Document ID: chunk:federal_register_of_legislation:F2007B00384:body:0:p8
Version: federal_register_of_legislation:F2007B00384
Segment Type: other
Provision Reference: 
Character Range: 19089–22078

above terraces (or cuttings of similar structure)
     * between about 110 and 255 metres elevation; and
     * often beneath or near Ficus microcarpa.

Populations can easily remain undetected in this habitat, since much of the terraces and associated cliffs (particularly on the northern and southern sides) are infrequently visited.  Survey of cliff-tops for populations is an extremely difficult undertaking due to inhospitable terrain and the nature of the vegetation (Claussen pers. comm.).  These same factors make it difficult to assess the suitability of such areas as potential habitat for colonisation or (re)introduction.

A number of informants (Tranter pers. comm.; Hart pers. comm.) suggest that the greatest potential for new populations (or for colonisation or reintroduction) is at the inland cliff-tops of the eastern terraces, broadly facing the prevailing south-easterly trade winds which provide moisture to an otherwise very dry and exposed situation.

This is the zone with the largest area lying outside the national park and is the focus of most of the island's recreational development (the eastern beaches) and some of the most significant infrastructure development (a new port and associated roading, and expansion of the airport), with possible expansion of phosphate mining on the inland side of cliff‑tops.

In view of this, all potential habitat (as described above) needs to be carefully surveyed for the presence of Asplenium listeri when proposed developments are assessed.

It has been suggested that potential habitat may also include artificially moist areas in the vicinity of water supply works, such as Jedda Cave and Jane-Up, within the altitude range for the species at 210 and 200 metres elevation respectively (Sewell pers. comm.).  However, these sites have previously been surveyed with no Asplenium listeri being located (Claussen pers. comm.).

B.2 Habitat that is critical to the survival of the species

B.2.1 Defining and mapping habitat critical to the survival of the species

Definition of habitat that is critical to the survival of Asplenium listeri is based on the following matters from EPBC Regulation 7.09:
    * habitat used in periods of stress
    * habitat used to meet essential life cycles
    * habitat used by important populations
    * habitat necessary to maintain genetic diversity and long-term evolutionary development
    * habitat necessary to ensure the long-term future of the species through reintroduction or re‑colonisation.

Based on current knowledge of the biology and habitat in known locations, habitat critical to the survival of Asplenium listeri needs to include:
    * all limestone rock crevices in the vicinity of known occurrences - reflecting uncertainty regarding reasons for the extremely limited distribution of the species and potential threats to survival; and
    * taller vegetation structures on the inland side of cliff-top sites and relatively open exposure to the coast (refer C.1