Tree Management Guidelines

Transcription

1 Tree Management Guidelines

2 Overview Tree Management Guidelines The trees that make up Brisbane s urban forest create much of our subtropical landscape character and biodiversity. Almost half of the city s 1330 square kilometres is covered with trees, and almost half of that is on public land, including approximately 543,000 street trees. The proper management of our trees will therefore play an important role in realising our Living in Brisbane 2026 vision as well as providing the foundation for a clean, green city, our trees also contribute to an active healthy city; a friendly, safe city; a well designed subtropical city and an accessible, connected city. Council and the community appreciate the many benefits of trees. In particular, that trees: provide shade and cooling, which encourages a healthy outdoor lifestyle and helps to reduce energy consumption (by buffering the urban heat island effect) provide the natural structure of Brisbane s subtropical character and scenic amenity produce oxygen and consume carbon dioxide, trapping carbon and helping to reduce greenhouse gasses support habitat for local wildlife and migratory birds help to reduce dust, pollution, wind speeds and the effects of UV radiation help to manage stormwater run-off and soil erosion provide strong links to nature, our natural and cultural history and a sense of local identity contribute to individual property values, tourism and the vitality of business centres. Trees in close proximity to people and property can also pose risks during storms and at other times. However, well planned prevention and management can minimise these risks and the possible consequences. Applicability This document guides the management of all trees under Council s direct responsibility, including trees in streets, parks, botanic gardens, bushland reserves, waterways, at Council facilities and on Council-leased land. The guideline and supporting procedures, in conjunction with statutory requirements, form the basis for consistent Council decision making and resource management. 1

3 Outcomes This guideline and the associated procedures aim to balance the needs of our trees and our community, in line with the aspirations of the 2026 vision. Specific aims include to: optimise the capacity of our urban forest to provide both present and future residents with environmental, economic, and social benefits achieve a balance between minimising risks and liabilities to the community whilst delivering a sustainable urban tree cover achieve target canopy cover, stocking levels and projected life spans for the city s trees, including replacing removed trees and planning for deteriorating and ageing street and park trees achieve efficient, cost-effective, and sustainable management of the city s trees by coordinating efforts across Council and others programs minimise the way that trees interfere with existing above and below ground services, signage, street lighting, public and private structures encourage space for street tree planting through design coordination between Council divisions/business units and utility organisations minimise impacts on existing trees by providing clear approval processes and ensuring coordination across Council's planning guidelines and improvement programs, and between Council and others in infrastructure development and management uphold Council s duty of care, and commitment to public safety, including a good neighbour approach to managing trees adjacent to private property engage the community, provide open and accountable decision making and encourage stewardship and partnership support sustainable development and management practices. Guidelines Urban trees are living organisms that interact with the environment in which they live. They require varying amounts of management in order to minimise conflicts, while optimising their survival, longevity, growth and value as living assets. Council will use the following guidelines to ensure that trees are planted, protected, maintained and ultimately removed or replaced in a way that is sustainable, economically sound and socially acceptable. Council is committed to an integrated and proactive approach to urban tree management, supported by high quality customer service. 2

4 These guidelines include: 1. Retaining trees Keeping established trees, particularly in areas undergoing a change in land use, is the most cost-effective way to sustain Brisbane s urban forest. The Natural Assets Local Law (NALL) and Tree Protection Guidelines (Draft addition to the City Plan, Subdivision and Development Guidelines) will be used to ensure that, where appropriate, established trees are protected through all stages of a proposed development. In particular, the needs of existing trees should be considered at the pre-construction stages of planning and design. The NALL includes provision for protecting significant trees, including trees of cultural, ecological or historical heritage importance. For the purposes of this guideline, the Tree Protection Guidelines will be equally applicable to Council projects. The Tree Protection Guidelines refer to AS : Protection of Trees on Development sites, and provide advice on how to decide if a tree should be retained and how to protect worthy trees throughout the following stages of a development: site investigation and planning design and documentation construction 'on maintenance'period post development 3

5 2. Tree planting Planting new trees is important in enhancing and renewing urban tree cover. Council is directly involved in planting trees as well as requiring tree planting by others. Tree species should be selected according to the: purpose of the planting available space conditions of the site (including consideration of climate change effects). While endemic tree species are the most appropriate for restoring habitat, some non-native species (excluding pest plants) are part of the subtropical landscape character and botanic history of Brisbane s streets and inner urban parks. Guidelines relating to the three main tree planting areas are outlined below. In these areas, planting is based upon the: needs of the urban forest support of local residents opportunities provided by development/improvement alignment with Council s approved vision and strategies access to non-potable water for establishment. Streets The planting of street trees should: promote subtropical boulevards along arterial roads and major entry roads to the city, including feature tree species iconic to Brisbane s subtropical landscape contribute to local streetscape quality, stormwater management and 50% footpath shade cover targets be guided by existing canopy cover density, urban hot-spots, and resident requests favour whole-street plantings or blocks within streets in preference to individual plantings (this is more efficient for establishment and ongoing maintenance) favour clear trunked, small to medium shade tree species in residential streets to minimise nuisance encourage high quality vistas encourage community participation in street tree planting programs to promote ongoing stewardship. 4

