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Once again inequity of the urban environment has been shown to impact the health of the community, this time pregnant woman & newborn babies.
New research published in ‘Environmental Health Perspectives’ by researchers from Oregon State University USA, the University of British Columbia Canada & Utrecht University in The Netherlands has shown that that a leafy environment in urban areas has an impact on birth weight & full-term gestation of human babies.
Live in a green leafy area & it is more likely that there will be fewer premature births & babies will be born with a higher birth weight. The opposite is true for pregnant women who live in areas with less greenery & less green space.
“The findings held even when factors such as socioeconomic status, walkability, & exposure to air pollution & noise were controlled for…” http://bit.ly/1pUW7pl
The researchers think that reduced stress levels & depression, plus the ability to connect with others while out in green spaces are factors.
Mental health & connectivity have been the subject of recent research that clearly shows that street trees, leafy parks & green spaces all help raise the mental, physical & spiritual health of the community. In contrast, areas with few trees, & I would include good-looking trees, & few green spaces increases the incidence & duration of depressive illness.
Not only does Marrickville municipality have the least green space in Australia, but in 2010, Marrickville was found to be the unhappiest suburb in Australia according to the Australian Unity Wellbeing Index conducted by Deakin University. Add to this the incredible increase in traffic in some parts of the municipality & I think street trees & green leafy parks are once again showing their importance to public health.
The more street trees, green walls, verge gardens & leafy parks we can have, the better off the health of our community will be. I also think that new high-rise housing developments should include green space. Now it has been shown that trees & green space play a vital part in the start of life.
You can read the research in here – http://ehp.niehs.nih.gov/1308049/
It happened two years ago, but I’ve just seen it.
“The City of Playford has commenced a program of retaining selected standing dead street trees for their habitat value – this video explains the process and details the first such tree to be created, on Judd Road in Elizabeth, in the northern suburbs of Adelaide, South Australia.”
The tree is a ancient Red gum & a street tree. Interestingly, the Arborist carved the ends of the branches to create more natural aesthetics & also to provide homes for insects. Natural holes were used to create access holes to man-made hollows. This has been happening in Europe.
The video is almost 18-minutes long, but worth watching for the information it provides. It is interesting watch the Arborist create the hollows with a chainsaw.
Playford Council also provided native plants to the resident to add to the local biodiversity close to the habitat tree. It’s great to see such enthusiasm from all involved, including the resident who lives closest to the street tree. It’s a wonderful video.
To watch see – https://www.youtube.com/watch?v=mPLWrmMjmnc
City of Sydney Council has recently created two ‘habitat trees’ in Sydney Park. Both trees are Eucalypts & are located close to the lower pond. They are surrounded by other tall trees & so would make attractive homes for wildlife.
A significant difference from the ‘habitat tree’ created by Marrickville Council in McNeilly Park is that the branches have not been ring-barked – at least it had not been done when I saw these trees. It appears that Sydney Council has created more holes in each tree than the one in McNeilly Park.
Like Marrickville Council, the City of Sydney Council is also using these trees as a demonstration for professionals on to how to create nesting hollows for birds & animals.
I really like this movement to retain trees that would have been removed previously. The idea is to mimic dead trees found in the bush.
The more I read about dead trees the more I realize how important these old dead trees are to the ecology of the environment. Standing dead trees in the bush are called snags & stag trees.
Only old trees have hollows & these trees often need to be 100-150 years old before they start creating hollows. Eucalypts start creating hollows after dropping branches & we know that once branch-dropping starts, the tree is removed for the safety of the human population.
“Australia-wide, 15% of all land birds use hollows. These 114 species include parrots, owls cockatoos & lorikeets, ducks, treecreepers, owls, owlet-nightjar, kingfishers, pardolotes, martins & woodswallows.” ~ Sourced from Wildlife Notes, Department of Conservation & Management April 2005.
“One of the least known characteristics of Australian animals is their high utilisation of tree hollows. For example, the proportion of Australian animals that use tree hollows is three times greater than in North America & twice as great as in South Africa.
About 350 Australian animals use hollows for either roosting or nesting. This includes:
- half of our small bats,
- nearly 90% of our parrots,
- all of our gliders,
- all but one of our owls
- all of our tree-creepers.
Nearly 20% of our birds use hollows in some way. For 60% of these, hollows are essential.” http://www.ozbox.net.au/anim&holl.htm
Of the 22 species of bats that have been recorded to utilise tree hollows in NSW, 10 of these are listed as threatened. (Gibbons & Lindenmayer 1997).
