Melbourne’s Urban Forest Strategy

Melbourne trees are under threat, with almost 44% projected to disappear in the next 20 years, so the city had to come up with a plan to includes increasing canopy cover and improving biodiversity, vegetation and soil moisture. The city was received an award of excellence for research, policy and communication from the Australian Institute of Landscape Architects, with judges calling their ‘Urban Forest Strategy – Making a Great City Greener 2012-20132′ a glowing example of ‘how to transform policy into practice to create a distinctive and liveable city’.



The City of Melbourne’s urban forest will be resilient, healthy and diverse and will contribute to the health and wellbeing of our community and to the creation of a liveable city. To link to full text click here

Key challenges

Melbourne is currently facing three significant challenges: climate change, population growth and urban heating placing pressure on the built fabric, services and people of the city. A healthy urban forest will play a critical role in maintaining the health and liveability of Melbourne. Over the next 20 years and beyond, Melbourne will experience a changing climate, becoming increasingly warm, dry, and liable to more frequent extremes of heat and inundation. The city’s urban heat island effect will intensify.

One of the important functions of the urban forest is to provide shade and cooling. Increased canopy coverage throughout the city will minimise the urban heat island effect and improve thermal comfort at street level for pedestrians. Increased water sensitive urban design will play an important role in managing inundation and providing soil moisture for healthy vegetation growth, as well as enhancing the city’s ecology.

Climate change science and international urban forestry research both indicate that a range of threats facing the urban forest will increase in the future, particularly vulnerability to pests, disease and extremes of weather. Melbourne’s residential, worker and visitor populations will increase. An associated growth in the urban forest, ‘green infrastructure’ and ‘ecosystem services’ would respond to these pressures, reduce the cost of grey infrastructure and improve the quality of the urban environment.


The recent period of drought and water restrictions triggered irreversible decline for many trees. This exaggerated the age-related decline of many significant elms and other trees. Modelling shows that within the next ten years, 23% of our current tree population will be at the end of their useful lives and within twenty years this figure will have reached 39%. To guide future planting, a series of tools and programs have been, and will continue to be, developed. Building the urban forest as a living ecosystem and ensuring that it provides the maximum benefits for our communities will rely on smart species selection, improving soil moisture retention, reducing stormwater flows, improving water quality and re-use, increasing shade and canopy cover, and reducing infrastructure conflicts.

Urban forestry is entering a new era in Australia and this strategy highlights how important it is, particularly in context of enhancing liveability and adapting to predicted climate change. An urban forest provides a multitude of benefits for ecosystems, the economy, and community health and wellbeing.


Photograph source: City of Melbourne

Principles, strategies & targets

The vision is of a healthy, resilient and diverse urban forest that contributes to the health and wellbeing of our communities, and to a liveable city that will create better urban environments for everyone. The principles outlined in the strategy are to guide decision-making to create a future forest. The strategy highlights proactive and adaptive management, and will transform an asset that has a current amenity value estimated at $700 million and a future value that is potentially priceless.

The strategy’s guiding principles are to:

  • mitigate and adapt to climate change
  • reduce the urban heat island effect
  • become a ‘water sensitive’ city
  • design for health and wellbeing
  • design for liveability and cultural integrity
  • create healthier ecosystems
  • position Melbourne as a leader in urban forestry

The strategies and targets proposed to achieve this vision are:

  • Strategy 1: Increase canopy cover Target: Increase public realm canopy cover from 22% at present to 40% by 2040.
  • Strategy 2: Increase urban forest diversity Target: The urban forest will be composed of no more than 5% of any tree species, no more than 10% of any genus and no more than 20% of any one family.
  • Strategy 3: Improve vegetation health Target: 90% of the City of Melbourne’s tree population will be healthy by 2040.
  • Strategy 4: Improve soil moisture and water quality Target: Soil moisture levels will be maintained at levels to provide healthy growth of vegetation.
  • Strategy 5: Improve urban ecology Target: Protect and enhance a level of biodiversity that contributes to a healthy ecosystem.
  • Strategy 6: Inform and consult the community Target: The community will have a broader understanding of the importance of our urban forest, increase their connection to it and engage with its process of evolution.

