Effects of fire on rainforest: evidence from seedling dynamics and canopy tree response to trunk scorching in the Border Ranges, New South Wales

Context Post-fire seedling demography and the effect of trunk scorching on large trees were investigated in rainforest in the Border Ranges region, New South Wales, after a major fire in 2019–2020. Aims To examine changes in post-fire seedling demography and diversity in rainforest in the early post-fire period, investigate compositional turnover of the seedling population, replacement of stem mortality by seedlings in resprouter species, and measure bark damage and repair in canopy trees. Methods Seedling density, diversity, and turnover were monitored in permanent plots, 1 and 3 years after fire. Seedling density was examined in relation to functional groups and rainforest types. Fire effects on canopy trees, including bark scorching, fire scars, and bark regrowth, were examined 3 and 5 years post-fire. Key results Seedling populations in rainforest were characterised by very low density, increasing density and diversity with time since fire and rapid compositional turnover; number of species with seedlings rose from 150 in Year 1 to 215 in Year 3; 79% of 258 resprouter species exhibited turnover above replacement and 21% were below; 62 resprouter species recorded no seedling recruitment, but most populations were buffered by high rates of resprouting. Trunk fire scars showed partial bark regeneration after 5 years. Conclusion The woody flora of rainforest displayed a moderate degree of resilience to a single low-intensity fire through strategies of resprouting, seedling recruitment, and bark repair. Implications If fires are infrequent, low intensity and followed by adequate rainfall, such as in the 2019 fire disturbance, rainforest can potentially recover from fire damage.