Ecological observations on a remote montane occurrence of Bedfordia arborescens (Asteraceae), Cape Barren Island, Tasmania

Bedfordia arborescens Hochr. is a tree listed under the Tasmanian Threatened Species Protection Act 1995 and is known in Tasmania only from an outlying population in cloud forest on Mt Munro, Cape Barren Island in the Furneaux Group. While the species is a common component of some rainforest and mixed forest in southeast mainland Australia, the outlying population on Cape Barren Island has apparently been eroded by a high fire frequency over the previous 200 years. The species occupies an ecological zone that is marginal to Atherosperma moschatum Labill.-dominated rainforest. Some stands occur adjacent to grasslands separated by a sharp ecological boundary.
Even-aged cohorts represent the population structure on the mountain with no evidence of recent regeneration in or adjacent to any particular stand. A range of different aged cohorts occurs within the forest across the mountain. Mt Munro intercepts cloud moisture, resulting in the development of a cloud forest and a steep precipitation gradient between Mt Munro and the nearby coast. The persistence of B. arborescens on Mt Munro can be attributed partly to the sharp topographical boundaries that have been reinforced by fire due to the burning frequency on the mountain. The vegetation patterning has responded to frequent anthropogenic fires during the past 200 years.
Comparisons are made with subalpine grasslands in New Guinea and elsewhere. Future fire management on Cape Barren Island will be critical to the survival of B. arborescens in Tasmania. On the basis of modified IUCN criteria used in Tasmania for listing of threatened species, it is recommended that the status o/B. arborescens be up-listed from rare to vulnerable.