number of trees
planted per year. Population information sourced from Australian Bureau of Statistics (2010).
COUNCIL
POPULATION (2009)
STATISTICAL SUB
LGA SIZE
DIVISION
(HA)
AVERAGE COUNCIL TREES
Bayside
Southern
Melbourne
3,718
96,329
2,100
Boroondara
Boroondara City
6,016
168,090
2,658
Brimbank
Western
Melbourne
12,368
185,890
18,357
Hobson’s
Bay
Western
Melbourne
6,461
87,486
1,396*
Melbourne
Inner Melbourne
3,755
93,105
1,798
PLANTED/YEAR
*street trees only
As shown, there are significant numbers of trees on average being planted across metropolitan
Melbourne. However, to make this data more meaningful, the number of trees being removed also
needs to be considered.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
12.
All councils interviewed indicated that, anecdotally, they were planting more trees than they were
removing. This trend is backed up by the data supplied by a number of the interviewed councils whose
records included tree removal. This can be most clearly shown by comparing the number of trees
planted per year on council land (streets and parks) to the number of trees removed per year on council
land. Using this information, we can ascertain a ratio of trees planted/removed, where positive values
indicate net planting and negative indicate net removal – see figure 3.
Figure 3. The ratio of planted trees to tree removals. The positive figures indicate that since 2009 all
councils who supplied data have planted more trees than removed on council land.
Figure 3 may also provide clues about the nature of the street tree population. With more trees being
planted than removed in recent years the limited data indicates that there has been
a general ‘renewal’ in the street tree population since 2009. As the population generally ages, one would
expect the number of trees being removed to increase.
There are, however, issues with this form of analysis. Most importantly, it does not tell us much, if at all,
about what happens to these urban trees once they are planted. It would be erroneous to assume that
all trees planted will survive – vandalism, water stress, soil compaction and species suitability are all
factors that play a part in the successful establishment of trees in urban areas. Therefore, the number of
trees planted may provide an ‘idea’ of potential tree cover, there are many factors that stand in the way
of this becoming reality.
Therefore, the following method of analysis – occurring at the finer suburb scale – is an attempt to make
a more accurate assessment of this.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
13.
Aerial image analysis
Figure 4. Comparison between a section of St. Albans in the Brimbank City council over a 20-year
period
The Department of Sustainability and Environment has access to a satellite and aerial imagery taken
over a number of years as part of its corporate database. This data was utilised to analyse the changes
in canopy over as long a period of time as possible. To off-set the limited time available to undertake the
analysis and the particularly time-consuming nature of this task, a selection of five suburbs across
metropolitan Melbourne were selected – Balwyn, Carlton, North Melbourne, St Albans and
Broadmeadows. Their location is shown in Figure 5, and information about their area and population and
dwellings dynamics is included in Table 2.
Figure 5 Suburbs studied for tree cover
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
14.
Table 2. Each of the five study suburbs, with information about their size, relative to the entire LGA, in
addition to information about the changes in the number of private dwellings and population between
2001 and 2006, drawn from Census information (ABS, 2001; ABS, 2006b).
SUBURB
LGA
SUBURB
AREA (HA)
SUBURB AREA
AS % OF LGA
AREA
∆ DWELLINGS/
HECTARE,
2001-2006
∆ POPULATION/
HECTARE,
2001-2006
Balwyn
Boroondara
438
7%
0.5%
2.1%
Carlton
Melbourne
175
5%
10.0%
11.9%
North Melbourne
Melbourne
237
6%
2.9%
3.3%
St. Albans
Brimbank
1304
11%
0.3%
-1.4%
Broadmeadows
Hume
841
2%
0.2%
0.0%
A grid of points at fixed intervals was laid over the extent of each suburb for a given year. Each point
was then assessed as to whether the point fell on a ‘tree’ or ‘non-tree’ area of the suburb. This analysis
was complete across each suburb for two points in time – the year 2000 (1989 for St Albans) and 2009.
It is important to note that these points represent a ‘present/absent’ analysis of canopy cover at that one
point – as opposed to an assessment of canopy cover for the whole suburb.
In general, the aerial images available to the DSE have high resolution (50cm) to at least the year 2000.
For Balwyn, Carlton, North Melbourne and Broadmeadows, the aerial maps studied compared tree
cover in March 2000 with tree cover in January 2009. For St. Albans, however, aerial imagery of more
