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Urban International & Australian Speakers



 

Dr Stephen Livesley
, University of Melbourne

Bio: Stephen is a key member of the Green Infrastructure Research Group at the Burnley campus of The University of Melbourne. Stephen studied in the UK gaining a PhD in Tropical Agroforestry and Soil Science from The University of Reading. He has held research positions in Univ. of Western Australia, DSE and Monash University. Stephen has been a Chief Investigator in four ARC Linkage projects and one ARC Discovery project and numerous smaller research projects. Stephen's urban research focuses on the role of trees, soil and other vegetation to provide environmental and social benefits, such as microclimate cooling, energy saving, C sequestration and biodiversity habitat. Stephen currently leads two ARC Linkage research projects that focus on urban trees, one on “Species Traits, Substrates and Stormwater Grates: Improving the Health of Urban Trees by Using Polluted Stormwater as a Resource”, and the other “Managing Urban Trees for People and Wildlife”.

Talk Title: How trees can contribute to urban stormwater control measure

Abstract: Flood risk to people and property in our cities is a growing concern as our climate becomes more variable and our cities become denser and even more ‘sealed’. To reduce flood risks, surface runoff from these sealed, impervious surfaces is rapidly directed to streams by stormwater drainage systems that may have been designed 50 to 100 years ago. Both the quantity and quality of urban runoff can be highly damaging to urban waterways.  Stormwater control measures (SCMs) provide an alternative, or an additional, way to reduce flood risks by retaining runoff and/or slowing runoff rates throughout the urban landscape in our cities. For example, rain gardens, swales, biofilter tree pits and constructed wetlands are all engineered SCMs found throughout our urban catchments.
Trees can also provide two very important functions within out urban landscape. Firstly, trees can intercept rainfall, slow its movement and store some of that rain within their canopies and woody architecture, thereby reducing runoff amounts and rate of flow on impervious surfaces below. Secondly, trees can make use of runoff that is retained in the urban landscape within engineered SCMs. This second function can lead to greater urban cooling benefits through transpiration, greater tree health and growth rates, but also improved performance of SCMs as tree water uptake will empty them more rapidly, making space available for them to receive runoff during the next storm event.
This talk will present recent research on these two key functions, and the proportional contribution that trees can make to the many engineered SCMs installed to capture and retain stormwater within our cities.  These functions are now recognised and expected by urban planners, engineers and arborists in a modern urban forest, but not all trees provide these functions in equal measure and perhaps they contribute little to the overall function of SCMs. The evidence base is small, but rapidly growing in Europe, North America and in Australia.





Niels Rüegger
, University of NSW

Bio: Originally from Switzerland, Niels worked as a Forest Ranger and Arborist before he migrated to Australia 15 years ago. He has since completed a Bachelor of Environmental Science where he developed an interest in wildlife research. He then worked as a self-employed Arborist and consulting Ecologist. He is currently working as a Tree Landscape Officer and is also undertaking a PhD on microbat roost ecology. His research area focuses predominantly on hollow-dependent vertebrate fauna, including the use of artificial hollows as a management tool. He has published a number of papers on this topic and is expecting to complete his PhD later this year.

Talk Title: Artificial tree hollow creation for cavity-using wildlife: trialing an alternative method to that of nest boxes

Abstract: Tree hollow scarcity is a threat to cavity-dependent vertebrate wildlife world-wide across many landscapes. Currently, only nest boxes are commonly used to mitigate or offset lost cavity-bearing trees, with a number of shortfalls reported using this technique. There is a need to trial alternative techniques to improve artificial cavity provisions. This preliminary study investigated the use of carving hollows directly into tree trunks using chainsaws. Sixteen hollows of two simple cavity types were created in a timber production forest in south-eastern Australia. One cavity type comprised a basal entrance (38 mm in diameter) which provided a space above the entrance, intended for bats, and the other cavity type provided a space below a 38 mm or 76 mm entrance, intended for marsupials and birds. Five species used the hollows over a 15-month cavity monitoring period; feathertail glider (Acrobates pygmaeus) (in 75% of the hollows), brown antechinus (Antechinus stuartii) (75%), sugar glider (Petaurus breviceps) (63%), long-eared bat (Nyctophilus sp.) (50%) and white-throated treecreeper (Cormobates leucophaea) (25%). Camera monitoring revealed hollow inspection after only one day post hollow creation by white-throated treecreepers and feathertail gliders, and nest building by white-throated treecreepers after three days. No hollow host tree failure occurred for either of the two hollow wall widths trialled over two years of monitoring tree stability. Wound-wood formed and partly enclosed the hollows’ faceplates over time, improving the sturdiness of the hollow and likely resulted in hollows closely resembling natural cavities. Mechanically created tree hollows have a broad application potential across many landscapes with the prospect to overcome some of the reported drawbacks of nest boxes. More research is required to document long-term performance and effectiveness of this technique.