Nature-based solutions: flood management and policy development

Research:  Collentine, D. & Futter, M.N. (2016). Realising the potential of natural water retention measures in catchment flood management: trade-offs and matching interests. Journal of Flood Risk Management. DOI: 10.1111/jfr3.12269.

Natural water-retention measures, which ‘keep the rain where it falls’, have great potential to be used as part of flood-risk management plans. But their benefits for downstream urban areas can bring costs to the upstream agricultural areas where they are installed. The researchers suggest that we need new and/or improved policies and institutions to oversee the trade-offs and benefits for agriculture and flood management, and a better scientific understanding of the measures’ likely impact on urban flood risk.

The analysis, conducted by academics in Sweden, draws on various studies to discuss the many benefits of natural water-retention measures and how to encourage their uptake. Floods, which have caused annual economic losses of €4 900 million in Europe, are a serious problem. Natural water-retention measures could play an important role in managing floods, the researchers say, and help meet the goals of the EU’s Floods Directive and Water Framework Directive. These nature-based solutions store rainfall and allow it to evaporate back into the atmosphere to help prevent water flowing into urban areas, where it can cause the greatest damage.

Nature based water-retention measures are a key example of how green infrastructure can work alongside traditional grey infrastructure (e.g. flood gates). They take many forms, from small green roofs to large forests, and bring multiple benefits. As well as reducing flood risk, they can have value for biodiversity, recreation and water quality because they reduce soil erosion and can prevent agricultural pollution running into rivers.

However, this multi-functionality may also act as a barrier to their uptake. Because they bring benefits that fall under different policy areas, it is not necessarily easy for decision makers to determine who should pay for these measures. For some measures, the effect on flood risk may be an additional, secondary benefit — as in the case of agricultural buffer zones, which are primarily intended to reduce fertiliser run-off.

Alongside flood-management benefits, measures installed on upstream agricultural land can also lead to trade-offs, notably reduced crop yield. This loss occurs either because cropland is replaced by the measures or because soil in fields becomes too wet. A payment-for-ecosystem-services (PES) model could, therefore, be used to finance natural water-retention measures, possibly through national agri-environmental schemes. Research from the USA has indicated that it is less costly to pay farmers to temporarily flood their land upstream, than it is to pay for urban damage downstream.

Other barriers to widespread uptake of natural water-retention measures include specific knowledge gaps. There is plenty of evidence to show the effectiveness of individual natural water-retention measures, particularly in small catchments. Computer-modelling studies suggest natural water-retention measures could contribute to downstream flood risk reduction, but there is a lack of real world studies which show how to incorporate such measures into flood-risk management plans and their likely impact on downstream urban flood risk. Such studies are needed to encourage further uptake by decision makers and land managers.

The exact area of responsibility of decision makers with regard to flood-risk management also remains unclear. As such, water policy at the national level is accountable to EU water directives and national decisions must be consistent with the decisions made at the EU level. This is also true for regional-level policy, which is based on national policy and, similarly, local decisions are founded on regional policy. Unfortunately, this set of embedded decisions seems to break down with flood-risk management and has led to a lack of distinction between jurisdictions. Each jurisdiction attempts to reduce flood damage within a limited area and thus tends to focus on the use of preventive structural measures, such as dams or retaining walls, rather than measures to reduce flooding (1).

The authors recommend that institutional structures and mechanisms are created or enhanced to oversee the urban/rural trade-offs that natural water-retention measures may bring, to match potential costs with benefits and ensure an appropriate compensation scheme is put in place; for example, one which links PES with flood-risk management plans.

1. This shortcoming should normally be addressed by the inclusion of a river basin approach within the flood risk management plans:


Kingston Student wins Landscape Institute Student Travel Award 2017

The LI has announced two recipients of its 2017 Student Travel Award. Ruth Chittock, Kingston University and Isabel Swift, Leeds Beckett University have been awarded funding for a single trip anywhere in the world where they can learn more about this year’s LI topic, ‘healthy landscapes’.

The night sky is ingrained in human culture … it has inspired generations of poets, philosophers, scientists, and writers alike

The LI awards judges were impressed with the in-depth and unique proposals of both winners. Congratulations to Ruth, a Masters of Landscape Architecture student at Kingston University, who chosen focus is the adverse effects on health and well-being of light pollution, and how landscape design can ameliorate these impacts. Ruth plans to visit the Great Basin National Park, a designated Dark Sky Park in Nevada, in September.