Repurposing trees that would have been removed so that they become useful for wildlife is a great idea. Tree hollows in urban environments are very rare. I look at trees all the time, but only know of three trees on public land in Marrickville LGA that have natural hollows. I applaud this move to help wildlife & improve on biodiversity by both Councils. It will be interesting to see what wildlife do take up residence in these hollows.
Tree-planting volunteers in Western Australia are waiting for official confirmation of a new Guinness World Record after planting more than 100,000 tree seedlings in one hour. How fantastic is that!
The current record holder is India with a record of 99,103 trees, which was set in 2012.
The event organized by the ‘Men of the Trees,’ who are well known for their tree planting, gathered more than 2,200 volunteers in Whiteman Park in Perth. Twelve hundred participants were school children.
Confirmation from Guinness World Record should happen within the next two weeks.
See – http://ab.co/1l2PZKN
I love it when I receive emails pointing me to media articles that prove to me that my observations about Marrickville’s urban forest are correct. An article in yesterday’s Sunday Telegraph said -
“A survey of the city’s tree canopy shows Botany Bay has fewer trees than any other suburb, with just 12 per cent leaf cover.
Next comes nearby Randwick, with 14 per cent, and beachside Waverley is also near the bottom with only 17 per cent. Other suburbs under 20 per cent include Auburn, Marrickville, Holroyd and Strathfield.”
Suburbs blessed with a tree canopy of above 50% were Pittwater, Warringah & Ku-ring-gai. Suburbs with more than 30% canopy were Lane Cove, Hunters Hill & Ryde. Manly, North Sydney, Penrith, Liverpool & Burwood followed. These statistics were gathered by the University of Technology Sydney & compiled by the 202020 Vision.
The 202020 Vision is a national initiative that includes government, local councils, the private sector, individuals & academics. The initiative was launched in November 2013, well before Marrickville Council’s new Street Tree Master Plan was released.
The 202020 Vision has the wonderful aim to increase urban green space by 20% by 2020. They want more trees, gardens, green walls & green roofs, because these will improve the livability of our suburbs & cities, as well as the health & wellbeing of the community & wildlife. The use of hard surfaces, increased development & a rising population is creating urban heat islands & poor air quality.
Of course the urban forest & public trees are a major part of this. I have heard some of the Marrickville Councillors saying on a number of occasions in Council Meetings that we have enough public trees & one even said that we may even have too many. Another Councillor even wanted all the street trees removed from the historic Abergeldie Estate in Dulwich Hill.
I must say that I find it exciting to see a strong movement to increase the canopy of Sydney. To me trees are a public health issue & the research backs me up on this. Maybe one day Marrickville Council will publicize on their website & in newsletters such as ‘Marrickville Matters’ just how many trees they target to plant & how many they actually planted each year. That would be good.
I will post more about the 202020 Vision soon. To read the Sunday Telegraph’s article, see – http://bit.ly/1zixCtJ
Next Sunday 27th July is National Tree Day. To commemorate this day, the National Trusts of Australia has, in a world first, put together a national register of 25,000 significant trees. Information about these trees will be available on a new website & also available as an app. This means that you can look for significant trees while you are out traveling the country.
You can also nominate any tree that you think is significant. The tree/s you nominate will be assessed by the Significant Trees Committee for each state ot territoty to see if they are suitable for inclusion in the Register.
This is not just about celebrating trees, but also about their protection. A registered significant tree has a greater chance of being protected from development. Not always, but any tree is safer being on a National Trust Register.
To get a national map like this is very special & I predict that it will be a popular download both for residents & visitors to Australia.
The National Trust of Victoria has an excellent free app that maps & provides information on more than 24,000 significant trees in Victoria. I have long enjoyed perusing this app because of the photographs & often detailed information about the trees. You can download this app here – https://itunes.apple.com/au/app/trust-trees/id426819442?mt=8
You can download the National Register of Significant Trees app on & after National Tree Day here – http://trusttrees.org.au
Planet Ark has just released their 2014 research in the lead-up to National Tree Day – ‘Valuing Trees: What is Nature Worth?’
The following are just some of the research findings -
- “Australians would be willing to pay an average of $35,000 more to buy a home in a nature-filled neighbourhood than for an identical home in an area with little nature.
- 4 out of 5 Australians (78%) said they would prefer to live in a home with many natural elements, such as trees, plants and a garden, over one that does not have these features.
