Street Tree
Strategy
July
July 2010
PO Box 220 / DX 70506
19 King Edward Street
Ulverstone Tasmania 7315
Tel 03 6429 8900
Fax 03 6425 1224
[email protected]
www.centralcoast.tas.gov.au
Contents
1
Introduction................................................................................................. 2
2
Benefits of Street Trees ................................................................................ 3
3
Street Tree Strategy Plans............................................................................. 4
4
New Street Tree Planting .............................................................................. 5
5
Management of Existing Street Trees ............................................................ 7
6
Community Consultation.............................................................................. 9
7
Unauthorised Street Tree Planting, Pruning and Removal ............................. 10
8
Risk ........................................................................................................... 10
9
Subdivisions .............................................................................................. 10
10
Revision..................................................................................................... 10
11
References................................................................................................. 11
Appendix A: Benefits of Street Trees................................................................... 12
Appendix B: Street Tree Strategy Plans - 1541.01/1541.02................................. 15
1
1
INTRODUCTION
Street trees are regarded as an essential and important asset in an urban
environment for a variety of health, aesthetic, social, economical and
environmental reasons.
The purpose of this Strategy is to achieve a coordinated, consistent and
strategic approach to street tree management.
The aim of the Strategy is to:
•
Improve the aesthetic quality of the streetscape for residents and
visitors.
•
Ensure trees are planted and preserved for future generations.
•
Provide a consistent approach to managing tree related problems and
responding to residents grievances.
•
Increase the number and the sustainability of street trees in the urban
areas within budget constraints.
The Strategy will provide a long-term direction for the implementation of new
appropriate and desirable trees and the preservation of existing trees.
The Strategy is comprised of three parts including:
•
establishing new trees in those identified streets currently without trees;
•
preservation of existing trees; and
•
substitution of inappropriate or unsafe trees with more desirable
species.
The Strategy has prioritised the main arterial roads, gateways and key CBD
streets around Ulverstone and Penguin as a focus for new tree planting and
species substitution. These streets were selected because it was considered
the beautification of these streets would benefit the greatest number of
residents and visitors.
The establishment of new street trees and preservation of existing trees will
begin to be implemented in the short-term and the substitution of
inappropriate or unsafe trees will be carried out on an as needs basis.
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Whilst trees play an important role in the urban landscape, it is also
recognised that trees of the incorrect type, or growing in an inappropriate
place can create problems and risks that are not reasonable in the urban
environment.
Increased understanding of the problems street trees can create has
highlighted the importance of developing a structured approach for their
active management. Through planning and the use of sound planting and tree
care practises, this Strategy endeavours to minimise:
risk to the public;
interference with overhead services;
damage to private property;
damage to kerb and channel;
damage to footpaths and naturestrips;
damage to underground services;
interference with sightlines for intersections, driveways and signage;
street lighting;
birds roosting;
excessive build up of leaf litter; and
excessive shading.
The Strategy will be a progressive document and will continue to assess other
areas where the establishment of new street trees would provide maximum
benefit to the community.
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BENEFITS
BENEFITS OF STREET TREES
An understanding of the types of benefits trees provide to the community is
fundamental in highlighting the need to provide a Strategy which ensures
trees within the urban area are established and protected for future
generations.
Increasing amounts of information are now available on the
diverse range of social, economic and environmental benefits trees provide. A
list of these benefits has been included in Appendix A.
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3
STREET TREE STRATEGY PLANS
PLANS
The major roads and streets identified for required planting are shown in the
Street Tree Strategy Plans for Ulverstone and Penguin (see Appendix B). This
will ensure that the tree species pattern will be maintained along the same
street to promote a unified character.
A mix of evergreen, deciduous, exotic and Australian native species have been
chosen to provide variety and diversity.
This list can be substituted with
species of similar size and characteristics at the discretion of the Parks/NRM
Officer. Location and number of trees required will also be at the discretion of
the Parks/NRM Officer.
All planting and ongoing maintenance will be
undertaken by Council staff in accordance with the Tree Management Manual.
