Until 1998, three distinct lists existed for threatened flora at a national level:
On 16 July 2000, the Commonwealth Government introduced the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). This act superseded the Endangered Species Protection Act 1992 (and several other Acts). In conjunction with the introduction of the EPBC Act, the aim is to now have a single list of threatened flora which will be reflected in Schedules to that Act.
In respect of threatened plant species, the EPBC Act recognises the following categories:
The website for the Department of the Environment, Water, Heritage and the Arts has a Guide to the EPBC Act and also has a list of threatened species currently protected under the Act.
Despite the move to a combined national flora list, the ROTAP coding system devised by Leigh, Briggs and Hartley is still commonly seen in numerous scientific and general publications. Although having no legal standing, the system provides a relatively simple means of categorising the 'at risk' status of Australian plants, including many that are not currently listed in the EPBC schedule. For this reason, an understanding of the ROTAP coding system is worthwhile.
The ROTAP system is based on the combination of three categories:
An outline of the coding system is given in Table 1 followed by an example of how the coding system is applied in practice:
Table 1: ROTAP Coding System for Plants at Risk
| Category | Coding | Definition |
| Plant Distribution | Known only from the type* collection | |
| Restricted distribution - range extending over less than 100km | ||
| Range more than 100km but in small populations | ||
| Conservation Status | Presumed extinct - not collected for 50 years or the only known populations destroyed | |
| Endangered - at serious risk in the short term (one or two decades) ** | ||
| Vulnerable - at risk over a longer period (20-50 years) ** | ||
| Rare but with no current identifiable threat | ||
| Poorly known species suspected of being at risk | ||
| Reservation Status | Species is known to occur within a proclaimed reserve | |
| Species is considered to be adequately reserved. 1000 or more plants occur within a proclaimed reserve | ||
| Species is considered to be inadequately reserved. Less than 1000 plants occur within a proclaimed reserve | ||
| Species is recordered from a reserve but the population size is unknown | ||
| Total known species population is within a reserve | ||
| Western Australian Department of Conservation and Land Management (CALM) Priority Flora Code. Range from P1 (highest priority) to P4 (lowest priority). | ||
| Species also occurs outside of Australia | ||
| * The "type" is the plant specimen used to originally describe a species. ** Species considered to be either Endangered or Vulnerable are classified as "Threatened". |
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| Dillwynia tenuifolia Photo: Brian Walters | |||
As an example of the use of the codes, consider Dillwynia tenuifolia, one of the "bush peas" of eastern New South Wales. This species is listed as Vulnerable under the EPBC Act and has a ROTAP Code of 2RCa which means:
Further examples of Australian plants at risk, including the EPBC Act categories and ROTAP codes can be found here.
In addition to the national lists of threatened flora, each State and Territory has its own listing. These will often include species not included on the national list or will apply a higher conservation category than the national category for a specific plant. These apparent anomalies occur for several reasons but are often due to a plant occurring in several states but being very restricted or under a greater threat in one state.
For further information on State and Territory lists, refer to the specific Parks and Wildlife authority.