Policy - Home | City of Fremantle€¦ · Planting and pruning of street trees. Policy That Council has a scheme to plant street trees, where appropriate, upon request by owners of

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Policy

Tree planting

Reference Number: SG28

Type: Strategic

Legislation: "<Legislation or NA>"

Procedure: "<Insert hyperlink or NA>"

Delegation: 3.27

3.53

Other related document: Tree planting and preservation policy (adopted 18.12.95

ES207)

Objective

Planting and pruning of street trees.

Policy

That Council has a scheme to plant street trees, where appropriate, upon request by

owners of properties in the district. Implementation of the scheme is to be at the discretion

of the Manager city works.

Council may prune such trees within its district which are considered by the Manager City

works to require such treatment.

(refer to separate document "Tree planting and preservation policy" file 7.33.6) adopted

18.12.95 ES207.

Responsible directorate: Technical services

Reviewing officer: Manager physical services

Decision making authority: Council

Policy adopted: 19 June 1985

Policy amended: 18 December 1995.

Next review date: 2003


Tree Planting

&

Preservation

Policy

Revised by John Csendes

Parks & Gardens Co-ordinator

05 February 2005

SDRCP0502-38


ACKNOWLEDGEMENTS: Many people have contributed to the production of this Policy and special thanks must go to the following people for their efforts:-

JAC Crawford Mary Ross

Kylie McKellar Richard McManus

David Edwards Andrew Stevenson

For further information please contact:- Assets & Infrastructure - Parks & Gardens Section City of Fremantle PO Box 807 FREMANTLE WA 6160 Telephone Number : 9432 9855 Fax Number : 9430 4634


TREE PLANTING AND PRESERVATION POLICY LIST OF CONTENTS

1. INTRODUCTION

2. BACKGROUND 3. ARBOREAL ASSET PLANNING 4. TREE SELECTION

4.1 Aesthetics 4.2 Biological Considerations 4.3 Function 5. TREE PLANTING 5.1 Planting Location Guidelines 5.2 Planting 5.3 Street Tree Establishment 5.4 Unauthorised Street Tree Planting 5.5 Purchasing 6. POST-ESTABLISHMENT CARE 6.1 . Watering 7. TREE PRUNING 8. TREE ROOT MANAGEMENT 8.1 Tree Root Damage to Services, Pavements and Drains 8.2 Tree Root Damage to Buildings, Walls and Other Structures 8.3 Preservation of Existing Trees on or adjacent to Construction Sites.

9. TREE REMOVAL AN REPLACEMENT DECISIONS

9.1 The Principles underlying tree removal and replacement strategies 9.2 Practical Tree Removal and Replacement Strategies 9.3 Conditions Allowing for Removal 9.4 Conditions Not Allowing Tree Removal

10. TREE PRESERVATION

10.1 Tree Preservation on Development Sites 10.2 Tree Preservation Generally


10.3 Register of Significant Trees 10.4 Tree Evaluation

11. TREE MANAGEMENT INVENTORY 12. TREE EDUCATION

12.1 Arbor Day 12.2 Management Plans 12.3 Staff Training 12.4 Community Education/Liaison 12.5 Conflict Resolution

13. APPENDIX

13.1 Fremantle Street Tree List 13.2 'Encroaching Branches and Roots – Who is Responsible?’

14. REFERENCES


1. INTRODUCTION Trees are an integral part of the fabric of the urban environment. Their contribution is

both physical and psychological. The urban environment is essentially hostile to trees, particularly street trees, so it is important to establish strategies for their protection and long term management.

Trees are arguably the most significant form of vegetation used in the urban

landscape, and can generate great benefits for urban dwellers. By virtue of their size and longevity, trees can also generate significant costs, both directly in terms of budgets and salaries and indirectly in terms of conflict with individual residents and groups within the community. Some of the key areas of conflict include: trees and overhead power lines, residential property (such as houses, walls and driveways) and public infrastructure such as paving, kerbs, underground services etc. The issue that is most likely to generate conflict with the community is tree removal and replacement. To maintain an acceptable balance between benefits and costs in what is likely to be a time of static or even declining resources, it will be necessary for Council to manage its tree assets better.

Some of the means by which this can be addressed are to utilise tree selection more

effectively, to arrive at more successful landscapes, to develop a comprehensive tree management policy and other means of formalising decision making on tree management, and finally to develop information systems on trees to facilitate decision making and allow prioritisation of management resources.

2. BACKGROUND Council's existing Tree Planting Policy (ES4) was adopted on 16 February, 1970,

amended on 18 March 1974 and revoked, resubstituted and adopted on 17 June, 1985. The existing Policy in total states:

"That Council has a scheme to plant street trees, where appropriate, upon request by

owners of properties in the district. Implementation of the scheme is to be at the discretion of the Co-ordinator Parks & Gardens.

Council may prune such trees within its district which are considered by the Co-

ordinator Parks & Gardens to require such treatment". The existing Policy is totally inadequate as a means of managing Council's Arboreal assets and the purpose of this Policy is to formalise some decision making premises which have been applied, to date, on an ad-hoc basis.

The Policy is intended to provide clear guidelines without being so rigid as to exclude

flexibility or to prevent new opportunities or technological developments being introduced.


The Policy attempts to:

(a) provide a workable framework for selecting, planting, protecting, maintaining and removing trees in Public Open Space - the streetscape, bushland reserves, parks, playgrounds and reserves;

(b) identify and retain significant trees on private property through the Development

Application process; and (c) support the introduction of a comprehensive tree management inventory; (d) the Policy should be reviewed annually or more frequently if deemed necessary.

3. ARBOREAL ASSET PLANNING The advantages of trees in the urban environment far outweigh the disadvantages, however, Council needs a framework for maintaining and enhancing this significant asset. It is the objective of this Policy to facilitate the creation of functional, aesthetic and innovative streetscapes as part of any planning process involving street and land use development, whether on public or private property. Factors to consider in the planning process include:

(i) Liaison with other Departments, Authorities, residents and other interested parties and groups, in achieving landscapes which best suit everyones requirements.

(ii) The design strategy in major roads is to have formal avenue plantings of a single

species, whereas more flexibility in species selection is possible on secondary roads. Other factors to consider could include street alignment, deciduous versus evergreen, different species on opposite sides of the same street, etc.

