Characterising ecosystem composition structure and function of alternative stable states in temperate forests of south-eastern Australia

Increasingly frequent and intense wildfires threaten to push ecosystems beyond their ecological thresholds. Fire-adapted forests can be vulnerable to ecosystem conversion under shortening fire-return intervals. To evaluate the impacts of fire regime change, we contrasted <i>Eucalyptus</i> forests that retained canopy cover under tolerable regimes (reference forests) with alternative states of markedly reduced canopy. These alternative states established following short-interval wildfires and have persisted through subsequent fires. Field surveys were conducted across 20 sites within Shrubby Foothill Forests at Wilsons Promontory National Park, evenly distributed between mapped alternative and reference forest states. At each site, vegetation structure, composition, and ecosystem function were quantified using nested transects and subplots, recording species presence, growth forms, tree size distributions, litter, coarse woody debris, and canopy cover. Data were processed and analysed in R (v4.4.2) to calculate ecosystem attributes (e.g., carbon stocks, structural indices, and biodiversity metrics) using established allometric, ordination, and diversity methods, ensuring reproducibility and standardized comparisons between states