Table 1: Street Tree Species Identified for Required Plantings
STREET
BOTANICAL NAME
COMMON NAME
ULVERSTONE
Pyrus calleryana
“Aristocrat”
Ornamental Pear
Mixed species
Coastal natives
Acer negundo and
Fraxinus griffithii
Box Elder and Evergreen
Tristania laurina,
Acer negundo and
Betula pendula
Water Gum, Box Elder
Alexandra Road (Beach
Acer rubrum
Maple “October Glory”
Road to Main Street) and
“October Glory”
Main Street (Crescent
Street to Eastland Drive)
and Queen Street (South
Road to Bertha Street)
Water Street and Victoria
Street (Water Street to
Beach Road)
King Edward Street
Reibey Street
Risby Street
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Ash
and Silver Birch
Table 1 (cont’d):
(cont’d): Street Tree Species Identified for Required Plantings
STREET
BOTANICAL NAME
COMMON NAME
Prunus x blireana
Flowering Cherry
Agonis flexuosa
Willow Myrtle
Gleditsia triacanthos
var. inermis
Gleditsia “Sunburst”
Hobbs Parade
Eucalyptus ficifolia
Red Flowering Gum
Patrick Street and Grove
Acer platanoides
Maple “Crimson Sentry”
Street
“Crimson Sentry”
Alexandra Road (Main
Street to Lovett Street)
Victoria Street (Water
Street to Alexandra Road)
Kings Parade,
Crescent Street and Lovett
Street (Leven Street to
Kings Parade)
PENGUIN
Main Road (Kentish Street
Mixed species
to Johnsons Beach Road)
Macrocarpa, Norfolk
Pines and Coastal natives
TURNERS BEACH
Esplanade
Mixed species
Coastal natives
Mixed species
Coastal natives
FORTH
Forth Road (Walker Street
to Leith Road)
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NEW STREET TREE PLANTING
Tree species selected may occupy their planting site for 50 or more years, so
tree selection is very important.
Tree species will be selected for planting
depending on suitability for the site, aesthetics, functional and biological
attributes, proximity to infrastructure and services and potential to contribute
to the streetscape and community. It should be noted that there is no perfect
street tree and that every selection has some compromise between positive
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and negative values. The key is to minimise the negative values and ensure
that the tree makes a positive contribution to environmental, social, aesthetic
and economic values.
The aim is to use the criteria below to ensure the
species selection is the most desirable and appropriate for the right location.
Criteria that will be assessed include:
Environmental tolerance and impact – this criterion includes suitability
with climate, geology and soils, topography, tolerance to sealed areas
and pests and diseases, potential for wildlife habitat and native versus
exotic species.
Functional and biological attributes – this criterion assesses performance
record, stock availability at the selected nursery, leaf and fruit litter,
chance of becoming an environmental weed, safety aspects, life
expectancy, chance of infrastructure damage, sun/shade requirements
and maintenance.
Aesthetics and design criteria - this criterion investigates appearance,
form and scale (including canopy size), relationship with distinctive
landscape characters, any historical and cultural associations and
deciduous versus evergreen.
Proximity to infrastructure – a criterion to assess distance of the planting
location to infrastructure and underground services.
During the selection process the Council will assess each location and
determine whether a local native species (species that originally grew in the
area), an Australian native (native to other parts of Australia) or an exotic
ornamental species is selected.
Whilst the native species may be the most
appropriate for the local environmental conditions due to suitability with
climate and pests, it is not always the most appropriate choice.
Local and
Australian natives promote greater biodiversity, create wildlife corridors,
reinforce an “Australian” sense of place and can be drought resistant.
However, natives such as Eucalyptus trees can display variable forms which
make it difficult to establish and maintain a planted avenue of trees and they
generally provide shade and create leaf litter all year round. The majority of
exotic species have the advantage of being deciduous allowing greater sun
access during winter, shade during summer and provide a changing
streetscape with the seasons. Stock quality can usually be assured meaning a
higher rate of success.
They are more pollution tolerant, more resilient to
cope with root interference and damage and most will better tolerate pruning
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required for urban infrastructure. Deciduous trees do, however, have issues
with leaf fall for 4 – 8 weeks of the year. In summary, natives and exotics both
have strengths and weaknesses for use as street trees and each location will
be assessed to ensure the right tree is selected for the right location.
Trees will be spaced between 8 and 20 metres apart depending on the
species.
Trees will also be spaced at 5 metres from driveways wherever
possible.
In areas where infrastructure and services exist, special consideration should
be given to the species of tree selected and its location.
There will be no
planting under power lines unless an appropriate species is selected if
planting is required.
Trees may also be planted along roads and streets other than those prioritised
within this Strategy if requested by the property owner and at the discretion of
the Council as the budget allows.
If a new street tree that has been planted is removed or vandalised, the
Council will supply a replacement tree as soon as practical.
Specific guidelines to establishing trees, including planting and maintenance,
are documented in the Central Coast Council Tree Management Manual.
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MANAGEMENT OF EXISTING STREET TREES
The management of existing trees includes annual urban tree assessments for
public safety, pruning, proactive protection from unintentional damage,
principles of plant health care and implementing best practice tree care.
