Adopt a Tree Programs

A while ago I wrote about an idea I had for Marrickville Council to start an Adopt a Tree program to encourage people to take care of the street tree out front.  I have also written about other ideas to increase & look after the urban forest in Marrickville LGA. These have been collected in the following page – https://savingourtrees.wordpress.com/tree-planting-ideas/

This young street tree has a fighting chance of surviving because it is planted in a grassed area. Still the odds are very much against it.

When I posted these ideas I had some anxiety as to whether I was asking too much of the community & whether the community would even consider taking part if such programs were in place.

Yesterday, to my delight, I discovered that Randwick City Council has a program that goes much further than what I thought about & asks a whole lot more from the community.  They instigated an Adopt a Street Tree Program. The following is directly from their brochure:

This program provides residents with the information they require should they wish to personally contribute in a practical way to the long-term maintenance of newly planted street trees. By ‘adopting’ a street tree, residents voluntarily take on the role of not only watering a street tree, but also regularly inspecting it for pests & diseases & informing the Council of acts of vandalism or other problems. http://www.randwick.nsw.gov.au/Looking_after_our_environment/Greening_our_city/Trees/

Randwick City Council also prunes trees when needed & ask residents to notify them if they think a street tree needs pruning. I have written a couple of times that I think dead or dying branches of street trees could be pruned before they fall as this is a normal cycle for trees. I think in Marrickville LGA, if a street tree drops branches, they are marked as dangerous trees & put on the death-row list.

I tend to write about trees as issues come up & then research the issue. This approach works for me because the urban forest is a big subject & any research generally has to be specific.  Today I Googled ‘Adopt a Tree Programs’ & found that this is being done by a number of Municipal Councils in Australia & overseas.

Some examples follow.  I have quoted directly from their website & bolded particular points because they impress me.

The City of Stonnington, Inner city Melbourne. Residents in streets where trees are 3 to 6 years of age are being asked to adopt the tree in front of their home & by doing so commit to watering it twice a week with recycled water. http://www.stonnington.vic.gov.au/www/html/4578-adopt-a-tree-program.asp

The City of Port Phillip Melbourne. By simply adopting a tree in your street or neighbourhood, & watering it weekly, you will help to save the trees within the city from the ravages of drought. …. the Port Phillip Council is giving away Free Buckets which can be collected from any of the locations provided onsite. http://www.freestuff.com.au/gardening-products/port-phillip-adopt-a-tree-and-get-a-free-bucket

The City of Marion, Sturt South Australia. People who register will receive a free watering bucket & detailed tree care instructions. Watering a tree outside your home once or twice a week will help preserve one of the city’s most important natural resources. http://www.marion.sa.gov.au/site/page.cfm?u=556

Moonee Valley City Council. Launched in 2006, the Adopt a Tree program invites residents to care for a street tree during this period of dwindling water supplies. Parents of adopted trees will get an official adoption certificate, a bucket & a litre of environmentally-friendly laundry liquid.

http://www.mvcc.vic.gov.au/Page/Page.asp?Page_Id=1995&h=1

Torres Shire Council. A special “Adopt A Tree” award category has been included in our 2010 Torres Shire Garden Awards that will be held in June this year. http://www.torres.qld.gov.au/news/2010/adoptatree.shtml

Wollongong City Council. Since its State pilot in Wollongong during 2003… Other residents interested in planting more native trees in their own yards can take advantage of Council’s Greenplan which offers 5 trees for $15.

http://wcc.wollongong.nsw.gov.au/MediaReleases/Adopt%20A%20Street%20Tree.pdf

The City of Unley South Australia. Currently the Council provides a bucket and fact sheet to residents when a new street tree is planted. The fact sheet provides some detail as to how the resident can assist by watering the tree in its formative years.  Part of the strategy relates to Unley’s street trees, & includes a recommendation that the Council launch an Adopt a Tree program.

