Meeting papers

Saving Noosa’s pandanus palms

Noosa lost more than 75% of our pandanus palms during the pandanus leaf hopper outbreak in the
1990’s, and perhaps another 10-15% of these palms have been lost in subsequent years, due to
later leafhopper infestations, natural senescence or succumbing to earlier damage, and broader
vegetation impacts such as fire and vegetation damage. Many of the battle-scarred survivors still
show missing limbs, reduced crowns, and reduced health, and most of the current healthy
pandanus in the dunes were planted later by community groups and Council. Natural pandanus
germination is significantly reduced by the reduced numbers of mature and healthy seed producing
adults, and by the degradation of the understory with weeds such as glory lily, asparagus fern and
Singapore daisy.

Prior to the pandanus leafhopper outbreak, Eastern Beaches natural pandanus populations were
likely affected by artillery training into the dunes during WW2, anecdotally reported sandmining,
and the impacts of residential and community land development. With these losses, and
subsequent protection and planting, it is estimated that Noosa’s pandanus population is currently
about half of that at European colonisation, with ongoing significantly reduced natural germination
rates 14

Preventing advanced leafhopper infestation and plant decline and expanding pandanus
populations is the community and Council’s current two-pronged approach to saving Noosa’s
pandanus. Twice yearly inspections and immediate treatment if needed means that treatment
occurs before significant plant decline, leafhopper numbers are kept low, and predator wasp
populations are maintained at an effective level. Planting local pandanus tube-stock and direct
seeding are contributing to population increases while we wait for the numbers of mature and
healthy seed producing pandanus to increase. Planned increased regeneration will help improve
natural germination as understory health is regained.
During the survey in November 2022, only seven wasp re-introductions were needed and only 12
plants needed leaf stripping. No insecticide treatment was needed 15. This shows the health of the
population is significantly improving, alongside reduced impact on native insects.




14 Ecosystem Management and Biosecurity Solutions. (2018). Pandanus Preservation Project Noosa:

Protecting an icon and coastal biodiversity with science, collaboration and action. Unpublished
15 Ecosystem Management and Biosecurity Solutions. (2023). Pandanus Dieback Surveys and Mitigation -

Noosa Shire Council November 2022. Unpublished

Eastern Beaches Foreshore Reserves Management Plan 2023                                       Page 38

                                                                                                  Page 49 of 476