This project is supported by the Queensland Government’s Community Sustainability Action grant program.

In June 2017, Cape York Weeds & Feral Animals were successful in obtaining conservation funding under Round One of the Community Sustainability Action grant program.

This has been possible with the help of the Department of Environment and Heritage Protection.

Thunbergia grandiflora is classified as a "Level 1" weed has the potential to greatly expand its distribution within a suitable habitat, in this case rainforest areas.

• Both locations, Rossville and Bloomfield, consist of, and are encircled by tropical rainforest.

• As far as we can ascertain from extensive survey work that has been conducted throughout Cape York Peninsula over a 25 year period, the thunbergia only seems to occur in these two known areas.

• These locations are also adjacent to the World Heritage Wet Tropics Area and have no physical impediment to prevent transition to these areas if left unchecked.

• This weed has the ability to easily reach the canopy of mature rainforest vegetation.

• It will kill palm trees by binding the crown, smothering other trees, and causing extensive branch braking and tree fall under the weight of the dense vine mass.

• The result of an infestation of thunbergia on rainforest areas is a greatly altered forest structure with vulnerable vegetation being eliminated. This will also have a negative impact on fauna which are dependent on the natural rainforest habitat.

• Most importantly control work will prevent this destructive weed from establishing in this part of the World Heritage Wet Tropics rainforest – if we are not too late.

• Thunbergia grandiflora classified as a "Level 1" weed as Restricted Matter Category 1 under Bio-Security Act 2014.

• The Thunbergia control program began on 14 August 2017.

• After reporting in October, we then commenced the follow up work as and when we could get to the areas, and when we could successfully control any regrowth or new growth.

• The next lot of follow up work commenced on 16 January 2018.

• Accessed the locations at Wyalla gardens, Bloomfield and continued the control work with the help of CYWAFA_INC.

• We effectively treated the remaining infestation at the location with herbicide.

• We accessed the Thunbergia infestation site at Rossville and effectivly treated the remaining Thunbergia with herbicide.

• We had already GPS mapped the extent of the remainig infestation.

• The area of follow-up control was very much smaller than the original extent surveyed.

• Control work was conducted over 22-man days during the initial control work, including in-kind work from Cape York Weeds and Feral Animals Incorporated.

• Liaised with the local Land holders, on which these two infestations were located, within the Wet Tropics World Heritage Areas.

• They had also completed some work on the regrowth that they were able to find.

• All stakeholders were keen to fulfil their obligations under the Biosecurity Act.

• A strategic follow-up control program was designed and established.

• The Thunbergia was surveyed, and we found that we have been very successful in getting rid of nearly all of the mature vines within these two rainforest sites.

• The Thunbergia has been successfully controlled, amongst these rainforest canopies.

• The efficient control program has allowed a lot of the native species to recover, especially during our recent wet season.

• Subject to one more follow-up survey to be conducted after we get our final payment, we are very confident that we have controlled all the remaining Thunbergia vines at both locations.

• We have significantly reduced the Thunbergia’s potential to spread further along the river and gully systems.

• With the Thunbergia no longer there, vehicles, humans and stock will not be able to spread it.

• CYWAFA_ INC has developed a comprehensive Strategic Control Plan.

• The infestation at Whyalla began on the edge of a cleared area and extends into the adjacent rainforest and across a small stream. A secondary infestation was also discovered further down the stream where the driveway crossed. A preliminary survey of the stream did not locate any more plants, but a more extensive search has been conducted. Nothing has been found.

• The infestation was treated by exposing the underground tubers and stem injecting bio-degradable herbicide into them as well as stem injection into the stems.

• The landholders were very supportive of working in partnership.

• At the location in Rossville both landholders had done a considerable amount of control work on the infestation since the initial consultation.

• One of the landholders had cut the large vines and regularly applied glyphosate to the new root suckers.

• The other landholder had used glyphosate foliar spray and then fire to reduce the quantity of sprawling vine which had been spreading across some undeveloped area and steep banks.

• At both locations a small amount of regrowth had occurred. Some of this would have been due to tubers and stems being missed, which is inevitable due to the dense viny thickets.

• Also, much of the regrowth was from areas where the landholders had used glyphosate which killed the above-ground plant but as we entered the wet season, the remaining underground tubers began to sprout.

• This highlights the benefits of doing the job effectively, as well as the value and importance of follow up treatment.

• Other weeds species controlled includes Singapore Daisy, Sicklepod, Guinea Grass etc.

• Conducted a tool box talk and carried out a risk assessment before any follow-up control work was commenced.

• Peripheral areas such as the wider community of Rossville and the areas adjacent to the Whyalla Gardens property were surveyed again and the follow up control completed.

• Over six hectares of strategic survey and control was carried out, including the opening up of the undergrowth so we could get at the Thunbergia.

• Even though there was only 0.4 ha of control work has been mapped, we had to cover a lot of area to follow the vine back to where they were growing from.

• As the areas were thick rainforest, we controlled what we could find.

• There was as far greater area surveyed (8-10 ha) to see if we could find out if it had spread.

• All areas of control work were mapped using the GIS and QGIS systems.

• All reports been sent to the Department of Environment and Science.

• The data and herbicide usage sheets were also completed.

• Cape York Weeds and Feral Animals Incorporated spent as much time as possible controlling all trafficked areas, watering points, and high conservation areas.

• Hopefully follow-up control on regrowth, if any, will be done by the landholders. Cape York Weeds and Feral Animal Incorporated will keep an eye on it and try to keep the areas clean, if resources are available.

Cape York Weeds and Feral Animals Incorporated are extremely proud of the efforts that have been undertaken in getting rid of the Thunbergia in both areas of the Wet Tropics World Heritage Area.

The Strategic Thunbergia Control Program that was conducted was extremely successful.

The Department of Environment and Science, Cape York Weeds & Feral Animals Incorporated, and the landholder are to be commended for their professionalism and willingness to get the job done.