Restoring ecosystems through bitou bush control

Why is restoration intervention needed?

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The invasive South African shrub bitou bush (Chrysanthemoides monilifera ssp. rotundata) has spread along 80% of the New South Wales coastline, threatening native plant species from the king tide mark to coastal woodlands and forests. This threat was acknowledged with the listing of bitou bush as a key threatening process under the NSW Threatened Species Conservation Act 1995. The NSW Bitou Bush Threat Abatement Plan (Bitou TAP) was subsequently developed to ensure that control of the weed led to the protection and restoration of coastal plant communities.

Restoration actions

Across coastal NSW, control of bitou bush is under way at over 100 sites encompassing 21 different land tenures and 33 land managers. In accordance with the Bitou TAP, each of these sites has a five-year site plan to control bitou bush and save native species. Implementation of the Bitou TAP across high priority sites involves extensive support from the five coastal Catchment Management Authorities involved, local government, the NSW Land and Property Management Authority (former NSW Department of Lands) and Department of Environment, Climate Change and Water (DECCW), and numerous community groups, assisted by a dedicated coordinator within DECCW.

Detailed monitoring of the effectiveness of the control program is based on sound ecological techniques and extensive field testing with stakeholders. Understanding how bitou bush causes native species to decline is a key component of the TAP and DECCW is currently exploring this field with the University of Wollongong. There has also been an economic assessment of the TAP in conjunction with the University of New England.

Monitoring native species recovery at a Bitou bush TAP site

Planning and prioritisation

While recovery and natural restoration of native vegetation is generally assumed to follow the control of bitou bush, there was no way of ensuring that this is the case, particularly for the species and plant communities most at risk. Given that bitou bush is unlikely to be eradicated, a 'triage' system has been used to establish the priorities for protection and restoration. The Bitou TAP uses a two-pronged process that assesses the native plant species and communities and sites where invasion has occurred to determine priorities based on ecological principles. A species model assesses the susceptibility of the species and their habitat to invasion and their ability to persist or re-establish following control. Additonally, a site model examines the actual impacts present, the condition of the species and site, other threats and the ability to deliver effective control. This triage process established a list of priority sites at which control would deliver the greatest protection and chances of restoration (both natural and active).

Site-specific management plans were developed with site managers to ensure that control and restoration actions at these sites actually met the desired aim of decreasing the impact of bitou bush on coastal plant communities. Management plans are based on the use of control and associated restoration measures that take great care to avoid damage to native species.

Progress to date

High priority TAP species Plectranthus cremnus following bitou bush control

The Bitou TAP identifies 169 high priority sites for the control of bitou bush at a landscape scale (i.e. across coastal NSW) based on the threat to biodiversity and the probability of achieving a conservation outcome at each site. Implementation of the Bitou TAP across these priority sites is currently in its third year and significant progress to date includes:

• 107 site-specific management plans have been approved under the TAP. Control and monitoring programs have commenced at these sites in accordance with the Bitou TAP.
• Control of bitou bush is under way to save over 60% of the 184 native species, populations and ecological communities identified as being at risk from the weed in the TAP.
• A range of tools has been developed to help stakeholders to implement the TAP: (1) a dedicated implementation orientated website, (2) Native Species at Risk from Bitou Bush Invasion: A Field Guide for New South Wales, a free publication, (3) a site-specific management plan proforma, to be submitted for each site detailing the actions required to save native species and account for individual site variation, (4) a full-time dedicated Bitou TAP coordinator, (5) a generic scientific licence issued to stakeholders with approved site plans enabling them to work with threatened species, (6) the development of standardised monitoring guidelines, based on three tiers to encompass the range of stakeholder skills and resources, and (7) a range of best practice management guides and other publications.
• A significant Commonwealth grant to help with implementation over three years at 50 of the TAP's high priority sites.
• Cost:benefit analysis showed a $2.56 return for every dollar spent.
• Extensive community engagement
• Many papers published and talks given

Read a series of case studies from specific sites encompassed by the Bitou TAP which illustrate the success of this approach in protecting and restoring native plant communities previously affected by bitou bush invasion.

Further information

For publications and readings that relate to the Bitou TAP, see a list of Bitou TAP-related references. For other matters email the Bitou TAP coordinator.