Blue Thunbergia (Thunbergia grandiflora) is a biosecurity risk to Wet Tropics rainforest and stream bank vegetation. This aggressive introduced vine prevents natural recruitment and growth of old forest by smothering the tree canopy. The objective of the project was to protect Alexandra Palm Forest, an endangered ecosystem type in the Russell River catchment, from spread of Blue Thunbergia and other invasive weeds into the Russell River National Park (RRNP). The RRNP is part of the Wet Tropics World Heritage Area.
The project worked with landowners to survey and treat upstream sources of Blue Thunbergia that could re-infest the Alexandra Palm Forest site. It was carried out through a joint exercise with the Cairns Regional Council and built on previous exercises with the Council and Wet Tropics Biodiversity Foundation to control Blue Thunbergia.
On-ground survey was performed using GPS across 1.5 square kilometres between the Bellenden Ker Range and the RRNP. This included 1.7 kilometres along the periphery of the Bellenden Ker Range, five kilometres of waterway and connected agricultural drains.
Blue Thunbergia outbreaks were mapped using ArcGIS and chemically controlled through spray and injection methods. The project further eradicated a stand of Bamboo (Bambusa spp.) and controlled Pond Apple (Annona glabra) which is a Weed of National Significance.
Queensland Government (Department of Environment and Science)