(iii) where a dominant species already exists in a streetscape this should, in general, be

reinforced unless the existing species is inappropriate. (iv) The street tree inventory is a vital tool in the planning and management strategy. (v) Planning of street trees shall recognise the varied conditions and objectives to be

considered in the design of any streetscape including existing vegetation, pedestrian and vehicular traffic, street width and orientation surrounding buildings and the historic and/or cultural significance of the locality as well as physical conditions such as soil acidity/alkalinity, prevailing winds, closeness to coast (salt), etc.


(vi) Naturally occurring trees, where appropriate, shall be retained in the streetscape and a link between existing remnant bushland areas through the provision of endemic street tree species along ecological corridors shall be encouraged.

(vii) Street Tree Planning shall promote the creation of distinct ambience and character for

various streets through species selection and, where appropriate, provide unity within streets by consistent species use.

(viii) Selection of new species shall be in accordance and complimentary with existing

streetscapes and applicable to various arboreal zones within the City and to suit the character of particular localities.

(ix) New species will be trialled in the field regularly and information on the desirability of

new species will be actively sought. Emphasis will be placed upon the investigation of those species indigenous to various locations within the City.

(x) Lists of unsuitable species and trial species will be kept and these will be used to

guide the selection of street trees for replacement and new planting strategies. (The lists of suitable, unsuitable and trial species shall apply, however, these may be

updated with the approval of the Co-ordinator Parks & Gardens). (xi) Programmes for the removal and replacement of street trees will be developed on the

basis of priorities set in the planting plans and will include public consultation. Replacement programmes may involve removals on one side of the street or removal of alternate trees with remaining trees removed in 3 -5 years when newly planted trees are having some impact on the streetscape.

(xii) Where tree removals are proposed in a street the Parks and Garden Section will

inform all affected residents and invite comment on the proposed action. Residents shall be advised of proposed tree replacement time frames.

(xiii) Consultation with council's Planning and Development Division regarding private

developments shall be encouraged at the design stage to assist with appropriate negotiations regarding existing trees in the street on with significant streetscape impacts/contributions.

(xiv) Approval for planning, building and crossover permits shall only be granted if the

applicant can clearly state that no street trees are adversely affected by the development. If they are affected, a clear strategy is to be outlined for their care and protection during construction, upon which specific approval may be granted by the Co-ordinator Parks & Gardens. Ideally there should be 3 site inspections of all developments larger than Triplex size - prior to demolition, prior to laying of foundations and at foundation stage.


There shall be some flexibility with the retention of inappropriate existing trees subject to replacement trees planted at the developers/ applicant's cost. The application of a bond (of say $500) should also be considered.

(xv) The Co-ordinator Parks & Gardens shall seek discussions and review with those

organisations which have legislation and standards which impact upon street trees.

4. TREE SELECTION Tree selection is an enormously powerful tool that can address many, though not all, tree maintenance and management issues. Tree selection criteria can basically be summed up in three major areas: Aesthetics Biological considerations Function

4.1 Aesthetics - as the use of trees (and plants in general) in the urban landscape is of little value unless it enriches the experience of a place, aesthetic characteristics are of paramount importance in selection.

(i) Relationships with distinctive landscape characters.

(a) Cultural heritage - recognition of the heritage value of Fremantle should insist that where historical precedent has already been set in the selection of a species, then this species should be retained and strengthened. Some areas of Fremantle have signature' trees which help define the character of the suburb. Examples include:

Fremantle CBD - Ficus macrophylla (Moreton Bay Figs), Platanus species (Plane trees) and Araucaria heterophylla (Norfolk Island Pines).

South Fremantle - Agonis flexuosa (Weeping Peppermint) and Araucaria

heterophylla. Beaconsfield - Agonis flexuosa and Eucalyptus leucoxylen 1Rosea' (Pink flowered

Gum)

Hilton – Jacaranda mimosifolia (Jacaranda) and Erythrina indica (Coral Tree)


NOTE: Some of the above species have characteristics which make them unsuitable for planting in some circumstances, i.e. Ficus macrophylla is generally too 'large to be used as a street tree and Erythrina indica has characteristics which make it a less than ideal street tree (e.g. brittle wood, thorns, messy, etc. ) however it will be replanted where it has historical association.

(b) Natural heritage - Informal contemporary residential landscapes should be retained

and strengthened where appropriate i.e. planting of Eucalypts and other indigenous and native trees in Samson and areas of North Fremantle and Management Plans for Bushland Reserves will specify indigenous plants to be used for revegetation.

(ii) Colour of tree Foliage

In highly urbanised environments, such as Fremantle, a multiplicity of colours are provided by the facades of buildings, paving, signs and cars. An important role of tree planting in such an environment is to attempt to provide a neutral green theme to unify or enhance the other colours present. Use of trees with variegated foliage should be avoided in streetscapes except in very specific situations involving specimen plantings.

(iii) Ultimate size of tree canopies Tree species should generally be chosen to be in scale with the streetscape or landscape in question. From an aesthetic perspective, it is generally desirable to utilise the largest growing species of appropriate form and within the scale of a particular location possible.

(iv) The form of tree canopies There are two major issues associated with canopy form in streetscape trees.

(a) Visual suitability of canopies for training around overhead wires - most suitable are species which have a loosely defined canopy edge, a canopy that readily assumes an open centre and a canopy composed of vigorous outward growing branches.


(b) Form of canopy in relation to surrounding landscapes - except where there are good reasons to the contrary, trees with relatively relaxed free-form canopies that are neither markedly erect nor horizontal are generally most desirable in urban streetscapes.

(v) Floral displays versus tree foliage and form Although dramatic seasonal flowering displays can be spectacular this should not be a

dominant selection criteria as the flowering display is relatively short-lived. Far more important is the quality of less ephemeral display characteristics such as foliage, branching pattern, overall canopy form, bark pattern and colour.

(vi) Uniformity of growth The avenue-type plantings, which dominate many streetscapes, rely on the uniformity

of the individual trees to create the desired effect. Formal avenue plantings should ideally consist of clonal selections of superior forms

where this is technically feasible, rather than trees grown from seed which can result in much greater diversity of form.