Dr Timothy Wardlaw
, University of Tasmania

Bio: Tim has a research career in applied forest ecology and forest health management spanning almost 40 years. He has been the author, or co-author of more the 85 papers in scientific journals and book chapters. Since 2009, Tim has managed the Warra Long-Term Ecological Research site and was instrumental in getting Warra included in the Terrestrial Ecosystem Research Network that led to the establishment of a flux tower and become one of the twelve Supersites in the network. Tim is currently based at the University of Tasmania as an Honorary Research Associate within Plant Science where he maintains the role of Principal Investigator of Warra.

Talk Title: The ecology of tall, wet Eucalyptus obliqua forests – 20 years of discovery from the Warra Long-Term Ecological Research site

Abstract: The tall, wet eucalypt forests of south-eastern Australia are home to the tallest and largest flowering plants on Earth. These forests are immensely productive and have supported large timber industries in Tasmania and Victoria for a century and a half. In recent decades the other values these forests provide (notably water, carbon, amenity, recreation and biodiversity) have gained prominence. Decisions on how these many values can be optimally supplied and maintained have generated considerable community and political debate. To support decision-making on optimal management of these forests, there has been a growing demand for knowledge from scientific enquiry. Warra was established in 1995 as a site to foster such scientific enquiry in tall, wet eucalypt forests. The aim in establishing Warra was to improve our understanding of the ecology tall, wet Eucalyptus obliqua forests through multi-disciplinary and long-term research. Importantly, a lot of the knowledge gained from research at Warra has been adopted into refined management practices with an initial emphasis on forestry practices to sustain key habitats and their associated plants and animals. 
In 2009 the federal government provided funding for the establishment of the Terrestrial Ecosystem Research Network (TERN) to provide a more structured approach to observing and monitoring Australia’s terrestrial ecosystems. Warra has become an important site within that network has now hosts several TERN infrastructure installations including a Supersite and flux tower to intensively monitor the functioning of the tall, wet E. obliqua forest in real-time. The data from this infrastructure is providing new insights into nationally and internationally important questions such as how ecosystems respond to climate change and extreme weather events. 

 

 
Prof Francesco Ferrini

Bio: Francesco Ferrini Full Professor of Arboriculture at the University of Florence. Dean of the School of Agriculture of the University of Florence.
Formerly President of the Italian Society of Arboriculture and member from 2005 to 2016 of the Board of the International Society of Arboriculture.
His main field of research concerns the physiological and growth aspects of different plant species as affected by the urban environment.
He has published more than 270 scientific and technical papers in Italian and in English in international refereed and national journals. He has given more than 120 talks in several international and national congresses. He is a Member of the Editorial Board of several international journals, Associate Editor of both the Urban Forestry and Urban Greening plus Arboriculture & Urban Forestry journals and is the Senior Director of the Journal Advances in Horticultural Sciences.

Talk 1 Title: Plant Responses to Drought Stress: How traditional and innovative methods can help to maintain healthy green areas while limiting water consumption

