Tens of thousands of species are at risk of extinction globally. In many ecosystems, species declines are associated with deforestation. However, forest degradation also can profoundly affect biodiversity. I present a detailed case study of species declines associated with forest degradation in southeastern Australia’s montane ash (Eucalyptus spp.) forests. The case study is based on ~40 years of long-term monitoring focused on declines (and potential extinction trajectories) of arboreal marsupials and birds, with a particular emphasis on key drivers, especially logging, wildfire, habitat loss, climate change, and interactions among these drivers. I discuss policy failures contributing to species declines, including ongoing logging of high-conservation-value forests, poor regulation of forest management, and inadequate design of reserves. I conclude with general lessons for better conservation and forest management efforts aimed at reducing forest degradation and loss of ecosystem integrity. I contend that ongoing logging in already highly degraded montane ash forests is inconsistent with the Australian government’s commitment at the Glasgow COP26 meeting in 2021 on halting forest degradation. Similarly, the Australian Government has committed to preventing further extinctions in Australia, yet its current support for ongoing logging in montane ash forests through federal–state legislation will likely promote extinctions for some species. The inherent conflicts and contradictions between conservation and logging policies need to be addressed.