Biological diversity is better achieved via an overview of Public open Space, using

different growth forms of the same species in different streets rather than having genetically variable forms within a single street.

In informal plantings in parks, uniformity is less important, and diversity readily achievable and in the bushland reserves, this diversity is actively encouraged, however, these are exceptions rather than the rule.

(vii) Deciduous versus Evergreen?

In the urban environment it is desirable to use both deciduous and evergreen trees. Evergreen species provide year-round screening, greenery and shelter from winds. Deciduous species provide stimulating seasonal events, such as leafing up in spring and leaf fall in Autumn and provide summer shade whilst maximising winter light.

As a general principle deciduous trees should dominate close to domestic residences

to maximise summer shading and winter light (solar hot water heaters), and evergreen trees used where year-round screening, shelter or statement is most important.


(viii) Dominants and sub-dominants Visual dominants are tree species that because of their aesthetic, biological and

functional merits will be used widely in the municipality. Given the rigorous criteria employed in the selection of those species, they will inevitably be relatively few in number and in the future will create the streetscape character of the area in question.

Sub-dominants embrace a wider range of species and cultivars which, whilst not so

appropriate or serviceable as the dominants, possess characteristics of real value. Sub-dominants should be used to create more local themes within the overall landscape structure generated by dominant species.

4.2 Biological Considerations - The capacity of trees to establish and deliver aesthetic and other benefits, depends upon whether the conditions prevailing at the planting site are within the tolerance range of the species in question. Some of the recurring biological factors that affect tree selection are as follows:

(i) General climatic suitability Climatic factors tend to be responsible for sub-optimal performance rather than the

death of trees. This sub-optimal performance is generally expressed as low growth rates, sometimes

unhealthy foliage, a tendency for branch die back or drop and restricted flowering. The unsuitability of the climate of the planting site for carbohydrate production is

generally a fundamental cause of these problems. Fremantle is a warm, windy, coastal environment with poor, alkaline, free draining soil

and trees most suited to these conditions are recommended for planting unless planting conditions can be significantly (artificially) altered.

(ii) Tolerance of air-blown salt spray

In Fremantle the effect of salt-laden winds will be felt to approximately 1000m from the coast and even further inland in exposed sites.

High tolerance is generally best developed in species that have naturally occurring

coastal distributions and planting of these species is recommended for coastal plantings and as screening plants for non-coastal species further inland.

(iii) Tolerance of low levels of soil oxygen


Many soil profiles in urban areas are poorly oxygenated as result of compaction associated with building and engineering works and the presence of near impermeable coverings such as paving and road surfacing. where the latter conditions prevail most non-adapted species will grow relatively slowly and in some cases very poorly. In areas dominated by paved surfaces, species tolerant of low soil oxygen should be selected.

The differentials between soil oxygen levels in paved and turfed areas are often

considerable and tree selection should address those two locations separately.

(iv) Tolerance of compacted soils Many species which have a high tolerance of soil deoxygenation also have above

average tolerance of soil compaction as their roots are able to penetrate compacted soil whilst it is very wet and penetrative resistances are low. They therefore have access to a greater volume of water as the soil dries out thus becoming unpenetratable again. In many, cases, it is drought stress that ultimately kills or debilitates plants on heavily compacted soils. For this reason, it is imperative that all unnecessary compaction is avoided within a tree's dripline during building and construction work. Conditions are to be placed on Development Applications where this may be perceived to be a problem and parking of heavy vehicles and placement of heavy loads under trees is to be discouraged.

(v) Tolerance of drought In most cases, tree selection for public open space should be based on the

assumption that trees must be capable of surviving an average drought period in reasonable condition without irrigation. Trees are to be planted in early Autumn to allow for an extended watering-in over winter to maximise root establishment and minimise drought stress as much as possible.

(vi) Tolerance of pests and diseases Trees which are known to be highly attractive to debilitating pests and/or disease,

should not be used as dominants, in public open space unless overriding reasons dictate their selection, therefore, more stringent management practices need to be adopted.

(vii) Tolerance of atmospheric pollution The most - significant form of atmospheric pollution in Australian urban. landscapes is

photochemical, the product of vehicle exhaust systems.

The effects of pollution appear to be largely confined to a reduction in growth rate, however, is unlikely that atmospheric pollution in Fremantle is high enough to cause significant tree damage.


4.3 Function - Some important functional criteria for urban tree selection are:

(i) Readily available at the appropriate time and transplantable at advanced size of good quality and form

There is substantial evidence that planting trees as advanced specimens is, from an

establishment perspective, a sub-optimal practice. Despite this, the high initial impact of such trees combined with their resistance to causal vandalism, makes it almost inevitable that many street tree plantings utilise this planting stock.

Species vary considerably in both their capacity to initiate new roots post planting and

their inherent vigour during and immediately after the establishment period. Species that establish roots very slowly are often unsuitable as dominant urban trees in rigorous situations such as streetscapes, although acceptable in less intensively used landscapes such as parks.

As a general rule, the minimum size plant to be planted in a suburban verge would be

a 13 litre container size or greater with a minimum height of 1.2m. (ii) Above average tolerance of root damage and disturbance Root damage to established trees in streetscapes as a result of construction work,

access to services, etc. is almost an inevitability in urban landscapes. Capacity to recover can often be correlated to tree age, tree vigour and the amount of

root loss. Damage to tree root systems should be avoided wherever possible, minimised where it cannot be avoided and tree removal considered only as a last resort. Co-operation with service authorities is of the utmost importance.

(iii) Average or below average capacity to invade services Tree roots do not grow through ducted facilities (water etc.) but will exploit cracks in pipes caused by poor workmanship, soil movement, mechanical breakages etc. Greater use of flexible PVC piping is seeing a decline in root invasion problems and use of 'root routers' and chemicals can effectively treat blocked pipes. Generally, though, trees should not be planted directly over underground services and should preferably be at least lm away in order to minimise any possible future problems.

(iv) Acceptable leaf and fruit fall characteristics Species with fleshy fruits or leaves that become mucilaginous on decomposition are

not suitable for planting in paved areas. Likewise, shedding of leaves, fruits, flowers and twigs can block gutters and drains and may interfere with machinery such as


mowers (i.e. gumnuts). Such species can however be planted in areas where high maintenance levels are acceptable.

