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Councillor Macri put up the following Question on Notice at this week’s Council Meeting dated 19th April 2011. Because it was a Question of Notice it could not be debated.
1. How many street trees were planted this year?
Answer: 461 street trees were planted in calendar 2010. The 2011 season has not commenced.
2. How many trees were lost?
Answer: That data is not available as it has not been previously collected. The data is currently being collected using suitable duties staff & it will be advised to Councillors when available.
3. Is planting this many trees sustainable? If not why not?
Answer: Yes. It is recognised that not all trees planted in any one year will survive. Reasons for failure include theft, vandalism, climate (excessive heat, dry, wet etc), pests & diseases, inherent defects (root system damage during nursery operations etc), poor receiving soils, incorrect planting (e.g. too deep or shallow) & poor establishment watering & maintenance. No information is currently available to identify the cause of failure of street tree plantings. Council’s current resources are able to manage planting & establishment of approximately 500 trees p.a. In years of prolonged drought, when extended & frequent watering of newly planted stock is required, the number of trees that can be maintained will reduce. Where Council funds capital tree planting programs, the implementation of that program will require assessment of the need for external contractors to provide establishment watering & maintenance services.
4. What is the maintenance cycle time for the maintenance of existing trees?
Answer: Tree maintenance is undertaken reactively as required. A tender for tree maintenance is currently being prepared & it is intended to introduce proactive tree maintenance into the tender contract works. Until prices have been received it is not possible to estimate how much proactive work can be afforded each year & therefore what the future cycle time would be.
5. How many street trees did we have in 1998 & how many now?
Answer: That information is not available. It is estimated that there may be up to 25,000 street trees in the Council area. A budget bid for 2011/12 requests funds for inventory data collection of street tree assets.
6. How many staff are involved in maintaining new plantings & existing street trees?
Answer: It is estimated that 111 person days were required to plant street trees in 2010 & a further 171 person days were required for watering & establishment maintenance of the new trees.
Not being at all reliable when it comes to numbers I asked my husband to calculate how many people worked on street trees.
- That is a total of 282 days per year working on street trees.
- 240 days makes a full year or 1 whole person.
- 111 days makes 46.25 per cent of a whole person, or, 5.55 months, which is just under half of a person per year planting street trees in 2010.
- 171 days makes 71.25 per cent of a whole person, or, 8.55 months, which is almost three quarters of a person per year looking after the watering & establishment maintenance of the new trees in 2010.
- Put these 2 figures together and you have: 282 days per year allocated to planting & maintenance of new trees equals 117.5 per cent of a whole person.
- In plain language this makes 1 whole person & 17.5% of a person, or, differently put, 1 person & 1/6th of a person.
Not much is it.
I have mentioned recently that Portland Oregon in the US has for a while been my number one favourite with all things environmental in an urban environment. If it can be done & improves the livability of the environment, they do it. If it extends the life of a street tree, they do it. If it improves stormwater management, they do it. They also have what appears to be large community interest & involvement with a thriving community of volunteers across many programs that better the urban environment. Portland shows the rest of us what can be done.
The latest that I have discovered is depaving. There is a push coming from the community to remove unnecessary concrete in urban environments for the following reasons –
- It’s ugly & not seen as conducive to creating livable cities.
- It’s bad for stormwater management. Hard surfaces increase stormwater, over-burden drains & carry large amounts of ground pollution to rivers, lakes & oceans.
- Impervious surfaces prevent much of the rainwater seeping into & refilling the groundwater table.
- Impervious surfaces increase the Heat Island Effect making our environment hotter than it needs to be resulting in increased power usage just to cool our buildings.
- Concreted surfaces have destroyed habitat & made whole areas unsuitable for urban wildlife.
- In some cases these kind of surfaces have disconnected people from the natural world. Some people see concrete as ‘clean’ & fallen leaves as ‘dirty.’ This creates a cycle where more & more trees in gardens & along streets are seen as pests & either removed or vandalized. Once the overall canopy is lessened, the Heat Island Effect grows, power use also grows, but what doesn’t grow is urban wildlife who has fewer places of habitat & food supplies.
