Managing the impact of lantana on biodiversity
The former Office of Environment and Heritage and Biosecurity Queensland, in conjunction with the National Lantana Management Group, developed a National plan to protect environmental assets from lantana. Environmental assets are defined here as native species, populations, regional ecosystems and ecological communities.
This plan was part of the implementation of the Weeds of National Significance (WONS) Lantana (Lantana camara L.) Strategic Plan 2012–17 and established a national framework to guide and coordinate Australia's response to Lantana camara (lantana) invasion in native ecosystems. It identified the research, management and other actions needed to ensure the long-term survival of native species and ecological communities affected by the invasion of lantana.
The plan established national conservation priorities for the control of lantana and is consistent with actions in the Australian Weeds Strategy, which outlines the need for asset protection for the management of widespread weeds.
The main aim of the lantana plan is to minimise the impact of lantana on threatened native species and ecological communities, and to prevent further species and ecological communities from becoming threatened, by:
- developing a strategic framework for targeting lantana control to areas where the biodiversity benefits will be the greatest
- promoting best practice management
- monitoring the effectiveness of control programs in terms of the recovery of threatened biodiversity
- fostering community education, involvement and awareness
- identifying and filling knowledge gaps where possible.
In New South Wales, site priorities from this lantana plan have been incorporated into the Biodiversity Priorities for Widespread Weeds. This site-led approach will ensure maximum benefit from the resources available for managing widespread weeds.
The national plan to protect environmental assets from lantana
Prior to the development of the National plan to protect environmental assets from lantana, the native species and ecological communities at risk from lantana invasion were not known on a national scale. In order to abate the threat of lantana invasion to native biodiversity, the specific biodiversity at risk needed to be identified.
Assessing the impact of weeds is notoriously difficult as there are few scientific studies which determine species at risk, given the lengthy time periods they take to complete, and the diversity and number of species at risk can be large.
In order to develop the Lantana Plan, 2 major steps were completed:
- determination of the biodiversity at risk from lantana
- assessment of priority sites for control.
Determination of the biodiversity at risk from lantana
The weed impact to native species (WINS) assessment process was used to assess the threat of lantana to biodiversity. This process enables the impacts and threats of weeds on biodiversity to be determined quickly, across large areas and across a range of different types of species and ecological communities.
The WINS process included 4 steps:
- a review of the existing literature of the invasive plant in question and known species at risk
- collation and assessment of the knowledge held by land managers and botanists with specific knowledge of and involvement in the management of weeds or the native species within infested sites
- rigorous examination and evaluation of an interim list that is derived from workshops held to identify species as being potentially at risk
- ranking a revised list to determine which native species and communities required urgent protection from the weed.
Assets at risk from lantana were assigned a high, medium or low priority based on the level of threat across their whole distribution and their conservation status under threatened species legislation.
See the full list of native species and communities at risk from lantana (XLS 1.3MB).
Assessment of priority lantana sites
The site selection process aimed to ensure that control is undertaken in areas where the outcomes will have the greatest benefit for biodiversity. It ensures efficient use of resources in areas that have the greatest likelihood of successful control and recovery of native species.
Sites were assessed based on the following 3 criteria:
- the ability to achieve effective lantana control at the site while minimising off target impacts, particularly with respect to protecting the environmental assets at risk
- the degree of impact of lantana at each site
- the condition of the assets present and the physical condition of the site.
Maintaining areas that are presently free of lantana or removing isolated infestations, including those within other states, will also be beneficial as biodiversity in these areas will be protected from lantana invasions.