Can’t we do more with trees in streets?
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This street could do with some trees! (click to look around)
This street in Melbourne’s Sunshine West (first exhibit) would look a lot more attractive if it had trees like this street in Melbourne’s north-east.
Some residents and local authorities think trees are too much trouble. They require attention to get started and are vulnerable to vandalism in their early years. Their roots interfere with services and foundations; their branches snag power lines; and their leaves, bark and seeds clog gutters.
Certain species drop death-sized branches from time to time. Natives perform well in drought conditions but block sunlight to houses in winter. In established areas with narrow streets new plantings will sometimes be at the expense of parking spaces.
However the benefits of trees far exceed their cost. Urban designer Dan Burden reckons it costs between $250 and $600 in the US to establish a tree over three years, but the direct benefits over its lifetime exceed $90,000 (excluding aesthetic benefits).
The NY State Department of Environmental Conservation estimates each mature tree removes around half a tonne of carbon dioxide and about 100 kg of pollutants from the air each year. Trees can lower home and vehicle cooling costs, improve residential amenity, and increase property values.
Trees support bird life and some even claim they lower crime. I suspect the latter is primarily the result of a selection effect but nevertheless there’re lots of good reasons to have more trees in our streets.
I found this extraordinary map of street trees in San Diego County (second exhibit) via Kain Benfield’s blog. What’s remarkable is you can click on each individual tree to get information about its species, location, size and any alerts concerning its welfare (see here).
The inventory was produced by San Diego County Trees, an initiative of the California Center for Sustainable Energy. But all the data on individual trees is crowd-sourced – it comes from residents who care about their trees.
Here’re a couple of similar maps for Washington DC. The DC street trees map shows the location and species of trees planted by the District’s Urban Forest Administration. The Casey trees planting map shows trees planted by a non-profit organisation, which also publishes an annual report card.
It’s hard to think of a more cost-effective way of improving urban streetscapes than planting trees. Yet while almost all established suburbs have at least some trees (e.g. here, here and here), in many cases they don’t seem to be incorporated as a “designed” part of the streetscape.
Existing trees are often small – presumably so they don’t interfere with power lines in older suburbs – and not planted closely enough to create a strong sense of an avenue or a canopy. To my eye, some of the species also look scrappy with thin foliage. Whatever their merits as individual trees, they don’t contribute as effectively to the whole as alternative (native) species would.
There’s plenty of green along the main roads through Melbourne’s sprawling middle ring eastern and south-eastern suburbs, yet they’re often cited as the epitome of boring and featureless suburbia. A key reason, I think, is there’s little sense of visual containment. That could be provided by a “wall” of taller buildings or, more feasibly in the short to medium term, by a “wall” of taller trees.
Undergrounding power lines in established suburbs would be expensive, but it could be done in a limited number of locations – such as along major roads – so taller trees could be planted at closer intervals. The trade-off might be slower traffic speeds.
What I’d like to see more generally, though, is greater attention given to the potential of trees to create streetscapes. I’d like to see a larger role given in decisions on tree selection, location and spacing to those with a designer’s eye for the public realm.
Crowd-sourced inventory of street trees in San Diego. Each tree has its own 'biography'
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…Is there a reader who can quantify the honey production from street trees? I am unable to recover my essay from a few years ago. However, my recollection is the potential for honey production is significant, even in the City centre. The hives could be placed in urban roof gardens…
Alan, completely agree with you. We should have more trees as an integrated part of the streetscape design. Great for liveability, environment and carbon capture. But will mean more bird poos on cars parked along the street.
Mature trees can supply the temperature moderating effects of four, typical air conditioning units in summer and in winter trap heat to moderate extremes of cold.
Now that’s the kind of moderation everyone should like.
Wasn’t there something called “The Melbourne Principles for Sustainable Cities”?
Did they include tree planting?
Technically I think the best bang for buck solution would be to underground the lower voltage power along most local roads and leave undergrounding the more expensive higher voltage power that runs along main roads until later (pick off the low hanging fruit).
