Without management interventions, endemic wet‐sclerophyll forest is transitioning to rainforest in World Heritage listed K’gari (Fraser Island), Australia

Abstract

Wet‐sclerophyll forests are unique ecosystems that can transition to dry‐sclerophyll forests or to rainforests. Understanding of the dynamics of these forests for conservation is limited. We evaluated the long‐term succession of wet‐sclerophyll forest on World Heritage listed K'gari (Fraser Island)—the world's largest sand island. We recorded the presence and growth of tree species in three 0.4 hectare plots that had been subjected to selective logging, fire, and cyclone disturbance over 65 years, from 1952 to 2017. Irrespective of disturbance regimes, which varied between plots, rainforest trees recruited at much faster rates than the dominant wet‐sclerophyll forest trees, narrowly endemic species Syncarpia hillii and more common Lophostemon confertus. Syncarpia hillii did not recruit at the plot with the least disturbance and recruited only in low numbers at plots with more prominent disturbance regimes in the ≥10 cm at breast height size. Lophostemon confertus recruited at all plots but in much lower numbers than rainforest trees. Only five L. confertus were detected in the smallest size class (<10 cm diameter) in the 2017 survey. Overall, we find evidence that more pronounced disturbance regimes than those that have occurred over the past 65 years may be required to conserve this wet‐sclerophyll forest, as without intervention, transition to rainforest is a likely trajectory. Fire and other management tools should therefore be explored, in collaboration with Indigenous landowners, to ensure conservation of this wet‐sclerophyll forest.

Fire frequency has a contrasting effect on vegetation and topsoil in subcoastal heathland, woodland and forest ecosystems, south‐east Queensland, Australia

“…Fire frequency has a contrasting effect on vegetation and topsoil in subcoastal heathland, woodland and forest ecosystems, south-east Queensland, Australia Madeline Dooley 1 | Tom Lewis 2 | Susanne Schmidt 1 Peterson & Reich, 2001;Russell-Smith et al, 2013), and wet sclerophyll forests (Krishnan et al, 2019). Australia has a long history of fire over the past 24 million years when the continent's climate dried, rainforests retreated and Eucalyptus and related genera began to dominate woodlands and forests (Pennington et al, 2004).…”

“…Fire has a strong influence on the structure, composition and function of plant communities including Mediterranean‐type ecosystems (Keeley et al, 2012), tropical savannahs and woodlands (Ansell et al, 2020; Peterson & Reich, 2001; Russell‐Smith et al, 2013), and wet sclerophyll forests (Krishnan et al, 2019). Australia has a long history of fire over the past 24 million years when the continent's climate dried, rainforests retreated and Eucalyptus and related genera began to dominate woodlands and forests (Pennington et al, 2004).…”

Ecological and Cultural Understanding as a Basis for Management of a Globally Significant Island Landscape

“…Today, many remaining forests dominated by Lophostemon confertus and Syncarpia hillii are in gullies and in moister parts of the high dunes where fire has not been able to penetrate. They contain little regeneration and exhibit rainforest elements in the understory [57].…”

“…These areas are becoming dominated by rainforest elements such as Syzygium spp. [57] which regenerate in the absence of fire. Therefore, without fire, a more diverse rainforest community may dominate.…”

Reconstructing Holocene fire records using dune footslope deposits at the Cooloola Sand Mass, Australia

“…AD 1870 (Hawkins, 1975; Spencer and Baxter, 2006). The consequent shift to less frequent fires is easily identified in paleoecological studies (e.g., Moss et al, 2015) and has led to the transition of wet sclerophyll forests to rainforest through local fire exclusion (Krishnan et al, 2018). It is also linked to rare, higher-intensity fire events.…”