emr_262.fm Page 79 Wednesday, June 28, 2006 1:22 PM doi: 10.1111/j1442-8903.2006.00262.x FEATURE BlackwellBitou Publishing Asia Bush control (after fire) in Bundjalung National Park on the New South Wales North Coast By Jeff Thomas, Damien Hofmeyer and Andrew S. Benwell Bitou Bush has already invaded extensive coastal dunes in subtropical and temperate eastern Australia. Can it be treated at a large enough scale to make a difference? Results to date of a targeted aerial spraying program (applied after wildfire at Bundjalung National Park) are showing strong recovery of high conservation value dunal vegetation along 35 km of the northern New South Wales coastline. Figure 1. Prior to 2002 about 75% of the foredunes in Bundjalung National Park contained heavy infestations of Bitou Bush (the lighter-coloured vegetation visible along the coast). This is just Jeff Thomas (North Coast Region, PO Box 361, a portion of the approximately 900 km of the New South Wales coastline (80% of the coast) already Grafton, NSW 2460, Australia. Tel. 02 66 411506. infested by Bitou Bush. Without successful control, this nationally declared environmental weed is E-mail: [email protected]) is considered to have potential to expand its range across a much larger area of the Australian Pest Management Officer and Damien Hofmeyer coastline. (Photo: Department of Environment and Conservation) (Richmond River Area, PO Box 856, Alstonville, NSW 2477, Australia. Tel. 02 6627 0221. Email: [email protected]) is a Introduction (Box 1 and Fig. 2) had shown that in Ranger at the Parks and Wildlife Division of the 2002, about 75% of the foredunes in the Department of Environment and Conservation ver the Christmas and New Year park contained heavy infestations (i.e. (NSW). Andrew Benwell (PO Box 641, Mul- Operiod of 2001/2002, an intense greater than 40% of total vegetation lumbimby, NSW 2482, Australia. Tel. 6684 5496. wildfire burnt through approximately cover) (NPWS 2001; Fig. 3). Based on Email: [email protected]) is an ecological consu- two-thirds of Bundjalung National Park, the high level of Bitou Bush infestation ltant engaged within the program. This article pro- including its extensive dune system of the dunes and understanding of the vides an overview of 4 years’ treatment of Bitou (Fig. 1). Mapping of the nationally signi- role of fire as an important component Bush and the effects of this treatment on the ficant weed Bitou Bush (Chrysanthe- in Bitou Bush control ( Weiss 1983; Flower recovery of native vegetation. moides monilifera ssp. rotundata) & Clarke 2002), a proposal was developed © 2006 Ecological Society of Australia ECOLOGICAL MANAGEMENT & RESTORATION VOL 7 NO 2 AUGUST 2006 79 emr_262.fm Page 80 Wednesday, June 28, 2006 1:22 PM FEATURE Box 1. Bitou Bush (Chrysanthemoides monilifera ssp. rotundata) Bitou Bush is listed as one of the initial 20 Weeds of National Signi- ficance (WONS – see ARMCANZ, ANZELL and ANZFM 2000) and is a declared noxious weed. Invasion of native plant communities by Bitou Bush is listed as a Key Threatening Process under the TSC Act 1995. Mapping of Bitou Bush in 2000 found approximately 900 km (80%) of the New South Wales coastline infested, with a conservative esti- mate of 36 000 ha infested (NPWS 2001). Bitou Bush originates from South Africa and was introduced into Australia in 1908. In the 1950s, Bitou Bush was Figure 2. Bitou Bush is listed as one of the initial 20 Weeds of National Significance (WONS) and is a declared noxious weed. Invasion of native plant communities by Bitou Bush is listed as a among a number of plants trialled Key Threatening Process under the NSW TSC Act 1995. Bitou Bush, originated in South Africa and for sand-dune stabilization and was was introduced into Australia in 1908. (Photo: T. McDonald) still being recommended for planting in 1970. A mature Bitou Bush plant can produce up to 48 000 seeds per plant per year (Weiss et al. 1998). Prostrate stems enable vegetative reproduction to occur by sending roots from adventitious buds. Seeds can be spread over large distances by animals such as birds and foxes. Dispersal of seeds also occurs by wind, water, vehicle movements, and movement of contaminated soil. In established infestations, soil seed banks can contain up to 5000 seeds/m2, with a small percentage of seeds remaining viable in the soil for up to 10 years, thereby providing a source for reinfestation. Disturbance, especially by fire, promotes seed germination, but germination still occurs in undisturbed situations. A variety of controls including biological, chemical and physical methods are available to control Bitou Bush with site-specific assessment required to determine the most appropriate technique or combination of techniques for a particular location. In recent years, national, state, regional and local strategies have been prepared and are being implemented to reduce the impacts of this plant. Many coastal community ‘care