Arborist Brief

3. Inspection Results:
A total of three trees have been identified along the council verge of No. 25 and No. 27 Dwyer
Street. Tree No. 1 and tree No. 2 are situated on the council verge fronting 25 Dwyer Street with
tree No. 3 situated on the verge fronting property No. 27.
Tree No. 1 is a mature Red Bloodwood (Corymbia gummifera) with several over extended branch
structures and deadwood Greater than (<) 50 mm in diameter. A co-dominant, first order branch
on the Northern side of the tree over hangs the driveway and service wire to the house. The
branch has poor taper with excessive end weight applying mechanical load force on a right-angle
bend in the branch estimated at 1.5 meters from the stem bark ridge. A shear plane crack is
evident as the result of this excessive mechanical load force. Kino* exudate is also evident around
the wound area.
Well-formed reaction wood is evident around a second shear plane crack on the dominant side
of the tree to the south. The apical section of the canopy is displaying indications of die back
perhaps resulting from canopy edge exposure and salt sheer from coastal prevailing winds to the
south.
Tree No. 2 is a semi-mature Red Bloodwood (Corymbia gummifera) with large to moderate
deadwood throughout the canopy. This tree displays signs of poor vigour with a 10-20% live crown
ratio. Indications of stress are evident with the presence of kino* exuding along the surface of the
trunk in local areas. Several girdling roots have formed at ground level with a well-developed
cavity extending beneath the soil level.
Tree No. 3 is a semi-mature Red Bloodwood (Corymbia gummifera) with an 80% live crown ratio
and minor deadwood. Large, exposed surface roots extend to the east and west from the root
collar. Although this tree is situated outside the proposed development area, sensitive works
methodologies should be considered to avoid damage to the root system, trunk, and branches of
the tree whilst all earthworks and construction activities are carried out.
Determining the Tree Protection Zone (TPZ): (Extract from AS 4970:2009) The radius of the
TPZ is calculated by multiplying its DBH x 12. TPZ = DBH x 12 DBH = trunk diameter measured
at 1.4 metres above ground. Radius is measured from the centre of the stem at ground level.
Determining the Structural Root Zone (SRZ): SRZ radius = (D x 50)0.42 x 0.64 where D = trunk
diameter, in metres, measured above the root buttress or Diameter Above Root Buttress (DARB).

 Tree No.     DBH (mm)              TPZ (M)                DARB (mm)              SRZ (M)

 1            430                   5.16                   470                    2.41
 2            310                   3.72                   370                    2.18

 3            390                   4.68                   420                    2.30


Table 2: TPZ and SRZ radius calculations.




Arborist Brief– TSA: 25 Dwyer Street Sunshine Beach. (* See explanatory notes)
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