Abstract for Talk 1: Climate change manifests itself in two fundamentally different ways: as a change in the average yearly temperature and/or rainfall, and as a change the frequency and intensity of rain pulses and heat waves (Rumukainen, 2012; IPCC, 2013). The Mediterranean-like environments appear to be more affected by climate change than most of other climatic zones with a drastic reductions in precipitation and an increase in temperatures which will result in extreme drought events during summer, when low water availability is paralleled by heat and high sunlight radiation (Bussotti et al., 2014). Also the average intensity of rainy events is predicted to increase, but their frequency will decrease to a greater extent, particularly during spring and summer months. 
The effects of climate changes will be exacerbated in the urban environment which is already characterized by specific microclimatic conditions, such as temperature 3-5°C higher than the surrounding countryside ("urban heat island")(Mc Carthy et al., 2010), low-quality and impermeable soils (Ferrini and Fini, 2007), that impose several stresses on plants. Also the multiple interactions between water stress, increased temperature (diurnal and nocturnal) and increased atmospheric CO2 is particularly interesting and controversial. 
This said a question arises: what we know about the effects of climate change on trees and how they will guide our choices?
In order to specify the future effects of climate change on arboriculture and urban forestry, reliable predictions of the transient changes in regional and global climate are required because we need to select plants that will tolerate the climate change. Drought is predicted to be the most significant factor not only in the Mediterranean-like climates and this will strongly affect survival and growth of newly planted trees and will probably influence the development of diseases and tree pest resistance. Not only the short-term effects on growth or survival in extreme years deserve attention, but also the long-term impacts on tree growth have to be considered in selecting planting material. With impending water shortages in many urban areas leading to prohibitions of irrigation or watering, planting trees that are more tolerant to prolonged drought conditions is the best long-term solution to a healthier, low-maintenance landscape.
In this scenario, possible adaptation measures include changes in the establishment practices and tree management, better matching of species to site, both under current and future climates, and the planting of non-native species and provenances in anticipation of climate change. Current opinion is to encourage the planting of local provenances of native species, citing their adaptation to local conditions, and the requirement to maintain biodiversity and a native genetic base. However, indigenous or naturalized species may not be able to adapt to a changing climate, particularly given the rate of change predicted (Ferrini, 2011; Bussotti et al., 2014). Sourcing planting stock from regions with a current climate similar to that predicted for the future may provide one option, although care must be taken to ensure that suitable provenances are selected which are not at risk from, for example, spring frost damage as a result of early flushing or have a potential to become invasive. It is indeed possible that in a long term, phenological responses from different tree species to temperature changes could lead to permanent changes of the geographical distribution of the same species.
As already said, in the typical urban conditions, plants have often to respond to simultaneous stresses (e.g. drought, plus excessive light and heat) and their response is usually not predictable from single factor studies (Harris and Bassuk, 1993; Schulze et al., 2002; Valladares and Pearcy, 2002; Valladares and Niinemets, 2008). For example, the excess light stress experienced by trees growing in urban plazas, may be exacerbated by drought, which limits the use of radiation in the photosynthetic process because of both biochemical and non-stomatal limitations (Fini et al., 2012). Despite it is conceivable that moderate shading may reduce excess light stress, some research showed that the capacity of tree species to survive severe drought may be reduced by shade, because of shade-induced changes in leaf morphological, physiological and biochemical traits, resulted in lower capacity to counteract oxidative damage and in higher photoinhibition during sunflecks or after transplanting in very sunny environments (Valladares and Pearcy, 2002; Fini et al, 2014). This is particularly true in Mediterranean-like climates, when high irradiance is coupled in the long period with drought during the summer, all conditions that strongly limit carbon assimilation and promote photoinhibition of the photosynthetic apparatus (Bussotti et al., 2014). 
Plant tolerance of combined shade and drought, typically considered irresolvable due to trade-offs in morphology and physiology, potentially determine important vegetation patterns, especially as drought spells are becoming more severe worldwide. Existence of inverse correlations between ecological requirements of species involves the ad hoc hypothesis that being tolerant to a certain environmental factor involves a cost such that the plant cannot adjust simultaneously to multiple environmental stresses. 
Selection of the right species is therefore a primary requirement for successful tree planting (Ferrini, 2011; Ferrini and Fini, 2013). To this regard, pre-conditioning of nursery trees can be a supplementary tool to improve tree performances in the different urban light environments. It has been shown that acclimation in the nursery to mild stress resulted in the production of hardened nursery stock, better able to tolerate transplanting and other environmental stress during establishment (Franco et al., 2006; Fini et al., 2011). Exposition to full sunlight during cultivation in the nursery may act as a mild stress and may induce stress tolerance through changes in plant and leaf morpho-anatomical traits, increased leaf solute accumulation and enhanced photosynthetic, photoprotective and antioxidant capacities (Fini et al., 2014). Conversely, shading in the nursery of shade-tolerant trees to be planted in urban canyon can acclimate leaf anatomy and physiology to low light and increase growth rate.  

Conclusion 
In looking to the future, it is progressively critical to understand how plant will respond to climate change and to fully recognize the important role of tree in mitigating the effects of such changes. Beside climate change, other factors must be considered in order to ensure that the proper plant is placed in a specific site in the specific time and with the proper techniques. In general, these factors, which, however, are somewhat influenced by climate change, are divided into three major categories: design, site, and maintenance considerations. More specifically, factors to consider when selecting trees for city streets or park landscapes include pruning requirements and response, tree stability, disease resistance, catastrophic insect pests, soil adaptation, complementary planting, shade or sun tolerance, provenance, and adaptive cultivars.
Finally, the selection should be based on the potential benefits brought by trees in the urban stand though, while we are all aware of these, only in the last ten years some efforts have been done to select plants for this kind of use and to adopt management practices to maximize the net benefits of urban forests on atmospheric carbon dioxide.



