On Tuesday, January 9, 2018, I attended a talk by Dr Gregory Moore OAM about the value of trees and public open space, hosted by the Kingston Residents Association.
It was a timely talk in more ways than one to make us aware how important a tree canopy is not only to healthy living but sustainable survival:
- Kingston Council is seeking submissions regarding a Tree Management Plan with January 19th being the closing day so please HAVE YOUR SAY!
- The latest statistics regarding climate change and increased temperatures in Australia show more bleaching of the Great Barrier Reef – and it’s changing the sex of turtles!
- The severity of the devastating landslide in California is being blamed on the tremendous loss of trees from earlier bushfires.
A perfect storm of land development, fire, wind and then rain conspired to create the deadly avalanche of mud and debris that levelled homes in Southern California this week.…
Councils and governments often ask Dr Moore for advice from regarding Tree Management Plans and has been a member of the National Trust of Victoria’s Register of Significant Trees since 1988.
He has been on the Board of Greening Australia (Victoria) since 1989 and chaired TREENET since 2009 which is an Independent Non-profit Organisation dedicated to improving the urban forest.
Dr Greg Moore, Honorary Senior Fellow Melbourne School of Land and Environment was a lecturer and Principal at Burnley from 1979 to 2007 with interests in horticulture, plant science, revegetation and ecology. He is a well-known advocate for arboriculture and urban trees.
Greg is an active contributor to industry and community standards, and professional associations in the field of trees in the urban environment and revegetation. He is regarded as an international expert in tree biology and tree management.
How ‘Green’ Is Melbourne?
Remember when Victorian number plates proudly boasted ‘The Garden State’? (1977)
People were outraged when Premier Jeff Kennett not only changed the colour from green and white but also the slogan to “On The Move” as this article from 2012 relates.
It also states some statistics about why Melbourne was considered the ‘greenest’ city, including:
- Victoria has the most public parks and gardens within 5km of the CBD of any state, with a total of 124. 16 parks covering 480 hectares are located within the City of Melbourne alone.
- The City of Melbourne has 60,000 trees valued at $650 million amenity value
- Victoria’s nursery and garden industry is the largest of any Australian state, with an estimated economic value $2.72 billion, and employing over 15,000 Victorians
it is now 2018 and Dr Moore shocked us when he announced Melbourne is not as green as we think with less than 20% of the 30% tree canopy considered necessary for our health and well-being.
Kingston has less than 12%!
Melbourne has less than Brisbane and Adelaide and considerably less than London, England, which has 50% green space with 22% of a canopy classified as forest.
(And the UK is actively tackling the predictions of climate change scientists by planting a Northern Forest linking Liverpool and Hull with 50 million trees!)
A frightening picture for Melbourne was revealed in a 2016 article in The Age when the effects of global warming hit home in a report commissioned by the State Government.
Winners and Losers
Australia is a continent – the world’s driest continent – but not everyone will be affected the same way by climate change. There will be winners and losers. Some areas will be able to grow crops they can’t at the moment, others will be unable to sustain the crops they now grow.
According to CSIRO modelling, Victoria, some consider the nation’s food bowl, “cops a whacking”. Mostly out west and inner parts of Melbourne.
Throughout Melbourne, tree canopy and vegetation are lost at the rate of 1-2% a year from private land, mainly because of private development.
Dr Moore warned that in Kingston there will be a battle as developers aim for golf courses. If not protected, privatised golf courses will be sold for redevelopment or will apply to have vegetation removed. It has happened in other areas and we must remain vigilant.
Reality is that developers and those pro-development have control of Plan Melbourne and planning laws in their favour. The Housing Industry Association a powerful body Australia-wide.
I live opposite the railway line near Mordialloc railway station, and development is happening at a rapid pace. Sadly, I watch familiar trees being removed and wonder what shrubbery will replace them:
Time Running Out
We must take biological changes caused by climate change seriously – the change of sex of Green Turtles a huge shock, yet we’ve had 30 years to prepare.
At Burnley College, the first question about the effect of climate change appeared on exam papers in 1988.
We have squandered lead time.
The pathetic shenanigans over the Carbon Tax, the political point scoring and response over Energy needs (policy and cost) have led to ridiculous decisions and nonsense by politicians.
While they play party politics, the consumers and citizens pay the price.
The Victorian Government has a reasonable track record with good bipartisan policies, but it is not good enough. Most people are too ignorant and unaware of the urgency – more needs to be done regarding educating for changed behaviour and for local councils to act and the State government to pick up the slack when councils don’t.
In the Docklands there is an iconic sculpture ‘Cow up a tree’.
The artist John Kelly’s sense of humour also made a statement about Australia:
Cow up a Tree is the conjunction of two Australian histories – Australian floods and Dobell’s cows -– which contain these opposites. Floods occur frequently in Australia, usually wreaking destruction and tragedy. But they can also have absurd outcomes, such as objects ludicrously stranded in trees.
