With almost 800 weed species recorded on lands managed by the DBCA, it is not possible to control every weed everywhere. Prioritisation helps ensure resources for weed control are directed to the species that will deliver the greatest long-term environmental benefit.
Many of the weeds that effect each region have been assessed by botanical experts at DBCA based on their invasiveness, ecological impacts, and the feasibility of effective management. This process helps identify which species pose the greatest risk to biodiversity and where management efforts are most likely to succeed.
In many cases, widespread weeds cannot be eradicated with available resources. Instead, management focuses on reducing their impacts on high-value ecological, cultural, and recreational assets.
The weed impact and invasiveness rating summaries are designed to help landholders, community groups, local governments, and private enterprises make informed weed management decisions. DBCA's impact ratings are assessed through a conservation lens, focusing on the effects of weeds on biodiversity, ecosystems, and natural values. As a result, these ratings may differ from the priorities of other land managers. For example, buffel grass is considered a high-impact weed in conservation areas because of its effects on native ecosystems and fire regimes, while some pastoral landholders may value the species for its grazing benefits. Another example is stinking passionflower, which has high impact smothering vegetation in waterways in the Kimberley and Pilbara but is a highly valued cultural food by Traditional owners.
Additionally, it’s important to note that prioritisation rankings are intended as a guide only and are also under review by DBCA. They do not replace legal obligations under the Biosecurity and Agriculture Management Act 2007 or conditions and requirements issued under the Environmental Protection Act 1986. Some native Western Australian species may also appear in the prioritisation lists where they have demonstrated invasive behaviour outside their natural range.