Also of interest in the City of Unley papers regarding street trees was:

The economic value of trees is derived from:

• Their association with reduced energy consumption (a well placed shade tree can reduce consumption by up to 30%)
• Contribution to property values (trees in the metropolitan area contribute 13-20% of property value), & potential for contributing to higher profits for businesses.
• The monetary value of Unley’s 22,000 street trees is estimated at approximately $150.2 M (Burnley Method). To remove a tree costs on average $1000, and to replace costs $200.

http://www.unley.sa.gov.au/webdata/resources/files/Att_1_Item_515_Council_Sept_2009.pdf

The University of Melbourne. Although the University of Melbourne is not a Council, I have included them here as their Adopt a Tree Program assists Melbourne Councils.

Many trees have dropped their scorched leaves from the extreme drought & this summer & many are under stress from a lack of water. The local councils cannot save every tree as they are under-resourced & under water restrictions themselves. The City of Melbourne, for example, has over 60,000 trees to care for & they need our help as a community by contributing our own grey water to help water our beautiful trees. http://www.sustainablemelbourne.com/movements/adopt-a-tree-in-melbourne-share-the-idea-around/

Planted in paving, under an awning, all the odds are against this tree surviving unless it is cared for.

I wish Marrickville Council would follow these other Councils & set up an Adopt a Tree Program.  It may not take off immediately, but it may prove popular.  Needless to say, all programs need time for the community to get to know about & decide to get involved.

Even if it did only amount to a couple of hundred households/businesses participating during the first couple of years, at least 200 trees or more a year could be helped to survive.  This is significant, as Council plants up to 500 trees a year.

Harvey Norman axing car park trees

On 24^th June 2010 I saw an item in the Inner West Courier saying, “A last minute appeal from WIRES has postponed tree surgeons felling trees containing Ibis nests in an Auburn car park.” Harvey Norman, the retail store & owners of the car park, agreed to wait 2 weeks for the fledglings to leave the nest. There was no further information except for a gallery of photos –

http://inner-west-courier.whereilive.com.au/photos/gallery/respite-for-auburn-ibiss/

A Google search failed to find anything further about this story. In today’s issue of the Inner West Courier there is an article saying workers who arrived to chop down 2 palm trees in Harvey Norman’s car park rang WIRES for help when they saw many baby Ibis. Despite care, during the removal, one baby fell from the nest breaking its leg & will have to be euthanized. All up, 9 baby birds were removed from the tree & taken into human care to be raised & then released when they are old enough. Another 12 Ibis will be able to stay a further 2 weeks as was negotiated by WIRES with Harvey Norman retail store Auburn. Page 7 – http://digitaledition.innerwestcourier.com.au/

Fabulous almost cement-free car park in Croyden with a shade tree for every 2 spaces. Rain gets to be absorbed into the ground rather than washing down storm water drains.

Is there something wrong with me? Why remove 2 Palms in a car park? We need trees to at least break up some of the grey infrastructure in a car park.  A car space either side of the 2 Palms could have been made into a garden so that Ibis poo didn’t fall on parked cars. Sure these birds are messy, but I have stood beneath a number of trees located on grass where Ibis nest & there is no mess to speak of.  Concrete is a different matter.

The workers sent to remove these trees & WIRES deserve applause for doing what they could do help these birds.  Thing is, I don’t believe it was necessary for them to go in the first place.  WIRES constantly have to deal with people & organizations who want what they want at the cost of habitat for wildlife & often resulting in the death of wildlife.

That WIRES had to remove 9 chicks from their parents to be reared by humans before being released is pretty sad.  It’s not as though the chicks didn’t have parents. They did, but for the sake of a neat car park that Harvey Norman wanted now, the adult birds had to lose their chicks & the chicks lose their parents.  This would be okay if you believe that only human beings have emotions.

I know people don’t like Ibis, but remember, they migrated to

Ibis eating at low tide at the Cooks River Marrickville

Sydney because of the drought. They had to come because they had nothing to eat or drink.  Could you expect them to do anything different?

