Proteaceae Dominated Kwongkan Shrublands of the southeast coastal floristic province of Western Australia

Status: Endangered on the EPBC Act list

This ecological community is generally kwongkan / kwongan shrubland, ranging from sparse to dense, thicket-forming, where Proteaceaeous species form a significant component. It is confined to the southeast botanical province of Western Australia and primarily occurs on sandplains and marine plains and lower to upper slopes and ridges, as well as uplands across this region.

Government evidence of impact of climate change:

Expand all Close all
  • Approved Conservation Advice for Proteaceae Dominated Kwongkan Shrublands of the southeast coastal floristic province of Western Australia

    Subsequently; there is a very high level of variation and this has been described in broad terms by ecodistrict; based on similarities in physical and biological patterns of geology; climatic history; drainage patterns; major soil systems and existing native vegetation types (McQuoid; 2004; also see Table E2; Mt Manypeaks Two Peoples Bay mountain tops as climatic refugia for Gondwana relictual species including threatened birds Barren Ranges and Thumb Peak as a refuge for critical weight range mammals and proteaceous endemics Bremer Bay Pallinup area may provide relictual habitat for some species normally restricted to west of Albany and Two Peoples Bay including Austrostipa compressa; Eucalyptus calcicola subsp. unita; Banksia grandis; Baumea vaginalis and others Mondrain and Figure of Eight Islands of the Recherche Archipelago provide refugia for critical weight range mammals; such as Tammar Wallaby (Macropus eugenii derbianus); Southern Brown Bandicoot (Isoodon obesulus); Rock Wallabies (Petrogale lateralis lateralis and Petrogale lateralis hacketti); and reptiles including Pseudonaja affinis tanneri (Recherche dugite) and Morelia spilota imbricata (Western Australian carpet python) Near coastal hills of Cape Le Grand and Mississippi Hill are refugia for declared rare flora including Lambertia echinata subsp. echinata (Comer et al.; 2001a) and Mountain top and slopes of the Russell Range are refugia for short range endemic invertebrates; endemic proteaceae taxa and inland occurrences of kwongkan.

    Climate change It is expected that most species and ecosystems within the Mediterranean climate region of southwest Australia will be affected by both current and future climate change (Yates et al.; 2009).

    Demonstrated climate change since the mid 1970s has shown a decrease in rainfall across southwest Western Australia; especially in winter rainfall (Coffey Environments; 2009).

    It is expected that anthropogenic climate change will lead to warmer and more arid conditions shifting to the south and west of Western Australia (Yates et al.; 2009).

    South west Western Australia is acknowledged to be highly vulnerable to the impacts of climate change.

    South west Western Australia has experienced average annual warming consistent with global trends; however the south east of south west Western Australia has experienced a slight cooling in maximum summer temperatures (Indian Ocean Climate Initiative; 2012).

    Range collapse is predicted for many Banksia species in the South West Australian Floristic Region with climate change; which is of particular concern for southern Banksia species distributions where range movement to the south is restricted by the Southern Ocean (Yates et al.; 2009).

    Combined with other threats such as fire and P. cinnamomi; as well as its highly fragmented distribution; it is anticipated that climate change may have significant detrimental outcomes for the ecological community.

    Barrett et al. (2009) noted that multi decadal drought conditions in some parts of the ecological community may be a reflection of long term climate change and increased wildfire risk.

    This; coupled with long term climatic shifts; with component species responding in different ways; is likely to change the composition of the ecological community.

    The increasing fire frequency trend is expected to continue as the area is subjected to an increased drying trend due to climate change (Coffey Environments; 2009).

    Additionally; documented impacts of the disease appear greater following fire (Barrett; 2000 Moore; 2005; cited in Barrett et al.; 2009 Conservation Commission of Western Australia; 2011).

    Fire in P. cinnamomi infested areas increases the severity and extent of disease and impinges on the regeneration capabilities of susceptible species.

    Large fires will also change the hydrology of a catchment with potential increased surface and sub surface flow in the early years after fire and consequently increased opportunities for disease establishment and spread (Barrett; 2000 Barrett et al.; 2009).

    For example; fire is considered to pose a significant threat to the spread of P. cinnamomi outside of currently infested catchment boundaries in the Bell Track area of Fitzgerald River National Park (Massenbauer; 2009).

    Presence of invasive plants within the ecological community results in structural loss; increased fire risk and loss of species diversity.

    As well as the net decrease in rainfall; a change in timing of rainfall (from winter to summer); is likely to affect the life history cycles of some flora and fauna of the ecological community; and may exacerbate other threats such as fire and dieback.

    Changes to rainfall patterns may also result in the inability for seedlings to establish and survive following fire events.

    The reduction in the integrity of the ecological community is evident from observations of dieback due to plant pathogens; effects of altered fire regimes; weed invasion; and the subsequent decline or changes to flora and fauna within the ecological community.

    Patches within reserve Within reserves; major threats to the ecological community are dieback and altered fire regimes; as described in Appendix D Description of threats ( Stirling Range National Park; burnt in 1972; 1991 and 2000; while there are areas of Cape Arid National Park that have burnt four or more times in the past 33 years (Barrett et al.; 2009).

    This trend is likely to increase the length of the fire danger periods and increase the susceptibility of vegetation communities to extended and more intense flammability.

    As described under Appendix D Description of threats; the interaction of fire and dieback is a greater threat than either of these threats alone.

    Fauna have declined or changed in areas of the ecological community that have lost this component or have been subject to large scale intense wildfire (Barrett et al.; 2009).

    Perennial grassy weeds in particular are currently present in many of these patches; while others are under threat of invasion mostly in areas prone to the deposition of sand and nutrients from wind erosion and flood events that transfer nutrients and propagules from modified sites into the ecological community.

    Severe drought stress resulting in death of proteaceous species on some lateritic uplands of the ecological community has already been observed during extended periods of heat in summer.