Street trees have a limited life span and once they pass maturity they enter
into a state of decline. Street trees have a lower life expectancy than their
counterparts in parks and the bush as they are usually surrounded by
pavement, are subjected to higher levels of air pollution, higher air
temperatures, restricted water availability and vandalism.
Pruning is undertaken for a wide range of reasons including:
Removal of any dead, dying, dangerous or defective branches to
maintain tree health and safety.
To uplift the canopy (prune lower branches) to allow pedestrian and
vehicle clearance.
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Selective pruning to allow appropriate building clearance of branches in
conflict with adjoining buildings.
Selective pruning around light poles and powerlines for clearances.
Formative
pruning
to
improve
structural
stability,
health
and
appearance.
Selective pruning to allow sightlines for vehicles and traffic signs.
Pruning in accordance with the Australian Standard AS4373:2007
Pruning of amenity trees.
Street trees will not be pruned or removed to:
allow or improve a view;
reduce fruit fall, leaf litter, sap drop, bird droppings or similar;
increase street lighting onto private property.
Falling leaves, twigs, fruit and flowers are considered normal and expected
tree behaviour and therefore are not reason enough alone for removal or
pruning. Trees will however, be maintained in a safe and appropriate manner
to reduce nuisance issues.
Any requested work for street tree pruning from the public that is not of an
emergency nature (such as a fallen limb) will be carried out as part of the tree
assessment and maintenance program.
All trees that require removal, unless showing obvious signs, will require a
written report from a qualified arborist recommending the removal.
Street trees may be removed due to:
A report received from a suitably qualified arborist identifying a tree
with potential structural weakness, decay or other diseases.
Severe and damaging impact on infrastructure/services and no
alternative solutions are available such as relocation of tree/services/
infrastructure or the installation of a root barrier to be determined by a
relevant Council officer.
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In some instances where a tree is a poor performer and will not grow to
maturity, offers little aesthetic value or fails to maintain acceptable health,
then consideration for removal and replacement is appropriate.
If a street tree requires removal, a notification letter will be sent to residents in
the immediate vicinity of the tree notifying them of its required removal, the
reason for removal and the replacement planting proposed if required. If the
Council believes that a street tree is in an unsafe condition, the tree may be
removed immediately without notification, to ensure public safety.
Replacing existing trees in priority streets will be gradually implemented as
trees are identified as requiring removal.
A tree’s structural stability can be severely impacted upon with significant
damage to roots as a result of services excavation. In order to prevent root
damage during excavation works refer to Australian Standard AS4970:2009
Protection of trees on construction sites.
Root
barriers
around
established
trees
to
prevent
damage
to
infrastructure/services are an alternative solution to removal. A report from a
qualified arborist is advised before installation, as root removal can impact on
a tree’s structural stability and health.
More specific guidelines to pruning and protection of existing trees (including
Australian Standard AS4373:2007 Pruning of amenity trees) is documented in
the Council’s Tree Management Manual.
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COMMUNITY CONSULTATION
CONSULTATION
The community will be advised of street tree plantings in their area and will be
provided with a fact sheet on the maintenance of street trees and the species
of tree that has been chosen for the street. This should assist with alleviating
concerns that residents may have about a tree being planted in their
naturestrip.
Research indicates that with more appropriate tree selection,
resident’s willingness to appreciate newly planted trees increases.
The Council understands for this strategy to be successful it needs the
community to be involved in its implementation, particularly those ratepayers
directly affected.
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UNAUTHORISED TREE PLANTING,
PLANTING, PRUNING AND REMOVAL
There is to be no planting, pruning or removal of street trees by anyone other
than Council staff or its contractors.
Where tree(s) or vegetation have been planted by a resident in the naturestrip,
the Council will notify the relevant owner/occupier in writing that tree planting
without the Council’s authorisation is not permitted, request that the tree be
removed as soon as possible and advise that the Council will supply a street
tree of its choice if the location is appropriate. If this request is not complied
with, the tree will be removed by Council staff.
Where a street tree has been pruned or removed by a resident, the Council will
notify the relevant owner/occupier in writing that the unauthorised activity
must cease. They will be advised of the serious issues that can result from a
tree being pruned by an unqualified person, such as opening the tree to
disease and creating tree stability issues.
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RISK
Street trees will be inspected annually as a requirement of the Central Coast
Risk Management Strategy.
Street trees considered hazardous will be
prioritised and scheduled for the required works in the annual tree
maintenance program.
If a property owner believes that a street tree is responsible for damage to
their property or utilities servicing their property, the owner should contact
the Council in writing, giving details of the problem and supply any supporting
evidence relating to the problem.
Council officers will then assess the
problem and notify the owner of the outcome.
