Field assessment of the impact of the K’gari wildfire on ecological values, particularly vegetation communities, was undertaken from 31 January to 12 February by the Department of Environment and Science ecologists, local Rangers, and Butchulla Aboriginal Corporation staff.
The purpose of the field assessment was to ground-truth the draft fire extent and severity mapping to further refine it and examine the impacts to ecological values to inform future management, including monitoring and research effort.
The majority of the vegetation communities on K’gari are fire-adapted, with species having one or more mechanisms for surviving and/or recovering from fire. The latter being most common in ecosystems that are highly resilient even to intense fire.
Regeneration is occurring across the fire ground, including sites where the fire severity was extreme (see Box 1). For example, epicormic regrowth and seedlings of canopy species in ‘heathy’ woodlands and open forests dominated by Banksia aemula (wallum banksia) and Eucalyptus racemosa (scribbly gum) are common to abundant (Figs 1 & 2).
Resprouting is common and widespread in the open to tall open forests and seedlings of canopy species, such as Eucalyptus pilularis (blackbutt), Eucalyptus resinifera (red mahogany) and Lophostemon confertus (brush box), are common in the open ground created by the fire.
Regeneration in the fens and other peat-based swamps is advanced in most cases with dominant woody species (e.g. Banksia robur (swamp banksia), Leptospermum liversidgei (swamp may) resprouting from the base. Herbaceous species such as sedges, rushes and forbs, e.g. Drosera spp. (sundews) are also resprouting from underground organs such as rhizomes and bulbs (Figs 4 & 5).
Flowering is well underway in these systems. We were treated to an abundance of blooms from various species, e.g. Drosera binata (forked sundew) Fig. 6, Hibbertia salicifolia, Stylidium spp. (trigger plants) Fig. 7, and Burmannia disticha Fig. 8.
The near-threatened Litoria cooloolensis (Cooloola sedgefrog) and vulnerable frog species Crinia tinnula (wallum froglet), Litoria olongburensis (wallum sedgefrog) and Litoria freycineti (wallum rocketfrog) were found within these regenerating wetlands.
Rainforests, which are fire-sensitive, appear to have escaped relatively unharmed, with less than 1% recorded as fire affected. A range of rainforest species within the understorey of open to tall open eucalypt forests are also resprouting.
The foredune complex includes fire-sensitive communities, particularly the Casuarina equisetifolia (coastal she-oak) woodlands-open woodlands.
The foredune complex has been significantly impacted in places (Fig. 9), and full recovery is expected to be slow, particularly in the coastal she-oak communities. Nevertheless, a range of species are resprouting strongly from the rootstock, e.g. Austromyrtus dulcis (midjim berry) and/or stems and seedlings of some species are common (e.g. Acacia spp.) (Fig. 10). Recent rains will further assist the recovery process.
Acoustic recording devices have been deployed in regenerating areas to ‘listen’ for and record rare and threatened species, including acid frogs and ground parrot. Recorded data will be shared with other conservation groups working on evidence-based species of concern distribution mapping.
Contributed by the Natural Resource Management Team (K’gari), QPWS&P