Trees with known littering characteristics should be avoided in areas where it may

cause problems i.e. low maintenance areas.

(v) Low risk of becoming an urban or environmental weed

Species that produce large amounts of readily germinable seed or which easily sucker should be avoided.

(vi) Not prone to major limb shear The abscission of major limbs in response to soil moisture stress is a highly

undesirable characteristic of a number of tree species. Limb loss also occurs on an occasional basis due to wind - induced mechanical breakage. Tree species known to have this particular characteristics are to be avoided in the streetscape and the practice of lopping is to be avoided as this leads to the production of poorly attached epicormic shoots that may be prone to shedding even in species not normally subject to this problem in their natural form.

(vii) Tolerant of severe (significant) pruning 'Tolerant' refers to species that recover quickly from pruning away from overhead

wires and produce well-secured extension growth and rapidly callousing wounds. Note: severe pruning does not imply pollarding or lopping.

(viii) Long Lived Many of the costs associated with the management of trees in the urban environment

are associated with the establishment and over-maturity phase (particularly the latter).


Consequently, it is desirable in many situations to plant species which require replacement on as infrequent a basis as possible. In the case of trees under power-lines, the costs of management are spread more uniformly across the life of the trees.

(ix) Satisfactory form to allow pedestrian and vehicular clearances. There is a need to select species that minimise conflicts with pedestrians and

high-sided vehicles. Formative pruning to encourage a number of semi-erect scaffold branches to lift the eventual canopy to the desired height is also advised. Less intractable problems exist with pedestrian clearances, and can be addressed via species selection, rigorous stock inspection prior or post purchase, and formative pruning.

(x) Capacity to lift kerbing and pavements As a general principle, damage appears to be most commonly associated with

vigorous, large growing species and becomes progressively more marked as radial thickening of major, scaffold roots occurs. Species known to have this characteristic should not be planted near paving and kerbs, however, if planting in this situation is unavoidable, some form of root barrier should be utilised.

(xi) Tolerance of Poor Sandy/Limestone Soils Plants in the Fremantle area have to survive in depleted sandy soils with large

concentrations of limestone in most areas and species should be chosen accordingly, unless specific measures are taken, such as excavating a large planting pit, backfilling with 'soil' and regular supplementary feeding.

5. TREE PLANTING

Council is responsible for the planting of all street trees, however, residents/occupants will be encouraged to plant their own street trees of approved varieties and to Council specifications. Residents, community groups and "Friends Group” will also be encouraged and supported to complete various planting projects throughout the City.

5.1 Planting Location Guidelines The following planting locations shall serve as guidelines for all street tree planting and shall only be varied in specific situations with the approval of the Co-ordinator Parks & Gardens.

To avoid problems, the location for a tree on the verge shall be:

3 metre minimum from vehicle crossover, power pole, fire hydrant or inspection pit box;


a minimum of 15 metres from kerb corner alignment on any side of an intersection;

a minimum of 15 metres from the approach side of pedestrian crossing

and 5 metres from departure side;

7 metres front any laneway or vehicle right of way;

6 - 15 metres between trees, depending on mature specimen final size, or generally one tree per property frontage;

generally central to average block (house);

10 - 15 metres from approach side of bus stop and 5 metres from

departure side. Shade is desirable at bus stops and opportunities to plant between them and adjoining properties should be investigated where possible.

These distances may vary depending on species and planting

objectives.

5.2 Planting

(i) Council shall undertake tree planting on streets as identified under its long term programme. Requests from residents/occupants will also be considered subject to the constraints of the City's financial and labour resources.

(ii) Residents/occupants will be encouraged to plant their own street trees from a list of

approved varieties/species and they will be given planting guidelines to facilitate this as well as guidelines for the selection of good quality nursery stock.

5.3 Street Tree Establishment In order to ensure the long term survival of all street trees the following accepted principles of tree establishment shall be adopted:

(i) Tree planting shall occur during the cooler, wetter months of the year - May to July, except where an agreement is made with residents to regularly water the new tree.

(ii) The planting of street trees, whether carried out by Council's staff or residents, must

be in accordance with the prescribed planting location guidelines and Departmental Street Tree Planting Procedures and in accordance with long or short- term design strategies.


(iii) Additional protection shall be provided for establishment of street trees where they may be prone to vandalism, soil compaction, climatic extremes, vigorous weed competition or presence of underground utilities or services. In addition, protection of structures and hard surfaces against damage by street trees may be needed. Where appropriate the following protective measures will be provided:

root barrier membrane to protect surrounding kerbing and paving from

root damage;

tree grates to minimise soil compaction and to improve water and oxygen infiltration into the root zone;

mulching or weed matting to control invasive, competitive weed growth;

reticulation;

tree guards and/or bollards to provide protection from cars, pedestrians and animals;

tree staking to ensure erect form or marker stakes to provide some degree of protection from mowers;

maintenance crews shall be instructed/ educated to not damage newly planted trees by mowing operations i.e. partial or total ringbarking caused by brushcutters.

(iv) Ongoing post-planting maintenance that ensures continual survival of young street

trees such as follow up watering, weed control, staking and formative pruning.

5.4 Unauthorised Street Tree Planting Street trees planted without Council Approval are considered unauthorised plantings, but may be retained subject to certain conditions being met.

(i) An unauthorised street tree planting shall constitute any one of the following:

a tree planted without the Authority of Council; a tree planted of an inappropriate species for the location as determined

by the Co-ordinator Parks & Gardens; a tree planted in an inappropriate location as determined by the Co-

ordinator Parks & Gardens. (ii) Where an unauthorised street tree planting is identified, Council shall determine

whether the planting can be retained (if it conforms to Council's planting specifications and to varietal choice).


(iii) Where the planting is of a recent undertaking (i.e. within 12 months) and the tree is of

an approved species but not on the appropriate alignment, Council shall relocate the tree after the resident is notified and providing the tree is suitable for doing so.

(iv) Where the planting is of a recent undertaking (i.e. within 12 months) and of an

inappropriate species, the resident shall be given the option of relocating the tree into their property prior to its removal by Council.

(v) Where the planting is more established and the variety considered not appropriate to

transplant, associated policies relating to pruning and/or removal shall apply.