The night sky is ingrained in human culture,’ Ruth said. ‘It is a universal heritage which we share with millions of people across the globe and it has inspired generations of poets, philosophers, scientists, and writers alike. My aim is to investigate how light pollution is leading to the loss of our night skies and how this is affecting us both physically and mentally. I am really excited to meet with people who are working to protect this incredible natural heritage and try to understand what can be done in the future.’

Great Basin National Park, Nevada is comprised of 31,230 hectares of U.S. federal lands centered on the eponymous Great Basin, a dry and mountainous region between the Sierra Nevada of California and the Wasatch Mountains of Utah, USA. Situated north of Las Vegas, Nevada, the Park protects stands of ancient bristlecone pine trees, the world’s oldest known non-clonal organisms, and the Lehman Caves at the base of 3,982-meter Wheeler Peak.

The Park is located in one of the least-populated regions of the lower 48 U.S. states, and the typical basin-and-range topography of the Great Basin serves to help shield the site from sky-glow from distant cities. The result is a truly notable dark-sky resource worth protecting. To this end, the Park has undertaken efforts to improve its own lighting as well as to educate both Park visitors and residents of neighboring communities on the importance of dark skies at Great Basin and the need to protect them.


New evaluation tools for biodiversity and sustainable drainage system assessment.

Sustainable drainage systems (SuDS) could be improved for biodiversity and local people with the help of two new evaluation methods presented by a recent study. The methods, which assess the value of SuDS sites for wildlife habitat, carbon sequestration, recreation and education, are described by the study’s authors as cost-effective, quick and reliable, and could help designers plan and retrofit SuDS that are wildlife-friendly and socially inclusive.

Source: Mak, C., Scholz, M., & James, P. (2016). Sustainable drainage system site assessment method using urban ecosystem services. Urban Ecosystems. DOI:10.1007/s11252-016-0593-6. This study is free to view at:


SuDS mimic nature to manage and treat storm water. There are various forms of SuDS which help prevent flooding and clean up contaminants; these include ponds, green roofs, artificial wetlands and absorbent pavements. The green infrastructure provided by SuDS is seen as an important way of helping EU Member States achieve good surface water status under the Water Framework Directive.


Fig 1. Rural conditions – impacts of urbanisation on a catchment. (Ciria)

In the UK, where this study was conducted, the Construction Industry Research and Information Association (CIRIA) has recently updated its influential SuDS manual (1), which provides guidance on the planning, design, construction, operation and maintenance of SuDS. This latest version promotes the design of SuDS design that provides a range of ecosystem services.

The evaluation methods presented by this study are intended to support this ecosystems-services approach (2). They can help designers understand and improve the value of a SuDS site. They also give designers a better understanding of which features (2) of a SuDS site provide which ecosystem services, to help guide new developments.


The first method considers which features provide biodiversity-related services, specifically habitat for wildlife and carbon sequestration. It is adapted from an existing method (3) and based on evidence that diverse vegetation, at various heights, is best for providing habitat. The method involves assessing which broad types of vegetation are present, such as trees and grasses, at which heights (e.g., upper canopy of a tree, low bush, long grass, cropped grass), and if there are any plants in water.

Designers can then give a SuDS site a score to indicate its potential for providing habitat and carbon ecosystem services. In general, points are given for every layer of vegetation (including aquatic plant species, if present). However, the method considers ecosystem disservices as well as services, and the scoring system deducts points for some layers; for example, cropped grass, which is unbeneficial for carbon sequestration. The presence of any built and impermeable layers at a site (e.g. concrete surface) also leads to points being deducted.

The second method considers which features contribute to recreational and educational ecosystem services. It assesses public accessibility to a site (both legal and physical), evidence of the site being used for educational purposes by community groups, educational signs, the distance to the nearest educational establishment, and recreational infrastructure (e.g. benches and footpaths). Again, ecosystem disservices are considered, so the presence of litter and dog faeces is also assessed, as well as bins, which help reduce these two problems. Each feature is scored on a scale of 0 to 3. Scores for recreational features and scores for educational features are combined separately to produce two total scores.