- Having a home with a backyard and living in a “green” neighbourhood with trees, parks and gardens was rated as more important than being close to work, having easy access to public transport, and having good shops or a shopping centre nearby.
- More than two-thirds of Australians (68%) agree that living in a neighbourhood with lots of trees, gardens, and parks would reduce their stress levels.
- 2 in 3 Australians (66%) agree they would be more likely to do outdoor exercise if they lived in a green neighbourhood.”
Trees are a public health issue. Having lots of good trees & a visible canopy makes for happier & healthier communities. Marrickville Council should allocate more funding in the annual budget to allow the urban forest to be increased & also to create equity of streetscape across the whole municipality.
You can download Planet Ark’s full Report or the shorter Key Findings here. It is an interesting read – http://treeday.planetark.org/research/
National Tree Day is celebrated across the Australia on Sunday 27th July 2014. Marrickville Council will be holding their National Tree Day event two weeks later on Sunday 10th August from 10.30am – 1.00pm at Tillman Park Sydenham. Council says the community will be able to participate in “planting local native trees, shrubs, sedges, grasses, ferns and groundcovers.”
The staggered dates will give us a chance to participate in other National Tree Day events held locally, as well as our own.
The City of Sydney & Planet Ark’s National Tree Day event is held on the traditional date – Sunday 27th July 2014 from 10:00am – 2:00pm at the southern end of Sydney Park. Participants will be able to experience the joy of planting trees. Last year’s event was fabulous. They plan for the community to plant between 4,000 & 5,000 trees during the event. This is a small forest! Judging by previous years crowds, I’d say the target will be achieved, probably with time to spare. Can you imagine how great 5,000 trees will look as they start to grow! It is a nice feeling to walk past growing trees that you have helped plant & I imagine that this feeling is even greater for children who helped plant a tree/s.
I’ll post a reminder of these events closer to the date.
A month or so ago I watched a segment on the television program ‘Trust me I am a Doctor’ about how an experiment with birch trees placed along a high traffic street impacted on air quality. See -http://bbc.in/1fjuxnm
The results were surprising, particularly because these were only small trees in pots. The experiment, developed by Professor Barbara Mahar from the University of Lancaster England consisted of twenty-four young Silver birch trees in pots lined up along the footpath beside four terrace houses. The trees were left in place for two weeks. The adjoining four other terraces were also included in the experiment.
Prior to installing the trees, the computer & television screens were cleaned in all terraces. They were then left on stand-by as these items produce static electricity & would continue to collect airborne dust & particulate matter.
At the end of the fortnight, all the computer & television screens were cleaned again. The air pollution collected on the screens was found to 50-60% lower in the four terraces that had the birch trees between them & the road, showing how vital street trees are for collecting particulate matter, dust & other pollutants from passing traffic.
Whether this percentage of protection happens with all street trees is not known, but the birch trees were chosen specifically because their leaves have hairs & ridges, which collect small particles. It may be that birch trees are found to be superior trees at collecting air pollution.
Every tree collects particulate matter & other air pollutants on their leaves, though it may be that some are better at collecting than others. According to the article, trees with a denser canopy are not as effective at trapping air pollution as are the sparse canopy Silver birch, which allows for free airflow. Denser canopy trees tend to collect pollution at ground level, where people are.
Rain cleans the leaves allowing the process to start again. Deciduous trees would only provide this benefit while they have leaves.
Vehicle exhaust releases very fine particles of particulate matter (PM), which is breathed into our lungs. From there it enters our cardiovascular system. “A recent government report [English] suggested that as many as 29,000 people a year die because of breathing in too much PM.”
The article lists three ways to limit exposure of particulate matter when outside -
- School drop off zones have high levels of particulate matter because of all the idling cars. “So a quick drop-off, & fewer cars at the school gates is important.”
- To reduce your intake on particulate matter when driving, especially when stuck in heavy traffic, keep the windows & vents closed. Also keep some space between you & the car ahead.
- Cyclists are advised to avoid routes with heavy traffic. Pedestrians are advised to walk as far away from the traffic as possible & also avoid walking along streets with heavy traffic. See – http://bbc.in/1tSRh1m
A 2013 study by the Laboratory of Aviation & the Environment at Massachusetts Institute of Technology found that premature death caused by air pollutants was the highest from road transportation – that is vehicle exhaust. http://bit.ly/1k0tbtH
The humble street tree continues to demonstrate its worth. They provide the community with many benefits, including better respiratory & heart health. It is already known that residents in suburbs with fewer trees have poorer health, so increasing the canopy must be a priority.