5.5 Purchasing Trees shall be contract grown or purchased from commercial plant lists as Council does not have the facilities or the resources for growing on its own stock. Parks and Gardens Officers shall be responsible for inspecting the root systems of a sample number of trees prior to accepting deliveries. Periodic inspections to monitor the quality of stock during the contract growing period shall be made by Parks and Recreation officers.

6. POST ESTABLISHMENT CARE Council is responsible for the post-establishment care of trees it plants and this maintenance work can include:

fertilising pesticide application root pruning and barrier installation aeration and other site improvements application of soil wetting agents re-staking (Marker stakes) weed control formative pruning watering removal of poorly established or dead trees

Decisions regarding the appropriate maintenance work will be based on the amenity and aesthetic value of the tree versus the benefit cost of any anticipated maintenance. All relevant values will be taken into consideration, not merely monetary considerations.

6.1 Watering

(i) Council shall undertake the watering of all new street trees, as and when required, until established (two, summers).


(ii) Programmed plantings and tree requests shall be watered. (iii) Residents shall be encouraged to water their street tree during the establishment

period. A written request with watering guidelines shall be lodged with residents soon after tree planting seeking this undertaking.

7. TREE PRUNING Council is responsible for the pruning of all street trees.

(i) Council shall undertake the pruning of all street trees affected by powerlines on a programmed basis.

(ii) Programmed tree pruning shall include trees on the sides of streets affected by

overhead power lines as well as trees affected by electrical feeder lines to individual properties on the opposite side.

(iii) Programmed pruning shall not normally include trees unaffected by overhead power

lines see (v) below. (iv) Programmed pruning is to be planned each year, on a regular basis in consultation

with Western Power and in accordance with predetermined regions of the City. (v) Programmed tree pruning shall be to normally fulfil any of the following requirements:

(a) To clear canopy from interference with overhead powerlines and other essential

services. (b) To remove overhanging branches considered hazardous to traffic, buildings,

structures or pedestrians. (c) To underprune low growing branches considered. dangerous/hazardous to traffic,

pedestrians etc. (d) To form the shape of developing trees. (e) To redefine the framework of mature trees. (f) To rejuvenate vigour in old growth. (g) To reduce crown density so as to redistribute growth to lateral branches. (h) To remove dead, dying, diseased or pest infested limbs or branches. (i) To carry out remedial or corrective surgery as required.


(vi) Council will actively pursue the installation of Aerial Bundled Cabling (ABC) or

underground power services where possible to minimise the requirement for tree pruning.

(vii) Tree removal shall be in accordance with the guidelines contained within this Policy.

Residents will not be granted permission to remove street trees due to the hazardous nature of the operation and owing to legal liabilities.

(viii) Pruning may, in addition to programmed work, be undertaken at the request of

residents, Councillors, utility authorities etc. but only with the approval of the Co-ordinator Parks & Gardens.

(ix) Pruning practices shall be outlined in guidelines to ensure current industry standards

and in accordance with clearly defined objectives. (x) Pruning shall be undertaken by trained staff under the supervision of a qualified

Arboriculturist.

8. TREE ROOT MANAGEMENT As a discipline with its origins in craft rather than science, arboriculture has tended to focus on the above ground portions of trees, rather than their root systems. With increasing involvement of scientifically trained personnel in arboriculture this deficiency is being addressed. It is the condition of the root system that ultimately determines the success or otherwise of the whole tree. The most recent research on tree roots has established that:

the diameter of tree root spread is commonly 2 - 3 times the height of the tree the bulk of root growth is predominantly lateral in soils, parallel with the surface the bulk of the root mass is found within 600mm of the soil surface with up to 75% of

the root mass within the top 300mm. horizontal scaffold roots form the major structural roots of the tree the soil environment is just as important as the species type in determining rooting

patterns and depth tree roots do not grow towards anything in particular but are opportunistic and concentrate wherever conditions are favourable for their development

8.1 Tree Root damage to services, pavements and drains.

Root entry and damage to underground services such as drains, sewers and telecommunication ducting, etc., is a common problem, however, as already stated in section 4.3, tree roots do not actively seek out these services but exploit weaknesses and leaks where they occur.


Depth of placement of services in relation to oxygen levels, the form of backfills, the use of root barriers, can all contribute positively, but the problem is best addressed by engineering solutions such as pipes or ducts that are designed to resist root ingress ie. replacement of terracotta pipes with P.V.C. pipe with pressure seals.

Replacement of old terracotta pipes with P.V.C. pipe is to be actively encouraged with the relevant service providers.

To minimise kerb and pavement damage by roots, the use of root barriers and guards is encouraged and utilised, where appropriate, in Council planting and in proposed planting by Developers.

Vertical black plastic sheeting barrier or similar to a minimum depth of 30Omm or preferably 600 mm is recommended.

8.2 Tree root damage to buildings, walls and other structures

In the sandy Fremantle loams, most tree root damage to structures is caused by either planting of an inappropriate species initially or the subsequent installation of a structure in close proximity to an already existing tree.

Many of the Ficus species (Figs) have large structural roots which break the surface

of the soil and, where inappropriately planted, they have lifted footpaths, kerbs, driveways and even buildings. Likewise, most other large trees will, as their girth increases, displace soil from around the base of the trunk causing movement upwards and outwards thereby undermining any nearby structure.

Species selection prior to planting will minimise later problems and the use of vertical

root barriers is also recommended. Proposed installation of new paths etc. in close proximity to existing trees shall be

dealt with by liaison between the appropriate Parks and Engineering Officers. Existing problems shall be dealt with by way of root pruning carried out under the supervision of a trained Arboriculturist and, where this is not appropriate, the removal of either the structure itself or the tree (depending on the significance of the tree).

8.3 Preservation of existing trees on or adjacent to construction sites.

In making an assessment of the likelihood of a tree surviving construction works in reasonable biological condition the following factors need to be addressed:

(i) The position of the root system in relation to the proposed development and associated activities-as a rule of thumb, the assumption can be made that the root zone will extend out 2 -3 times the height of the tree and that the majority of the root mass will be located within 600mm of the soil surface (this can vary with different species and different soil structures / features). Trees growing in turf verges are likely


to have most of their root mass located just below the turf itself where growing conditions are most favourable.