Talk 2 Title: Planning the green city of 2050: species selection in a global change scenario

Abstract for Talk 2: The presentation will focus on the technical and practical solutions for the selection of trees that might be the best choice in the urban environments for the next 100 years, given differences in urban sites (infrastructures, climate, soils, etc.), species attributes, management requirements and climate change. The presentation will be divided in the following parts:
• Trees and climate change in the urban environment (main characteristics of the urban areas).
• Tree physiology as influenced by typical environmental constraints of urban stands.
• Trees and infrastructures (improving relations between technical infrastructures and vegetation). 
• Selection of planting material in a global change scenario

Rapid increases in human population and economic development have led to tremendous urbanization: more than 50% of the world human beings is now living in an urban area and 70% will do that in the year 2050, but urban areas are estimated to be less than a mere 3% of the total land of our planet. As more people's lives are predominantly urban, opportunities for interaction with the natural world decrease, with potentially serious effects for human health and wellbeing. An urban area is a living complex mega-organism, associated with a lot of inputs, transformations, and outputs: heat, energy, materials, and others. Urban activities have now become a threat to the global environment. Solving and mitigating problems, including the design of ecologically efficient urban areas, is therefore of prime importance.
Trees are essential in the urban environment not only because of their aesthetic and social values, but also for their effects on air quality. Trees offer double benefits: first by directly sequestering and storing atmospheric C and other pollutants; second, by providing a natural cooling mechanism through evapotranspiration and shade, green space dissipate solar energy that would otherwise be absorbed, so reducing air-conditioning energy needs and avoiding pollutant emissions. 
Urban vegetation is often subjected to more extreme environmental conditions than vegetation of the peri-urban and rural areas. These conditions are related not only to higher atmospheric pollution levels caused by traffic and other anthropogenic emissions, but also to limiting water availability and higher temperatures, typical of the city microclimate. Due to the negative future prospects for the urban environment caused by global climatic change, there is a need to monitor and manage pro-actively urban greening and peri-urban forests and to gather more basic data about urban trees, and urban green in general. 
Research projects have shown that, in the short time, the exposition to high CO2 levels, reduces the stomatal conductance, but increases photosynthesis and growth up to 20-50%, according to the species, plant age and water and nutrients availability. For this reasons, understanding how the increase of temperature will modulate plant responses to increased atmospheric CO2 has been described as a priority for the research on climate change. The majority of studies concerning the effect of temperature raising on tree growth shows that a 10°C increase in growth temperature resulted in a 1.7-fold increase in total biomass. This has been particularly noted in regions with temperate-cold climate and in the northern part of the distribution range of each species and suggests that plants, at present, live in suboptimal conditions are able to adapt to a moderate increase temperature. On the other hand, plants that live in the southern portions of the natural distribution area seem to have a lower plasticity of response to temperature increase compared to their counterparts that live the northern regions and, consequently, they have less adaptability to climate change. Similar considerations hold for the species that populate environments characterized by above-optimal temperatures in summer, such as the Mediterranean and the urban one.
According to recent evidences, the urban environment will be the one that will experience the strongest effects of climate change, because of the multiple interactions between water stress, increased temperature (diurnal and nocturnal) and increased atmospheric CO2. For example, a study has shown that Liquidambar plants exposed to elevated CO2 were most affected by drought, despite of the increased in root biomass and of lower stomatal conductance. The interactions between climate change and urban forests include at least two main elements: urban tree contributions and urban tree vulnerability.
There are two facets of an adaptation response in an urban forest setting: adjusting the urban forest to change and using urban forests to help cities adapt to change. Also a number of existing stressors on urban trees and challenges to urban forest management makes it difficult to maintain a healthy, multi-age, multi-species forest and make trees more vulnerable to the impacts of climate change. Urban forest management strategies to help improve air quality in future scenarios include: increase the number of healthy trees (increases pollution removal); sustain existing tree cover (maintains pollution removal levels).
The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (2013) predicts that the surface air temperature will increase 2-5 °C by the end of this century. The report also predicts significant changes in wind and precipitation patterns. Trees will be affected by this rapid climate change because of their long life spans and the slow rate of genetic adaption. However with a proactive management strategy (i.e. acting in advance of a future situation), vegetation greening and belts of peri-urban forests also have strong potentials to mitigate the impact of global warming such as extreme heat waves. Clear guidance is therefore needed for local authorities and other practitioners on how to better manage public urban green spaces in order to respond to climate change. Therefore, as a proactive measure, urban foresters should consider using species suitable for future climates in current urban greening project. 


Workshop Title: Research projects to improve growth and stress tolerance in the nursery and after transplanting in the urban environment

Workshop abstract here.

 


Dr Duncan Slater
, Myerscough College, UK

Talk 1 Title: The anatomy of branch junctions

Abstract for Talk 1: A new anatomical model for how branches are attached in trees has been generated through recent scientific investigations. Through a series of experiments involving CT scanning and electron scanning microscopy, assessing a wide range of tree species, this work emphasises the importance of dense, twisting wood grain patterns that are formed under the branch bark ridge as a key aspect of the mechanical join that is made between branches.  Dr. Duncan Slater will provide an outline of this new branch attachment model, including unique images and the outcomes of validating investigations.

