Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p185
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 185/276)
Character Range: 684823–687973

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.
Sykes W & Atkinson I (1988) Rare and Endangered Plants of Norfolk Island. Unpublished report to the Australian National Parks and Wildlife Service, Norfolk Island.
TSSC (Threatened Species Scientific Committee) (2003a) Commonwealth Listing Advice for Norfolk Island Flora – 11 Critically Endangered Species.

Blechnum norfolkianum—Norfolk Island water-fern
Family BLECHNACEAE

Conservation significance
Found on Norfolk Island and on other Pacific Islands.
EPBC Act Listing Status: Endangered.

Description
A medium-sized terrestrial fern with fronds growing to between 30 and 80cm long and a short erect rhizome (underground stem).

Distribution and abundance
Australian distribution is restricted to Norfolk Island but also occurs in the Kermadec Islands, Vanuatu, Samoa and the Society Islands (TSSC 2003c). It is listed in New Zealand as "at risk—sparse" because it exists as widely scattered, small subpopulations or has restricted ranges (de Lange et al. 2004).
The total number of plants recorded in 2012 in Norfolk Island National Park was 708, including small plants to mature individuals (Mills 2012b). Plants ranged from small ferns to plants over one metre in height, although most specimens were under 50 cm tall. There were marked differences between populations in the moister, southern valleys and the drier valleys on the northern side of the mountains. The number of plants counted in the wetter valleys averaged 22 plants per 100 metres of transect, while in the drier valleys the figure was 0.4 plants per 100 metres (Mills 2012b). The population is considered to have remained stable since 2012.
The distribution is shown in Map 27.

Ecology
The species is found in damp and shady places mostly occurring in the south-facing valleys of the Mt Pitt section of the national park (Sykes & Atkinson 1988), particularly on the upper slopes of Mt Bates.

Habitat
The species occupies moist palm valley forest along the watercourses in the national park, particularly those on the moister, southern side of the mountains (Mills 2012b).

Threats
Drought/dry conditions due to climate change. Changes to hydrology within the national park (Braggins 1996). Weed invasion and competition.

Impact on other species
None known.
Map 27 Distribution of Blechnum norfolkianum
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 Endangered ferns as a grouping. The risk assessment is shown in Table 71.
Table 71 Risk assessment for Endangered ferns 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