(ii) The nature and proximity of the proposed works to the tree Severe damage to trees will generally come as a result of cuts in ground surface

resulting in massive root loss, fills over the root systems that reduce soil oxygen, and intolerant species, cause root death and tree decline, and finally trench excavation across the root zone of the tree.

Attempts should not be made to save a tree where 50% or more of the root mass has

been severed or removed as it will not survive and will probably be unstable, and therefore dangerous.

In the case of fills, there are a number of techniques available to attempt to maintain

oxygen to existing roots long enough to allow them to grow up into the fill. Trenching is the most avoidable source of damage as in many cases lateral auguring

beneath the root place can be used to install cables or service ducts. Digging straight at and under a tree is preferable to trenching alongside of it.

Other indirect causes of damage involve either a significant increase or decrease in

soil moisture around trees, surface compaction of the surface soil resulting in deoxygenation, and mechanical damage to the tree trunk and major branches as a result of machinery, materials storage, site fires,- chemicals and vandals.

(iii) The amount of root loss that is likely to occur The loss of 50% or more of a trees root system will usually result in the decline and eventual death of the tree.

(iv) Tree species, age, physiological vigour, and the management regime post root severance Some, species are undoubtedly more able to initiate new roots post damage than others, although this depends to a considerable degree on tree capacity to produce carbohydrates to support this new growth. The ability to do this diminishes as trees age and or lose their vigour. Ultimately the success of retention decisions rests on the capacity to ensure that site works are carried out in the least damaging manner possible, and that initiatives to fence off areas around trees, etc. are undertaken and respected. This is often very difficult to achieve as the results of much planning can be destroyed within a few minutes With an excavator bucket.


All of these scenarios must be considered before making a decision on tree removal and replacement strategy. If at the end of this process it appears likely that existing trees cannot be maintained in viable condition then removal and replacement is the most sensible decision. Tree valuation should recover full replacement costs from the Contractor/ Developer. One innovation which can minimise damage to a trees root zone is to locate all underground services in a common trench on a known alignment - trees can then be planted away from the trench altogether or planted as far away as possible so that any excavation of the trench only results in minimal damage to the outer edge of part of the root zone. Council should actively lobby all service providers to install their services in common trenches and should specify this requirement in all new developments where appropriate.

9. TREE REMOVAL AND REPLACEMENT DECISIONS The past decade has witnessed great interest in tree planting in Fremantle, and elsewhere. It is unfortunate that this movement has not been balanced by greater interest in tree management and, in particular, what happens at the end of a trees life cycle. Some of the factors that contribute to this situation are: the long term nature of the problem, public veneration of trees, and significant costs associated with tree replacement programs.

(i) The long term nature of the problem

The commonly used urban trees of the Perth Metropolitan area appear to have useful lifespans of between 50 and 150 years at least. There are numerous examples of Agonis (Weeping Peppermints) approaching 100 years, Araucaria heterophylla (Norfolk Island Pines) approaching 70 years and Ficus macrophylla (Moreton Bay Figs) approaching at least a similar age in the Fremantle area. Tree replacement strategies require that a. consistent approach to management is applied over a long period of time. This, in turn, requires a commitment to planning and a program of community education and involvement.

(ii) Public Veneration of trees Most people are concerned about their immediate environment and respond strongly

to proposals to remove trees that are not dead. Objective arguments as to why the trees are being removed rarely has much impact in these conflicts. Public reaction to tree management proposals is not always based on altruistic or esoteric concepts of ecological or aesthetic value. In many situations a fall in property value following the removal of mature trees will be an equally important factor. In addition, there are always subcultures in urban societies who will wish to use even the most well-considered tree management programs as a vehicle for their own agenda. In a


democratic society there are no clear cut solutions to these conflicts, other than for Council to be pro-active, communicate effectively before such actions are undertaken, and attempt to win the trust and respect of the bulk of the community.

(iii) Significant costs associated with tree replacement programs In the short term, there is nothing cheaper than leaving well alone, and

understandably inaction is a convenient option. T he major factor that encourages the implementation of tree replacement programs is

the fear of litigation as a result of injury to people and damage to property from senescent trees.

9.1 The Principles underlying tree removal and replacement strategies

A hypothetical curve for the aesthetic returns generated by a tree plotted against time from planting shows that the aesthetic returns generally increase as a tree ages until a plateau is reached. After this, returns fall away as the tree enters the overmaturity and decline phase. It is not uncommon for this latter phase to begin twenty or more years before the death of a tree. Conversely, the management costs for a tree that is not subjected to regular pruning and maintenance costs increase dramatically as it ages, as it requires increasing arboricultural input to maintain it in a safe attractive condition. In many cases there is a crossover point beyond which the aesthetic return from the tree is decreasing whilst the costs of management are increasing. It is difficult to justify such non-productive expenditures, and removal and replacement is a rational decision at this point. Where this argument is ignored and the tree "propped up" for another 20 - 30 years, the opportunity to utilise this time, to re-establish the level of aesthetic return that the tree delivered before it entered the decline phase is lost. Consideration must however be given to trees of historical or cultural significance from time to time.

9.2 Practical tree removal and replacement strategies. All tree removal and replacement strategies have varying degrees of trauma and lost amenity in the community. The basic strategies employed are:

Replant and then remove singular trees which have reached a certain level of decline.

Replant and then remove only dead, structurally unsound and dangerous trees.

Remove and replant systematically, over a number of years, all of the declining trees.


Remove and replant all of the trees in a street or location once they have reached such a level of decline that they detract from the aesthetics of an area.

Council 'Policy' up until this point has been to utilise the first two options, however, it is recommended that all four options be employed, where appropriate, combined with community consultation and the opportunity to plant existing gaps in the streetscape. Delegated Authority to remove trees currently rests with the Co-ordinator Parks & Gardens and this should continue. It should be stressed that in all cases, trees are currently, and should continue to be in the future, only removed after assessment by a trained arboriculturist or horticulturist and consultation with the adjoining resident, residents or community association. Where street trees or trees that have been identified as needing to remain are illegally removed or damaged by Developers or residents, then an assessment will determine the value of the tree and compensation will be sought by Council, on behalf of the community. Where an adjacent property is being subdivided a street tree may only be removed to provide vehicular access if:

Permission of the Co-ordinator Parks & Gardens is granted.

