Risk status of Australia's alpine and subalpine ecosystems

Alpine and subalpine ecosystems are threatened by changing climate and disturbance regimes because they exist under extreme geographical and climatic conditions. Understanding the threats to and risk status of alpine and subalpine ecosystems is vital to guide their conservation, inform monitoring programs and identify the relative impact of activities currently degrading these ecosystems. We applied the IUCN Red List of Ecosystems criteria to 15 alpine and subalpine ecosystem types across Australian mountains. We found that seven ecosystem types were classified as threatened and three as Near Threatened, together accounting for 83% of the alpine and subalpine region. The primary threats were climate change and associated changes in fire regimes. There were insufficient data to quantify the environmental or biotic integrity of six ecosystem types, and one ecosystem type was listed as Data Deficient overall. Our study highlighted key knowledge gaps in the integrity of alpine and subalpine systems that limited our capacity to reliably assess risk to these ecosystems. We recommend expanding on-ground monitoring of ecosystem integrity to improve understanding of risks, key threats and actions to mitigate them. To reduce risks to these ecosystems, climate change must be aggressively mitigated, collateral pressures from invasive plants and animals must be reduced, and critical knowledge gaps that will allow conservation action prioritisation must be quickly filled. These strategies should be co-ordinated, resourced and enacted urgently in cross-jurisdictional Alps-wide work plans.