Harvey Norman in Auburn caused all this simply for a nice, neat treeless car park.  Cement wins once again.  The time will come in the future where people will respect commercial businesses that make space & create or keep habitat to share with urban wildlife.  Right now, few people probably care, but to me, this whole affair stinks & is cruel. No wonder there was no information to be found on the net.  I wouldn’t imagine that Harvey Norman would really want people to know about this as it may negatively impact on their image.  I thank the Inner West Courier for bringing this issue to the attention of the public & to WIRES & the other workers who did what they could to help these poor birds.

Trees are restaurants

Currawong

This months Festival of the Trees is looking at food for wildlife.  Marrickville LGA has quite a lot of  wildlife for an inner city urban area, especially with the Cooks River, the Tempe Reserve & Wetlands & some of our major parks.   The presence of nearby Girraween Park  at Wolli Creek helps our urban wildlife enormously.  However, when we first moved into our home 15 years ago there weren’t many birds in our immediate neighbourhood.  There were some of course, but we were not as aware of them as we were in our previous home.  They were mostly Pied Currawongs in winter, Common Mynas all year round & a couple of Turtle Doves as well.  Over the years this has changed significantly.  Now birds feature strongly in our neighbourhood.  So what happened to bring the birds here?

The neighbourhood around us changed in that many new people moved in & they did 3 things.  They removed the cement from their garden, reduced the size of their lawn or did away with it altogether & they planted trees & shrubs, many of them Natives.  Some of my neighbours are spectacular gardeners converting their bare gardens into mini-botanical havens filled with a variety of bird-attracting plants.  The transformation has been dramatic & they still kept the lemon tree.

birds sunning themselves

The other thing I noticed was that many people started putting birdbaths and/or ponds in their gardens.  This combination of water & food brought the birds back in droves.

It also brought the frogs seemingly by magic.  We put in a pond & 2 days later a rare frog breed arrived.  Now we have small frogs that hibernate under our very small piece of lawn.  They wake up in summer & leave at night.  We hear them, but rarely see them.

At least 24 Turtle Doves live in our block now so their family extended. There are many White Eyes, Willy-Wag Tails, Red Wattlebirds, Magpie-larks, Australian Magpies, large groups of Noisy Miners, Red-whiskered Bulbuls, Crested Pigeons, a Common Koel or two, Grey Butcherbirds, Olive-backed Orioles, Silvereyes, Figbirds & Pallid Cuckoos.  Masked Lapwings fly over-head on their way to the river.  Even a couple of Spotted Pardalotes have moved in.  This is amazing as they live in areas with many Eucalypts, not Sydney’s Inner West.

small part of a large flock of Cockatoos who visited

Large groups of Cockatoos fly over most days & when the nuts & fruit are ripe, they descend on mass devouring them.  It’s a gorgeous sight & they are very noisy.  The powerlines can be covered with white birds all with something to say.  Both neighbours who grow the food the Cockatoos like to eat do not mind the invasion of these birds.

We still have the Pied Currawongs & Common Mynas, but they are not so destructive now they are out numbered.  The Common Mynas tried to get everyone to move, but the sheer numbers of birds had their power reduced to almost nil.  They now just get on with living.  We also have native bees & a Ring-Tailed Possum or two.

From a reasonably quiet area in terms of birds, our neighbourhood has become filled with bird song & bird activity.   I love the change.  It seems somehow more like I remember things used to be when I was a child & the presence of birds was taken for granted.

The Australian Museum has a wonderful web-site called Birds in Backyards. They list 40 birds & provide a fact-sheet & a short sound-bite of each bird call.  It is a wonderful reference for school children as well as people like me who don’t know much about birds.  Through this site I have been able to identify 20 of the 40 birds listed that I can hear & many times see from our own back garden.  http://birdsinbackyards.net/feature/top-40-bird-songs.cfm

Birds provide white noise that is soothing & helps block out traffic & other noises that can lead to stress.  They also help you in the garden by eating the insects that eat your plants.