Talk 2 Title: The effects of natural bracing in trees

Abstract for Talk 2: An important breakthrough in understanding how weak bark-included junctions persist in trees has been made recently through a scientific survey of three cohorts of trees.  Natural bracing is the action of branch rubbing, crossing, touching and fusion, as well as other configurations that prevent normal loading being experienced by a branch junction set lower down in the crown of a tree.  Dr. Duncan Slater has identified a major association between the formation of weak bark-included junctions and these natural bracing types, which leads to important changes in how bark-included junctions should be managed, and how trees should be pruned.  This break-through research has been delivered to over 1,300 arboriculturists and looks likely to require significant changes to professional practice and pruning standards.  Essential research outcomes for anyone involved in the management of trees.

Workshop Title: Further training in natural bracing

Workshop description: Supplementing the two main conference talks given by Dr. Duncan Slater, delegates are invited to attend a two hour workshop.  These workshops will provide more detailed analysis of the scientific principles behind natural bracing, the rating of branch junctions and supply further examples of instances of natural bracing leading to the production of weak junctions and failures of junctions in trees.  This workshop is recommended to those involved with practical tree work, surveying  and assessment of trees or with a practical urban forestry role.


 



Dr Tony Matthews, 
Griffith University, Gold Coast 

Bio: Dr Tony Matthews MRTPI (@drtonymatthews) is a Lecturer in Urban and Environmental Planning at Griffith University. He is widely published in international planning literature, consults widely and regularly speaks at national and international conferences and symposia. Tony’s research interests include: the role and function of green infrastructure in climate change adaptation; managing climate change impacts in urban systems through planning; institutional, governance and policy change processes; and community, cultural and spatial rejuvenation led by informal local networks. Tony developed and co-presented ‘The Urban Squeeze’, the award-winning urban affairs radio program that ran for two seasons on ABC Radio. He is also the founder of the Urban Broadcast Collective (@urbanpodcasts), an international network of podcasts and radio shows dedicated to all things urban.

Talk Title: The functions,benefits & services of Green Infrastructure for rapidly growing cities

Abstract: Why are some parts of cities hotter than others? As we pursue policies of urban densification might we inadvertently be increasing problems with heat? What might be done about this? 

This presentation discusses research being conducted between Griffith University and the University of Tasmania on the benefits of green infrastructure for rapidly growing cities. Green infrastructure – a term referring to street trees, verges, parks, green walls, green roofs and other green spaces – is gaining international prominence for its purported functions, benefits and services. 

Benefits include the potential to combat urban heat islands, promoting social inclusion, improving sense of place, boosting property values and increasing physical activity and residents’ wellbeing. Green infrastructure is an emerging and critical facet of contemporary urban, environmental and natural resource planning. 

The seminar provides an overview of the positive contributions of Green Infrastructure in Australian neighbourhoods, as well as some potential disservices that planners, architects and other built environment professionals need to know about. Specific ways in which Green Infrastructure can be added to existing urban planning toolkits will are identified. Pathways and barriers to uptake of Green Infrastructure are examined, highlighting lessons for subtropical cities.
 


Dr Caroline Mohammed, University of Tasmania

Bio: Professor Caroline Mohammed has had an impressive career that has spanned many continents. She graduated with a degree in tropical agriculture from Trinidad and spent the next 10 years working there as a plant pathologist. She then completed her doctorate in France (and in French no less) in forest pathology. From 1989-1993 Caroline worked at the University of Oxford, where she took part in and led three multi-country EU funded projects in forestry including Italy, Germany, France, Zimbabwe, Kenya and the Congo. She arrived in Tasmania in mid-1995 to accept a co-funded position between CSIRO and the University of Tasmania and since that time has been actively involved in, facilitated and promoted research in forest health, initially focusing on pathology (and lecturing in plant pathology), then adopting a systems approach to the management of biotic stress.
She has held leadership roles for the two Forestry Cooperative Research Centres (Program and Project Manager) which involved the supervision of a large team of nationally based scientists and technical staff. In 2009 she returned to the University of Tasmania as Theme leader for Climate Change Adaptation, then as Program Convenor for Future Farming until 2014, developing agricultural projects in climate change and soil carbon research. Currently she is a Centre Leader for Agricultural Systems at the Tasmanian Institute, University of Tasmania, co-ordinates a unit 'Agricultural Technology and Innovation', leads a major ACIAR project in forest disease management in Indonesia and Vietnam (forestryhealth.org) and is working to build capacity in agricultural systems research within TIA.