Also lower speed local roads are more capable of safely accommodating mature trees. That said a tree will generally present the same hazard on a high speed road as a power pole all be it at a more regular spacing.
Alan – on a related topic, would be great to see you write a post specifically on the issue of putting power lines underground. Intuitively I would have imagined there would be opportunities in at least looking at this for new estates, but not sure how the economics stack up. Would appear to have some safety benefits along with obvious aesthetic benefits.
A bouquet for Darebin bureaucrats. This week I received a letter from council explaining the changes to street trees in High Street. Informative, rational, polite and yet almost conversational. Really engaging. I’ve written and read any number of government letters in the last thirty years but this one explaining the replacement of trees and the removal of very popular mosaic planter boxes was a work of art.
Actually the street youve shown is a sort of side street, whereas the ‘main’ streets that the houses actually face in sunshine west do have trees – though they are smaller ‘specimen’ native trees like paperbarks, that are I guess low maintenance, and quite widely spaced, and sort of pathetic in some cases – not nice to look at nor provide shade, little more than overgrown shrubs, none of the delight or coverage of larger trees like planes for instance. These seem to be typical of suburbs from the the 50s – 70s from memory and a quick view by google maps.
New subdivisions are planted with plenty of street trees, mostly plane trees from what I can see. And of course the inner and middle suburbs are well tree’d.
So do the Councils with the the minimal street tree type actually not want bigger and better trees ? or is it just that they havnt thought about it / residents havnt brought it up ? I know some residents in tree’d inner and middle areas often blame trees for cracks, wobbly footpaths etc. but also are appalled when trees removed (both have happened in my street in Fitzroy). Be interesting to know whether these formerly outer now outer-inner Council areas have even thought about it.
Re the ‘selection effect’ on the relationship between trees and reduced crime: Yes, very tempting to conclude exactly that. I note that the authors of the study — which found a 10 percent increase in trees roughly equaled a 12 percent decrease in crime — claim that they controlled for “all kinds of socioeconomic factors, including income, housing age, and owner race, plus adjusted for other variables associated with tree cover, like ruralness and population density. After holding all of these points steady, trees still wound up on top.” Discussed in Kaid Benfield’s blog of 13 June 2012
Port Phillip Council in Melbourne has embarked on some tree planting recently (We have 4 new natives in front of our block of flats). I personally prefer a mix of native & non-native so we can have some green during the winter as well as some sun.
Parker Alan • OAM .
I believe that housing developers need a more creative approach to the use of fruit, nut and native trees wherever there is space in the nature reserves along existing streets and in new housing areas. Its time to give house buyers more choice than what is now provided to produce more efficient house air conditioning.
For existing streets running from east to west, plantings in the reserves of large native trees would block out winter sunlight and shade the north or south facing windows. To
block sunlight on east and west facing windows in the summer heat, planting fruit or or nut trees along east or west side windows is needed
Consider existing north to south streets with large native trees they could provide shade all year round on east or west facing windows. On the north or south facing windows planting fruit or or nut trees may shade them.
The grid iron street layouts in many existing suburbs allow this to be done but in the new developments the use of a bastardized system of English Cul-de-Sac planning which prevents more direct and safer travel patterns for walkers and cyclists, and reduces choice available to new house buyers.
A new choice offered to consumers never considered before is the use is of the the nature reserve for producing fruits and nuts and vegies, reduced heating and cooling in a way that may enable some existing streets new housing schemes more useful and more aesthetically pleasing.To give one example the blossom and the fruits of trees
Imagine if you will. That in a new housing development we are to grow fruit and people have choices, We have Gumtree gully, Bottlebrush Road oad, Avacado Avenue, Marmalade alley full of citrus fruit trees, apricot avenue, bannana boulevard ( for Queensland ), Tea Tree Terrace, and She Oake Street, Peartree Parade, Black Plum Bi-Way, and Red Delicous Road.
As part Housing scheme rules all little boys would be given permission to fertilise the trees and little girls to climb them.
