Risks to a mountain summit ecosystem with endemic biota in southwestern Australia

Abstract

Abstract Throughout the world, mountains provide unique environments with attendant endemic species. In the otherwise subdued landscapes of the floristically diverse Southwest Western Australian Floristic Region, the Stirling Range provides the region's only distinctly montane environments. On the highest peaks of the Range the characteristic heathland (Kwongan) of the region becomes a dense shrub thicket with many endemic species and is known as the Eastern Stirling Range Montane Heath and Thicket. We assessed the conservation status of the Montane Heath and Thicket using the IUCN Red list criteria for ecosystems. We found the ecosystem to be Critically Endangered based on its naturally limited geographic extent and area of occupancy in combination with the impacts of the plant pathogen Phytophthora cinnamomi. Historical sources and long‐term monitoring were critical to our assessment of this ecosystem highlighting their importance in detecting and understanding likely causes of change. The ecosystem is predicted to decline further in the absence of intensive management due to current threatening processes as well as the potential future impacts of climate change. The Montane Heath and Thicket, while substantially modified still retains areas with highly significant conservation values and these pose many challenges for management. Continued management of P. cinnamomi through phosphite application and management of fire return intervals will be critical to conserve the remaining areas of the thicket where sensitive plant species occur together with an ex situ conservation program including ongoing seed collection and translocation for the most threatened species.