Cooloola—Post-fire ecological assessment
Overall, 14,608 hectares burnt across the Cooloola section of Great Sandy National Park. A more detailed assessment of the ecological impacts of the fires was undertaken which was initiated by detailed fire severity mapping.
Fire severity
Across Cooloola, a quarter of the area burnt was at a low level of fire severity, where fire did not scorch the canopy but fire sensitive low shrubs were lost. A similar proportion of the burnt landscape (22–27%) was burnt at a moderate, high and extreme level. As a result, 4,009 hectares of the Cooloola area had all vegetation completely consumed by the fire given the extreme fire severity level.
| Fire severity | Hectares |
|---|---|
| Low | 3762 |
| Moderate | 3281 |
| High | 3747 |
| Extreme | 3817 |
Ecological impacts
The diverse vegetation of Cooloola includes coastal heath, foredunes, swamps and rainforest as well as eucalypt forests and woodlands. The eucalypt communities are fire adapted and most plant species can recover relatively quickly, provided there are no other fires in the short term. This habitat type mostly experienced limited to moderate ecological impacts, depending on the fire severity. Some areas, which included fire-sensitive species such as Cypress pine, had high to catastrophic ecological impacts, with significant canopy loss that can include important habitat features, such nesting hollows in old trees.
The coastal rainforest communities are fire-sensitive with high to catastrophic ecological impacts likely from a fire. Across Cooloola, only small areas were burnt by the 2019 fires. In contrast, more than 300 hectares of the fire-sensitive foredune vegetation was burnt with a high to catastrophic level of ecological impact (refer map below). The beach she-oak and pandanus are characteristic of this plant community and readily killed by fire, with a slow recovery enhancing the risk of coastal erosion. Restricting the recreational use of vehicles on the foredunes is especially critical to support natural regeneration.
More than 2,000 hectares of the wet heath community was burnt mostly at a high severity level. Whilst the extent of the fire is of concern, the habitat is fire-adapted and the ecological impact was mostly at a limited to moderate level. The natural vegetation is quickly recovering given that the flammable peat layer was not notably ignited. For the grass and sedge swamp habitats, the peat layer also seemed to have been minimally burnt, despite the preceding drought conditions. As a result, approximately 180 hectares was burnt at a low to minimal level of ecological impact and is expected to recover quickly.
More than 2,500 hectares of tree swamps, dominated by paperbarks, was burnt. This habitat can be fire tolerant although some areas burnt at high to extreme fire severity levels and experienced a moderate to high level of ecological impact with complete consumption of the canopy making recovery a much slower process.
The dry heath communities are also recovering well, although more than 600 hectares of heath containing wallum banksia (Banksia aemula) was burnt at a moderate to high level of ecological impact and will be relatively slower to recover.
| Potential ecological impact class | Intolerant | Low tolerance | Mod tolerance | High tolerance |
|---|---|---|---|---|
| Limited or none | 0 | 691 | 2347 | 5137 |
| Moderate | 252 | 272 | 1615 | 2404 |
| High | 163 | 202 | 1250 | 0 |
| Catastrophic | 189 | 86 | 0 | 0 |
Read the full report Post-fire Assessment Report— Natural Values: 2019 Bushfire, Great Sandy and Noosa National Parks, South East Queensland Bioregion, December 2020 (PDF, 1.7MB).