Correct selection of the street tree can overcome many of the potential drawbacks. In SE Melbourne, Knox Council has a policy preference for indigenous trees. Trees such as Allocasuarina littoralis – black sheoak or Acacia implexa – lightwood, are two smallish trees with few bad habits which have been found to be tough, highly suitable street trees, although female sheoaks drop the occasional cone.
To post 2 I would say I would be more than happy to clean the occasional bird poo off the car if it means there is still a bit of biodiversity around.
11
When choosing trees, trees that don`t drop berries or fruit across the footpath.
Who would own the fruit?
There should be more trees to reduce the urban heat island effect.
You don’t get decent tress on main roads any more because the road authorities require wide clear zone to reduce crashes.
While they always cite safety, which makes you look like a baby killer if you argue against it, there are alternatives. The key one is speed. While I have never subscribed to the view that 5km/h makes a meaningful difference, 20 km/h certainly does, especially for motorists in side-on crashes, pedestrians and cyclists on the receiving end of somebody’s bonnet.
Street trees and speed go together, with narrower feeling roadways (read those with an enclosed feel due to street trees) leading to lower travel speeds. So, instead of building wide roads with 80 or 90/km/h speed limits and then saying we can’t plant trees in case somebody dies, make the speed limit 60 and narrow the roads (like it is in inner suburbs already) and plant out the roadside.
Often in so called “working class” suburbs, you’ll find far less trees which are not highly valued. Usually the leafy suburbs are the prestigious, high value areas in most capital cities. I know this from my own family background and it’s a pity really because, ironically, it adds tremendous value and amenity to an area if trees are planted. My council has just put a lot of new trees into my street and I shall be looking after my new lovely eucalypt. I consider it a matter of pride and a kind of competition. I’m determined mine will be the biggest and healthiest – so plenty of weed control, water and native fertilizer!!
Last Name First Name’s species and positioning suggestions are excellent, and critical. The costs to passive solar heating and, increasingly, solar hot water and PV performance would add up to much more than $250-$600 over the lifetime of a large evergreen tree situated just north of a house. Such as the one in front of mine, which I keep having illegally herbicidal thoughts about.
Costs and benefits will vary with latitude, too. Urban heat island amelioration and general shading and cooling aren’t often welcomed in Tasmania, whereas passive solar heating almost always is.
I think the example you’ve used in fairy street are plane trees. These have been criticised as a street tree choice for causing allergy symptoms.
http://www.abc.net.au/gardening/stories/s1215645.htm
We have some lovely medium sized flowering gums, paper barks and bottle brush in Reservoir. They do the job nicely!
Those new sets in darebin are attractive but odd. Made for a single person to ponder the shopping strips? ( I obviously didn’t read my letter!) They are going to need a lot of cleaning to make sure they don’t turn into giant ash-trays.
Right on! On east-west street, indigenous evergreens on the north side to provide a windbreak in winter and deciduous trees (foreigners, even!) on the south side to provide shade in summer and allow winter sun to warm the south side homes and yards. Someone else can work out what should be planted on north-south streets! Probably a mix. The big thing there is to provide shade from the baking western sun in summer.
Productive trees! Great idea!
Also — think of the trees and the need for the climate control they provide as a priority. As my part of Australia (Melbourne) gets warmer and drier with climate change, we must skew our tree planting to take that into account. Indigenous trees, but also indigenous veg from neighbouring areas which are a degree drier. The local council makes a total fetish of having trees clear the road by 2.5 metres. They cut back mightily every couple of years. Why? This is not a main road, high vehicles rarely penetrate it. If they do come in (e.g. a furniture van) let them proceed down the middle of the road, not with one wheel in the gutter! They’ll HAVE to go down the middle much of the way, in any case, because of cars parked st the side. Stop savagely cutting back overhanging branches and let the trees grow up and out to overhang the road and provide much-needed shade. Also, encourage overhang to shade footpaths. Essential.
