Showing posts with label Trees. Show all posts
Showing posts with label Trees. Show all posts

Monday, 13 January 2014

What makes trees so special ?

 The best trees of, course, are the ones that grow in intact native forests, supporting complex ecosystems ...and their conservation is of premium importance. Tragically, Australia’s government wants World Heritage listing for Tasmania’s iconic forests to be revoked so they can be logged. Tassie's Forests ; they allow Victoria’s fragile forests to be pulped to make Reflex Paper. Ethical Paper Campaign; whilst majestic Karri and Jarrah forests in Western Australia continue to fall. Logging in W.A.

 But if you live in a city environment, the “urban forest” is pretty significant too. 

 In my suburban street at Manly Vale, Sydney, the community has planted a 1.5 km avenue of native trees and shrubs alongside a moderately busy road called King St. This was done with the assistance of a NSW government grant and it is now maintained by volunteers. 

 We did this because we wanted to plant species that were endemic specifically to this area and to help replace some of the biodiversity that was missing from the street (and most other local streetscapes). 

King St Tree Planting in Manly Vale.
 It was hoped maybe that the species chosen could be a template for other street plantings (where, traditionally, foreign or “out of area” species were selected). Native trees grown from  locally sourced  seeds, are naturally already suited to our soil and weather conditions and won’t escape into our bushland areas as invasive weeds.

 Unfortunately a new plan by Warringah Council to plant trees in a few selected streets contains a significant proportion of “exotic” trees (some invasive weed species) and numerous natives not local to our region.  Warringah Council Tree Plan This isn’t exactly following the “Landcare ethos”

 The avenue was also planted as memorial “avenue of honour” to pay tribute to the service and sacrifice of Merchant Navy personnel in two world wars. Often, these servicemen were not included in other traditional war memorial settings. Avenue of Honour

A stone monument to the Merchant Navy acts as a centrepiece in Kings Reserve.

The species planted are endemic to the suburb of Manly Vale, NSW. On the left is a Banksia Serrata (Old Man Banksia) on the right is
a Banksia Marginata (Silver Banksia)

 This one is a rare Angophora Crassifolia.
All this was important..but it seems that the value of street plantings far exceeded our wildest expectations.

Here is a selection of the additional benefits that planting, or preserving, urban trees can bring.

1/ Shade provided by urban trees can cool buildings by up to 20 degrees in the summer. Researchers at Curtin University in Perth found that a lack of trees in the city contributed to heat-related problems for residents. Without tree cover, conditions could get worse, as predicted temperature increases associated with climate change, posed a "significant threat" to human health.

2/ A single tree can produce a day’s oxygen for four people.

3/  In one day a large tree can remove up to 380 litres of water from the ground and release it into the air.

4/ A tree living for 50 years will generate $62,000 worth of pollution control plus increase soil fertility and control soil erosion to the tune of $31, 250. It will also generate $31, 250 worth of oxygen, recycle $37,500 worth of water and provide a home to animals worth $31, 250. In total, one tree is worth $193, 250 (Professor T.M.Das, The University of Calcutta).

5/ Research has found that motorists slow down whilst travelling through a tree lined portion of a street as drivers tend to go more slowly when something is in their peripheral vision. (Texas A and M)
6/  According to the real estate sector, tree lined streets can add $15-25,000  of value to homes and businesses versus  non tree comparable streets.

7/ Studies conducted in California show that shade from urban trees can add 40% to 60% more life to road and pavement surfaces through the benefits of shading.

8/ Trees create a safer walking environment by providing distinction between road edges.

9/ Trees create more pleasant walking environments, provide a sense of place and encourage more pride, ownership and care in (and of) an area.

10/ Businesses on treescaped streets show 20% higher income streams.

11/ Trees reduce storm water run-off and flooding by absorbing water  Water sinks into the soil under trees at 67 times the rate at which it sinks into the soil under grass! 

12/ Trees provide protection from rain, sun and heat.

13/ Trees absorb car and truck exhaust pollution including carbon monoxide, nitrogen oxides, organic compounds and particulate matter which add to asthma and other health impacts. They also convert harmful gasses back into oxygen.

14/ A properly shaded urban street can reduce energy bills for a household by 15% to 35%.

15/ Trees convert streets, parking areas and walls into more aesthetically pleasing environments and act as a screen and filter of "visual pollution".

16/ Trees reduce blood pressure and improve emotional and psychological health. They have a calming effect on ADHD effected adults and teens.

17/ There is compelling evidence to suggest that motorist ‘road rage’ is less in green urban environments compared to stark urban areas.

18/ Research has shown that healthy street trees help lessen the levels of domestic violence.

19/ An analysis of numerous studies in BMC Public Health found evidence  for street trees having "direct and positive impacts on well-being," in the form of reduced anger and sadness. Getting people actively involved in the planting process makes communities even happier.
20/ A Dutch study suggests every 10% increase in green space can postpone health complaints in communities by five years. And a US study is suggests patients that have a view of nature through hospital windows recover better after surgery.
21/ Street Trees help improve biodiversity as as tree-lined streets provide wildlife corridors for birds, animals and insects to travel. In Australia, “hollow bearing’ trees are vital in creating homes for arborial marsupials, bats and birds.
22/ Dutch researchers at VU University discovered that even glimpsing “green” through a dingy urban window can push the brain to consider the long-term future. People who watch plants grow exhibit better spending impulse control. Inner-city girls with views of green space from their window have proved more adept at concentration, impulse inhibition, and delay of gratification.

Why not contact your local Council for assistance and plant endemic native species from your own specific environment in your street ! If you live on Sydney sandstone country..the one below would be perfect!

Angophora Costata (Smooth-Barked Apple)

Thursday, 20 June 2013

Barking up the right tree.

  I can never understand why someone would want to cut a tree down to enhance their view. To me the tree is the view. Would you really prefer to stare incessantly into a vacuous distance or witness a living, growing, ever changing life-form, up close? 

  In Australia we’re lucky to have an amazing diversity of trees, many with wonderfully textured bark and curiously decorative seed pods. Take our locally iconic Sydney Red Gum (Angophora Costata) for example. With its smooth, salmon pink trunk and wrinkly, intricate limbs, it is gracefully architectural. 

 But trees have much more than good looks going for them. According to T.M. Das of the University of Calcutta, a tree living for 50 years will generate $31,250 worth of oxygen, provide $62,000 worth of air pollution control, prevent soil erosion and increase soil fertility to the tune of $31,250 and recycle $37,500 worth of water. He didn’t consider the fact that shade provided by trees can cool buildings by up to 20 degrees in the summer (hence massively reducing air conditioning bills). But trees do even more than that. Real Estate agents estimate that there is a $15-$25,000 increase of a home or business value in a tree lined street compared to one without trees. There is also compelling research to suggest that road rage is less in green urban areas  than in stark treeless ones and the aesthetic qualities of trees is well known to reduce blood pressure and ADHD.

 So embrace your trees, perhaps hug them if you’re so inclined and if possible, plant one yourself. If you do, remember - trees which are native to our area, are suited to our own soil and climatic conditions and provide food and shelter for our local wildlife. It makes sense, therefore to choose a species which is indigenous to the Northern Beaches.  


 A gorgeously tactile Sydney Red Gum.

  For some ideas on planting low growing, non obtrusive, endemic street trees and shrubs, check out the King St Avenue of Honour in Manly Vale   Green Tribute to the Merchant Navy.