The researchers tested the two methods on 49 sites in and around the city of Manchester, UK. This revealed that large sites (over 5 500 m2) with permanent aquatic features such as ponds tended to be more capable of providing habitat and carbon sequestration services. Scores for habitat and scores for recreation were positively linked to each other. The researchers acknowledge that there is some subjectivity to the evaluation methods, but say that they provide the right balance of reliability, speed and cost-effectiveness.



  2. Scholz, M., Uzomah, V., Almuktar, S., Radet-Taligot, J. (2013). Selecting sustainable drainage structures based on ecosystem service variables estimated by different stakeholder groups. Water, 5:1741–1759. DOI:10.3390/w5041741.
  3. Tzoulas, K., James, P. (2009). Making biodiversity measures accessible to non-specialists: an innovative method for rapid assessment of urban biodiversity. Urban Ecosystems, 13: 113–127. DOI:10.1007/s11252-009-0107-x.

Green walls may help cut noise levels entering buildings.

Green walls, designed so they are covered in vegetation, could help cut the amount of noise that enters buildings, a new study has found. In laboratory tests, researchers found that a modular green wall system reduced sound levels by 15 decibels (dB). This may be a promising sound reduction device that could improve quality-of-life for city residents.

Source:  Azkorra, Z., Pérez, G., Coma, J. et al. (2015). Evaluation of green walls as a passive acoustic insulation system for buildings. Applied Acoustics 89: 46–56. DOI:10.1016/j.apacoust.2014.09.010.

Green walls and green roofs can provide ecosystem services in urban areas. Their benefits include: lower energy use in buildings, support for biodiversity and storm-water control. Studies have also shown that they reduce noise levels. However, most studies have focused on green roofs’ ability to insulate buildings from external sound, and very little research has looked specifically at green walls.

This Spanish study, carried out under the EU-funded SILENTVEG project (1), conducted laboratory tests on green walls’ acoustic properties. Its aim was to help predict their sound insulation performance in the real world. The design of green walls can affect their sound insulation properties with the type of plant grown having a big effect. In this case, the study focused on a modular green wall system, which is composed of compartments or boxes attached to a vertical frame and is the most widely used system.

The boxes in this study were made of recycled plastic and filled with coconut fibre, acting as ‘soil’. They were all planted with Helichrysum thianschanicum, a popular shrub for gardening in the Mediterranean region, with an average height of 40 cm. The researchers placed 10 of the boxes, totalling 2.4 m2 in area, onto a wall which separated two rooms. They emitted noise in one room at frequencies ranging between 100 hertz (Hz) and 5 000 Hz, and then measured the reduction in noise levels in the neighbouring room caused by the green wall.

The green wall reduced noise levels in the neighbouring room by an average of 15 dB. The researchers note that this reduction is quite low compared with other solutions; thermal double-glazing can reduce noise by 30 dB, for example. A sound barrier made from two layers of plasterboard, separated by a wool-filled cavity, can reduce noise by 70 dB.

Nonetheless, they believe it still has good potential to help cut noise levels in urban buildings and could be used effectively in public places, such as hotels and restaurants. Furthermore, if its design was improved by sealing the joints between the boxes, then it could reduce noise by an extra 3 dB. The other benefits of green walls, such as increased biodiversity, visual attractiveness, air purification or climate regulation, also make them an attractive option.

This experiment considered noise that is transmitted directly through a wall, but in a realistic situation noise bounces off different surfaces and can be transmitted indirectly through a number of routes. Therefore the logical next step in this research would be to test the green wall on actual building façades, the study’s authors say.

To further improve their understanding of the wall’s basic acoustic properties, the researchers also investigated how much sound a green wall can absorb. In this experiment, they placed the green wall (this time 10 m2 in area) on the floor of a room in which sound was emitted, again at frequencies of 100–5 000 Hz. The wall was calculated to have a ‘sound absorption coefficient’ of 0.40, i.e. it absorbed 40% of the sound.

