Document ID: chunk:federal_register_of_legislation:F2024L00408:front:0:p347
Version: federal_register_of_legislation:F2024L00408
Segment Type: other
Provision Reference: 
Character Range: 1054902–1057778

the plantations (primarily dead, diseased, dying or dangerous trees) and various management issues have been identified in previous reports over the years.  There have also been gaps in the plantings because of losses, and wildlings.  Many issues have now been addressed.

The condition of the individual Blue Gum trees varies, but in general the tree asset is in a fair to good condition (95%) based on a 2018 survey.  Tree health is assessed annually.  They have undergone a significant management program since 2014, which has:
      * seen their soil cored and enriched with large amounts of composted material;
      * the surface mulched extensively to 100 mm;
      * wildlings removed;  and
      * dead trees systematically removed and replaced.

  Figure 114.  Re-planting of Eucalyptus bicostata, 2019
  Source:  Amanda Evans

However, the trees will require a continuous management and maintenance program in coming years as rainfall and temperatures vary and the soil profile breaks down from time to time.  This can be achieved by a landscape management plan for the plantation, as at present there are no guidelines for the maintenance or management of the plantation.

Native grasses
There has been limited success in the establishment of an understorey of native grasses due to several factors, most notably:
      * the lack of sufficient direct sunlight in their chosen locations;  and
      * the species used.

Establishment has been poor where the tree canopy is heavy and competition is high.

  Figure 115.  Native grasses in shadow are failing to thrive
  Source:  Amanda Evans

Hebe plantings
In 2012, the Hebes which had previously performed poorly were replaced with a new cultivar namely Hebe 'Otari delight'.  This was implemented over a period between late 2011 and November 2012 and handed over to NCA in November 2013 after a 12 month consolidation period.

The replacement cultivar was chosen after a trial was run of two species over a six month period which included the summer months.

In general terms, the re-planting has mostly been unsuccessful, and a separate review has been commissioned by the NCA into the reasons for this outcome.  The review has found that the plants have performed poorly because of several soil-borne diseases and other contributing factors.

The NCA will develop a replacement strategy, including a comprehensive manual for ongoing maintenance which will address any lessons learnt from the recent investigation which led to the discovery of the diseases.  Further laboratory testing is also proposed to help ascertain the heat tolerance of the plants so that appropriate details can be added to the manual.  Protocols to minimise the future introduction of diseases will be documented.

Full replacement of the plants is required due to the diseases being expected to be located throughout the soil profile