White-eye

If you want to attract birds into your garden & neighbourhood, all you need to do is plant a variety of bird-attracting Australian native plants & provide a source of water.  The water is best placed near other plants as this gives the birds a sense of safety.  They will use a birdbath in the middle of a lawn, but if there is another in a better location, they will use that one first.

Our birdbath needs filling often & sometimes daily during hot weather.  A wide range of birds use it to drink & bathe at many times during the day.  Sometimes there is a line up.  The larger birds go first with the smaller birds in surrounding trees watching & waiting for them to finish.  At night, much to my delight, the bats use it. I haven’t managed to see them yet, but I hear the “woop, woop, woop “as they take off vertically.

If you can, plan to plant a range of plants of different heights & thicknesses.  Some birds love to go into small shrubs & eat the nectar from flowers & insects while hidden from sight.   Others are not afraid to sip nectar from flowers high up & in open view.  A range of plants will ensure a variety of birds visit.

Cockatoo eating something from my neighbours garden

Native grasses offer a great source of food as well.  I have seen them used in very creative ways by my neighbours.  Most Australian Natives do not require much water once established & thrive in poor quality soil, though they do appreciate mulch & regular fertilizing with a Native fertilizer.

Native plants can be used successfully with a cottage garden if that is your preferred look.  Many are prolific flowerers & some have flowers all year round.  Most respond to pruning allowing them to be kept in a shape you like. Pruning encourages more flowers & bushiness.

From being a person who preferred cottage gardens I have become someone who would rather plant something that gives food to another.  I do think the long drought we had stressed the wild birds & animals, as their water sources shrunk & their food sources didn’t flower or simply died.  The Ibis who have decided to stay in Sydney are an example of this.  Even though it’s raining torrents in Sydney & parts of NSW have flooded, the drought is not over by a long shot.  16 areas or boundaries in NSW (a little over half the state) are classified Exceptional Circumstances. This is done when drought is regarded as severe.

As a number of people have indicated they want ideas for native shrubs & trees, I’ll do some research & put together a list soon.  It will be good learning for me as I am not an expert in this area either.

Kookaburra

That tree could be worth BIG money

I recently came across a video segment from the program Stateline on ABC from March 2010 where they discussed the dollar value of trees.  This video discusses the following & more:

• The loss of Adelaide’s street & park trees for lack of water
• Melbourne has decided to water their street & park trees
• A real estate agent talking about how both street trees & trees on the property increase the value of the property
• How much trees are actually worth
• What it will be like to live in an area that has few or no trees
• Councils used to irrigate street trees
• Residents used to give trees both on their property & in front of their property regular watering
• The cost of watering trees to save their life far outweighs the cost of losing a tree through lack of water
• How the fact that a tree is not a native somehow gives permission for it to be cut down
• Trees can be worth as much as $100,000
• Trees are assets & investments which appreciate over time

roots of a big, beautiful Fig

In Melbourne, they are talking about how their 100-year-old trees are “an extremely valuable asset” while Marrickville Council talks about our older trees as “senescent” & past their time.  You may remember earlier this year Marrickville Council put up a plan before the Councillors to remove many of the old trees over the next 5 years.  The designated amount was 1,000 trees to be removed per year for 5 years targeting senescent trees.  Thankfully the Councillors did not accept this Tree Strategy Issues Paper, but it was a close call & a revised Paper will be returning for consideration soon.

This video is 7 minutes duration.  I whole-heartedly recommend watching it.  If you do, check out the hole in one of the larger trees right at the end.  I have seen a

Pine tree in Brighton le Sands

tree like that closer to home along the beachfront at Brighton-le-Sands.  A few of the tall pines had substantial holes in their trunks. Rather than chopping them down, Rockdale Council had the rot treated & the hole cemented allowing the tree to remain stable & continue to live for the benefit of the community.  I would imagine those trees are heritage listed.

