Stop 8 - Wildfires
Take a few moments to look back over the way you have come. The vista provides a wonderful overview of the extent of the park. While enjoying the view, ponder on the management issues facing park managers today. One of the most challenging and perhaps the most controversial is fire.
Fire is a natural occurrence on
Kangaroo Island and many plants and animal species have evolved to live with it. Lightning strikes are responsible for the majority of wildfires within this park.
Kangaroo Island’s native flora has evolved to depend on fire to reproduce. Some species need heat to crack open their hard seed capsules; some need chemicals in the smoke to kick-start epicormic buds that grow beneath their bark; others need heat to stimulate regrowth from underground lignotubers. Fire also clears the undergrowth and allows dormant plants to emerge into the sunlight.
Banksias (Banksia marginate and B. ornate) are large shrubs found in this area, which have biologically adapted to thrive in a fire-prone environment. They have tough, woody fruits sealed with fire-proof resin that stops the seeds from falling into the fire. Banksia seedpods have a winged seed separator that prevents seeds from falling onto the ground until after rain.
Their seeds get a great start to life by floating into newly watered, fertile soil away from competition with other seedlings.
Banksias take about eight to nine years to reach maturity. Therefore fires that occur before new seed set, can eliminate species, providing a competitive advantage to other faster growing species.
Like plant species, animals, including birds and invertebrates also need different fire regimes. The needs of animals differ according to the habitat they prefer and their diet. Some mammal species, such as the
Kangaroo Island kangaroo (Macropus fuliginosus fuliginosus), favour frequent fires and repopulate a burnt site rapidly, taking advantage of the exposed nutritious food supply. However, bush rats (Rattus fuscipes) favour a longer fire frequency because the area takes longer to provide a suitable habitat for them
The
Kangaroo Island dunnart (Sminthopsis aitkeni), found only on
Kangaroo Island, may prefer vegetation which has been burnt at different times by fires of varying intensities, creating a mosaic effect.