than satisfactory resolution (15cm) was also available for February 1989. This allowed a 20 year
comparison and a 9 year comparison for differing suburbs.
From this gridded analysis, we were able to estimate high-level changes in the tree canopy presence or
absence across the suburbs. The suburb-wide summary can be found below in Table 3. It is very
important again to note that this represents the percentage change in the number of points identified as
‘tree’.
Table 3. Percentage change in points defined as ‘tree’ in each suburb.
SUBURB
LGA
ANALYSIS
PERIOD
% CHANGE IN
TREE COVER POINTS
Balwyn
Boroondara
2000-2009
-3%
Carlton
Melbourne
2000-2009
1%
North Melbourne
Melbourne
2000-2009
-6%
St. Albans
Brimbank
1989-2009
-1%
Broadmeadows
Hume
2000-2009
2%
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
15.
Table 4. % Change in tree presence, using the initial year of aerial observation as a baseline.
SUBURB
LGA
ANALYSIS PERIOD
% CHANGE FOR
PUBLIC TREES
% CHANGE FOR
PRIVATE TREES
Balwyn
Boroondara
2000-2009
0%
-16%
Carlton
Melbourne
2000-2009
0%
20%
North Melbourne
Melbourne
2000-2009
-18%
-55%
St. Albans
Brimbank
1989-2009
N/A
N/A
Broadmeadows
Hume
2000-2009
38%
-4%
Table 3 indicates that the change, on a suburb-wide scale for the points analysed, has not been
discernibly large. To gain a better understanding of the change that has occurred, the point data for the
suburbs can be divided into private and public (council) land. All but two councils interviewed believed
the number of trees on private land was in general decline. Maroondah and Bayside both have stringent
controls on tree removal on private land and, as a result, felt there was a generally stable to increasing
trend in private trees in their municipality. Revising these above figures in terms of public and private,
we are able to see where the changes do occur. These figures are shown in Table 4.
Figure 6. Increases in area of suburbs in St. Albans 1989 (left) and 2009 (right).
For the City of Melbourne sites, we see that for Carlton the number of tree points across both public and
private divisions is broadly stable. In North Melbourne, however, a slight decrease in the number of
public tree points is matched by a dramatic decrease in the number of private tree points. Balwyn also
demonstrates stability in terms of their public trees too, the change being shown in private land only.
Continuing this theme, in Broadmeadows, we see an increase in the number of public tree cover, and a
slight decrease in the cover of private trees. In general, we can conclude that the changes we see in
tree canopy cover points – in terms of decline – has primarily been observed on private land within this
selection of suburbs.
This distinction, between the change in tree cover on public and private land, is broadly consistent with
other observations of change in canopy cover in other small scale studies in canopy cover (Mullaly,
2000) and other Australia-wide studies into the loss of the ‘Australian backyard’ (Hall, 2010).
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
16.
It is interesting to compare this to the trends seen in the changes in the numbers of dwellings and
population (Table 2). All suburbs show an increase in the number in dwellings per hectare – however,
the suburb that has, by and large, seen the greatest percentage increase in both population and number
of private dwellings is Carlton – yet this is also the suburb that shows generally static or increasing tree
cover points. This may be explained by the increased density and urban infill seen in Carlton over other
suburbs analysed.
Another issue to consider in regards to tree cover is the expansion of suburbs – in the Western suburbs,
for example – into areas that have previously been treeless (grasslands). This was demonstrated in our
example of St. Albans, where the change from 1989 to 2009 saw an increase in approximately 140
hectares of buildings and roads. This presents an opportunity to rethink how green-field sites are
developed to maintain permeability, integrating features such as water sensitive urban design more
prominently.
Despite the general coarseness of our analysis, we were able to discern a trend in these newer suburbs
– tree point cover increasing by nearly threefold. While it is arguably a desirable outcome that these
areas of expanding suburbs do demonstrate increasing tree cover, it is important to realise that the
landscape being traded off – pervious grasslands – are being replaced with an impervious, sparsely
treed landscape. This has implications for heat island affect (young canopy, lack of shade, increase in
heat absorbing surfaces) and storm water management and is worth due consideration.
Key trends
Our three-tiers of analysis, while having relative benefits and shortcomings, allow us to determine some
high-level trends in metropolitan Melbourne’s tree canopy cover.

