Priority Weed Species in the WCL
Bitou bush is a native of South Africa. It is declared noxious throughout New South Wales, and listed as one of the Australian Government’s Weeds of National Significance. Invasion by bitou bush leads to a decline in the species diversity of affected plant communities and the fauna that depend on them and is listed as a key threatening process under the TSC Act. It readily invades a wide variety of disturbed and undisturbed coastal plant communities, out-competing native vegetation.
A threat abatement plan for bitou bush has been prepared (DEC 2006) which lists actions to abate, ameliorate or reduce the threat posed by bitou bush to threatened species, populations and ecological communities. Bitou bush is prevalent along the beach and swale areas of the WCL, where it commonly occurs in clumps of mature bushes. Prevailing winds wrap around these clumps, eroding sand from around the base of the plant and hindering the establishment of native species such as spinifex grass. Bitou bush is also invading the forested areas of the WCL, and in some areas dominates the shrub layer.
Regular control of bitou bush has focused on vehicle-based herbicide spraying, targeting areas around the Gan Gan and Lavis Lane accesses, and the forested areas around Bobs Farm off Nelson Bay Road. The WCL is also part of the aerial bitou bush spraying program, which has included treatment of bitou bush along the mobile dune–forest interface.
Sharp rush occurs in the moist depressions throughout the swale areas of the WCL. It is most common in the south-western and north-eastern sections, where it has colonised the beach wetland communities and is displacing native sedges and rushes such as knobby club-rush (Ficinia nodosa) and narrow-leaved cumbungi (Typha domingensis) (Bell & Driscoll 2010). Penny-Wort is also common throughout the swale areas of the WCL.
Pampas grass is present in the swale, and most commonly in the north-eastern end of the WCL. Some initial herbicide control of pampas grass has been achieved and follow-up control is continuing.