Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p199
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 199/276)
Character Range: 733301–737712

The distribution is shown in Map 35.

Habitat
Grows in moist upland hardwood forest, pine-hardwood ridge forest and plateau hardwood forest (Invasive Species Council & TierraMar 2021).

Ecology
Little known.

Threats
D. bijugum is threatened by cattle grazing and weed invasion and competition. Phytophthora cinnamomi is potentially a major risk.

Impact on other species
None known.
Map 35 Distribution of Dysoxylum bijugum
Green outlines indicate reserves within which the species occurs. Green shading shows plant communities within which the species may occur (Christian & Mills 2021).

Risk assessment
Risk assessment undertaken for Vulnerable trees/shrubs as a grouping. The risk assessment is shown in Table 87.
Table 87 Risk assessment for Vulnerable trees/shrubs as a grouping
Risk                                                                                                               Likelihood of exposure    Consequence  Threat rating
1. Loss and fragmentation of native vegetation through past land clearing                                          Almost certain (91–100%)  Extreme      Extreme
2. Loss and fragmentation of native vegetation through current or future land clearing                             Rare (0–10%)              Negligible   Negligible
3. Degradation of native vegetation through past grazing or loss of nutrients                                      Almost certain (91–100%)  Extreme      Extreme
4. Degradation of native vegetation through current or future grazing                                              Possible (26–50%)         Moderate     Medium
6. Predation by rodents                                                                                            Likely (51–90%)           Moderate     Medium
7. Predation by cats                                                                                               Rare (0–10%)              Negligible   Negligible
8. Predation or damage by chickens                                                                                 Rare (0–10%)              Negligible   Negligible
9. Predation by swamphens                                                                                          Rare (0–10%)              Negligible   Negligible
10. Predation by Argentine ant                                                                                     Possible (26–50%)         Minor        Low
11. Competition from/change of habitat because of weed invasion                                                    Possible (26–50%)         Minor        Low
12. Infection by pathogens already present                                                                         Possible (26–50%)         Moderate     Medium
13. Impacts of potential new invasive species or pathogens                                                         Unlikely (11–25%)         Minor        Low
14. Changes to vegetation, increased fire risk and/or direct physiological stress as a result of climatic changes  Possible (26–50%)         Minor        Low
15. Problems caused by small populations, including lack of genetic diversity                                      Rare (0–10%)              Minor        Negligible

Management actions
Undertake targeted weed control and maintenance. Undertake revegetation/habitat restoration. Exclude or manage cattle grazing. Undertake propagation and planting within suitable areas, including public reserves.

Recovery target
The recovery target is shown in Table 88.
Table 88 Recovery target for Dysoxylum bijugum
EPBC Act status  Estimated population (2023)                             2034 target
Vulnerable       940                          >95% in the national park  2000
                                              1% in the reserves

Relevant literature
Christian NE & Mills K (2021) Vegetation Mapping of Norfolk Island 2021. Unpublished data.
Invasive Species Council & TierraMar (2021) The Native Plant Communities of Norfolk Island. Invasive Species Council, Katoomba, NSW.
Mills K (2009b) The Vegetation of Phillip Island, Norfolk Island Group. Envirofund 2007/2008. Kevin Mills & Associates, Jamberoo, NSW.
Orchard A (ed) (1994) Flora of Australia. Vol. 49. Oceanic Islands 1. Australian Government Publishing Service, Canberra.
TSSC (Threatened Species Scientific Committee) (2003b) Commonwealth Listing Advice for Norfolk Island Flora - 15 Vulnerable