6 Council parks Tree planting in Council parks should: conserve historically significant tree plantings and designs promote shade and amenity at picnic nodes, pathways, spectator areas, playgrounds and carparks offer opportunities for education and showcasing colourful tree species throughout the seasons use the placement and grouping of trees to minimise maintenance and risk exposure enhance and protect habitats and waterways encourage community participation in park planting programs to promote ongoing stewardship. Bushland and broad scale areas Tree planting in bushland and broad scale areas should: add to biodiversity by revegetating degraded land such as landfill and former farmland assist the natural regeneration of desired species within significant conservation areas favour endemic species to provide safe corridors for fauna and flora improve biodiversity value of remnant vegetation by suppressing weeds species contribute to the conservation of Brisbane s unique biodiversity and waterway health contribute to Brisbane s 40% native vegetation cover target. 3. Tree maintenance All trees go through a natural life-cycle of establishment, growth, maturity, decline and replacement. For trees growing in an urban environment there are times when Council needs to intervene in the life-cycle to address concerns regarding tree health, structure, risks, emergencies, nuisance (as defined by common law) or weed management. The extent of intervention will depend on the species, location, significance and functions of the tree, with most intervention required for trees growing closest to high use areas. Council recognises that trees are an important asset with measurable monetary values. Understanding this monetary value helps Council to make decisions about the cost-effectiveness of proactive rather than reactive maintenance activities, including the following Inspection Council will routinely carry out visual inspections of large trees in high visitation areas of parks (e.g. paths, playgrounds, carparks, playing fields and areas adjacent to private property boundaries) Council will prioritise visual inspections of street trees to inform annual maintenance programs Council will carry out additional visual and technical inspections in response to community concerns or suspicion of a tree s health or safety. 5

7 3.2. Pruning Pruning a tree helps to maintain its appropriate form and function. Where appropriate, Council will prune young trees to encourage strong and functional tree growth patterns, and periodically prune branches to address structural weaknesses and prevent foliage from obstructing street signs, traffic, street lighting, powerlines, rooflines, and pedestrians All pruning will be done by properly trained and qualified staff Watering Tree species will be carefully selected so that most trees only need to be watered during their establishment period (up to two years) and can subsequently survive on rainfall There may be some exceptions such as significant trees in streets and parks or gardens Only non-potable water should be used for tree watering Root management A healthy tree relies on a strong and healthy root system. Council will, wherever possible: avoid interfering with root systems provide adequate space for root growth actively manage tree roots to promote good tree health reduce impacts caused by roots. Interference with tree roots should always be the last option. The Tree Root Management Procedures provides additional guidance on compacted soils, managing root spaces, minimise damage to structures, root pruning and diseases management and pests Tree health The amount of tree health management required should be minimised through appropriate species choice, placement and establishment. However, external factors may mean that some trees occasionally need surgery, pest control, disease control and preventative health management. Tree maintenance work will be prioritised in the following order: risks to personal and public safety storm clean-up risks to property or infrastructure hazard reduction/fire safety maintaining healthy and structurally sound street and park trees maintaining natural habitat for wildlife tree establishment genuine nuisance issues. 6

8 4. Tree removal The decision to prematurely remove a tree will consider the tree s: risk to public safety significance and value life expectancy and condition (health and structure) ongoing maintenance costs risk to public safety nuisance level and weed status. Removing a valued, healthy, structurally sound, functional, low nuisance tree should be considered the last resort. The consideration to remove a tree may be in response to a customer request or routine inspections and maintenance. The decision will be made by a qualified Council officer or contracted arborist (in accordance with Tree Removal and Replacement Procedures and accepted best practice). The following guidelines should apply to all tree removals: The removal of highly significant Council trees is to be avoided, unless it forms part of a Tree Management or Succession Plan approved by the Manager Local Asset Services Council trees will not generally be removed for private views, to eliminate litter, or to eliminate over-shadowing of private properties Projects and private developments generally require a permit under NALL to remove public trees. Council projects require a similar internal process Unsuitable trees planted illegally on Council streets since 2003 (as per section 29 of NALL) may be removed in consultation with the adjacent property owner and local councillor Unsuitable trees agreed to in the Council-Energex Memorandum of Understanding (MOU) may be removed by Energex contractors. The Tree Removal and Replacement Procedure, and Council s Vegetation Management Procedure EP006 provide more guidance on tree removal assessment, decision making criteria, community notifications and appeals. 7

9 5. Tree replacement Council is committed to replacing removed trees as follows: In general, when a tree is removed according to the above guidelines, it should be replaced with at least one new tree of standard Council stock size Where the removal of the tree requires a permit under NALL, or does not satisfy the guidelines, it is to be replaced with a number of trees, so that within three years there will be no net loss in tree canopy area Three hectares of new native planting is required for each hectare removed from areas of regionally significant ecological value All replacement trees are to be planted as close as possible to the removed tree(s) or at least within the local area. 6. Community engagement To help encourage community involvement in establishing and maintaining Brisbane s urban forest, Council will: encourage residents to report sick or damaged street trees encourage residents to register their preferred locations and types of trees for street tree plantings provide opportunities for residents to participate in community street tree planting provide opportunities for residents to participate in the Habitat Brisbane and Creek Ranger programs, which help community groups restore natural habitats in parks, remnant bushland and wetlands, and along waterways encourage/facilitate conservation partnerships and other incentive programs for private property owners encourage residents and business to make philanthropic donations to assist tree planting projects (e.g. the Brisbane Environment Trust, administered by Signature Brisbane, accepts donations for a range of projects including tree planting throughout the Brisbane area)encourage/facilitate the establishment of private or commercial farm forestry enterprises in Environmental Protection Areas and Rural Areas of City Plan. Council will notify the community of any street and park tree removals and proposed tree replacement programs through local media and utilising local mail outs. Council will adopt a good-neighbour approach to managing trees near property boundaries by undertaking tree maintenance works that address genuine nuisance to the adjacent property owner. Review Date October