19 Viewland Drive Arborist Report · OPW19/0180

Consult Arborist ,,..

 

APPENDIX 1 - DEFINITION OF TERMS

The following criteria have been used in the VTA and arboricultural appraisal to gather information and determine the required
management options on the grounds of public health and safety. Measurements are approximate, made visually by eye unless
otherwise stated.

 

 

 

 

Young: Early stage of growth, immature size

Early Mature: Fast-growing well-established tree which has not yet reached mature size

Mature: The tree reached its mature size, exhibits slowing growth rates with early stages of naturally forming dead or dysfunctional wood,

Over Mature: Tree has reached mature size and is unlike to increase significantly in height or mass, Retrenchment of the upper crown with
increased vegetative vitality in lower crown, increased fungal activity and wood decay, increase colonisation by flora and fauna.

Veteran: Tree with advanced retrenchment, a reduced crown size and annual increment growth, extensive hollowing, crown collapse, low

 
 
 

vigour, advance heartwood decay, advanced colonisation by fauna and flora.

 

 

 

 

 

 

 

Good: ‘Tree with no defects or disorders which are notable. Full canopy with good colour foliage. Minimal pathogen damage.

Fair: Tree with minor defects or disorders which are notable. Some deadwood within what can be an unbalanced canopy, foliage generally
with good colour although some discoloration may be present typical of species in location. Minor pathogen damage.

Poor: Tree with major defects or disorders which are notable. Tree has considerable deadwood present, discoloured or distorted leaves
indicating further decline of the tree. Detrimental pathogen damage.

Dead: Dead or dysfunctional moribund tree.

Good: Tree with good unions and no branch defects. Sound trunk with no / minor defects. Good buttress and root structure,

Fair: Tree with minor defects or disorders which are notable. Small areas of bark missing. Small cavities or minor unfavourable branch
unions may be present. Minor damage to roots.

Poor: Tree with major defects, large hollows, weak unions and/or problematic damaged roots.

 

Hazardous: This implies a tree with major defect that may fail at any time

 
  

   

As specified in the AS 4970-2009 Protection of trees on development sites, the Tree Protection Zone (TPZ) is the principal means
of protecting trees on development site. The TPZ is a combination of the root and crown area fequiring protection. This area should
be isolated from construction disturbance so that the tree can remain in a viable condition. The TPZ incorporates the Structural Root
Zone (SRZ).

The radius of the TPZ is calculated for each tree by multiplying its trunk diameter at 1.4m above ground by 12, e.g. 300mm [email protected] x 12 = 3.6m Tree Protection Zone (TPZ)

A TPZ should not be less than 2m or greater than 15m (unless crown protection is required).

SRZ: Structural Root Zone (SRZ), as specified in AS 4970-2009 Protection of trees on development sites, is the surface area of protection
required to maintain a tree's stability — a larger area is required to maintain a tree in viable health. It is only necessary to calculate
the SRZ when major encroachment into a TPZ is proposed.

The SRZ for trees with a trunk diameter less than 150mm will be 1.5m.

 

 

 

 

 

 

 

 

DBH: Diameter at Breast Height - The yximate diameter of the trunk is measured visually in millimetres at a height of 1.4m.
Low Low risk potential / proactive management Within 12 months

Moderate Medium risk potential / reactive management Within 6 months

High High risk potential / reactive management Within 30 days

Severe Severe risk potential / Risk management ASAP - Urgent

 

 

 

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