Fraser Island Defenders Organisation (FIDO) started attacking weeds at Happy Valley as far back as 2006. Peter Shooter first went there with a group of volunteers from Greening Australia in 2006, under the leadership of Andrew Sinclair. He recalls removing vast amounts of Easter cassia (Senna pendula var. glabrata) and umbrella trees (Schefflera actinophylla) around the village.
Irregular weeding trips continued up to 2013 when it was observed that crab’s eye (Abrus precatorius subsp. africanus) had become a serious problem.
John Sinclair, Su Dawson and FIDO volunteers set up eradication trials for crab’s eye around the Rotary shed area. The trials included digging out and hand removal, cutting off/painting cut stems with 100% Roundup (Glyphosate 360g/L) and foliage spraying with 1% Roundup.
Digging and hand removal proved a complete failure, as the plant re-grew vigorously from roots left in the ground. While the cut and paint technique was effective, it was impractical given the magnitude of the problem. Foliage spray was highly successful and subsequently adopted as FIDO’s primary weapon for crab’s eye control.
Happy Valley was very badly weed-infested at that time, with a range of weeds, and concern mounted as the invasive crab’s eye become widespread in and around the township. It was thought to be the Australian subspecies (Abrus precatorius var precatorius). This Australian plant does not extend further South than Gladstone naturally and is not an aggressive invader.
The plant was then identified as the African subspecies, almost certainly brought to Happy Valley as a garden plant. It was, by then, out of control, with the population extending well away from the village into the Unallocated State Land (USL) surrounding the village. It was highly invasive.
Crab’s eye is an attractive climber with compound fern-like leaves and spectacular bright red and black clusters of seeds that can remain on the plant for more than a year. It will extend to 100% ground cover in open areas, smothering all the native vegetation. It extends well into the canopy of shrubs and trees, again smothering them out by blocking out sunlight.
As plants have turned up across the landscape, we assume the seeds are spread in bird droppings. To the best of our knowledge, crab’s eye is restricted to in and around Happy Valley on K’gari. We want to prevent it from extending into the National Park, and worse still, becoming established at other locations on the island. It is our number one target weed.
A concerted attack on weeds at Happy Valley commenced in 2014 with four week-long trips per year, which has continued up to the present. Most trips consist of five volunteers, but sometimes we have had up to 12.
FIDO has done extensive surveying and GPS recording of Abrus locations across the approximately 250ha of USL. Abrus is eliminated by hand pulling small plants and foliar spraying larger ones. The population is now a small fraction of when we commenced this work, but we are still finding outbreaks. Continual follow up is necessary, as the seed has a hard seed coat, and our observation is it can remain viable in the soil for several years.
Seed collection is a central element of FIDO’s eradication program. The success of our program can be seen from the number of seed pods we have removed over time. On early trips, we were removing up to ten large black plastic bin liner bags of pods per trip. This has decreased to less than a standard shopping bag, and on our last trip in March 2021, we removed just 1.3Kg.
Weeds, Easter cassia, and lantana (Lantana camara) are widespread on K’gari. Both are from Central and South America, and again both are garden escapees. Both have attractive and abundant flowers.
Over the years, FIDO has massively reduced the density of both these weeds around Happy Valley. There is all but none left inside the dingo fence in the areas we control, and with the cooperation of owners, there is practically none left on private property.
This work has extended right across the 250ha of land where FIDO is permitted to work. In some areas (notably East of the Yidney Rocks bypass Road), these plants were so dense it was impossible to walk through. Both had scrambled well into the canopy of native trees. In many cases, these had then fallen over and rooted where they came in contact with the ground. Through a long process, FIDO pulled weeds out where we could, cut them off at the base, and treated them with a herbicide (previously 100% Roundup, now Vigilant gel). There are now large areas of lovely open forest where once there was a tangled, impenetrable mess. There is still lots of work to do, but we are making great progress. By removing the cassia and lantana, we can access the crab’s eye scattered throughout the area.
We have had a series of “Cassia Blitzes” over the years in March and April. They are in full bloom then, as the name Easter cassia implies, and are easy to detect. We have eradicated a large area south of the village, opposite Sailfish of recent years.
For over a year now, we have had the pleasure of having Butchulla Land and Sea Rangers (BLSR) working with us. This has been of great benefit to FIDO, our volunteers and the Rangers.
We share the love of Country.
Regrettably, there have been a couple of incursions of crab’s eye into the National Park, and together with the BLSR, we have eliminated it in all but one area at Yidney. Yidney is of special significance to the Butchulla people. Rangers Myles Broom and Blayde Foley recently performed a ceremony on-site calling on the spirits of their Butchulla ancestors to protect and guide us as we worked together to rid their country of weeds.
While crab’s eye, Easter cassia and lantana are the three main weeds on our radar at Happy Valley, there are plenty more.
These include three tree species. They are beach almond, umbrella trees, both from North Queensland and broad-leafed pepper trees from South America. Seeds in bird droppings spread all three, and while not in dense communities, they are widely spread. We control them all by cut and paste with Vigilant gel herbicide.
Weeding is never-ending. Many of the species we seek to control have long-lived seeds that persist in the soil. To be effective, you have to commit to long term work. Preventing seed set by not allowing plants to reach maturity and set more seeds is most important. Collecting any seeds that do set is equally important.
So, weeding never ends, but FIDO, with the support of our volunteers and partners, is up to the task!
Contributed by Peter Shooter, FIDO