Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p179
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 179/276)
Character Range: 664633–667841

& Atkinson I (1988) Rare and Endangered Plants of Norfolk Island. Unpublished report to the Australian National Parks and Wildlife Service, Norfolk Island.

Achyranthes arborescens—chaff tree, soft-wood
Family AMARANTHACEAE

Conservation significance
Endemic to Norfolk Island.
EPBC Act Listing Status: Critically Endangered.

Description
Soft-wooded trees to 9m tall.

Distribution and abundance
Occurs in in viny hardwood forest, in valleys extending southwards and south-east from Mt Pitt and Mt Bates, with 99% of the natural population in Norfolk Island National Park (Sykes & Atkinson 1988).
Only 55 individuals were located in 1988 (Sykes & Atkinson 1988) and the species had declined further by 1989, particularly in Filmy Fern Gully (Gilmour & Helman 1989b).
The total number of mature individuals in 2003 was 57 and the population was severely fragmented, with none of the four subpopulations containing more than 40 individuals (TSSC 2003d). Outside the national park it occurs in moist valleys, with three mature trees and some natural regeneration identified.
Propagation and planting in the national park, particularly in the valleys, greatly increased the population of the species. 109 plants were recorded in 2012 ranging from seedlings to trees, and mainly growing on valley floors where the species had been planted (Mills 2012b). A few individuals have also been planted in Hundred Acres Reserve and Selwyn Reserve.
The population estimate in 2021 was 391 individuals. Propagation has occurred through the Norfolk Island National Park threatened flora program.
The distribution is shown in Map 24.

Ecology
Requires canopy gaps to successfully establish. Established seedlings on valley floors can be washed away by heavy rain.

Habitat
Achyranthes arborescens can grow in the shade of Norfolk palm (Rhopalostylis baueri), occasionally on ridges but most commonly in gullies on valley floors or lower valley sides.

Threats
Weed invasion and competition, especially in suitable canopy gaps that are filled rapidly by wild tobacco (Solanum mauritianum) and vines such as coastal morning glory (Ipomoea cairica), which smothers young and adult plants (Sykes & Atkinson 1988). A. arborescens is also threatened by cattle grazing and predation of seeds by rats. Phytophthora cinnamomi is potentially a major risk.
Map 24 Distribution of Achyranthes arborescens
Green outlines indicate reserves within which the species occurs. Green shading shows plant communities within which the species may occur (Christian & Mills 2021). Points show recorded locations (Mills 2017d).

Impact on other species
None known.

Risk assessment
Risk assessment undertaken for Critically Endangered trees/shrubs as a grouping. The risk assessment is shown in Table 65.
Table 65 Risk assessment for Critically Endangered 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