A Tasmanian endemic restricted to fire refugia in the alpine and subalpine regions of the mountains of central and western Tasmania, Australia. This species is highly susceptible to fire and other impacts related to climate change. Currently, it is assessed as Near Threatened.
Distribution
Endemic to the central and western mountains of Tasmania, Australia
Habitat and Ecology
Pherosphaera hookeriana occurs in the subalpine regions of the Tasmanian highlands, usually above 1,000 m a.s.l. It is frequent in wet moors and often fringes the lakes and tarns that are numerous in these mountains. Precipitation is high and occurs year-round; temperatures are cool with sleet and snow falling in most months of the year, but mostly in winter. There is no extended period of snow cover as the climate is extremely oceanic. Bedrocks are acidic granites, gabbro, and gneiss and the waters have a low pH of 4.5-5 on average. This species is often associated with Athrotaxis cupressoides, Microcachrys tetragona and, usually on somewhat drier sites, with Diselma archeri; frequent angiosperms are Nothofagus gunnii, Richea pandanifolia, R. scoparia, and Eucalyptus coccifera, while cushion forming peat mosses (Sphagnum) cover the ground in many places.
Human Uses
A rare shrub in cultivation.
Conservation Status
Global Status & Rationale
Near Threatened
This species has a limited range and both the extent of occurrence and area of occupancy fall within the thresholds for Endangered. The current total population size is estimated to be less than 20,000 individuals in 30 main subpopulations (Worth et al. (2021). A substantial part of the global population is in protected areas, Throughout its range it is restricted to wet habitats that usually protect it from most fires. Regeneration after fires is very slow if it occurs at all. Climate change impacts such as severe droughts leading to catastrophic wildfires are the main threats; recent fires in Tasmania have impacted some marginal subpopulations. It is therefore appropriate to list it as Near Threatened as it almost qualifies for listing under the B criteria.
Global Threats
The main threats relate to impacts of catastrophic fires and drought events.
Conservation Actions
Pherosphaera hookeriana occurs in the Mt Field, Franklin-Gordon Wild Rivers, Southwest and Cradle Mountain-Lake St Clair National Parks. Almost all known occurrences are within formal conservation reserves (Lazarus and Potts 2009)
References and further reading
Balmer, J., Whinam, J., Kelman, J., Kirkpatrick, J.B. and Lazarus, E. 2004. A review of the floristic values of the Tasmanian Wilderness World Heritage Area. Nature Conservation Report 2004/3
Brummitt, R.K., Mill, R.R. and Farjon, A. 2004. The significance of ‘it' in the nomenclature of three Tasmanian conifers: Microcachrys tetragona and Microstrobos niphophilus (Podocarpaceae), and Diselma archeri (Cupressaceae). Taxon 53(2): 529-539.
Fitzgerald, N.B. and Whinam, J., 2012. Establishing a monitoring program for Tasmania's montane conifers. In Papers and Proceedings of the Royal Society of Tasmania (Vol. 146, pp. 9-24).
Kirkpatrick, J.B., Bridle, K. and Dickinson, J.M. 2010. Decades-scale vegetation change in burned and unburned alpine coniferous heath. Australian Journal of Botany 58: 453-462.
Marris, E., 2016. Blazes threaten iconic trees: as Tasmanian climate warms, bushfires are encroaching on forest ecosystems that date back more than 180 million years. Nature, 530(7589), pp.137-139
Worth, W.R., Marthick, J.R., Harrison, P.A., S. Sakaguchi and G.J. Jordan (2021) The palaeoendemic conifer Pherosphaera hookeriana(Podocarpaceae) exhibits high genetic diversity despite Quaternary range contraction and post glacial bottlenecking. Conservation Genetics. 22, 307–321. https://doi.org/10.1007/s10592...