When I was a child, it was quite common for a Tree Surgeon (as Arborists were called then), to be employed to save trees on private property. I remember watching them scrapping out the hole, using chemicals to stop the disease & filling the hole with cement, just like a dentist fills dental caries.  I saw trees bolted together if they had a split in their trunk & other such things that seem to be out of vogue today.  Nowadays, the simplest intervention seems to be to cut the tree down saying “everything has to die.”  True, but many tree species live far longer than what we are led to believe.  Melbourne is proof of this.

As we have been in a long & protracted drought that is not over yet, trees dying from lack of water is going to become a significant issue, especially if the culture changes & trees are truly recognised as significant green assets.  We may yet return to the days where Councils water the public trees & property owners take care of the trees on their property as well as the tree out front.  I have my fingers

lovely Fig in Enmore Park

crossed.  Already around the municipality there are trees dying.  Some of them were stunners that now stand brown & present a danger of falling, damaging property & perhaps a risk to life.  I find it sad as many of these tree deaths could have been averted if they had been watered.

Another article in the same vein that may be of interest says Adelaide City Council is considering putting a dollar value on its trees following in the footsteps of Melbourne.  This may lead to developers being required to compensate for the trees they say they need to chop down by planting trees to that dollar value.  So if trees are valued at $100,000, they will be required to plant trees to that value.  I’m hoping it may bring business to those tree companies who are skilled at large tree relocation.  Relocation costs may actually be cheaper than paying for the trees that would be lost if chopped down.

http://www.abc.net.au/news/stories/2010/04/13/2870993.htm

The Stateline video & a transcript of the main points can be accessed by clicking on the following link- http://www.abc.net.au/news/video/2010/03/26/2857693.htm

This beautiful tree-lined walk along the Cooks River offers respite from the city's hectic life. The tall trees which make this section special.

Sydney’s Royal Botanic Gardens Trust wants ‘threatened species’ bats banished

Cooks River at dusk - the black marks in the sky are the bats leaving their home in Wolli Creek - I am told it is a spectacular sight to see them leave from the vantage point of just outside the park

Sydney’s Royal Botanic Gardens Trust have been concerned about a large colony of bats who have made their home in the Gardens for years.  The bats are grey-headed flying foxes, which are listed as a threatened species in Australia.  The Trust say the bats are destroying trees in ‘Palm Grove’ & it’s true, they are denuding the trees.

Federal MP Peter Garrett is about to decide whether to allow the Trust to get rid of the bats (they say humanely) by causing a noise, which the bats are unable to tolerate, hoping they will move & find another home.  There are many problems with this.

• They intend to do this in the breeding season when many of the mothers are pregnant.  The dispersal techniques of noise, harassment & sleep deprivation result in many miscarriages.
• The bats become disorientated & exhausted (as we all would) during this intervention.  As a result there are many injuries.
• It’s cruel & at the risk of sounding like a zealot, all about man’s domination over animals.  The gardens are 75 acres in size.  Yes, they are destroying a certain amount of trees on the south side of the gardens, but there are a lot of other trees & the grove can be replaced.
• The Trust says the bats will find another home, but on the small chance they do, this itself will likely result in problems.  They may try to join other colonies, which will make other areas overburdened with bats.
• They may stay in the gardens moving to other trees they have so far left alone.
• They are disliked in residential areas for good reasons.  If they relocate to these areas, it is likely residents will campaign to get rid of them or take the matter into their own hands.  It’s moving a ‘problem’ to another area & another community.

I was at the NSW Art Gallery at dusk last week. It is a truly beautiful & special sight to watch the bats quietly fly over the Domain as they go off to search for food during the night.  It is also a very good thing for tourism.  Many countries do not have such nature in the CBD.  The tourists & I stood for a long time watching them & we all loved the sight.  The Trust & the City of Sydney should be promoting the bats as a tourism highlight.

