Smart city planning can preserve old trees and the wildlife that needs them



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Mature trees have horizontal branches that are attractive to wildlife and birds.
from shutterstock.com

Philip Gibbons, Australian National University

Australia’s landscapes are dotted with mature eucalypts that were standing well before Captain Cook sailed into Botany Bay. These old trees were once revered as an icon of the unique Australian landscape, but they’re rapidly becoming collateral damage from population growth. Mature eucalypts are routinely removed to make way for new suburbs.

Good planning can ensure many more mature eucalypts are retained in urban developments.
Philip Gibbons

This has a considerable impact on our native fauna. Unless society is prepared to recognise the value of our pre-European eucalypts, urban growth will continue to irrevocably change our unique Australian landscape and the wildlife it supports.




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Why are old eucalypts worth saving?

In urban landscapes, many consider large and old eucalypts a dangerous nuisance that drop limbs, crack footpaths and occupy space that could be used for housing. But when we remove these trees they are effectively lost forever. It takes at least 100-200 years before a eucalypt reaches ecological maturity.

Birds use old eucalypts as places to perch or nest.
Philip Gibbons

As trees mature, their branches become large and begin to grow horizontally rather than vertically, which is more attractive to many birds as perches and platforms where they can construct a nest.

Wildlife also use cavities inside ageing eucalypts. These are formed as the heartwood – the dead wood in the centre – decays. When a limb breaks it exposes cavities where the heartwood once occurred.

This is such a ubiquitous process in our forests that around 300 of Australia’s vertebrate species, such as possums, owls, ducks, parrots and bats, have evolved to use these cavities as exclusive places to roost or nest.

Mature trees also support high concentrations of food for animals that feed on nectar, such as honeyeaters, or seed, such as parrots.




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One study found that the number of native birds in an urban park or open space declines by half with the loss of every five mature eucalypts.

How can we keep old trees?

Decaying heartwood in older eucalypts leads to some large branches falling. This is when most eucalypts are removed from urban areas. So we remove trees at the exact point in time when they become more attractive to wildlife.

Plantings around the base of a mature eucalypt discourage pedestrian traffic or parked cars.
Philip Gibbons

A well-trained arborist knows that old — or even dead — eucalypts don’t need to be removed to make them safe. A tree is only dangerous if it has what arborists call a target. Unless there is a path, road or structure under a tree, then the probability of something or someone being struck by a falling branch is often below the threshold of acceptable risk.

Progressive arborists first focus on eliminating targets. For example, they might plant shrubs around the base of dead or rapidly ageing trees to minimise pedestrian traffic, rather than eliminating trees.

Where targets can’t be managed, trimming trees can remove branches that have a high risk of falling. Trees can also be structurally supported (braced) to remain stable. Such trees remain suitable as habitat for many native species.

Developers can plan around old trees.
from shutterstock.com

How to design around trees

The removal of mature eucalypts is, in part, due to urban developers not considering these trees early in the planning process.

I have worked with one developer on the outskirts of Canberra to identify important trees. The developer then planned around, rather than in spite of, these trees.

The outcome has been around 80% of mature trees have been retained. This is much greater than the proportion of mature trees retained in other new urban developments in Canberra.




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The ConversationAustralia’s population is projected to double in 50 years, so our suburbs will continue to infill and expand. This will result in the continued loss of our mature eucalypts unless our approach to planning changes.

Philip Gibbons, Associate professor, Australian National University

This article was originally published on The Conversation. Read the original article.

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How tree bonds can help preserve the urban forest



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City trees don’t just look after themselves.

Joe Hurley, RMIT University; Dave Kendal, University of Tasmania; Judy Bush, University of Melbourne, and Stephen Rowley, RMIT University

Great cities need trees to be great places, but urban changes put pressure on the existing trees as cities develop. As a result, our rapidly growing cities are losing trees at a worrying rate. So how can we grow our cities and save our city trees?

Tree bonds have recently been proposed by Stonnington City Council as a way to stop trees being destroyed in Melbourne’s affluent southeastern suburbs.

Tree bonds are a common mechanism for protecting trees on public land, but have so far had limited use on private land. A tree bond requires a land developer to deposit a certain amount of money with the local authority during development. If the identified tree or trees are not present and healthy after the development, the funds are forfeited.

The size of the bond can be established based on estimated tree replacement costs, and/or set at a level that is likely to achieve compliance (likely to be thousands or tens of thousands of dollars).

Why are trees important in cities?

The concept of an “urban forest” includes all the trees and plants in cities. This includes tree-lined city streets as well as parks, waterways and private gardens. The urban forest contributes substantially to the quality of life of all urban dwellers, both human and non-human, and is increasingly used to adapt cities to climate change.