  1. SILENTVEG: Barreras vegetales autónomas y sostenibles para la mitigación acústica y compensación del CO2 en vías de transporte, con seguimiento telemático, was supported by the European Union’s Regional Development Fund. See: (in Spanish)

This study is free to view at:


Assessing effectiveness of Flood Emergency Management Systems

A new framework has been developed to assess how effective Flood Emergency Management Systems (FEMS) are in Europe. Examining FEMS in five European countries, this study highlights the strengths and weaknesses of existing systems and makes recommendations for improving their effectiveness, particularly in relation to institutional learning, community preparedness and recovery.

Source: Gilissen, H. K., Alexander, M., Matczak, P., Pettersson, M. & Bruzzone, S. (2016). A framework for evaluating the effectiveness of flood emergency management systems in Europe. Ecology and Society, 21(4):27. DOI: 10.5751/ES-08723-210427. This study is free to view at:

Climate change is expected to increase the frequency and severity of floods and society must be able to respond to this evolving threat. To achieve this, FEMS, which are designed to ensure that emergency professionals are prepared for floods, should include assessments of risk to underscore flood-specific emergency planning, promote inter-agency working, professional training, facilitate community preparedness and support immediate recovery activities, such as restoring essential services and supplies. Whilst FEMS are embedded within broader legal and policy frameworks for integrated emergency management and civil contingencies, the pressing challenges posed by floods provide a strong case for examining FEMS in isolation.

This study, partly conducted under the EU STAR–FLOOD [see reference below] project, presents a new framework to assess and monitor the effectiveness of FEMS in European countries from legal and public-administration perspectives. To build the framework, the researchers conducted an appraisal of existing international academic and grey literature published since 1970, relating to emergency and disaster-management systems for any type of hazard at international, national and subnational levels. This informed the identification of seven key indicators that could be used to evaluate the performance of processes and actions in emergency flood management:

  1. Planning: development of an emergency plan to establish priorities, actions and decision-making in the event of a flood emergency;
  2. Institutional learning: procedures to be in place to promote learning at frequent intervals (e.g. post-event reviews and inquiries, opportunities for knowledge exchange across responding agencies);
  3. Exercising emergency arrangements: planning and operational procedures should be tested at multiple scales;
  4. Joined-up working: distribution of responsibilities within and between emergency actors must be clearly defined, effectively coordinated and collaborative;
  5. Community preparedness: should be supported by emergency professionals (e.g. raising risk awareness and direction on what to do when a flood occurs);
  6. Provision of resources: (financial, human resources, equipment, and decision-support tools) needs to be ensured and arrangements need to be established for sourcing and allocating additional resources as required;
  7. Recovery-based activities: arrangements should be in place to support evacuation, for temporary housing, restoration of essential services, help for businesses to function, dealing with physical damage and management of environmental impacts, such as pollution and contamination.

To put this framework into use, the researchers outlined key benchmarks against which a country’s performance can be scored; for this, they used a scale of one to five (absent/minimal, emerging, moderate, significant and outstanding).

The researchers then collected information from a variety of sources to evaluate the extent to which benchmarks are achieved in five European countries: France, the Netherlands, Poland, Sweden and the UK (specifically England). The information was drawn from the analysis of emergency-management policy documents and legislation, as well as stakeholder interviews and workshops with key practitioners and policymakers involved in emergency management and flood-risk management more broadly (for example, government departments, municipal and local authorities, and emergency responders).

National Flood Emergency Framework

The National Flood Emergency Framework for England (December 2014) sets out the government’s strategic approach to achieving the aims set out below and is intended for use by all those involved in planning for and responding to flooding from:

  • the sea
  • rivers
  • surface water
  • groundwater and
  • reservoirs

The concept of a National Flood Emergency Framework was promoted by Sir Michael Pitt in his report on the summer 2007 floods. Its purpose is to provide a forward looking policy framework for flood emergency planning and response. It brings together information, guidance and key policies and is a resource for all involved in flood emergency planning at national, regional and local levels. It is a common and strategic reference point for flood planning and response for all tiers of government and for responder organisations.