There is an interesting article in The Conversation written by Prof. Rod Keenan & Benjamin Preston, both from the University of Melbourne.
Some points in the article –
- Victoria currently has an average of 9 days per year of temperatures above 35C. No action on greenhouse emissions will likely result in an average of 21 days a year with temperatures above 35C by 2070.
- “Combine that with increasing urban density, more hard surfaces & less greenery, & a larger, older & more multicultural population, & the potential impacts from heatwaves start to multiply rapidly.” Think of the development already in Marrickville municipality & the huge amount of development to come.
The Authors suggest two ways to help mitigate this & I think these are applicable Australia-wide –
- Increasing the ‘green infrastructure’ by 10%. Green infrastructure means street trees, parks, green roofs, green walls & retaining water.
I’d suggest 10% is the absolute minimum, but can you imagine the positive change if the Marrickville urban forest was increased by 10%.
The City of Melbourne is planning on increasing their urban forest canopy cover from 22% to 40%. The City of Sydney is aiming to increase their urban forest by 50% by 2030 (just 16-years away) to help lower the urban heat island effect.
- 2. Education.
“Health awareness programs can promote related benefits such as improved air quality; planners can reduce the red tape involved in planting street trees; local governments can identify priority neighbourhoods for development, protect existing greenery, & implement water-sensitive urban design.”
“Increasing green infrastructure will also require the use of private space – one major challenge will be to give private landowners the incentive to keep or install greenery & incorporate vegetation into building design.”
Although Sydney has not experienced a true heatwave this summer, it has been very hot. Melbourne & Adelaide both experienced two heatwaves this January, baking over a number days. On 16th January, Adelaide was given the title of ‘the hottest city in the world’ with a temperature of 44.2C, still short of the forecasted 46C.
An article on Care2 discusses the American city of Phoenix trying to cope with 100-degree nights. “The city averages more than 100 days a year with temperatures reaching over 100 degrees. (37.7C) In 2013, 115 days hit 100 degrees. In 2011, the city set a new record for days over 110 degrees (42.3C) with 33. That’s over one month of the year with scorching highs. This winter has so far been warmer than average.”
Temperatures are rising everywhere. The urban heat island effect is increasing those temperatures, & importantly, not allowing the temperature to drop after the sun goes down. Phoenix has “a shade plan for the built environment & also a plan to “frankly just plant more trees.” See – http://bit.ly/LuA1xC
We need to start planting now in both private & public spaces if we are to ever hope to be able to cope with projected temperatures. Sydney’s temperature is expected to be like living in Rockhampton in Subtropical Queensland. See – http://bit.ly/1aLsaYf
Marrickville Council needs to decide how much to increase the urban forest & set & meet targets to achieve this. The yearly budget allocation needs to be such to allow this to be achievable. I have often wondered whether public trees & parks are lower down in the budget & whether these are seen as not as important as grey infrastructure.
Certainly we need to do what we can to keep the trees we have & this means treating them for diseases, fertilizing, mulching & pruning where necessary.
In my opinion, the community needs to help Council keep new trees alive by continuing to water trees once a week when Council has stopped water 12-weeks after planting. It only takes a few hot days to lose a tree & if we look realistically, the bulk of our street trees are living in very harsh conditions. Many are either hemmed in by concrete or in visibly dry & compacted soil.
I know there are many who will baulk at the idea of watering a public tree, but it is commonplace in many countries overseas. The US for example, has a strong community involvement in public trees, whether planting them or looking after them. Both the US & the UK have community ‘Tree Wardens’ looking after public trees. These people are not tree experts. They receive training by their Local Council to do the work they do.
Keeping that tree alive will help reduce your power bills as they help cool the air around your house. Street trees clean up the air by removing particulate matter from vehicles, so better quality air comes into your home. They also increase the value of your residence or business amongst many other benefits, so it stands to reason that taking care of the tree outside your property brings significant returns. Better a living healthy tree, than a dead tree or a sapling that struggles to grow & may take many years to reach a decent size.
Older larger trees are far better at carbon sequestration than smaller trees – another reason why it makes sense to look after them.
You can read the full article here – http://bit.ly/1mQumNW
“Few residential trees die of ‘old age.’ Mechanical damage and improper tree care will kill more trees than any insects or diseases.” This poster ‘How to Kill a Tree’ by Virginia Tech University (1996) was posted to my Facebook page. It’s so good I decided to share it here.
Like me, you have probably seen a lot of these yourself.
Click the photo for a larger image.