THE ART OF WEED MANAGEMENT

The project took place in the Spring Mountain rural residential estate, crossing the suburbs of Greenbank and New Beith within the Ipswich City Council jurisdiction.

The aim of the project was to manage weed species identified within a development area. As a part of the process, the importance of initial weed management comprising a major part of the rehabilitation of a site is often overlooked. Evolve Environmental take great pride in being highly skilled in all aspects of environmental landscape works, and the project at Spring Mountain has incorporated one of the most important of these aspects: weeds.

One of the major areas requiring extensive weed treatment was a 20m wide corridor on either side of Oxley Creek of Lantana infestation. The Evolve team were faced with what appeared to be an impenetrable wall of lantana. Listed as a restricted invasive plant under the Biosecurity Act 2014, this plant is native to tropical and sub-tropical regions of central and south America and grows into compact clumps that can form dense thickets, smothering native vegetation in the process. 

The forming of these dense thickets provides a habitat for native birds and animals, so the clearing of the plant on such a large scale needs to be undertaken with care and attention to ensure any animals who have made their home in the thickets can relocate to more suitable locations.

Evolve Environmental staff have taken fauna spotter training, which means that on each and every site a qualified staff member is on-hand to inspect and implement a fauna management plan, prior to broad scale clearing. The Spring Mountain Estate project uncovered a number of lace monitors and possums that the team dealt with safely before clearing began. 

While removing all weed species and taking a site back to its bare bones in preparation for replanting may be both aesthetically pleasing and gratifying, it is not always the best option for sensitive sites where erosion and sediment runoff are possible. The Spring Mountain site feeds directly into the Brisbane River then out into Moreton Bay, so ensuring zero sediment runoff during the revegetation process is paramount. Often weed species can be treated with methods that leave the root system in the ground until the revegetation planting has been established. This method ensures no runoff and allows for planting without a canopy cover to inhibit the establishment of new plants, which will take over the role of erosion and sediment control.

Weed species never grow in isolation as there is often an understorey or canopy of native plants that need to be correctly identified and protected during weed management. The Evolve Environmental staff undertook a weed survey of the site, marking native species requiring protection during the weed management process. Having adequately trained staff who can identify both native and weed species is imperative, as is the ability to determine the most appropriate method of weed management on a site-by-site basis.

After conducting both the fauna and flora surveys, the highly skilled Evolve Environmental staff determined it appropriate to utilise machinery to manage the weed species at the Spring Mountain site. The newly acquired Positrak with a mulching head undertook the works, moving through the lantana thickets in an efficient time frame but with a level of sensitivity that left the roots of the plants in place, providing erosion and sediment control. The machine provides a layer of mulch, aiding moisture retention in the newly exposed ground, encouraging any native seed that is unable to germinate under the lantana thicket to germinate. The machine is small enough that moving around the creek bank also reduces the potential for damage that larger machinery can cause.

The Spring Mountain Estate project has provided the opportunity for Evolve Environmental Solutions to showcase their skills and abilities across the spectrum of what weed management really means. It’s not just about eradicating weeds, it’s about setting up the building blocks of a functioning ecological system.