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Trees cool the streets, filter the air and stormwater, and create a sense of place and character. They provide food and shelter for insects, birds and animals.

There is growing research evidence for the physical, mental and social health benefits of urban trees and green spaces. Many local councils such as Brimbank and Melbourne are investing substantially in tree planting to increase these benefits.

However, despite new tree planting on public land, tree canopy on private land is declining.

What can we do to protect trees?

There are a range of existing policy and land use planning measures focused on landscaping requirements for new development. Recently, the Victorian government introduced minimum mandatory garden area requirements. Some Melbourne councils, including Brimbank and Moreland, have also included planning scheme requirements for tree planting for multi-dwelling developments.

Other mechanisms for protecting urban trees on private land include heritage and environmental overlays within local planning schemes, and listings of significant trees and heritage trees.

However, penalties, monitoring and enforcement of tree protection bylaws have not kept pace with the pressures of urban change.

If penalties are insignificant relative to development profits, developers can easily absorb the costs. If monitoring is weak and removal has a good chance of going undetected, tree protection is more likely to be ignored. And if enforcement is weak, or there is a history of successful appeal or defeat of enforcement, many trees may be at risk of removal.

Even when it is successfully pursued, after-the-fact planning enforcement action is a particularly unsatisfactory recourse for tree removal. Replacement trees may take decades to match the quality of mature trees that were removed. What is needed, then, are mechanisms that prevent tree removal in the first place.

Increasing use of tree bonds

The advantage of tree bonds is that they place the onus of proof of retention on developers, rather than the onus of proof of removal on local councils. If a tree is removed, the mechanism is already in place to monitor (the developer needs to demonstrate the tree is still there) and penalise (the financial penalty is already with the enforcing body).




Read more:
Concrete jungle? We’ll have to do more than plant trees to bring wildlife back to our cities


However, tree bonds still do not guarantee tree protection. Some mechanisms used to impose tree bonds may be vulnerable to challenge. For example, historically in Victoria, the planning appeals body VCAT has struck out conditions imposing tree bonds, arguing that punitive planning enforcement measures should be used where trees are removed.

Even where bonds can be imposed and enforced, developers may still be able to demonstrate that trees are unsafe or causing infrastructure damage, and thus need to be removed. In these circumstances, it is often hard to prove otherwise once the tree has been removed.

Nurturing an urban forest

Ultimately, if a landowner is hostile to a tree on their land, that tree’s health and survival can be imperilled, whether through illegal removal, neglect, or applications for removal based on health and safety grounds. It is therefore important that building layout and design realistically allow space for trees to flourish and be valued by landowners.

The urban forest needs protecting and enhancing. This calls for a range of policy mechanisms that work together to retain mature trees, maintain adequate spacing around them, and encourage residents to value and protect the trees around their homes.

The ConversationTree bonds provide an attractive solution for local governments in the absence of a strong land use policy framework for protecting trees.

Joe Hurley, Senior Lecturer, Sustainability and Urban Planning, RMIT University; Dave Kendal, Senior Lecturer in Environmental Management, University of Tasmania; Judy Bush, Postdoctoral Research Fellow, Clean Air and Urban Landscapes Hub, University of Melbourne, and Stephen Rowley, Lecturer in Urban Planning, RMIT University

This article was originally published on The Conversation. Read the original article.

Australia: Efforts to Preserve the Southern Brown Bandicoot


The link below is to an article reporting on efforts to conserve the Southern Brown Bandicoot on the NSW South Coast.

For more visit:
http://www.forestrycorporation.com.au/media/releases/helping-the-southern-brown-bandicoot-bounce-back

Colombia: Reserve to Preserve the Golden Poison Frog


The link below is to an article reporting on the establishment of a reseve in Colombia to help preserve the Golden Poison Frog which is threatened with extinction.

For more visit:
http://news.mongabay.com/2012/0305-hance_goldenpoisonfrog.html

Australia: Queensland – Pollution a Major Threat to our Reefs


Progress has been made in helping to preserve Queensland’s reefs from pollution, but more still needs to be done. The Reef Protection Package Impact Statement 2012, shows that improvements have been achieved.

For more visit:
http://www.wwf.org.au/?3760/Pollution-still-threatens-700-reefs-despite-progress

India: Village Moves to Preserve the Tiger


An entire village has been relocated in India to allow for the preservation of the Tiger. The village of Umri moved out of the area and were compensated for doing so. It is thought that only about 1700 tigers remain in the wild in India.

For more visit:
http://www.treehugger.com/natural-sciences/entire-indian-village-relocates-sake-tigers.html