Councils are generally planting more trees than they are removing on council land. However, the
records around this information are somewhat disjointed, and extrapolating this out to long term
trends is difficult.

Different suburbs exhibit different tree canopy change. Some suburbs are seeing an increase in tree
canopy, while others are seeing a decrease.

Decrease in tree canopy cover is occurring primarily on private land within urban areas. This can be
considered to be broadly consistent with prior observations around the changes in the Australian
backyard (for example, Hall, 2010).

It is important to be aware of the landscape being replaced by a change in character of suburbs. An
increase in urban trees may still be demonstrated, but there are other factors worth considering.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
17.
4. Drivers of urban tree canopy trends
Nine councils were interviewed across Melbourne to gain a better understanding about the drivers of the
trends being seen in Melbourne’s urban tree canopy. The councils were Moonee Valley, Maribyrnong,
Hobsons Bay, Boroondara, Brimbank, Bayside, Yarra Ranges and Maroondah. Council staff interviewed
included arborists, open space managers, tree managers, landscape architects, biodiversity officers,
environmental planning managers and sustainability officers and managers. Each council was asked:

What trends they were seeing in their municipality on both council managed and private land

The drivers of those trends

Activities council were undertaking around trees

Barriers they were facing

What role, if any, they saw for the state government to take around urban trees.
Trees on council land and private land
Consistent with the analysis undertaken, all councils interviewed believed they were planting more trees
than they were removing on council managed land. Further, seven of the nine councils believed there
was a decrease in trees on private land. However, of more interest is the reason why councils believe
this trend is occurring.
Council managed land
Key drivers of the net increase on council managed land included:

Community consultation – most councils mentioned undertaking community consultation within the
past 3-5 years where residents consistently said they wanted more trees/green spaces

Council leadership – a CEO or Mayor who influenced the council towards planting (or not) or a
general ‘pro-tree’ culture of a council

Inheritance of trees from developers – for example, Hume is currently inheriting 8,000-10,000 street
trees a year from developers

Planning laws – many single dwelling developments do not need a planning permit (no overlay, large
block size) and therefore council is not able to influence the impact to trees on private land or the
nature strip

Management of heat island effect – several councils in the west of Melbourne talked about a desire
to address exposure to extreme heat by planting more shade-bearing trees