Talk Title: Climate change, urban trees and pests

Abstract: This talk outlines the various ways in which climate change and variability may affect the health of urban trees in Australia. Changes in temperature and rainfall directly affects the development and survival of pests and pathogens, their natural enemies, and vectors. This may alter the impact of native pests and diseases, increase the populations of some species not currently recognized as damaging and most significantly the suitability of climate for a range of non-native pests and pathogens, many of which have the potential to be brought in unknowingly. Climate change and increasing climate variability will inevitably cause stress to trees in the urban environment and this may increase their susceptibility to certain insect pests and diseases through physiological changes. In summary climate change and variability will alter the urban ecosystem for trees. It will often be difficult to predict how relationships will change in a complex system but it is important that urban governance authorities and arboriculture practitioners be vigilant to the potential significance of changes in tree health for the future of urban forestry.
 


Dr Dave Kendal
, University of Tasmania

Bio: Dr Dave Kendal is a senior lecturer in environmental management, in the discipline of geography and spatial sciences within the school of technology, environments and design at the university of tasmania. He is interested in researching and teaching human-plant (and wildlife) relationships in cities and beyond, particularly the drivers and effects of environmental management. He completed his PhD in 2012 at the Burnley campus of the University of Melbourne, in the Department of Geography and Resource Management, Melbourne School of Land and Environment. Dave then worked at the Australian Research Centre for Urban Ecology, a division of the Royal Botanic Gardens Melbourne. In 2016 he was appointed as a Research Fellow in Urban Greening at the School of Ecosystem and Forest Sciences at the University of Melbourne, funded through the Clean Air and Urban Landscape hub of the National Environmental Science Program.

Talk Title: Urban tree vulnerability: tree selection in relation to increasing temperatures and climate change

Abstract: Global environmental change is occurring most rapidly in cities. While urban forests are being used as a strategy to adapt to the effects of increasing temperatures, there is little understanding of the likely effect of a changing climate on urban forests. Urban heat combined with projected climate change is likely to lead to temperature increases of 3-5 °C from historic levels by the end of the century. This would potentially place more than half the world’s existing urban trees in climates they have not previously experienced. These data were applied to the public tree database of the City of Melbourne (n=375 species). This showed that 48%-78% of currently planted species comprising 35%-62% of the total urban forest were outside known temperature envelopes under different climate change scenarios. Species from colder climates (e.g. northern Europe) and many locally indigenous species with narrow temperature windows were particularly vulnerable. However, hundreds of species not currently planted in the City of Melbourne had temperature envelopes within each climate change scenario. Climate change, combined with urban heat, is likely to lead to large changes in the composition of urban forests over time.

 


Anthony Van Zeeventer
, City of Darwin

Bio: Anthony Van Zeeventer moved to the Northern Territory from regional South Australia to undertake the position of Team Leader – Urban Forestry Management with the Corporation of the City of Darwin. Passionate about Arboriculture and Urban Forestry Management development the move to the “Top End” has allowed him to learn and explore the diversity throughout the Darwin region.
He studied his Diploma of Horticulture at Urrbrae Horticultural College prior to obtaining his Diploma in Arboriculture.
He has over 25 years within the Arboricultural industry working in various fields within South Australia, Queensland and South East Victoria both in the Government and private sectors.
He is a certified I.S.A. arborist and Q.T.R.A licenced working with planning and development as well as utilising his experience as a field arborist. 
He is currently studying his Post Graduate of Arboriculture at Melbourne Universities Burnley Campus.  


Talk Title: Urban Forestry Management

Abstract: Through the recommendations of two Coronial enquiries the City of Darwin was required to reassess the management of all the trees throughout the municipality with regards to risk management.

The City of Darwin was required to inspect all trees on all council leased properties biannually. Council had also implemented a procedure to inspect the numerous trees within areas within the CBD, foreshore areas, parks greenbelts and surrounding schools on a quarterly basis. Some of these areas were identified through public perception or concern with regards to potential target zone of large trees in particular the African mahogany tree which had failed in the both case of the two casualties.

A review by Council concluded that a Tree Management Plan was required as an operational document, which offered a clear approach to tree risk management standards within council. The Tree Management Plan was to remain a ‘live’ document subject to reviews with regard to technological advances and continually developments in arboriculture.

The City of Darwin engaged Mr William (Bill) Sullivan in consultation with the development of the City of Darwin Tree Management Plan and the implementation of a data management system.

Various options both internally and externally were considered when looking at potential software that could encapsulate the entire data requirement to record all the trees throughout the City.

The option selected for the City of Darwin Tree Management Plan was” Nemus” developed by the company Asset Edge.

The engagement and development of the Darwin NEMUS application has allowed Council’s Tree Management Officers to potentially record the location, health, risk assessment and works history of individual trees for their entire Useful Life Expectancy throughout the City of Darwin. 

 


Mark Hartley
,
Arborist Network

Bio: 
Mark Hartley is a second-generation arborist whose career spans over three decades. Mark has studied widely in Australia and the United States. His reputation and expertise in tree transplanting has taken him to 7 countries in 3 different continents. His expertise with palms resulted in him providing consultancy services in the UAE to the Royal Family.

