If you are submitting a development application, your council may require an arborist report produced by an AQF level 5 arborist in support of your submission. The types of reports required can vary and can include:
Preliminary Arboricultural Assessment -- a species inventory and determination of tree retention values and protection zones.
This is especially useful if conducted prior to the design phase of your project, so that high value trees can be considered in the design, rather than risking rejection of the submission if it is incompatible with high valued trees.
Arboricultural Impact Assessment - determine impact of proposed development on tree population, make removal and retention recommendations and produce a Tree Protection Plan.
Tree Removal / Retention Plan -- inventory of site trees with indication of trees incompatible with the proposed development.
Arbor Vision Consulting produces professional tree reports satisfying council's specifications. AutoCAD is used to produce detailed and accurate assessments if you can provide plans in this format. A site survey will generally be required.