Aesthetics – building and protecting ‘green leafy suburbs’.
A number of councils interviewed talked about the council making a significant change in their attitude
towards trees due to the influence of a particular Mayor or CEO. Hume gave the example of a previous
Mayor who was very supportive of council tree planting, having grown up in the area himself. He had
become a councillor after losing several battles with fellow residents petitioning to have street trees
removed. On becoming Mayor he set out to influence the CEO and other Councillors to support
council’s urban forest budget, setting the precedent for the importance and investment the council now
makes in their trees. Hume council estimates it now has so many trees established it would cost
approximately $70m to replace them. Hume also continued to plant 5,000 trees a year during the recent
drought, building adequate budget in for recycled waterto establish new plantings.
Hobson Bay mentioned a similar example where a new CEO, who walks and cycles regularly around
the municipality, has placed an increased emphasis on the aesthetic value of trees on the liveability of
the area, changing the council’s approach to the management of street trees and parks.
While not necessarily driven by any one individual, Bayside and Maroondah councils also talked about
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
18.
having a strong conservation culture, reflected in their local planning laws driving the protection and
management of trees both on public and private land. Bayside talked about the influence of the local
conservation society historically on their now stringent approach to street trees and trees on private
land. Residents wanting street trees removed for development are guided by the council’s own tree
valuation software. If a street tree is valued at having less than $5000 amenity value then the council will
enter negotiations with residents around its removal. If the tree is allowed to be removed, the resident
must pay the cost of removal, amenity value and cost to replace with two trees. If the amenity value of
the street trees is calculated to be more than $5000 the tree cannot be removed.
Residents requesting the removal of street trees was also an issue identified Boroondara. In many
instances, single dwelling development does not trigger the need for a planning permit (block is over a
certain size, no heritage overlay, etc). Therefore, the council has no interaction with the development
and is unable to influence the removal of trees on private land or the re-positioning of driveways.
Boroondara (and a number of other councils) spoke of receiving phone calls from builders or residents
to have a street tree removed so they could install a new driveway, having moved it from one side of the
property to the other during the redevelopment of the single dwelling. Both Boroondara and Bayside
mentioned they did not automatically remove trees in this situation.
Compared to the tree-rich suburbs in the east of Melbourne, councils interviewed in Melbourne’s
western suburbs – suburbs generally built on natural grasslands with very few trees – talked much more
about planting trees to address the impacts of the summer heat. Brimbank was particularly concerned
about the doubling of heat-related death in the elderly the municipality experiences during days over 33
degrees. Hume talked about the impact the heat exposure in the west has on tree species and their
experimentation with both introduced and native species to find the best trees for different situations.
The municipality experiences more evaporation than rain, making challenging growing conditions for
trees, which means the same species of tree in the west will rarely get as big as if it were planted in the
east.
Private managed land
While seven of the nine councils interviewed felt there was a decline in trees on private land, Bayside
and Maroondah’s stringent local laws guiding the maintenance and removal of trees on public land
meant the councils believed there was a stable or increasing trend.
The key trends driving the decline in trees on private land were:

Planning laws & single dwellings getting bigger (relative to block size) – many single dwelling
developments do not need a planning permit (no overlay, large block size) means councils are not
able to influence the impact to large trees on private land

Bush fire risk – clearing for bush fire risk reduction around houses and along fence lines was seen to
be having some impact in Yarra Ranges

Urban infill – while planning guidelines require multi-dwelling infill to have some landscaped spaces,
some of the councils interviewed felt this sometimes meant mature trees were removed and
replaced with small scale vegetation, not providing the same benefits

