Tuarts – the new TEC on the Swan Coastal Plain: what do they mean for your project?

The Department of Environment and Energy released the approved Conservation Advice for the newly listed ‘Tuart (Eucalyptus gomphocephala) woodlands and forests of the Swan Coastal Plain’ Threatened Ecological Community (TEC) in July 2019:

Approved Conservation Advice (incorporating listing advice) for the Tuart (Eucalyptus gomphocephala) woodlands and forests of the Swan Coastal Plain ecological community

If you don’t have the time and energy to read the whole Advice, read on for our initial interpretation of the Advice. For a more detailed understanding specific to your site contact Katrina Cooper and Scott Bird.

Is the ecological community present?

The Conservation Advice provides key diagnostic criteria to determine whether the TEC is present, and how big the patch is, some points for consideration include:

  • Is the patch located on the Spearwood, Bassendean or Quindalup dune systems, or the Pinjarra Plain?
  • Are there at least two living, established Tuart trees in the uppermost canopy layer? They may be single-stem or mallee-form, and they may co-occur with other species. An ‘established’ Tuart tree is one with a diameter at breast height (DBH) ≥15 cm.
  • A patch of the TEC is a discrete and mostly continuous area of vegetation that meets the key diagnostic characteristics. A patch may include a modified and disturbed understorey.
  • The patch boundary is 30 m beyond the outer canopy of the established Tuart trees. In the context of a patch, an established tuart need not be alive, dead tuarts (stags) can be part of the patch, and can extend the boundary of a patch. Note that the species of a stag tree is unclear, if the  edge of its canopy is within 60 m of an identified Tuart tree the stag is presumed to be a Tuart.
  • Patches can vary in structural or biological complexity and condition i.e. bare ground and can include roads, buildings and other human-induced landscape change if there is some part of the Tuart canopy within 60 m of the canopies of adjacent Tuart trees.
  • A patch smaller than 0.5 ha is not part of the ecological community.
  • A patch at least 0.5 ha and up to 5 ha depending on site characteristics in size may be part of the ecological community.
  • All patches of 5 ha or greater that meet the key diagnostic characteristics are part of  the ecological community, regardless of their condition.
  • Buffer zones to the ecological community to protect roots zones /physical damage to the community are strongly recommended by DEE, they recommend a buffer of at least 30 m from the outer edge of the patch (i.e. 60 m from the canopy boundary of established tuarts).

Revegetation areas/ areas of regrowth and disturbance

There is an interesting point in the CA that rehabilitated areas can be considered part of the TEC – will this drive a perverse outcome where landowners and managers cease to use tuart in revegetation programs to minimise the risk of the area being considered the TEC in the future?

  • Within the natural distribution range of Tuart woodlands if revegetated sites meet the key diagnostics and minimum condition thresholds for the Tuart woodlands and forests they are part of the ecological community.
  • Where a recently disturbed site (e.g. a bushfire) is likely to represent the TEC, DEE recommends that surveys should be delayed until there has been opportunity for regeneration (approx. 2 years).  During the disturbance period all patches of 0.5 ha or larger that were previously identified or likely to have been identified as the ecological community are considered to be part of the ecological community.

Considerations for land use planning and environmental planning design

  • Where are the Tuarts located and do they form a patch?  If over 0.5 ha undertake a survey (particularly in spring) and determine the presence of diagnostic criteria, determine patch size and condition.
  • Are there any other Matters of National Environmental Significance on site i.e. Banksia Woodlands and the Swan Coastal Plain Threatened Ecological Community, Sedgelands in Holocene Dune Swales ecological community or Aquatic root mat community of caves of the Swan Coastal Plain that also need to be considered or incorporated within a buffer area?
  • Determine an appropriate buffer for the TEC patch assess how that may affect your property/ developable area.
  • Design and Placement of Public Open Space and corridors to incorporate Tuart patches (and buffers if applicable) to reduce the significance of impact of the overall development footprint.
  • Consider future risks from proposed revegetation programs incorporating Tuart species (within POS or other areas).  When Tuarts reach DBH ≥15 cm and have canopies within 60 m of each other the patch may qualify as the TEC requiring consideration under the EPBC Act.  The long-term implications for future planning and land uses in these instances may be to be considered.

 

2019-07-18T15:22:20+00:00 July 18th, 2019|