I trust WIRES &, when they say there will be a problem with the dispersal intervention, I believe it.  There are a lot of other organisations who joined with WIRES opposing the bat dispersion. If there wasn’t a significant & valid reason, I do not think these organisations would take on the Royal Botanic Gardens Trust.

I found this birds nest in Dulwich Hill last week - they used all sorts of material to make it - they even have 3 little doonas for 3 little eggs

Personally I think we humans are constantly taking away habitat from wildlife.  We control ‘our’ environment at the cost of other living beings & many times we do this as our ‘given right.’

The bats are usually nomadic, seeking warm places.  Experts believe the Heat Island Effect caused by our love & prolific use of cement & paved surfaces has improved conditions for the bats in Sydney so they have stayed.  We have also had a long & protracted drought so why would the bats move on as they usually do when they know there is limited food & water outside the city?  They stay where there is food & water & once the drought is well & truly over, some of them may return to their nomadic lifestyle.  We just need to be patient.

I think the bats should be allowed to stay.  Although there are negatives, there are just as many positives, not the least these bats being a threatened species.  It is not as simple as the Trust makes out.  Trees benefit humans in many ways, but they are the homes for birds & animals.  Sometimes we have to give over areas & tree assets to them even if only out of fairness & compassion.

You can read a media release from the Humane Society, WIRES, Bat Advocacy & WWF written yesterday –  Eviction_of_Flying_Foxes

If you want to join the voices supporting the bats’ right to remain in the Royal Botanic Gardens, you can write to Peter Garrett MP via his online contact page – http://www.aph.gov.au/house/members/memfeedback.asp?id=HV4 or via his e-mail – mailto:Peter.Garrett.MP@aph.gov.au

You can read about them on the Royal Botanic Gardens Trust web-site – http://www.rbgsyd.nsw.gov.au/welcome_to_bgt/royal_botanic_gardens/garden_features/wildlife/flying-foxes Today’s news about the bats on ABC News – http://www.abc.net.au/news/stories/2010/03/24/2854578.htm?section=justin

Eucalypts & clay soils

The Cambridge Street Stanmore Lemon Scented Gum tree is going to be chopped down soon.  I feel very sad about this.  During the Council meeting to decide the fate of this tree, the people who wanted this tree removed spoke about a large branch that fell on the street needing 2 people to carry it away.  The danger the tree posed from falling branches would have been one of the major factors why their request was granted.

Gum street tree in Petersham - 2 Currawongs have a nest in this tree

Gums trees do drop dead branches as a normal feature of their species.  Unfortunately, I think this is the reason why Marrickville Council appears not to not regard Eucalypts favourably.  Then include the fact that they grow tall & have a significant canopy.  In comparison to the usual street trees Council plants, Eucalypts are an anomaly.  I would guess the Gums are left over from the 1970s & before.

Suburbs like Petersham which have a lot of Eucalypts as street trees look fabulous as a result.  Everyone I have spoken to in this area always mentions the trees, most saying they were a major reason why they chose to buy in Petersham.  However, the Cambridge Street issue is likely to repeat itself for two reasons unless these are managed.

Firstly, building movement that causes cracking.  The Inner West is mostly clay soils & when there is drought (we have had a long one which is still continuing) the clay soils shrink. This results in movement of buildings & cracks to the walls, porches & paths, especially as most of the housing is 100 years old & the mortar used then was of very poor quality.

Roots of mature trees would have stopped growing years, perhaps decades ago. Often the tree has nothing to do with movement.  Arborists constantly have differing opinions about the impact of tree roots on house foundations.  Personally, I think it is too easy to blame the tree.

This Gum street tree in Brighton St Petersham deserves a medal for surviving pruning by Energy Australia for power lines

Even buildings that do not have a street tree out front can suffer from movement & cracking, especially during drought.  If your property is built on clay soil, removing most or all the trees on or around your property is unlikely to prevent further house movement.  It is a fact of life in the Inner West.