Community perceptions about trees – some communities not having a strong connection with living
in a green environment, a general fear of native trees dropping limbs, and notions of trees being
‘messy’. An association of native trees with fire was also noted.
Both Baydside and Maroondah have in place local laws that heavily regulate what can and can’t be
done to trees on private land. Bayside residents cannot touch any tree on their property (over a certain
diameter), even to prune, unless they have a permit. The Council does not support cutting down of trees
under any circumstances and there have been instances where residents have been made to keep
dead trees for biodiversity value. Bayside receives about 2000 applications a year from residents to do
tree maintenance and employs 3 people full time to inspect permit requests and monitor private trees. It
was noted that a key risk of such a law was an overall aging population of mature trees in the
municipality. There was also a concern that as old trees come to the end of their lives there might not be
many younger trees as some residents had taken to removing trees before they got to a certain size to
avoid being locked in by the local laws.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
19.
Maroondah also has high levels of control over public and private land with an additional landscape
overlay in the council’s planning scheme. This overlay responded to its communities wanting a ‘green
leafy environment’. Maroondah’s environmental planning unit processes about 500-550 applications for
tree removal works on private land (in addition to 330 applications per year for development-related
clearing).
Key urban forestry barriers
Establishing trees on the western plains
All the western councils interviewed identified environmental conditions in the west – prevailing northerly
winds and low rainfall – as being harsh on trees. Hume talked about working to improve their
relationship with developers to ensure appropriate and adequate planting suitable to the western
climate. Brimbank also commented on the challenges of influencing development plantings and
managing the ‘mish-mash’ of species it has inherited in the past.
Built environment
One of the most significant barriers to urban tree management identified by all councils interviewed was
the change to the line clearing regulations that came into force in 2010. Councils (and distribution
businesses) are required to manage street trees for risk to security of supply as well as fire and
electrocution. While this has essentially always been the case, the interpretation of the regulations has
been tightened and more heavily enforced, which will mean increased costs for councils associated with
tree pruning and maintenance. Pruning to meet regulations is likely to see many establish street trees
with their canopy significantly modified or removed completely for the lines to pass through. Also, no
trees are to be planted within 7m of powerlines.
The Municipal Association of Victoria is working with Energy Safe Victoria to find a more manageable
solution and have commissioned consultants to prepare a risk management strategy approach councils
can use. A key issue of the regulation changes raised by the councils interviewed was the perceived
lack of data around the risk that trees pose to electricity line safety. The changes to the regulations may
have implications for heat island effect and the energy efficiency of houses if street trees are to be
trimmed in a way that reduces shading of buildings and roads.
VicRoads’ guidelines on planting of trees over 100mm diameter within 7m of a
roadside (on VicRoads managed roads) to manage for road accident risk were
identified as another issue for urban tree management by many of the councils
interviewed. The guidelines also prevent the replacement of medium strip trees if the tree dies or is
damaged. Councils, while acknowledging VicRoads’ concerns over safety, felt the guidelines were too
restrictive (very few roads that have a roadside verge over 7m) and in conflict with community requests
for more planting.
The built environment also provides councils with tree planting challenges due to:

Cars parking on nature strips – outer suburbs, poorly serviced by public transport and have multiple
cars in households

Retrofitting narrow streets with no off-street parking or nature strips – some residents are not happy
to lose car parking space on the street to trees

Underground and overhead services not designed to work with trees

Land contamination – Moonee Valley noted they had several sites that could be more heavily
vegetated but couldn’t afford to rehabilitate contaminated soil

Understanding the full value of a tree (benefits around energy efficiency and health) so business
cases for trees can be considered more equally with other council asset proposals.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
20.
Community perceptions
Community perceptions towards trees have already been discussed briefly as a trend driver however, a
number of councils also saw these perceptions as barriers. Maribyrnong talked about community
perceptions around council expenditure on trees, residents challenging why council is spending money
on trees when not all the roads are in good condition. They identified the on-going need to explain to the
community that the council can’t spend all its money addressing one issue; that it needs to do a variety
of things progressively over time.
Managing community perceptions towards ageing heritage trees was also a challenge for a number of
councils. Interviewees talked about the need to plan better for tree replacement and speak to residents
about the lifespan of trees and their need to be replaced for future generations.
Moonee Valley noted that prevailing myths were a barrier for them working with the community and that
more education was needed. For example, myths around trees near buildings; no hard and fast rule that
you can’t put a tree right next to a house (depends on species, root system, etc.). Myths and
perceptions about native trees was also identified as a barrier by many of the councils interviewed.
Action councils are taking
The councils interviewed were undertaking a variety of actions to improve the tree canopy cover in their
municipalities. All councils are planting trees on council-managed land and several councils also have
stringent local laws protecting trees on private land. All councils were also developing or updating
databases / asset registers of council-managed trees.
A range of actions being undertaken by the nine councils interviewed included:

Filling in gaps – street trees. Some councils have more spaces than others, however, all councils
talked about filling in identified gaps

Valuing Urban Trees project (Victorian Local Sustainability Accord funded) – Moonee Valley, along
with several other metropolitan councils, is updating American valuation software i-Tree with
Australian species