groups’ focus their attention on this plant. Successful control programs share a number of common features: • A variety of stakeholders working cooperatively, often with a formal plan that outlines priorities, roles and responsibilities • A commitment from decision-makers at all levels • Persistence and continuity for long-term commitment • The presence of key individuals who coordinate and motivate participants • The matching of the scale of work (including follow up) to the available resources 80 ECOLOGICAL MANAGEMENT & RESTORATION VOL 7 NO 2 AUGUST 2006 © 2006 Ecological Society of Australia emr_262.fm Page 81 Wednesday, June 28, 2006 1:22 PM FEATURE by the Department of Environment South Wales, occur in several places in For geographical and administrative and Conservation (New South Wales) the 35-km-long dune system. (Plant reasons the park is managed by both to take advantage of the fire and control nomenclature used in this note is con- the Northern Rivers and North Coast Bitou Bush to prevent it from completely sistent with Harden (1990–1993)). Regions of the Parks and Wildlife Divi- dominating and degrading the entire Aboriginal people have lived in the sion of the Department of Environment dune system (80% or more cover). area for thousands of years and have and Conservation, (NSW) formerly Prior to the fire (the extent of which continued to maintain strong links with known as the NSW National Parks and is mapped in Fig. 3), successful but the park. Impacts from this period on Wildlife Service. This arrangement works limited Bitou Bush control had been the dune are likely to have been minimal. well in practice, as there are distinct undertaken at a small number of sites However, European uses of the area park management issues in the differ- with community support. The Defence since settlement have caused significant ent regions, as well as issues requiring Department, which uses a large area of impacts primarily through mineral a consistent approach throughout the the park as a bombing range, agreed to exploitation and defence activities. park (e.g. fire and weed management). participate in this program and provide For example, gold was mined in the substantial resources. late 19th century and mineral sand- Bitou Bush invasion in mining occurred over extensive areas Site description Bundjalung National Park of dunes and heathlands between the Declared in 1980, Bundjalung National 1930s to the early 1980s. Quarrying for At the commencement of the project, Park, is a large (20 326 ha) conservation gravel and rock occurred in several Bitou Bush was the most abundant reserve on the subtropical northern locations and there was sporadic and weed in Bundjalung National Park. It New South Wales coast (Fig. 3). It seasonal cattle grazing throughout reached greatest densities in previous extends over approximately 35 km of much of the area. Commercial and re- foredune sandmined areas and can also coastline from south of Evans Head creational fishing have a long tradition be found in areas up to 5 km inland, Village to the Clarence River. Together and the park has always been popular remote from camping or residential with the adjoining World Heritage-listed with day visitors and campers. Two locations, where it can be the only Iluka Nature Reserve (136 ha) to the target areas occur in the north of the weed species present. south and the 3800-ha Broadwater park and are included within the With growing concern about the National Park to the north, the three 2572-ha Evans Head Air Weapons effect of this weed upon native vegeta- reserves form the second largest Range (known as the Bombing Range). tion (Box 2 and Fig. 4), the density and protected area on the New South Wales These have been used by the defence extent of infestation of Bitou Bush was northern coastline. A 10 655-ha area of forces since the 1940s with the south- mapped along the New South Wales the park is gazetted as wilderness ern part of the range still operational coast in 2000 as part of the preparation under the Wilderness Act 1987. and used for various military purposes. of the New South Wales and NSW Bundjalung National Park contains a Although all these disturbances have North Coast Bitou Bush management variety of coastal vegetation communi- had some effect on the dunes, the high- strategies (NPWS 2001; Scanlon 2001). ties including wet and dry heathland, est impact on the dunal system in the The survey, based upon aerial photo- littoral rainforest, mangrove, eucalypt southern section has arisen from sand- graphy interpretation and ground truth- forests and Melaleuca woodlands, as mining. This extensively disturbed the ing, found that Bitou Bush infested well as freshwater and estuarine wet- dune landforms, reshaping the dunes approximately 680 ha of Bundjalung lands, headland grasslands and dune to a much lower profile and leaving a National Park, occurring in a nearly communities (Griffith 1983).