More precisely, the purpose of the Framework is to:

  • ensure delivery bodies understand their respective roles and responsibilities
  • give all players in an emergency flooding situation a common point of reference – bringing together information, guidance and key policies in a single planning document
  • establish clear thresholds for emergency response arrangements
  • place proper emphasis on the multi-agency approach to managing flooding events
  • provide clarity on the means of improving resilience and minimising the impact of flooding events
  • provide a basis for individual responders to develop and review their own plans and
  • be a long-term asset that will provide the basis for continuous improvement in flood emergency management

Responding to floods in Europe: new framework assesses effectiveness of Flood Emergency Management Systems

Of the five countries, England’s FEMS were found to be the most effective, with all seven indicators achieving significant or outstanding ratings. In the absence of statutory rights to flood protection, a diversified approach to FEMS has existed for over 65 years in England; thus, flood emergency management has served as a crucial strategy for minimising the consequences of flood events. Dedicated policy for flood emergency management is seen, with multi-agency flood plans as a standard component of common practice. Moreover, formal legal mechanisms underpin effective integrated working between emergency responders (e.g. duties to cooperate, and formation of Local Resilience Forums) and certain responders are actively involved in activities to enhance community preparedness for floods.

In Sweden, given the low distribution of flood risk, flood protection management is organised at the local or municipal level on a relatively ad hoc basis by those municipalities affected by flooding, rather than being established at the national scale. Whilst this is considered to be an efficient strategy and provides the necessary flexibility for municipalities to adapt to local risks, there is a risk that some areas may be neglected. Moreover, the lack of national arrangements and supportive mechanisms may make it difficult for certain municipalities to mobilise the necessary resources, according to the researchers.

In France, emergency management has evolved over the past few decades and has been integrated into local disaster-management planning and policies, in line with broader initiatives towards decentralised governance. ‘Professionalisation’ of the public is one of the major aims of the French FEMS, where voluntary fire brigades play a key role. Municipalities can optionally call in voluntary civil-protection reserves to assist in response activities. Efforts to enhance community preparedness are becoming nationally more consistent. However, recovery guidance and regulation varies regionally and this is an area for improvement identified by the researchers.

In the Netherlands, historically, there has been a strong tradition of flood defence and protection, with a statutory right to be protected by the state from floods. Nonetheless, recent efforts have sought to diversify the range of strategies implemented, in order to manage flood risk more holistically and address the country’s increased vulnerability to flooding under climate change. However, certain aspects of flood emergency management (i.e., institutional learning, community engagement, and recovery) are less well developed. Moreover, the organisational structure requires some improvement, the researchers say.

In contrast to the other countries, the FEMS in Poland is still emerging in several aspects, particularly with regard to institutional learning, community preparedness and recovery-based activities. The occurrence of significant flood events (1997) has prompted establishment of the crisis-management institutional framework and efforts to improve the effectiveness of FEMS, yet gaps are seen between policy and practice. The researchers identify small-scale examples of good practice, such as the ‘flood leaders’ initiative in Wroclaw, but say these are yet to be scaled-up and implemented nationwide.

Although the researchers found that all countries had different approaches to flood-risk management, shaped by diverse political and administrative cultures and socio-economic conditions, they have produced some common recommendations to improve the effectiveness of FEMS:

  • Specific provisions for flood emergency management could prove beneficial in countries where flood risk is projected to increase. Lessons could be learned from the multi-agency flood-planning groups and subgroups within Local Resilience Forums, as seen in England, which provide further clarity on roles and responsibilities at times of flood emergencies;
  • National guidance could be provided for flooding in countries with a low risk of flooding, or where flood-risk areas are widely distributed, to help deliver consistent support and establish good practice at the local level;
  • Specific training for flood emergencies is necessary to test planning, responsive procedures and communication systems, as well as helping to raise community awareness of flood risks;
  • Efforts to encourage community preparedness require better communication of flood risks and need to be situated alongside wider efforts to normalise adaptation within society.
  1. STAR-FLOOD (STrengthening And Redesigning European FLOOD risk practices Towards appropriate and resilient flood risk governance arrangements) was supported by the European Commission under the Seventh Framework Programme.



Chandigarh Revealed – Le Corbusier’s City Today

Chandigarh, the capital city of the Indian states of Haryana and Punjab, was planned and designed in the 1950s and 60s by French-Swiss master architect Le Corbusier, along with architects Jane Drew, Pierre Jeanneret, and Maxwell Fry, and a host of Indian modernists. Envisioned by India’s founding prime minister Jawahar Lal Nehru, the planned city […]

via Chandigarh: Where Modernism Met India — The Dirt