Leading by example through demonstration projects – many councils are integrating water
sensitive urban design into their urban design and landscaping projects to demonstrate the important
role trees play. Hume’s rainwater garden in Dallas Drive, Broadmeadows is one such example.
Brimbank is also working with industrial developments to demonstrate how native plants and trees
can be used effectively in landscape design

Installing wire rope barriers on main roads to allow for planting on VicRoads managed roads,
where funding allows

Working with developers to improve planting standards and quality before a council inherits the
trees. Hobsons Bay has been doing some of the planting for developers (for a fee) to ensure it
inherits appropriate species and quality plantings. Other councils talked about asking developers not
to prune the trees they plant in the first two years before they hand them over to the council

Developing asset registers for all council-managed trees. Many councils are using GIS to map
their trees and build databases capturing information including condition, size and age

Community-based programs. Examples include sustainable gardening guides, Moonee Valley’s
My Smart Garden program and Brimbank’s two educators who have been appointed to work with
local schools and community. Maroondah also talked about working with the community over the
years to better understand it’s local tree laws, resulting in an increased level of compliance

Enforcing local laws. And being stringent in the interpretation of bush fire laws

Building relationships with key stakeholders – Yarra Ranges talked about working closely with
VicRoads and local distribution businesses to build good relationships to ensure roadside trees are
preserved while managing risks to trees from the new line clearing regulations.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
21.
The bigger picture – the role for state government
While many issues impacting urban trees can be tackled at the local government level, each council
interviewed also acknowledged there was a role for the state government.
Agreed position on the value of urban trees
A number of councils strongly believed there was a need to establish a partnership with the state
government to form a position on the value of urban trees, acknowledging them as a valuable asset for
the liveability of metropolitan Melbourne. By forming this partnership, councils were looking to have
greater influence on authorities such as Energy Safe Victoria and VicRoads, encouraging them to
rethink how roadside trees can be kept while maintaining safety standards. The councils interviewed
identified the need to undertake further research into valuing and identifying benefits provided by trees
in an Australian context, critical to informing Victoria’s position on urban trees.
State planning
It was proposed by some of the councils interviewed that there was a need for a whole-of-Melbourne
vision around urban forestry, linking green spaces across Melbourne (especially important when
considering population growth). This vision would also include consideration of the amount of (green)
space allocated to trees in housing and commercial developments. Councils saw an opportunity to
partner with the Department of Planning and Community Development and other relevant agencies to
develop this vision.
It was also felt there was a need for greater integration between planning and transport. Lack of public
transport available when new developments are first established drives households to have more cars.
Hume acknowledged one of the greatest threats to street trees in the newer suburbs they manage is
cars parking on nature strips due to households having 2-4 cars each.
Line clearing regulations
The new line clearing regulations were top of mind for many councils when interviewed. It was felt the
former state government could have done more to influence the regulations to ensure a greater
emphasis on risk management and to negotiate a longer transition time for the regulations to be
adopted. It was also suggested the State could provide funding to assist councils to transition
powerlines underground or to bundled cabling. Yarra Ranges acknowledged that bundled cabling was a
cheap and better option for them as there is no need to touch the root systems of mature trees and only
requires minimal pruning.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