To minimize cracking to your house during drought, you need to water thoroughly along the exterior walls on a regular basis.  If you keep the soil moist, the clay will not shrink & your foundations are less likely to move.  Many people have concreted their yards, so they will definitely have house movement & cracking, drought or no drought.  If you already have cracking, you can assist by watering around the building to get the moisture back into the soil.  Our front door, which had started sticking, returned to normal 2 months after I recommenced watering our front garden.  I have written more fully about clay soils in the following post –

https://savingourtrees.wordpress.com/2009/12/11/11th-december-09-much-ado-about-clay-soils/

Managing dry clay soils does take time & patience.

Secondly, Eucalypts develop dead branches, which they shed as a normal feature of their development.  This does not make the species dangerous.  The process of the branch dying off until it eventually drops is not a quick one.  I have been watching trees with dead branches for 12 months now.  (It’s been one of my ‘must do posts’ which hasn’t happened until now.)  However, Gums are called ‘widow makers’ for a reason. A falling branch can kill a person if they drop on their head, but then again, so can most things that drop from a height.  I was young when I first heard the term ‘widow maker’ & I remember being told the following with much laughter:

The tree branch is dying over many months, sometimes years.  The wife asks the husband to do something about it.  Time moves on.  She nags & nags, but he watches footy & says he will prune the branch later.  Then, one day when he is mowing or something, the dirty big branch falls on his head & the wife is left a widow. The moral of the story is that men should do what their wife asks when she asks it to be done, husbands are lazy & her nagging is warranted.

Maybe you had to be there & times have changed.  The story made a big impact on me because ever since I have a keen eye to notice these branches.

This tree cnr Illawarra & Addison Rds has multiple dead branches. 3 other Gums further down towards Marrickville Rd also have dead branches

Whether or not Council should be responsible for checking trees for dying branches is not something I have an opinion about.  However, I do think we see the street trees in our neighbourhood almost daily & if we notice a tree branch is dying, a quick call or e-mail to Council should have the branch pruned before it becomes a problem & drops.

If we leave it until the branch drops, Council is likely to say the tree is dangerous & needs to be removed.  Then the community suffers another loss of a tree & eventually we lose all remaining Eucalypts & other tall trees.  Our suburbs suffer as a result because we lose the beauty that tall trees offer.  We also lose out on property values because great street trees have a surprising positive impact on local property values.

The street trees near our homes, especially the large ones, remove pollution & particulate matter which causes breathing problems.  They collect CO2 & emit oxygen making the air cleaner & cooler.  They lower temperature which helps lower our power bills, they slow down traffic, make the footpaths safer for pedestrians & generally make people feel happier.  I have written more about the value of trees in the page 100 Tree Facts, which can be located on the left hand column of this site near the top.

Lastly, if Sydney’s North Shore can have hundreds of thousands of Eucalypts as street trees, why can’t Marrickville LGA?  Let’s look after & keep the ones we have left.  They are necessary for our wildlife.

11th December 09 – much ado about clay soils

What concerns me about the removal of  street trees when they have been accused of causing damage to property is the following:

1. We have just experienced a long & protracted drought & more than 3/4s of NSW is still regarded as drought-affected.  The long-range weather forecasters say we have entered into another phase of drought. The Inner West has been affected, as has the whole of the Sydney metropolitan region.  This drought has resulted in severe water restrictions & this has affected our soils to a great degree.  Trees are stressed & quite a few have died within our local LGA.  Many of the saplings Council plants do not survive the summer because they are not watered.  This must result in significant financial loss to Council.
2. Even though we had quite a bit of rain over winter, we are still on water restrictions.  The park trees were able to capture much of the water when it rained, but our street trees have only a slight chance at getting a proper drink.  Most of the street trees in our LGA have been given very little ability to capture rain water or storm water run-off.  Most have a small opening left open amidst the cement or
   