Mark has given evidence as an expert witness in the Local, District, Land and Environment, and Supreme courts of NSW and has served as a court appointed expert for the Land and Environment Court of NSW.


Talk Title: Tree Risk in the Urban Forest

Abstract:  
The Quantified Tree Risk Assessment (QTRA) is a system that quantifies the Risk of Harm (ROH) of a particular tree over the following 12-month period. Along with looking at the target and the size of the part that is likely to fail the process requires the practitioner to estimate the Probability of Failure (PoF). Ellison suggests that a normal, healthy whole tree failure is 1 in 1,000,000 or less. There is, however, limited statistical data to support the estimates for the PoF of branches with the process relying on empirical information collected by individual practitioners.

If we consider the PoF of a species that has a reputation for limb failures this data would provide us with a useful benchmark. By obtaining statistical data for a species that has a higher propensity for failure we can be relatively confident of a PoF that is at the upper end of normal branch failure. This PoF could then serve as a benchmark for an upper-end estimate of the likelihood of “healthy” branch failure.

Corymbia citriodora is a species that is often considered to be “brittle.” Limb failure within this species is often thought to be common. By looking at a number of Corymbia citriodora over a broad geographical area and looking at the number and sizeof the limb failure a statistical approach can be developed and applied to Tree Risk Assessments. Furthermore, the methods are relatively simple and affordable, so if the the process is effective, the same process could be readily replicated for other species and or geographic allocations.

 


Dr Melanie Davern
, University of Melbourne

Bio: Dr Melanie Davern is a Senior Research Fellow and Co-Director of the Healthy Liveable Cities Group within the Centre for Urban Research at RMIT University and an Honorary Senior Research Fellow, School of Population and Global Health, University of Melbourne. Melanie has specific expertise in the development and applied use of policy-focused social, economic and environmental indicators of wellbeing that assess the social determinants of health. Her research interests focus on the translation of research evidence into policy and practice using indicators of liveability, community and individual wellbeing. Melanie has expertise in policy focused research using indicators as measurement tools for policy development, program evaluation, knowledge translation and community engagement. Her research has created direct changes in policy and practice through collaborative partnerships within academia, industry, community organisations, local, state and federal governments.

Talk Title: The importance of greenspaces in building healthy and liveable cities

Abstract: Existing research has identified multiple benefits of urban greening including improvements in physical and mental health, biodiversity and ecosystem services. The positive impact of urban greening is also becoming more important with rapidly increasing populations, urban development and increasing densification of cities. Greenspaces provide a critical infrastructure in growing societies and aboriculturalists should embrace the developing evidence base and partner to demonstrate the benefits of new greening initiatives to support and promote the health and liveability of communities across Australia. Key findings from a number of research projects will be presented including a natural experiment describing an urban greening partnership project in a socio-economically disadvantaged area of Melbourne. The importance of indicators and measurement of greenspace in both the public and private realm will also be discussed to inform better policy and planning and direct greening initiatives into areas of greatest need for maximum community benefit.

 


Dr Sudipto Roy - Queensland University of Technology, QLD

Bio: Dr. Sudipto Roy is a lecturer, researcher and a practicing architect - landscape architect with over 20 years’ experience. He is a Fellow of UK’s Higher Education Academy, a registered landscape architect with the Australian Institute of Landscape Architects (AILA) and a registered architect with Council of Architecture (COA). As a master planner, landscape architect, architect and project manager he has worked with international, multi-disciplinary organisations across Australia, Asia, and the Middle East. His research interests include green infrastructure, urban landscapes and urban trees, urban ecosystem services and disservices, sustainable landscape patterns, smart cities, regionally adaptive environmental design, resilient landscape design and therapeutic landscape design. Dr. Roy is currently working on building community resilience through innovative landscape design and pedagogies in Landscape Architecture teaching and learning. In addition, he is interested in smart cities and smart systems.

Talk Title: Challenges: street tree selection and planting in South-East Queensland cities

Abstract: Municipal tree managers often face the challenge of selecting appropriate urban street tree species. The ecosystem services [benefits] and disservices [problems] linked with different tree species make this selection particularly challenging. Municipal tree managers reported environmental (100%), visual and aesthetic (92%), and statutory (92%) motives for planting street trees. However, street tree species selection was reported to be governed by species characteristics (100%), site factors (100%), costs (92%), and management and maintenance issues (83%). Interestingly, ecosystem services (50%), along with visual and aesthetic benefits (50%) seem to have less influence on species selection. Research focused on assessing, quantifying and comparing the benefits and problems of local tree species can empower municipal tree managers to incorporate ecosystem services and disservices as part of the species selection process and revise street tree legislation.

