Fire Management in Bushland Areas
Bushland within Mosman is largely made up of Sydney Sandstone Gully Forest (SSGF). This vegetation generally requires a burn every 10-12 years to maintain a high level of diversity. Conversely, burning more than twice within this period and then again before a further 12 years would seriously and irreversibly cause a decline in diversity. Over the last century Mosman’s bushland has suffered from very long inter-fire periods. This has, in many areas, lead to a mesic shift (a move towards a more closed monoculture canopy forest) away from fire-dependent species toward less fire-tolerant species. This mesic shift results in a greatly reduced level of flora diversity. Therefore by using fire as a tool to manage the bushland we can reverse this trend and create highly diverse natural areas.
Fire management is also important as Council has statutory responsibilities in relation to fire hazard reduction in bushland areas under its control. A program of hazard reduction burns is annually prepared by Council and submitted to the Mosman, North Sydney and Willoughby District Bushfire Management Committee. Once the Committee is satisfied with each Land Manager’s proposed burn programs for the year the list is then sent to NSW Fire Brigades and the burns are completed throughout the year when weather conditions are suitable and resources are available. Mosman Council’s hazard reduction program is partly based also on weed removal locations where weed debris is piled from bush regeneration activities. This program has been extremely effective in the last couple of years with fire hazard reduction and ecological burns regularly and successfully carried out in many bushland sites.
As mentioned above many native plant species found in Mosman rely on fire for their seeds to germinate. Undoubtedly there is remnant native seed lying dormant in the soil in all bushland sites in Mosman waiting for fire to start the germination process. Using fire has increased native plant species numbers in all bushland sites, increased there density and in general has significantly improved the health and amenity of these sites. Also the threatened plant species Acacia terminalis spp terminalis, is now found at more sites and in greater numbers, most likely as a result of the use of fire throughout Council bushland sites.