   Newtown street tree

   bitumen. I have only seen 4-5 street trees planted in cement where I feel they have been given adequate soil space around them to give them a fighting chance to capture rainwater.  Two were in a back street of Newtown & I doubt Council did this, as the kerb had been removed.  Both these trees had a lot of soil around their trunk.  The other example is new plantings bordered by raised brickwork on Unwins Bridge Road Tempe.  I think it would be wonderful if all our street trees that are in cemented areas could be planted in this way.  I would also very much like to see Council give funding for the watering of young street trees as they do in other Councils.

3. Much of the Inner West is built on clay soils.  Clay soils are quite volatile as they shrink when they do not get sufficient water & expand when there is too much water.  Both these extremes affect the foundations of buildings & footpaths.  The term Seasonal Fluctuations describes the normal variations of the moisture content of clay soils through the seasons.  When clay soil gets a lot of water it is called Field Capacity.  When the soil is dry due to evaporation, heat  & lack of rain during drought it is called Desiccated & suffering from Soil Moisture Deficit.  If a drought is lengthy & the soil does not return to Field Capacity after some rain & then enters into another dry period, it is called Persistent or Permanent Moisture Deficit.  This is likely to have already occurred in the Inner West or will do during the next period of drought in which we are now entering.
4. Soil movements cause what is termed Subsistence & Heave.  With Subsistence, the soil moves downwards.  With Heave, there is an upwards or lateral move of building foundations or footpaths.  While the clay soils go through Seasonal Fluctuations foundations of buildings don’t move much, though that depends on how much clay soil is directly under the foundations.  When the clay soil suffers from Persistent Moisture Deficit, foundations of buildings move & walls start to show cracks, paint peels & doors & windows are suddenly off balance.  Just last week our front door over night became hard to open & stiff on its swing.  It is recommended that you don’t fill in the cracks or shave wood off door or window surrounds when the ground is dry, but wait until the soils have returned to normal moisture content before doing repairs.  Most times the doors & windows will realign & the cracks will come closer together though paint work will need repairing.  If you do fill cracks while the soil is dry, the space will not be available for the building to move back into place & new cracks will appear, generally on the other side of the building.
5. The experts suggest occasional watering of the exterior of the house as this will help keep the clay soil moist so that your foundations don’t move during a drought.  In my case, I have been keeping the water up to the back garden, but to save water, I have left the front garden manage as best it can.  Here is the reason why our front door has moved. Also, it is our hallway & the front room that are suffering the cracks & peeling paint.
6. My research has shown that trees can increase the seasonal movements of clay soil, however, engineers also stress there are too many factors to consider before one blames the presence of a tree for causing the damage.  One of the problems is, if a mature tree is removed, this has a major impact on clay soil moisture & the property can actually sustain more damage as the soil fills with water & starts a process of Heave.  It is hard to stop Heave because there is no longer a tree to be taking up the excess water.  Because it is so difficult to categorically say that tree roots cause damage even if the roots do go towards & under the house, many engineers recommend using water to restore the water levels to clay soils rather than removing the tree.  I have read that a tree is not able to lift a house because of the weight of the house. A footpath is a different story.

Trees ... we need them

There are things we can do to minimize or prevent further cracking or movement of buildings which do not involve removing trees.  According to eminent scientists, we have entered a dangerous period of existence with CO2 levels actually threatening life on this planet.  All agree on the supreme value of trees.

Just today in Copenhagen, the Food & Agriculture Organisation of the United Nations & Brazil’s National Institute for Space Research signed an agreement to work together in the field of emissions measuring and reporting by monitoring forests & calculating CO2 sequestration.  Essentially they are going to map & monitor the green canopy of forests of the world.  This clearly demonstrates the value of trees in dealing with climate change.  We should only be removing them after all options have been exhausted.