Compensation for replacing the tree elsewhere in the streetscape is provided to Council on behalf of the community by the Developer or resident. (The amount of compensation will be determined by the Draft Australian Standards on Amenity trees, but may be varied at the discretion of the Co-ordinator Parks & Gardens).

9.3 Conditions allowing for removal Other than for the tree removal and replacement decisions already mentioned above, Council shall undertake the removal of street trees under the following circumstances:

(i) Trees that are dead or diseased and beyond remedial treatment. (ii) Trees that are assessed as being structurally weak and dangerous or place the public

at risk by virtue of some serious weakness. (iii) Trees that have been rendered dangerous and/or irreparable through storm damage. (iv) Trees that are a hazard to pedestrians/ traffic due to restricted vision of traffic

presented by a tree being inappropriate in location, species or alignment. (v) In the event of road widening or realignment where adjustment to property setbacks

and underground services has to occur and every option of preventing the tree being removed has been investigated without solution.


(vi) Where the tree is dangerously in contact with overhead powerlines or distribution

wires to properties and where for reasons of growth habit pertaining to the species, selective pruning is not practical with the only other option being severe lopping.

9.4 Conditions not allowing tree removal in all areas.

The following shall NOT constitute sufficient reason for the removal of trees: (i) Growth of tree obliterating scenic views. (ii) Dislike of the species planted or of its growth habit (trees are planted to benefit the

community at large). (iii) Leaf, fruit or bark shedding being a nuisance. (iv) Allergies and health problems being experienced. (v) The tree obstructing a proposed, second nonessential crossover. (vi) The shading of private gardens or solar hot water installations. (vii) For reasons of cultural, religious or superstitious origin.

Note: The Co-ordinator Parks & Gardens may, at his/her discretion, authorise work to remedy any of the above situations if deemed appropriate.

10. TREE PRESERVATION

Council shall develop guidelines for the Preservation of Trees as part of the Development Approvals System, preservation of trees generally on Council owned property (including street trees) and it shall create a register of significant trees. The development of a system of Tree Management Orders should be investigated and should have legislative backing in order to enforce compliance.


10.1 Tree Preservation on Development Sites Decisions on retaining existing trees in development sites are to be dealt with as part of the Development Approvals System. Decisions on retention should be objectively, not emotionally, based, and must consider the significance of the tree, in terms of cultural, historical, environmental, aesthetic and botanical factors and the role of the tree in the community. Issues to consider in making this judgement include condition, health, species, age, size, rarity, association with historical events or persons, position in relation to other trees and buildings, habitat value, and site management regime during the development (i.e. tree should be sufficiently isolated using a physical barrier to prevent damage and compaction, no storage of building materials nearby etc) . Assessment must be made in the context of both the site itself and the landscape beyond. An information sheet should be created for Developers advising them of preserving trees during the construction phase etc.

10.2 Tree Preservation Generally Council shall use all means possible to retain appropriate and suitable trees in the streetscape, and enhance the streetscape by means of tree planting programmes.

10.3 Register of Significant Trees Council shall develop a Register of Significant Trees that are located within the Municipality. Significant trees can be located on private property, within the public streetscape, on verges and in parks and reserves. A statement of significance, shall be prepared for each tree on the register and it shall include the following details in addition to the standardary tree management inventory details:

(a) category listing ie. cultural, commemorative, landmark importance, rarity etc. (b) date, location, map and photo (c) remedial needs (d) value

10.4 Tree Evaluation

As a means of preserving trees, penalties should exist for Developers and Residents who illegally remove or damage trees. Tree evaluations as per the Draft Australian Standard on Amenity Tree Valuation should be calculated for all significant trees and other trees as required. This will enable a standard means of recovering costs incurred in repairing damage or replacing those trees injured or killed as a result of service installation, construction activity, vandalism etc.


11. TREE MANAGEMENT INVENTORY

A comprehensive tree inventory is to be established and maintained and records kept from time of planting, plus details of pruning and other relevant treatments and growing conditions. This information can then be used as a tool in programming planting, maintenance, removal and replacement. The inventory shall be formatted into a readily retrievable system to suit planning and management purposes. This will involve updating existing tree data and investigation of an effective computer database system. The database should address the following issues:

Tree reference number Botanical and common name of the tree Size (height x width), either estimated, actual, or by class sizes Location by street number or grid reference (the former being preferable

when possible) Landscape type in which the tree is found, eg. street, parkland, traffic island

etc. Proximity to known services and buildings, eg. overhead power-lines,

underground ducting, fences and walls, etc. Surface details and condition around tree eg. in turf, in pavement cut outs etc.

Overall tree condition Tree significance Specific tree problems eg. extensive canopy decline evidence of cavitation

etc. Management actions required eg. canopy thinning, replacement, fertilisation Relative priority for most urgent management actions required Estimated time required to complete management action Last date work carried out and estimate of time spent Date of last inspection Estimated date for replacement Any additional comments eg. suggested value, is tree subject to a

Preservation order etc. Date for next inspection

Confirming the location of inventory trees on the ground is a recurrent problem. The use of grid references and street numbers does not always provide the desired level of specificity. One solution is to link the tree inventory databases to AutoCad drafting packages thereby creating a Geographical Information System (G.I.S). The application of G.I.S. principles to tree inventory system shall be explored further and resources allocated accordingly, where appropriate.


The collection of data and their entry into the database will be adequately resourced if the inventory is to fulfil its role as an integral management tool.

12. TREE EDUCATION

Council shall have an educative role in relation to the management of its tree assets.

It shall achieve this role by the following means:

12.1 Arbor Day

(i) Council shall actively encourage tree planting in schools by making available plants to schools for planting on Arbor Day (June each year).

(ii) Plants shall be made available at the rate of one plant per class or 1 plant per child for

one specific class or whatever the school requires as long as it is approved by the Co-ordinator Parks & Gardens.

(iii) The plants shall be delivered to the school by Council and planting shall be the

responsibility of the school. (iv) Guidelines for the ongoing management and maintenance of newly planted trees shall

be delivered to the school at the time of planting.

