RFI - Aboricultural Impact Assessment

6 F INDINGS
The assessment focused on the two Scribbly Gums, Eucalyptus racemosa, within the Noosa
Council road reserve, with one outside the adjacent property at #21, and the larger tri-stem
tree outside the site at #23.

Scribbly Gums are a common Eucalypt species found within the coastal area of Noosa. As a
species, they are often highlighted for habitable hollows within the branch and trunk structures,
which are caused by the tree’s natural, poor timber compartmentalisation, resulting in internal
decay and termite activity. Although beneficial for habitat, this often results in ‘random’ branch
failure, which raises questions regarding its suitability as a species in high population areas.

6.1 TRI-STEM TREE
Located on the right-hand side of the site entrance, the existing mature Scribbly Gum has a
multi-trunk/leader configuration and broad spreading canopy.

The tree’s general health and condition are classed as Good to Fair, with some branch defects
noted, as is typical for the species at this age.

The tree stands 14-16m in height with a canopy radius of over 10m toward the property side.

Having a tri-stem trunk, the tree’s Notional Root Zone (NRZ) radius has been calculated at
over 8.5m, with a Structural Root Zone (SRZ) radius over 3m.

Due to current ground conditions, with multiple in-ground obstructions and likely past ground
disturbance, the subject tree cannot have an even root spread that conforms to the AS 4970
calculations




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   Figure 4: Subject tree with Tri-stem trunk and existing in-ground infrastructure conflict with the root zone.

The project has been designed with the subject tree in mind, with the site access/driveway
and major services all sharing a similar alignment on the opposite side of the site frontage. As
part of the design, a Fire Booster is to be located within the property and connected to the
existing water main that runs parallel to the property boundary.




25_10_21_AIA_TPA_23BottlebrushAve                                                                      Page 7 of 19