Document ID: chunk:federal_register_of_legislation:F2007B00384:body:0:p11
Version: federal_register_of_legislation:F2007B00384
Segment Type: other
Provision Reference: 
Character Range: 26992–29957

is so, the occurrence of two distinct forms in the one crevice is of considerable interest.  Greater certainty would require professional taxonomic review.

C.2 Identification of threats

Potential threatening processes for Asplenium listeri include:
    * removal or modification of actual or potential habitat by phosphate mining or by construction of roads or other developments
    * weed invasion arising from rehabilitation of mined areas or from construction
    * predation by exotic species or changes in native species composition arising from activity of exotic species
    * human traffic
    * unauthorised collecting of specimens
    * stochastic disturbance events e.g. cyclones, severe dry seasons
    * fire.

The factors that have led to the limited occurrence and loss of locations for the species are not clear.  At the time of initial listing, stochastic events were presumed to be significant (TSSC 2002).

C.2.1 Mining

Mining of phosphate-rich soils from between limestone pinnacles began near Phosphate Hill in 1899 and has continued in most years to the present day.  The original mining took place on the eastern side of the island and spread westwards with associated construction of access roads.  In the late 1960's drill line surveying to map accurately the phosphate reserves resulted in a parallel grid of lines being cleared every 120 metres over most of the plateau (CofA 2002).

Rehabilitation of mining fields has been carried out in several phases.  The earliest rehabilitation involved levelling of pinnacles, reintroduction of stockpiled low phosphate overburden, and planting with exotic tree and shrub species.  In later phases, replanting utilised only native species.  Mining fields in the geographic area of the National Park were excluded from the Park to allow them to be worked out, subject to environmental controls.  In February 1998 a lease was signed to allow mining activities to continue for a further 21 years (CofA 2002).

The current distribution of Asplenium listeri on exposed cliff-tops suggests that it is unlikely that past mining or associated roading and surveying have removed actual or potential habitat.  It is not known whether deposition of dust from mining and associated roading and transport (which can smother vegetation) has affected any population of Asplenium listeri.

It is possible that Population 5 is adjacent to an area that may be proposed for mining in the future.  The draft EIS for the proposed expansion of mining submitted in 2003 states that all populations of Asplenium listeri will be preserved and sufficient buffer zones established (Bennett in litt.)..

Location of a population in an area likely to be affected by heavy dust deposition should result in specific requirements to mitigate this potential impact.

C.2.2 Construction

There are several recent, current or potential developments involving construction activity on the island.  These include:
    * proposed