Paul Sheehan wrote the following for the Sydney Morning Herald in July 2009 - “You, reader, live in a primitive city. In a hundred years from now, the society we are building will look back & marvel at how little we really understood about the world we have constructed for ourselves.
We are stewing in our own juices.
Last Wednesday, a night of driving rain, I attended a seminar where more than 100 professionals, a standing room-only crowd, had gathered to learn about practical, cheap, achievable ways of stopping Sydney’s pot from simmering. These were not wide-eyed utopians. In purely parochial terms, the heating of our biggest cities is even bigger than the global warming debate. Because the rise in temperature is mostly & demonstrably caused by outdated thinking.
The story starts on Observatory Hill, at the southern end of the Harbour Bridge, where weather records have been kept daily since 1860. What the observatory has recorded is a rise in the average temperature at the centre of Sydney from 20.5 degrees to 22 degrees. As Sydney grows, Sydney slowly heats.
At last Wednesday’s seminar we learnt why – 27% of the surface of the metropolitan area is covered by bitumen, the black tar which soaks & retains heat & thus changes the city’s climate.
Nearly all the rainwater run-off on this 27% of the city is lost to productive use, flowing into Sydney Harbour because it is designed that way. The city’s rooftops also gather heat. Roads & pavements maximise the waste of arable land. Tree-planting is stunted for legal reasons. Topsoil is “scalped” by roadworks. The increasing use of air-conditioners is creating more energy. More heat begets more heat.”
There is much more to this article, including the work Landscape Architect Micheal Mobbs & his neighbours are doing to green & cool the residential streets of Chippendale – http://www.smh.com.au/environment/climate-change/we-are-stewing-in-our-own-oven-20090726-dxew.html
I wrote about Micheal Mobbs & his green verges here – http://savingourtrees.wordpress.com/2010/10/24/verge-gardens-in-chippendale/
People & local Councils have paved whatever they could since the late 70s. It was a movement of convenience as concrete is easier to drive on, easier to walk along & easier to clean with a hose. The main beneficiaries were people with a disability who need flat surfaces to get around & parents with prams.
I believe we need to continue to provide safe & easy access for everyone & there is much need for improvement in this area. Just last month I watched a man in a wheelchair who was forced to travel along the road next to Petersham Town Hall with the cars because there were no wheelchair ramps on the high kerbs at all 4 corners of the cross road. There must be many such areas like this that make wheelchair travel dangerous & difficult.
Leaving aside wheelchair & pram accessible footpaths & kerbs, many government authorities overseas think that concrete worship has gone too far &, because of the above negative effects, are rethinking their concreting practices of the past.
Most car parks do not need to have concrete or asphalt/bitumen. They can easily be compacted permeable surfaces allowing stormwater to travel into the ground to the water table rather than into 100-plus-year-old drains. Permeable surfaces actually need less maintenance than do impervious bitumen surfaces & therefore are cheaper in the long run. Appropriate trees can be planted within the parking spaces improving the visual outlook & also helping with stormwater & pollution uptake.
Footpaths do not need to be wall to kerb, except in shopping strips where a greater use of the footpath space is required or where the space between building & kerb is unusually narrow.
Marrickville Council is adept in building bio-swales & rain gardens. There is no reason why a small rain garden or two cannot be built within a car park if there is a reasonable flow of water from nearby buildings & from the lie of the land when it rains.
I suspect these ideas will be dismissed in most areas of Australia as ‘too greenie’ because of the convenience of paved surfaces. However, in a few years depaving will be the norm because of the worldwide push to restore groundwater, lessen the Heat Island Effect, restore habitat & make cities more livable.
Although many governments are stalling any real action on climate change, some overseas already depave, create green space & plant more trees in public spaces in cities because they know what is coming. It is like a slow culture change. Once we get used to these changes back to softer infrastructure, we will cope with the bigger changes of gravel lanes & fewer paved surfaces.
If we can create a balance where people who require flat surfaces for mobility can have this, but remove unnecessary hard surfaces & green up, we will have a much cooler, prettier, more environmentally friendly & wildlife habitable environment to live in. It doesn’t take much to create a huge improvement on many levels.
