Document ID: chunk:federal_register_of_legislation:F2007B00384:body:0:p14
Version: federal_register_of_legislation:F2007B00384
Segment Type: other
Provision Reference: 
Character Range: 35005–37868

expected to take refuge in moist locations, including those favoured by ferns.  It is not known whether this species has had, or is likely to have, any impact on Asplenium listeri.  Although the presence of land crabs appears to restrict the distribution of the snail, this controlling effect may be compromised by reduced crab populations brought about by the yellow crazy ant infestation (CofA 2002).

Crazy ant populations are responding to a program of aerial baiting, however the potential for increased spread of the snail may be inferred, because there may be a gap of many years before land crabs recover to a level sufficient to control snail populations.  Parks Australia monitor presence/absence of the snail during surveys for crazy ant populations, and these data could be related to the distribution of Asplenium listeri to assess any interactions (Jeffery pers. comm.).

Also of potential concern is an exotic millipede which feeds on vegetable matter and occurs in very high densities in certain areas (Sewell pers. comm.).  No additional information was located on this.

C.2.5 Human traffic

The potential habitat for Asplenium listeri is for the most part highly inaccessible due to the steep and rocky cliffs, pinnacles and screes, and inhospitable due to the dry and exposed nature of the sites and the types of vegetation in the vicinity (often dense and dominated by stinging trees and prickly plants).  As a result, pressure of human traffic is not likely to pose a threat to populations of the species (Reddell pers. comm.).

C.2.6 Unauthorised collecting

There is no evidence of unauthorised collecting of Asplenium listeri.  However, members of this extensive genus are particularly attractive for cultivation, with some highly variable in habit and suitable for selection for cultivation, while others form excellent specimens for baskets (Jones & Clemesha 1981; DuPuy 1993b).

There is potential for collecting of specimens or propagules of rare species by or on behalf of fern enthusiasts.  The likelihood or extent of such a demand cannot be predicted.  However, in view of the small population numbers known and the uncertainty of factors restricting distribution, any such predation could pose a significant threat to the survival of the species.  Confidentiality of precise locations would appear to offer the best safeguard against this practice.

C.2.7 Stochastic events

Because of the tropical location of the island, severe rainfall events associated with the monsoon are common in the wet season, although the extent and impacts of these cannot be predicted.  Severe dry seasons tend to coincide with the El Niño effect in the Pacific (CofA 2002), and these events may be increasing in frequency and severity.

Confident assessment of the impact of stochastic events (as for other potential impacts) requires further study