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Breif for Arboricultural investigations

  • 1.  Breif for Arboricultural investigations

    Posted 13 March 2019 00:40
    Hi Guys,

    Does anyone have a sample brief for the procurement of a "Preliminary Arboricultural Report", "Arboricultural Impact assessment" and "Tree protection plan"?


    I am a Design Engineer within the roads team, the majority of our work is road reconstructions in urban environments, usually with trees involved. In the past we have just ignored the trees right up until construction, with any issues being left to the superintendent to deal with. We are now in the process of formulating a brief for the procurement of the above reports from consultants and im just looking for any sample templates I might be able to follow.

    Cheers.
    Liam.


  • 2.  RE: Breif for Arboricultural investigations

    Posted 14 March 2019 16:18
    ​Hi Liam,

    Please refer to the link below which provides Charelston Counties Tree Protection Requirements (Article 9.4). This may not be an apples to apples comparison as it is a Southeastern US county.  However, they are about as stringent as I have experienced in my career including work in locations such as Tweed Heads and the Gold Coast in Australia. Tree preservation can be a very frustrating albeit rewarding endeavor for a design project.
    https://www.charlestoncounty.org/departments/zoning-planning/zldr/CHAPTER9_ALL.pdf

    My best advice having done several designs in Charelston is this:
    - Identify the drip edge and chest height trunk diameter of all significant trees to meet local requirements on a survey (or say a diameter > 400mm in the absence of requirements).
    - Identify any protected or endangered species on the survey.
    - Identify all trees within riverine or other environmental buffers (in the absence of regulation assume a 10 -15 meter buffer from the edge of river)
    - Identify all remaining tree points (with estimated trunk diameters) or thicket edges for minor trees on the survey.
    - Have an arborist assess the health of all significant and protected trees and provide recommendations for the removal of sick trees and the protection of healthy ones.
    - Identify the remaining minor trees that will be removed for construction
    - Determine a biomass removal estimate (google search biomass estimate for methods and equations)
    - Determine a canopy shade removal estimate (generally in m2)
    - Determine the pre storm run off absorption rate vs. post rate
    - Determine the pre CO2 absorption rate vs post
    - Design mitigations for all of the above to lessen the impact of removal through:
    1. installing storm water flow reduction structures or bio retention areas 
    2. strategically planting landscaping trees (along roads and in green spaces) with a target of offsetting losses within a ten year growth period
    3. using pervious paving where possible
    4. contributing to local, state, or federal tree banks
    I realize this isn't a template but hope that the information and ideas are helpful for you in this very worthy pursuit.

    Regards,
    Earl DuPriest


  • 3.  RE: Breif for Arboricultural investigations

    Posted 14 March 2019 17:14
    Hi Charles,

    Thanks for the info, it will be interesting to see if our consulting arborists have performed some of your later items, such as shade removal estimates and CO2 or Biomass calculations.
    I know the Australian Standards AS4970 require most of the earlier items, so this should not be an issue for them.




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    Thanks again,
    Liam.
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  • 4.  RE: Breif for Arboricultural investigations

    Posted 17 March 2019 18:20
    ​Hi

    It depends what you want the arborcultural assessments to address. There are some standard methods that you could reference.
    A Visual Tree Assessment looks at visible signs of decay and vitality and can lead to a more detailed investigation being required if issues are noted.  In New Zealand the Standard Tree Evaluation Method (STEM) is commonly used to assess the condition, amenity value and notability of a tree. There are also risk-based methods such as Quantified Tree Risk Assessment (QTRA) and the ISA Tree Hazard Evaluation Method.
    Referencing a standard methodology that is endorsed by a recognised and relevant arborcultual organisation could save a lot of time when writing procurement documents or project briefs.

    As far as a tree protection plan is concerned, content is likely to depend on what the main threats/issues are at the site.  If it involves an individual tree or small group of trees and arborist may be able to report on the issues and develop a suitable protection plan. If it's a large stand of multiple species (e.g. remnant indigenous forest) then a forest ecologist may be better placed to look at it and develop a plan suitable to the site and the desired outcomes.

    Regards

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    Mark Naudé
    Parks and Facilities Planner
    Matamata-Piako District Council
    Te Aroha, New Zealand
    mnaude@mpdc.govt.nz
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