22.
5. Conclusion and next steps
Summary of findings
An increasing body of literature exists about the benefits provided by trees in an urban environment.
These benefits include providing shade to reduce the impacts of the heat island effect and energy
consumption, improving air quality, storm water management, aesthetic and health impacts. However,
this research has shown that there is a need for stronger, local evidence around the benefits associated
with urban trees and an agreed methodology for valuing those benefits beyond the cost to remove and
replace the tree.
Overall, councils are planting more trees than they are removing but there is a slight declining trend in
trees on private urban property. It is important to note not only the change in the number of trees, but
also the amount of trees versus the built form in both new suburbs and infill in existing suburbs.
The changes in urban tree canopy across metropolitan Melbourne are being driven primarily by council
policies, community desire for ‘green leafy environments’ (despite some dislike of native vegetation),
urban infill and, in particular, single-dwelling development. Barriers to establishing trees in an urban
context include climate factors in western metropolitan Melbourne, working around the built
environment, state government authority policies (line clearing regulations,
roadside planting) and community perceptions.
Future opportunities
This report has highlighted a number of gaps in research and opportunities that could help advance the
issues around urban forestry, including:
Build a local body of evidence and methodology for valuing trees and all their benefits
Building accurate and regularly updated inventories of urban forests (canopy cover, health, age, etc) at
a local government scale to enable better informed management and understanding of the benefits
provided by urban trees. High resolution satellite imagery is key to this inventory, as are council
records
While the number of trees in a suburb may increase, further research needs to happen to better
understand the right proportion of trees and vegetation to offset the amount of built form in the same
area to maximise the benefits provided by the trees
A vision for a green Melbourne, particularly in light of population growth and growth in the western
suburbs of Melbourne. This is supported by a recommendation in the Victorian Environmental
Assessment Council’s Melbourne Metropolitan Investigation around the preparation of a metropolitan
open space strategy by the Government that provides a long term plan for Melbourne (VEAC 2011).
This would also encourage greater integration between relevant government departments and
agencies, where appropriate.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
23.
6. References
ABS (Australian Bureau of Statistics), 2001, Census QuickStats: State Suburbs, Commonwealth of
Australia, available at: http://www.censusdata.abs.gov.au
ABS 2006a, Year Book Australia 2006: Urban and Non-Urban Population, Commonwealth of Australia,
available at http://www.abs.gov.au/
ABS, 2006b, Census QuickStats: State Suburbs, Commonwealth of Australia, available at:
http://www.censusdata.abs.gov.au
ABS, 2010. Population by Age and Sex, Regions of Australia, 2010, Commonwealth of Australia,
available at http://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/3235.02010?OpenDocumen
Bolund, P. & Hunhammar, S., 1999, Ecological services in urban areas, Ecological Economics, Vol. 29
Brack, C.L, 2002, Pollution mitigation and carbon sequestration by an urban forest, Environmental
Pollution Vol. 116
Cooke, R., Wallis, R. & White, J., 2002, Use of Vegetation Structure by Powerful Owls in Outer Urban
Melbourne, Victoria, Australia – Implications for Management, Journal of Raptor Research, Vol 36, Iss 4
Davies, Z.G., Edmondson, J.L., Heinemeyer, A., Leake, J.R., Gatson, K.J., 2011, Mapping an urban
ecosystem service: quantifying above-ground carbon storage at a city-wide scale, Journal of Applied
Ecology
Denham, L., 2006, Are Street Trees and Their Soils an Effective Stormwater Treatment Measure?,
Proceedings of The Seventh National Street Tree Symposium 2006.
Donovan, G.H. & Butry, D.T., 2009, The Value of Shade: Estimating the effect of urban trees on
summertime electricity use, Energy and Buildings, Vol. 41
Garden, J., McAlpine, C., Peterson, A., Jones, D. & Possingham, H., 2006, Review of the ecology of
