Response of Montane Wet Sclerophyll Forest Understorey Species to Fire: Evidence from High and Low Intensity Fires

Abstract

On the New England Tablelands wet sclerophyll forests typically form the ecotone between rainforest and dry sclerophyll forest. Currently there are few data on the response of wet sclerophyll plant species to fire. We compared the fire-response traits of woody understorey and sub-canopy species in wet sclerophyll forest after high and low intensity fires. The majority of species (>80%) resprouted after fire and the prevalence of resprouting did not differ with fire intensity. Obligate seeders were rare in these communities (<10% of species), and similar numbers of rainforest and sclerophyllous species were killed by fire. Resprouting from basal stems and root suckering were the most common mechanisms of vegetative regeneration; however, these traits may have arisen more in response to canopy disturbance than fire regime. We found that most rainforest taxa resprouted but lacked post-fire seedling recruitment, whereas most resprouting sclerophyllous taxa recruited from seed after fire. This dichotomy in seedling recruitment could reflect the productivity and disturbance gradients across the ecotone. We propose that gap-phase recruitment is favoured towards the rainforest margin and fire-related recruitment is more prevalent at the eucalypt forest edge.