And think VEG, not just trees. I saw venerable old red gums deteriorating in a golf course when the mowers went right in under them. The fix was simple: let the indigenous veg sprout and grow underneath them. That veg actually interacts with the big tree itself and with other life in the soil to the benefit of parties (provided golfers with a reason to stay on the fairway too!). So keep the understorey going, lay off the Victa.
And for heaven’s sake, stop planting the bl**dy brush gum (or whatever it is) everywhere. It’s indigenous to the glasshouse mountain area in Queensland, I believe, so please let it stay there! Many council tree people love it as a street tree because it grows in neat, predictable, modest ways. But the local birds and other animals won’t use it! And it sheds lots of nasty little gum nuts that can make footpaths like skating rinks in winter, and, of course, being from where it comes from, it’s a thirsty thing that dries out the soil, often killing everything under it.
And let’s get a mix of trees in! Forget English Avenues (even if they did steal the word from the Fwench!).
Some sort of direct action would accelerate the process. Upon owning my first home I discovered that my wife and I owned the council strip and not vice versa,
The plot of land went all the way to the roadway.
So some sort of ownership and control is in place here.
Are councils potentially paranoid about communities planting out their own property?
Councils have access to “Their” strip for the provision of services only.
Correct me if I’m wrong.
“Urban designer Dan Burden reckons it costs between $250 and $600 in the US to establish a tree over three years, but the direct benefits over its lifetime exceed $90,000 (excluding aesthetic benefits).”
This type of desperate accounting always seems unconvincing and ultimately self-defeating. Every environmental argument expressed in made-up dollar values. What do we then do with species with no discernable economic benefit? Arguing for street plantings on health grounds (respiratory illness etc) is probably stronger.
#11 — VicUrban’s newish Meridian estate in Dandenong South is to be planted with productive street trees, drawing inspiration from the Village Homes community in Davis, California.
Krammer56 Posted August 3, 2012 at 7:44 am
Quite correct. The road lobby, especially in the US (despite stories like this one concerning inner San Diego–take a look at many of the explosive exurban areas around SD and they look like Mars, possibly a water conservation issue?) is responsible for more loss of street trees than Dutch Elm disease. Street widening is the biggest culprit allied to pseudo-safety issues.
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Concerning plane trees (which are the most common avenue trees throughout the world including Paris, London and the frenchified Asia cities like Hanoi and either Nanking or Nanjing–I forget which but one of these is famous for its glorious avenues) there are now lots of productive bee hives kept on Parisian rooftops. That of course also begs the issue of allergies; I am not sure (despite profusion, see below) they are particularly allergenic and these days can be countered (I should know, I was almost hospitalized once but am now almost totally free).
Below is a note I posted last year on a story about the terrible loss due to disease of the trees lining the Canal du Midi (a story that for some reason the Australian media just picked up on):
.
Many people, including me (because I have yet to do my 20-year long dream of cruising the Canal du Midi from the Med to the Atlantic on a peniche) are very upset on this bad luck. The south of France is too hot and sun-scorched for wimpy photophobes like me but one can be on the canal, or walking/cycling on its adjoining pathways, in wonderful cool. IMO, forget walking the Camino or the Pyrenees because those two famous treks are just gruelling in summer (and worse in winter) with relentless shadeless sun and dusty paths etc.
And Mark D, plane trees are deciduous so of course in winter there is no cover. Obviously for places with seasons like Tasmania, they or similar trees make sense. In France it is one of the rituals of the changing seasons to observe the army of tree pruners at their job (towards the end of winter I think). Obviously they also do tree doctoring year by year so the risk of falling limbs etc seems to be non-existent AFAIK in France.
I only discovered an allergy to plane trees upon moving to Melbourne. There were so few in almost all of Perth that it was never an issue before that. Nonetheless, I think plane trees are the most wonderful street trees (having lived in a street that was lined with them). They provide cooling shade in Summer and allow light in during Winter. What’s not to love about that?
Let the Plane Trees Rule!
definitely want more trees!!
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