What are bitou bush and boneseed?
Bitou bush is native to South Africa and is thought to have been introduced to Australia in ship ballast but was subsequently used to stabilise sand dunes. After being planted along the NSW coast between 1946 and 1968 it spread rapidly and is now found along 46% of the NSW coastline. The north coast is particularly heavily infested. In some cases, the weed has spread 10 kilometres inland.
Boneseed, a species closely related to bitou bush, is also native to South Africa and classified as a weed in NSW. However, it is only established in a small number of areas, including Sydney and the Hunter regions.
Why are bitou bush and boneseed a problem?
Bitou bush invades native coastal heathlands, grasslands, woodlands and forests. It grows quickly and forms dense stands, replacing native plants and destroying the habitat of native animals. Infestations can smother sand dune, headland and coastal vegetation communities. Many threatened species and plant communities have been affected.
The NSW Scientific Committee has listed the Invasion of native plant communities by Bitou bush and boneseed as a key threatening process impacting both native plants and animals.
Managing bitou bush and boneseed
Strategy and planningThe management of bitou bush and boneseed in our national parks is guided by the:
- Bitou bush and boneseed threat abatement plan
A Threat Abatement Plan (TAP) has been prepared to reduce the threat posed by bitou bush and boneseed to threatened species, populations and ecological communities and species which may become threatened as a result of invasion by the weeds. The TAP identifies priorities for collaborative bitou bush control across public and private land in NSW at priority sites.
- National bitou bush and boneseed program
In 2000, bitou bush and boneseed were collectively listed as a Weed of National Significance (WONS). The Bitou bush and boneseed strategic plan
2012-2017 (National Strategy 2012-2017) provides direction for national management of these weeds.
The Weeds of National Significance website provides many resources for tackling Bitou and boneseed.
- NSW Biosecurity Act 2015
Under the NSW Biosecurity Act 2015, the Bitou Bush Biosecurity Zone covers all land within the State except land within 10 kilometres of the mean high water mark of the Pacific Ocean between Cape Byron in the north and Point Perpendicular in the south. North of Cape Byron and south of Point Perpendicular bitou bush is to be eradicated, containing bitou bush to its core distribution. Under the Act, boneseed must be eradicated from all of NSW, as outlined in the Biosecurity (Boneseed) Control Order 2017
Best-practice management techniques for bitou bush and boneseed
Guidelines for management techniques for the control of bitou bush and boneseed in our national parks include:
- Identification guide to the native species at risk from bitou bush in NSW.
The Bitou TAP identified 157 native plant species, three plant populations and 24 ecological communities at risk from bitou bush and boneseed invasions in NSW. Native plant species at risk from bitou bush invasion: a field guide for NSW (Department of Environment and Climate Change 2008) was developed as a companion document to the Bitou TAP. This field guide aims to assist all land managers, contractors and volunteer community groups working on bitou bush control or restoring bitou bush invaded sites.
- Bitou bush management manual
- Boneseed management manual
- Bitou bush aerial spraying guidelines
- A Framework to Guide Ecological Restoration: Coastal Foredune Scrub and Temperate Littoral Rainforest is available for use by land managers and community groups. The framework can be used to ensure the restoration of biodiversity following bitou bush and other weed control. These guidelines are specific to the NSW south coast, however, while the species are different, the methodologies may be used as a template for other regions.