RFI - 25_06_23_AIA_ SLa_3 Allambi Rise_V2

9.3     ESTABLISHING TREE PROTECTION
Figure 9 below shows a typical representation of a tree protection system. Tree root systems
are generally shallow with the majority found within the top 1m of soil and a higher density of
roots found closest to the surface where moisture and nutrients are more readily available.
The function of the TPZ is to ensure the tree has a viable root system, so it remains a functional
future as an amenity asset within the development.

The structural standing of a tree is linked to critical aspects of roots (found in the TPZ) to bind
the soil and create a mass that the tree can anchor to. These roots consist of ‘Secondary roots’
(medium size) and ‘Tertiary roots’ (small size).

Primary roots (large size) found in the SRZ connect the Tree to the anchor system. Primary
roots by themselves do not bind enough soil to create a stable anchor system.

The shallow nature of tree roots should be taken into consideration when working close to
trees and when installing the tree protection fencing for the TPZ.




                Figure 9: Example of an ideal generic Tree Protection System



9.3.1   TPZ SIGNS

The signs in Appendix 2 – Sample TPZ Sign, identifying the TPZ are to be placed around the
edge of the TPZ in locations visible to the site as per Tree Protection Fencing Standards
Australia marketing media AS4970 – 2009.

9.3.2   TRUNK PROTECTION
Trunk protection, to prevent direct contact with the tree’s trunk and buttress roots, can be
installed. This can comprise of Geo fab/20mm thick hessian and wooden battens
strapped/taped to the tree’s trunk with a skirt over the buttress roots.




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