Kaitlyn L. Hammond, Benjamin Wagner, Craig R. Nitschke
Abstract Context Climate change and altered disturbance regimes threaten forest persistence worldwide. Tree species, such as the endangered alpine ash ( Eucalyptus delegatensis ), an obligate seeder species in southeastern Australia, are vulnerable to climate-induced changes in fire regimes and to regeneration success and are therefore at risk of significant range contraction. Objectives We aimed to: (1) evaluate how climate, fire, and age of reproductive maturity influence alpine ash persistence over the next century, and (2) assess the effectiveness of aerial resowing as a management intervention. Methods We used the LANDIS-II forest landscape model to simulate 100 years (2022–2122) of forest dynamics across 720,000 ha of alpine ash forest in southeastern Australia. We modelled scenarios with and without climate change, tested 7- and 15-year reproductive maturity thresholds, and compared naive and targeted resowing strategies. Results Alpine ash forests are projected to experience an average contraction of 49–65% of the contemporary range over the next 100 years, irrespective of climate change. Reproductive maturity age had the greatest influence on alpine ash persistence: a 7-year threshold retained on average 96,000 ha (14%) more forest than a 15-year threshold at the end of the 100-year simulations. Aerial resowing increased forest retention by only 1–3%. Targeted resowing in moderate-risk areas was more effective than naive approaches. Conclusions Alpine ash faced significant long-term declines, with reproductive maturity age emerging as a key driver of persistence. Although resowing offers limited benefits at broader scales, targeted application can enhance local persistence. This spatially explicit analysis supports adaptive strategies for endangered obligate seeder forest communities, such as the resist–accept–direct framework, to guide the conservation and management.