Dictionary for Managing Trees in Urban Environments

Danny B Draper, Peter A Richards

• Publisher: CSIRO PUBLISHING
• Year: 2009
• ISBN:
  9780643098824
• Topic: Biological Sciences
• Subtopic: Horticulture
• Index: Biological Sciences

Dictionary for Managing Trees in Urban Environments is a comprehensive list of terms used in the universal management of urban trees.

Many of the terms are from arboricultural science, while others are derived from unproven but commonly applied concepts. Where the existing terminology to describe trees was limited or nonexistent, new terms have been introduced.

This dictionary allows for broad application and use by a wide variety of people and conveys in plain language concepts that are sometimes complex. Most major terms have been cross referenced and diagrams have been added for greater understanding. While a number of pertinent botanical terms have been included, those readily found within dictionaries of general plant sciences and botany have been omitted.

Dictionary for Managing Trees in Urban Environments promotes a greater understanding of arboriculture and urban forestry, and will assist in the preparation of reports for the management of trees, procedures and planning instruments, such as Tree Management Policies and Tree Management Orders.

A

Abatement law Law/s developed to avert or remedy nuisance.

Aberrant Not representative of normal form, atypical, unusual and not indicative.

Abiotic Not living, e.g. wind, rain, fire, light, snow, temperature and moisture extremes. See also Biotic.

Abiotic factors Non-living influences. 1. Environmental factors, e.g. wind, rain, fire, light, snow, temperature and moisture extremes. 2. Mechanical factors, e.g. root severance. 3. Chemical factors, e.g. high soil salinity and phytotoxic pesticides (Costello et al. 2003).

Abnormal vigour See High vigour.

Abrasion wound Mechanical wound causing laceration of tissue by an abrasive impact episode, e.g. grazed by a motor vehicle or the continuous action of the rubbing of crossed branches or stems where no graft has formed.

Abrupt changes Sudden changes rather than those occurring gradually, e.g. broken water pipes saturating soil, gas leaks.

Abscise To throw off or to shed.

Abscission Shedding of plant organs, e.g. fruit, leaves or branches, usually when the organ is mature or aged, by the formation of a corky layer across its base. This may be influenced by stress, drought (to prevent moisture loss), senescence, declining condition, reduced vigour and also occurs annually in deciduous trees.

Absorbing roots See Fine roots.

Acaulescent A trunkless tree or a tree supported by a very short trunk. See also Caulescent.

Accelerated growth The concept where large xylem formed at wound margins of wounded sapwood develops at a rate faster than growth rings especially in mature or senescent trees (NSW Dept. Environment & Conservation 2005, p. 76). Note: this concept appears contrary to CODIT Wall 4 which is laid down at a constant rate in seasonal growth rings except where a wound margin is stimulated by tropic responses to loading, e.g. torsion, compression or tension.

Accelerated growth callus The concept where xylem develops by accelerated growth at the wound margins of wounded sapwood (NSW Dept. Environment & Conservation 2005, p. 76). Note: this concept appears confused between the initially formed undifferentiated wood as callus wood and the later forming differentiated wood as wound wood. See also Wound margin, Wound wood, Callus wood and Compartmentalisation of decay in trees (CODIT).

Accessory bud Lateral bud associated with a main bud such as in a leaf axil and usually develops after damage to the main bud.

Accessory roots The lateral roots as with palms, which develop from the base of the trunk different to those arising from the radicle of the seed root system.

Accessory trunk Aerial root mass differentiated once it reaches the ground forming a vertical woody structure to support a trunk or branch, a columnar root or stilt root. Here the supported branch is able to extend further and tends to horizontal with the overall crown spread covering a considerable area, e.g. Ficus columnaris.

Acid sulphate soil Very acidic soil layers or horizons – the result of aeration of soil materials abundant in iron sulphides, mainly pyrite and the result of drying and aeration of previously saturated anaerobic soil material. Usually with a pH of <4.0 when measured in dry seasons conditions and overlying potential acid sulphate soils or soils with more than 0.05% oxidisable sulphur.

Acoustic resonance Auditory reverberation within an object and the air after the object has been struck. See also Sounding.

Active maintenance See Planned maintenance.

Acute branch crotch A branch crotch where the angle on the inner side of the union is less than <90°. See also Obtuse branch crotch.

Acutely convergent A branch growing in a direction towards its point of attachment where the angle in the crotch is less than <90°.

Acutely divergent A branch growing in a direction away from its point of attachment where the angle in the crotch is less than <90°.

Adaptive growth SeeAdaptive wood.

Adaptive wood Additional load-bearing wood formed in response to mechanical stresses and gravitational force upon the vascular cambium to provide a uniform distribution of loading. Examples are Ribs, Round-edged rib or Sharp-edged rib and Buttresses. See also Reaction wood, Compression wood and Tension wood.

Adaxial The side of a leaf, branch or other organ which anatomically faces towards the axis of the parent shoot (i.e. usually the upperside) (Lonsdale 1999, p. 309).

Adventitious A bud arising from points other than terminals or axils, e.g. from a root or at an internodal region (Harris et al. 2004, p. 15).

Adventitious bud A bud formed within the cambial zone and callus wood after wounding (Shigo 1989a, 134).

Adventitious shoot A branch from a bud arising in an unusual location, e.g. sucker.

Adventitious root mass Palms and other monocotyledons may form masses of fine roots or adventitious roots as primary growth where the radicle is replaced by branching many times and this may extend above ground and be evident at the base of the trunk. The extent of the root mass above ground may be extensive in some palms and increases with age giving the appearance of lifting the trunk, e.g. Phoenix canariensis.

Adventitious roots 1. Roots that may arise in an unusual location and may develop a structural function, e.g. (a) from a branch into a pocket crotch where accumulated leaf litter and moisture has formed humus, (b) into the hollow section of a branch or trunk often where humus has accumulated, (c) aerial roots, column roots, fibrous roots. 2. Roots that may arise where the radicle is replaced by lateral branching many times as with palms or grasses.

Advocate An individual or party acting as a representative in support of an issue.

Aerial ins...

Table of contents

• Cover
• Title
• Copyright
• Contents
• Foreword
• List of contributors
• Introduction
• How this dictionary works
• Dictionary terms
• References and further reading
• Topics within index
• Index divided into topics