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SUBDIVISIONS
SUBDIVISIONS
Proposed landscaping for new subdivisions will be assessed for suitability
against the selection criteria. Species suitable will be at the discretion of the
Central Coast Council.
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REVISION
This document is a working document and may be subject to review at
anytime, however a complete review should be undertaken within five years.
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REFERENCES
WEBSITES
http://www.flemings.com.au
http://www.frinkpark.org/trees.htm
http://www.streettree.org
http://www.burnside.sa.gov.au
http://www/cityofsydney.nsw.gov.au
BOOKS/REPORTS/STRATEGIES/POLICIES
Sucher, David 1994 City Comforts – How to build an Urban Village, City
Comforts
Mongard, John 1998 Ulverstone Streetscape Guidelines, John Mongard
Landscape Architects
City of Sydney 2005 Urban Tree Management Policy, City of Sydney
City of Burnside 2006 Tree Management Strategy, City of Burnside
Burden, Dan 2006 Urban Street Trees, Glatting Jackson, walkable communities
Inc.
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APPENDIX A: BENEFITS OF STREET TREES
The social, environmental and economic benefits of street trees are wide and varied.
Tree-lined streets contribute to aesthetic improvements, climatic modifications, a
healthy environment and social wellbeing. A literature review has been undertaken
to research the main benefits of street trees.
The benefits include:
HEALTH
Views of nature can relate to feelings of satisfaction, wellbeing, coping,
personal effectiveness and optimism.
Green surroundings reduce mental tiredness while enhancing concentration
and attention, leading to an improved ability to cope and make positive
decisions.
Creating positive psychological benefits, including lower rates of mental
illness, violence and crime.
Trees reduce exposure to ultraviolet light, lessening risk of associated health
problems such as skin cancer and cataracts.
SOCIAL
Residents walk more on streets that are lined with trees.
Greenery helps people to relax and renew, reducing aggression leading to less
violence.
The proximity of trees to dwellings has an effect on residents’ use of outdoor
space - the closer the trees, the higher the usage.
Many more people are involved in social activities in green environs than in
areas that have few or no trees and shrubs.
Gardens and other plantings contribute to residents feeling safer, more
supported and satisfied with their surroundings.
Green spaces bring residents together more often, promoting chance
meetings and encounters.
Residents get to know one another, producing
stronger, more cohesive neighbourhoods.
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Public safety - areas with higher levels of planting experience lower levels of
crime because it creates pride and care of place which results in ownership.
Road safety – tree-lined streets are perceived as narrower, resulting in
reduced speeds.
Trees along streets provide a buffer between pedestrians
and vehicles.
Surveys of landscaped and non-landscaped community areas have shown that
the incidence of crime, vandalism and graffiti is many times lower in areas
planted out with greenery.
AESTHETIC
Beautifying
and
softening
streetscapes,
the
appearance
and
general
environment of many streets is improved considerably by the presence of
trees.
Trees soften harsh lines of paving, kerbs and screen the ever-present and
monotonous ‘Hydro’ pole.
Frame good views and vistas.
Trees provide seasonal interest and natural beauty through foliage and their
interesting leaf patterns, flowers, bark, fruit and canopy.
Provide a welcome contrast to long stretches of asphalt road.
Play a significant role in determining the urban character of the townships and
a sense of place.
They enhance architecture; there are few buildings which do not look better in
the company of suitable trees.
ECONOMIC
Research indicates an increase in property values from high amenity, welltreed areas.
A garden adds to the aesthetic appeal of your home and
neighbourhood, and it adds real monetary value to your home. It is estimated
that property value can increase between 5% and 20%.
Roads and footpaths with good tree canopy cover are protected from the sun
and last longer.
13
ENVIRONMENTAL
Provide wildlife habitat and food sources and preserve biodiversity.
Trees are critical in the maintenance of a healthy environment as they produce
oxygen, trap airborne pollutants in their leaves (such as nitrous oxide and
ozone) and absorb carbon dioxide.
Large trees have a greater benefit in terms of reducing pollution than small
trees.
Trees have a positive effect on the environment by the transpiration of water
and the emission of oxygen by photosynthesis.
Tree roots keep the soil porous which allows the stormwater to be absorbed
rather than flow into the drain and sea.
Plantings around buildings are a proven method of reducing the demand for
artificial heating and cooling with a resultant, and important, lower use of
fossil fuels.
They provide shade in summer.
Trees can reduce asphalt temperatures of
carparks by as much as 13°C, and vehicle cabin temperatures by 17°C.
14
Provide buffers/wind breaks from strong winds.
APPENDIX B: STREET TREE STRATEGY PLANS
PLANS ULVERSTONE AND PENGUIN
PENGUIN 1541.01/1541.02
1541.01/1541.02
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