Here is a 4-minute film where the Portland community removed 278.7 sq metres (3,000 sq feet) of asphalt to create a community space with a perennial food forest. http://www.streetfilms.org/depaving-day/
On 26th June 2010 the Sydney Morning Herald published an article headlined: Why living near a road is bad for your health. A major study was done by the US Health Effects Institute who reviewed 700 worldwide health-pollution studies. They found:
- traffic pollution within a 500-metre radius of a major thoroughfare was likely to exacerbate asthma in children
- trigger new asthma cases across all ages
- impair lung function in adults &
- could cause cardiovascular illness & death
Because the results showed a clear health-risk for those living within 500 metres of a main road the National Environment Protection Council will consider the US study in a review of existing national air pollution regulations next month.
The National Environment Protection Council will be considering “whether a limit should be imposed on the concentration levels of particulate matter larger than 2.5 micrometres. Currently authorities need to adhere to limits set for particulate matter larger than 10 micrometres.”
That’s good, even if it is significantly overdue. 25 years ago a friend’s mother told me not to rent a house in Leichhardt because it was a block away from Parramatta Road. She said the pollution will be dropping in your yard & you will be breathing it every day, especially when the wind blows towards the property. I took heed & let that house go even though the rent was low.
The Australian Federal Chamber of Automotive Industries is already trying to find loopholes saying, “the industry supported moves to minimise pollution from cars, but added that air quality was good in Australia & warned against comparisons in US studies.” Except the 700 health-pollution studies were taken world-wide, not just in the US.
Recently I posted on the differences between Parramatta Road & the Pacific Highway. They are both main roads, but the differences between the two are astounding, so much so, one could believe they are in different countries, not in the same city separated by a bridge. The Pacific Highway has large trunk tall trees along its length. Tree canopies cascade over the road & no one is in fear even though the majority appears to me to be of the Eucalypt variety.
Parramatta Road however, has very few trees along the section managed by Marrickville & Leichhardt Councils & most of this road managed by other Councils are just as treeless. The Princes Highway also is almost devoid of trees, even though this road appears to have more obvious spaces that would allow for planting. I would think these Councils made a decision not to plant street trees along these main thoroughfares as these roads have remained in this state for decades. http://savingourtrees.wordpress.com/2010/06/10/north-shore-versus-inner-west-main-roads/
Now it is not just a matter of unsightliness (which has its own recognized impact on mental & physical health), it has been recognized as a serious health matter for the thousands of people who live within 500 metres of main roads. The pollution from Parramatta Road & the Princes Highway must be at astounding levels. I don’t know whether anyone has measured the pollution levels along these roads, but I doubt it will be too long before a study is done on this.
All the people who live within 500 metres of these roads are having their health compromised on a daily basis when all that needs to be done is plant decent sized street trees.
A tree with a 76 cm-diameter trunk removes 70 times more pollution per year than does a tree with a 7.5 cm trunk. This is not a big tree. Double the trunk size & you will be removing a much greater amount of particulate matter & other pollutants. The trees along the Pacific Highway are not small thin little things. They are big trunked robust growing trees with a significant canopy.
Trees are best known for their ability to sequester & store CO2, but they also absorb other pollutants such as Ozone, Nitrogen Dioxide & Sulfur Dioxide through their leaves. They reduce air temperature ground-level ozone, which contributes to greenhouse gas creation & global warming. They also remove up to 60% of street level particulate matter such as dust, smoke, ash & the sooty bi-product from car & truck exhausts. The more trees planted, the less heat is generated & the more air pollution is removed.
Now that health effects from pollution from main roads is finally being taken seriously in Australia, it is time all main roads are made safer. The cars & trucks are not going to go away for the foreseeable future & it doesn’t matter that engines of newer cars spew out lower levels of toxic material, it is still happening year in, year out & having a major effect on the health & lives of residents & people who work on or near main roads. Perhaps the Health Department will help cover the cost of trees for planting. It’s a valid argument as trees will help stop thousands of people becoming ill & landing up at hospitals.