A future affected by climate change threatens increased floods and storms and unless we change, there may not be many trees to collect stranded items!
Projected Future Temperatures
- 10% less rain
- higher rates of evaporation (so probably be 15% less rain in summer)
- temperature change + 4 degrees
- Recently Melbourne had a 42 degree day, which dropped to 22 degrees within hours.
We joke about four seasons in one day but climate change means a permanent increase resulting in too many storms, plus biological and lifestyle consequences.
Reality not Fake News
Northern Europe may have 5-8 degree rise, Mediterranean 4-4.5 degrees, USA 4 degrees.
In the developed world it may not be catastrophic, but in poorer countries, it will be devastating.
- Warmer winters
- Hotter summers
- More frequent storms
- In Victoria more days above 30 degrees (This prediction now a fact)
- Double the number of days above 35 degrees
Some crops may grow better but others will fail – energy patterns demand change.
Connectivity to Public Space Paramount
For better biodiversity outcomes, we need bigger interconnected systems to yield better benefits.
Parks and public open space linked for walking, jogging, cycling, running…
Kingston does well with Braeside Park and if the foreshore links improved, it will be a valuable connecting link with other areas of Melbourne. (Bayside Trail)
Contrast Kingston to the restricted access to open space experienced in western and northern suburbs.
- Melbourne’s Western and Northern suburbs have the least canopy cover.
- they have poorer health outcomes
- they have the least connectivity of existing open spaces
- the imbalance not fair or equitable
- some new suburbs the capacity tree cover only 10% because of development, sub-divisions and available land
- THERE IS NO SPACE FOR TREES!
Alma Park and the Esplanade St Kilda – treed and leafy.
We remember Black Saturday when 173 people died in bushfires
But 374 excess deaths in the period 26/1/09 – 1/2/09 because of heat.
- The deaths clustered in northern and western suburbs where few or no trees. (This correlation so strong health authorities warn ambulance and allied health workers in those suburbs to be worried and on alert on hot days.)
- 66% of such deaths in 75 plus age group
- in new estates there may be no deaths because usually younger residents, double incomes and can afford to run air-conditioners.
Leafy suburbs keep cooler in the shade, sheltering homes and streets. The West green with envy! Tree breeze blows better health outcomes!
Dr Moore showed two pictures published in the newspaper during a period of excessive heat.
- One picture of a railway worker in the west hosing rails to stop them buckling.
- The other picture showed a shady eastern suburban corridor where tramlines had trees for protection and no need of hosing.
** powerful to publish the truth – some suburbs luckier than others.
Trees Perform a Function and Service
Whether you live under Marxism or Capitalism, the tenet is if something is worth dollars then it has a value.
The Victorian Department of Health wants people to exercise outside and encourage activity – a report in 2010 about the health benefits is confirmed every year.
$274 million saved in health costs if people can exercise outside in safety.
- Build an open space and people will come.
- Health expenditure is double what is spent on maintaining trees.
- In 2016 a Treenet symposium in Adelaide dedicated to trees heard speakers from the medical profession conclude that $800 million per annum saved in treating Type 2 Diabetes and adding High Blood Pressure and its consequences $4.2 billion can be saved.
Trees provide links through time – often spanning several generations. There is the emotional attachment, heritage, sense of connection, identity with an area, symbols of events, individual beauty… all these add to the community’s wellbeing.
Jeff Kennett, the Premier who abolished the Garden State slogan, underestimated the anger Albert Park residents felt about the Grand Prix. They protested the destruction of heritage and history when trees were removed and maintained their rage for years.
When building City Link, the trees were dug up and saved and replanted when job completed. Kennett learned that politicians, mayors and CEOs lose jobs when they make wrong decisions regarding parks and open space.
- It is a tragedy when Red River Gums die. These trees can live to 800 years old and are a link to the pre-colonial past.
We have a host of attractive trees in Mordialloc, some ancient, others adapting to suburbia:
Urban Heat Island Effect (UHI)
Urban development is something that we and our audience are passionate about, and the process in which our cities grow is certainly paramount to our future prosperity as a community and society.
However, there is a phenomenon discovered by Luke Howard in the early 19th century that gets a bit lost amongst the construction and development. This phenomenon is known as the urban heat island effect (UHI) and it occurs when urban development replaces natural permeable surfaces such as grassland or bushland with dry and impermeable surfaces such as concrete and asphalt.
UHI is defined by a metropolitan area having an increased temperature of 1-3 degrees Celsius higher compared to that of surrounding rural or vegetated areas.
Further to temperature changes, UHI can also affect localised meteorology by altering wind patterns, creating fogs and clouds and changing the rates of precipitation.