 


Susanne Schmidt - The University of Queensland, QLD


Bio: Susanne is an ecophysiologist and educator. She leads a vibrant team at The University of Queensland to contribute plant-focused solutions to the problems of modern societies seeking environmental sustainability. Her specific interests are the adaptations and functions of plants and plant communities in diverse environmental settings, the preservation and use of the Australian flora, and the advancement of crop systems based on ecological principles and with view of the circular nutrient economy. She uses diverse techniques, from empirical research that uses molecular, biochemical, and physiological tools to modelling and wide-ranging interdisciplinary collaboration. With over 150 publications in the peer-reviewed scientific literature, she is an internationally recognised leader in plant and ecosystem biology who pursues rigorous, evidence-based science for informed decision-making.

Talk Title: Biogenicvolatiles from trees: how they can inform city tree-scapes 

Abstract: Benefits of urban trees include improved air quality and cooling, reduced rainfall runoff, habitat for urban wildlife, aesthetic and property values. Negative aspects of urban trees include emissions of biogenic volatile organic compounds (BVOC). Isoprene is the most prevalent BVOC and emitted by many plants during photosynthesis as a protective mechanism to prevent damage to cellular processes. Isoprene negatively affects air quality through the formation of phytochemical smog and ground level ozone. Only few studies have quantified this potential disservice of urban trees, although current decision-making tools, such as the i-Tree Eco model, use BVOC data to model regional air quality. However, BVOC emissions are often quantified in trees in temperate climates, which may lead to inaccuracies as emissions from tropical trees may differ. 
To advance knowledge of BVOC in subtropical urban environments, we tested if the i-Tree Eco model accurately reflects emissions. The three aims were to (i) quantify isoprene emission rates of three tree species in subtropical Brisbane that together account for 16% of inventoried trees out of a total of 200 species, (ii) compare outputs of the i-Tree Eco model using species-specific with the currently used generic isoprene emission rates, and (iii) relate these findings to regional air quality. 
Isoprene emissions of Xanthostemon chrysanthus ‘Golden Penda’ (Myrtaceae), Buckinghamia celissima ‘ivory curl’ (Proteaceae) were low compared to those of trees globally with 2.6 and 2.0 µg isoprene emitted per gram of dry leaf per hour, respectively. Harpullia pendula ‘tulip wood’ (Sapindaceae) was a non-emitter. Substituting the generic isoprene emission rates of the i-Tree Eco model with these values resulted a 97% lower estimate of isoprene emissions. Overall this amounted to a substantial reduction of 6284 kg isoprene per year when extrapolating to the target region.
These findings suggest that generic isoprene emissions values should be used with caution. Ideally, BVOC emissions of target tree species should be quantified in the urban environment. We discuss these findings in the broader context of BVOC emissions, including the need to fine-tune tools that inform decision making for the selection of suitable tree species that provide the greatest overall benefit for the urban environment.

 

 
Lyndal Plant, Ph.D. - Urban Forester Pty Ltd, QLD


Bio:
Dr. Lyndal Plant is an urban forester who has worked in local government policy and strategic planning for urban trees, including many years with Brisbane City Council. A Churchill Fellow, member of TREENET management committee and now a published researcher and consultant, Lyndal has helped advance urban forest evidence gathering techniques and make stronger business cases for investment in green infrastructure. Lyndal now focuses on policy development/review and cutting-edge urban forest initiatives. She sees the forest, not just the trees – helps plan and monitor outcomes, not just outputs and is committed to greener, cooler neighbourhoods for all.


Title: 
Making your case for urban greening: Adapting and applying evidence gathering techniques for urban forest planning and evaluation.


Abstract: The basis for effective urban forest planning and sustained investment is robust and relevant evidence. Technological advances in remote sensing, urban forest assessment software and access to a broader range of open data sets has improved the opportunity for public tree managers to build stronger business cases and help identify priorities for investment. Yet translating data to evidence and evidence to investment is dependent on identifying the context specific information needed to engage stakeholders and influence decision-makers. For example, although urban forest managers in each of four international cities with exemplar urban greening programs had access to measures of ecosystem service benefits, only two of those managers rated such information as important in gaining funding for their programs. Some researchers have begun to explore the question of the role of measures and values of urban ecosystem services in sustainable/liveable city solutions, especially when there are examples where place-based social and cultural negotiations and contests alone have successfully preserved urban forest elements. Similarly, efforts to understand and quantify levels of consumer DEMAND for expanding urban tree canopy cover offer an important balance to evidence expressed only in terms of forecast services SUPPLY. This presentation revisits the fundamentals of robust evidence gathering and provides examples of innovative, cost-effective techniques applied to urban forest planning and evaluation.


Please note that some presentation titles may be subject to change without notice.


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