12.2 Management Plans

(i) Council shall recognise the value of remnant urban bushland to the community by having a management plan completed for each bushland area within its municipal boundary.

(ii) Management Plans shall be made freely available to the public and Council shall

encourage the creation of Friends Groups and support these to achieve the goals of the Management Plans.

(iii) Council shall lobby the relevant authorities to have Clontarf Hill and Cypress Hill

included as "System Six" areas of significance, and that other areas of remnant vegetation within the City shall be preserved (eg. Hilton Primary School, Swanbourne Street Commonwealth land, John Curtin Senior High School etc).

12.3 Staff Training

(i) Council recognises the value of appropriate training and all members of staff, but

specifically the tree care crew, shall be encouraged to undertake appropriate tree care courses to., improve their skills.


(ii) The crew leader of. the Tree Care Crew shall be a qualified arboriculturist or arborist

who will conduct on-the-job training for the other members of the crew to improve their skills and knowledge and appreciation for correct procedure.

12.4 Community Education/Liaison

(i) Council shall develop a framework for effective liaison and for fostering greater

awareness, understanding and co-operation with the community and agencies on matters pertaining to trees.

(ii) Council shall actively promote the benefits of trees at every opportunity. 12.5 Conflict Resolution

(i) Council shall disseminate information from various authorities pertaining to neighbour

disputes and rights and responsibilities with regard to trees in private gardens without becoming directly involved in any dispute.

(ii) Council may take remedial action where the conflict is between a private residence

and Council owned property. (iii) Council shall, at its discretion, take action where a resident has undertaken

unauthorised planting or removal of trees in Council owned property. (iv) Council may demand remedial action where a tree is causing conflict and the tree is

clearly unsafe under Section 516A of the Local Government Act (1960). (v) where private gardens obstruct footpaths or cause sight line problems Council may

demand that the offending foliage is pruned back to the property line, and where this is not completed within a reasonable amount of time (2 weeks), Council shall prune the offending foliage itself and seek compensation from the owner.

(vi) All street trees are protected against damage and removal under Section 665(1)(c) of

the Local Government Act (WA). The prescribed penalties contained within the Act shall be adhered to.

(vii) Additional Local Government legislation shall be sought with the aim of discouraging

poisoning, lopping, topping, destroying and removal of any tree in any Public Open Space and on private property where it is subject to a retention order.

(viii) Council will on occasion seek the advice and services of Arboricultural consultants to

provide independent evaluation and assessments.

13. APPENDIX


Examples of street tree lists and handout information sheets.

13.1 Fremantle Street Tree List 13.2 'Encroaching Branches and Roots - Who is Responsible?'

14. REFERENCES

City of Fremantle Policy Manual June 1994 'Putting Nature Back into the Nature Strip' Guidelines for the Planning and

Landscaping of Roads in Perth (Nov 1987) - P.A. Sargent 'Draft Australian Standard (D.R. 91068:5) - Trees - Pruning Techniques' Standards

Australia (March 1991) ‘Draft Australian Standard (D.R. 92100:R) - Trees – Amenity’


CITY OF FREMANTLE

STREET TREE and GENERAL PLANTING SPECIES

Botanical Name Common Name Height

Agonis flexuosa WA Weeping Peppermint 6m Araucaria heterophylla Norfolk Island Pine 20m Callistemon ‘Kings Park Special’ Bottlebrush 6m Casuarina equisetifolia var incana Horsetail She-Oak 10m Erythrina indica Coral or Flame Tree 10m Eucalyptus calophylla Marri 20m Eucalyptus ficifolia Red Flowering Gum 8m Eucalyptus foecunda Fremantle Mallee 5m Eucalyptus gomphocephala Tuart 10m Eucalyptus lehmannii Bushy Yate 15m Eucalyptus leucoxylon ‘Rosea’ Red Flower Yellow Gum 10m Eucalyptus platypus heterophylla Coastal Moort 6m Eucalyptus sideroxylon Red Ironbark 10m Eucalyptus spathulata Swamp Mallet 8m Eucalyptus torquata Coral Gum 8m Jacaranda mimosifolia Jacaranda 8m Melaleuca quinquinervia Broad Leaf Tea Tree 15m Olea europaea European Olive 7m

Appendix 13.1


Sapium sebiferum Chinese Tallow 8m Ulmus parvifolia Chinese Elm 6m Please note: Due to Policy Guidelines and site conditions, not all species listed above may be suitable for the verge in your street. Please discuss tree selection and location with an officer from Parks Section on 9432 9999.


Overhanging Branches and Roots

Cutting Back

If a branch or root comes onto your side of the fence, you are allowed to cut and remove it up to the boundary of your land. You must not cut the branch or root on your neighbour's side without their agreement.

You do not have to let your neighbour know you intend to cut things back from your property, but it is sensible to let them know there is a problem and what you are going to do.

Disposal

Any root, branch, flower or fruit growing on a branch that you cut back still belongs to the tree's owner and should really be returned to your neighbour.

Be careful about how they are returned. You are responsible for any damage or littering that might happen. Again, it is sensible to let your neighbour know what you are going to do.

Payment for Damage Caused by Neighbour's Tree

Repairing damage caused by a neighbour's tree can be costly. Roots can damage foundations, block drains or raise brick paving; overhanging branches can drop leaves into your gutters or prevent your own trees and crops from growing.

If you need to have repairs done or have to get a specialist in to remove the roots or branches, write to your neighbour setting out what the damage is and giving them copies of quotes for getting the work done. In your letter, ask them to pay and to fix the problem so it does not happen again. You should keep a copy of the letter.

Once your neighbour is aware of the problem (or should have become aware of it) they have a responsibility to fix the problem so it does not continue or worsen.

If you cannot reach an agreement, it may be necessary to apply to court for an order that your neighbour has to have the branches or roots removed.

Legal action against neighbours can lead to bad relationships that cannot be repaired. Where possible, you should think about negotiating an agreement, or going to a dispute resolution service instead of taking court action.

Before taking any steps that may become costly or starting any legal action, get legal advice or call Legal Aid Information Line on 1300 650 579 for further information.

Appendix 13.2













Documents

Policy - Home | City of Fremantle€¦ · Planting and pruning of street trees. Policy That Council has a scheme to plant street trees, where appropriate, upon request by owners of