Australian urban fauna: A focus on spatially explicit processes, Austral Ecology, Vol 31
Hall, T, The Life and Death of the Australian Backyard, CSIRO Publishing
Maller, C., Townsend, M., Pryor, A., Brown, P. & St Leger, L., 2005, Healthy nature healthy people:
‘contact with nature’ as an upstream health promotion intervention for populations, Health Promotion
International, Vol. 21 No. 1
McPherson, E.G, Simpson, J.R., Peper, P.J., Maco, S.E., & Xiao, Q., 2005, Municipal Forest Benefits
and Costs in Five US Cities, Journal of Forestry, Dec. 2005
Miller, W. & Boulton, A.J., 2005, Managing and rehabilitating ecosystem processes in regional urban
streams in Australia, Hydrobiologia, Vol. 552
Moore, G.M., 2006, Urban Trees and The Global Greenhouse, Proceedings of The Seventh National
Street Tree Symposium
Mullaly, J, 2000, Aerial Photographic Analysis of the Urban Forest, Honours Thesis, Burnley College,
University of Melbourne.
Naderi, J.R., Kweon, B.S & Maghelal, P., 2008, The Street Tree Effect and Driver Safety, Institute of
Transportation Engineers Journal, February 2008
Spencer, R., 1986, Fashions in Street Tree Planting in Victoria, Landscape Australia, Iss 4 1986
Nowak, D.J., 2000a, Tree Species Selection, Design, and Management to Improve Air Quality, 2000
American Society
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
24.
of Landscape Architects Annual Meeting Proceedings, Washington DC, USA
Nowak, D.J., 2000b, The Interactions between Urban Forests and Global Climate Change, In: Abdollahi,
K.K., Ning, Z.H., & Appeaning, A., 2000, Global Climate Change & The Urban Forest, Franklin Press
Inc.
Nowak, D.J., 2002, The Effects of Urban Trees on Air Quality, USDA Forest Service, Syracuse NY, USA
Nowak, D.J. & Crane, D.E., 2002, Carbon storage and sequestration by urban trees in the USA,
Environmental Pollution, Vol 116
Nowak, D.J., Crane, D.E. & Stevens, J.C., 2005, Air pollution removal by urban trees and shrubs in the
United States, Urban Forestry and Urban Greening, Vol. 4
Pickett, S.T.A., Cadenasso, M.L., Grove, J.M., Nilson, C.H., Pouyat, R.V., Zipperer, W.C. & Costanza,
R., 2001, Urban Ecological Systems: Linking Terrestrial Ecological, Physical and Socioeconomic
Components of Metropolitan Areas, Annual Review of Ecological Systems, Vol. 32
Penuelas, J. & Staudt, M., 2010, BVOCs and global change, Trends in Plant Science, Vol. 15, No. 3
Pouyat, R.V., Yesilonis, I.D. & Nowak, D.J., 2006, Carbon Storage by Urban Soils in the United States,
Journal of Environmental Quality, Vol 35
Salim, M.S., Buccolieri, R., Chan, A., Di Sabatino, S. & Gromke, C., 2009, Urban air quality
management: effects of trees on air pollution concentration in urban street canyons, In: Kendal, D. (ed),
2009, Proceedings of the Universitas 21 International Graduate Research Conference: Sustainable
Cities for the Future, Melbourne & Brisbane
Spencer, R., 1986, Fashions in Street Tree Planting in Victoria, Landscape Australia, Iss 4 1986
Spennemann, D.H.R. & Marcar, N., 1999, Urban and heritage landscapes: under the saline threat,
Australian Association of Natural Resource Managment, Vol 2 Iss 1
Stringer, R. 2007, The Benefits of Adelaide’s Street Trees Revisited, Annual TreeNet Symposium
Proceedings, 2007
Sutton, P.C., Goetz, A.R., Fildes, S., Forster, C. & Ghosh, T., 2010, Darkness on the Edge of Town:
Mapping Urban and Peri-Urban Australia Using Nighttime Satellite Imagery , The Professional
Geographer, 62: 1, 119 — 133
Tarran, J., 2006, Trees, Urban Ecology and Community Health, Proceedings of The Seventh National
Street Tree Symposium, 2006
Treiman, T. & Gartner, J. 2006, Are Residents Willing to Pay for their Community Forests? Results of a
Contingent Valuation Study in Missouri, USA, Urban Studies, Vol. 43, No. 9
Victorian Environmental Assessment Council, Melbourne Metropolitan Investigation Final Report,
August 2011
Wettenhall, G., 2006, Green Streets: Creative Stormwater Design, Ecological Engineering, Proceedings
of the Seventh National Street Tree Symposium 2006
Wolf, K.L., 2007, City Trees and Property Values, Arborist News August 2007
Wong, T.H.F., 2006, An Overview of Water Sensitive Urban Design Practices in Australia, Water
Practice & Technology, Vol. 1 No. 1
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
25.
Victorian Local Sustainability Accord Urban Forestry Background Issues Paper
26.