by Spencer Shaw
with contributions from Bree Jashin and Tina Raveneau
It was only a few years ago, that as a professional bush regenerator, I thought that non-herbicide based weed control was pretty much a fringe activity, and that the only way we could undertake weed control in bush regeneration (the way that we currently practice it) was with herbicides. For so many of us in the Bush Regeneration Industry, the use of herbicides could be seen as being synonymous with being professional. However, a few years can be a long time and inspiration from a range of sources has challenged me to look at alternatives to the herbicide-only option so dominant in the mainstream bush regeneration industry in South East Queensland (I must add here, that I believe this is not so much driven by bush regenerators but by clients e.g. local government). One such inspiration (and demonstration of practice) has been the community volunteer chemical free weed control project, Zero Chemical K’gari, at the township of Happy Valley, on K’gari.
K’gari (Fraser Island) is the largest sand island in the world, over 123 km long (north to south), up to 22 km wide at its widest point and is located approximately 250km north of Brisbane. Happy Valley is a township about half-way up the east coast of the island and like many townships in natural areas like this, are sources of many environmental weeds that find their way into the bush, which in this case, also just so happens to be a World Heritage Listed site. “K’gari” is the Butchulla name for the Island and roughly pronounced in English as “Gurri”. The Butchulla people are the Traditional owners of K’gari.
The Zero Chemical K’gari chemical free weed control project (approx. 8ha), as the name suggests, is and always has been herbicide-free project focusing on manual reduction and removal of environmental weeds that are present in the bushland within and surrounding Happy Valley. As community concerns increase over the use of herbicides and pesticides in agriculture and public spaces, the time has come to recognise the benefits of chemical-free methodologies in bush care. Chemical use has become the orthodoxy for weed control in bush regeneration over the last few decades in SE QLD, displacing manual techniques. It is now hard to find examples of long-term successful bush regeneration projects that are taking place without the use of herbicides, but this is a great example. This far sighted and innovative project was founded in 2005 by local resident Bree Jashin. Since 2014 the project has been operating under the umbrella of Fraser Coast Regional Council’s (FCRC), Community Environment Program (CEP). The strong support of natural area’s environment team, along with a solid volunteer base contributing many hundreds of hours each year, has generated not only a highly successful environmental weed control project in this World Heritage listed site, but also a training ground in the application of the concepts and methodologies of chemical-free invasive species management. This is one of SE QLD’s first no herbicide projects, supported by local government.
I have found this site particularly inspiring as the techniques and methodology implemented are a solid demonstration of the efficacy of manual chemical-free weed control. Weeds managed include but are not limited to Gidee Gidee – Abrus precatorius subsp africanus, Lantana – Lantana camara, Painted Spurge – Euphorbia cyathophora, Easter Cassia – Senna pendula var. glabra, Morning Glory – Ipomoea indica, Green Panic – Megathyrsus maximus ssp pubiglumis, Mile a minute – Ipomoea cairica and Singapore daisy – Sphagneticola trilobata
What I particularly like about this project is the pace, it initiates and enables a long-term return to a stable, functioning native ecosystem by manual removal of environmental weeds with no off-target damage, by working at the pace of native vegetation recruitment and resilience.
An example of what is considered a relatively intractable weed in coastal areas of the Queensland is Gidee Gidee – Abrus precatorius subsp africanus. The focus of management of this weed is removal of propagules from site e.g. bag and dispose of seed, manual removal of seedlings – this is surprisingly easy in the deep sand, even tap roots 0.5m long can be persuaded to let go with a firm grip and a little bit of digging if necessary. Mature vines are cut, and the tap root dug, which again sounds like hard work but given the deep sand it is a relatively easy process with minimal disturbance to surrounding native vegetation. The alternative chemical-based methodology is to either cut and paint with herbicide, or foliar spray herbicide on the Abrus, with, in too many cases, the inevitable damage or loss of surrounding native vegetation – collateral damage. Also, of concern on a sand-based area like this is there is no clay in the soil to bind with the residual herbicide that makes its way to the ground, and from there into the water table – of this World Heritage site.
Another example is the management of exotic grasses such as Green Panic Megathyrsus maximus var. pubiglumis. They are “peeled” back from a native vegetation edge, gradually at the pace taken by the native vegetation to recolonise and dominate this “frontier” between native dominated and exotic dominated vegetation. Usually only a metre or two per run, which might be repeated every few months. Again, an easier/quicker solution to remove the Green Panic from a large area is to foliar spray herbicide, but any native recruitment is also killed, and herbicides are again introduced into the sandy soil. This pioneering community volunteer project demonstrates the efficacy of working with the pace of recruitment and regeneration of the native vegetation, by targeted manual removal of weeds from amongst native vegetation in a manner that allows native vegetation to dominate and displace weed colonisation of the given niches.
Speaking as a professional bush regenerator who has been operating on the Sunshine Coast and throughout South East Queensland for over 20 years in a mainstream industry dominated by herbicide use, this project has been an inspiration. Beyond that, it is also a very practical demonstration of the efficacy of manual techniques and the speed / timing of assisted regeneration being focused on observed recruitment.
From 2021 onwards, this project will once again be conducting on ground activities independently, no longer beneath the umbrella of council’s CEP program. As awareness of the work of the quiet achievers who have driven this project grows, hopefully it will receive the recognition it deserves and continue to go from strength to strength.
