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, NSW, 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 five 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.