The main cause of UHI is that buildings block surface heat from radiating into the relatively cold night air as the changes in thermal properties of the surface materials and the lack of evapotranspiration (i.e. natural cooling effect in vegetated areas) significantly alter the heat capacity and the thermal conductivity compared to rural areas.
Chris Peska, Urban Melbourne
Why should we care about UHI?
- The elevated temperatures from UHIs during the summer months can affect the community’s environment and quality of life.
- Increased energy consumption: Higher temperatures in the summer periods increase the energy demands from people trying to keep cool and in turn add pressure to the electricity generators.
- Compromised human health and comfort levels: As UHIs are characterised by increased temperature, they can potentially increase the magnitude and duration of heat waves within cities.
- Impacted water quality and aquatic life: As the storm water is not absorbed naturally, the increased temperatures of pavements and rooftop surfaces transfer their excess heat to storm water after a rain event which then drains into waterways.
Rainfall in metropolitan Melbourne:
- Melton 600ml rain
- Kingston a metre
- Ringwood 1200ml
When we pay for water, it is not fair to have this disparity between eastern and western suburbs. UHI definitely matters!
- Shade prolongs life of tarmacadam and bitumen, and of roads and buildings
- trees keep them cooler
- trees help soil stabilisation
- if more humidity in the air it helps asthmatics
- trees absorption of water can reduce the risks of local flooding and remove the need for storm water gutter and pipes,
- tree canopy can hold water and slow a deluge
- climate change means heavier rainfall and increased flooding, therefore, we need trees.
- trees offset carbon emissions
- trees give social and psychological benefits – more vegetation less violence and graffiti
- shade lowers evaporation from soil, saving water.
WHAT IS DOLLAR VALUE OF TREES?
- Savings in energy estimated at $180 a year, if running a 6kw air conditioner. (Studies estimated an unshaded home cost $360, this bill reduced by $50 if one shady tree and reduced by $90 if two shady trees.)
- After the death of a school student from lightning strikes, the government ordered the removal of trees and the installation of shade sails. The value of shade by the trees quantified – $5000 over ten years.
- There are an estimated 100,000 trees in Kingston – using the Gillard Government’s $23 value for carbon offset they are worth $30 million!
Everybody knows the damage done to footpaths by tree roots, but not how much shade saves the life of bitumen on roads.
Why are there no trees planted in parking areas and school grounds?
The biggest polluters in Victoria are power companies, yet they are the ones chopping down trees in case of fire, or damaging trees to protect overhead lines. WHY AREN’T LINES UNDERGROUND?
Trees prolong the life of bitumen and tarmac. The shaded life is triple or quadruple in North America, here it is 50%.
Maintenance Cost Versus Value Added
In Adelaide in 2002, high school students studied elms and plane trees and worked out citizens get $171 value every year because of the previously listed benefits, yet government only spent $10 per tree in maintenance.
It was considered there were lots of indeterminable in the high school study, so a PhD study in 2009 redid the research. The value more than doubled in seven years to $424 per citizen!
Real Estate Turf Australia in 2014 worked out –
- A good tree in your front garden adds about 5.4% to domestic property value ($25,000)
- A green lawn worth $75,000 added value.
- A tree-lined nature strip added $30,000 to properties.
- More trees present higher value but if over 30%, people tend to not like it and values drop.
- The City of Brimbank changed their planning laws – developments must have room for two trees in frontyard and one tree in the backyard. They had a very low amount of canopy cover and are worried about climate change.
- The current Minister of Planning sat on his decision for a year before approving and allowing Brimbank Council law to go ahead. THIS IS NOW A PRECEDENT – councils can act to implement important planning decisions to protect and/or increase tree canopy.
Planet Ark statistics:
- Tree roots stabilise soil and reduce erosion
- A forest is defined by a tree canopy cover greater than 30%
- To maximise benefits you need to be at 30% canopy cover
- Melbourne Council aiming for 40% so better chance of getting 30%
- Kingston currently at 10%!!
What Can Be Done?
When council receives a request to remove a tree, they should insist on a tree being planted as a replacement.
Councils need to follow up if developers plant the trees and vegetation they promise in submitted plans. Make developers submit photographs one year on perhaps?
What is the budget for trees – in Kingston is it 100,000 X $10? Most of the budget is probably spent on parks, so how can we know? Councils don’t have the staff to inspect every tree – perhaps strengthen Friends groups, ask residents to adopt a tree?
A tree canopy is the most benefit if height more than 8 metres but not that much benefit if 30 or 60 metres, therefore 2 trees @ 30 metres better than one tree of 60 metres.
A diverse canopy – shrubs turf etc provide benefits just as much as trees but there is no benefit from artificial turf at all as far as Urban Heat Island effect.
Planting indigenous trees better but years ago oaks and elms were planted outside lots of post offices and police stations and other public buildings. These can be replanted as a link to heritage.
Remember, a tree is a loss of habitat too – insects, possums, birds – a whole ecosystem.