Analysis of the photoseries showed some clear and consistent trends:
No Event Management Implications
1. Grass cover after the fire quickly entered a non-fire-affected sequence that reflected the drought level. Biomass peaked before the 1997 drought, and has stayed lower since. The heavily drought-affected state is not dissimilar to the one-year post-fire state. Grassland management effort should reflect the wetness of a season, as is established practice.
2. Small shrub layers are patchy and inconsistent. Small shrubs have little direct impact on fire risk. No effort is needed.
3. Tall shrubs exhibit three strong sequences:
A) the pre-fire tall shrub layer was either killed off by the fire or became senescent after the fire.
The dead tall shrub biomass may, if bulky, produce a transient risk surge, requiring their removal. Remove within Asset Protection Zones (APZs).
4. B) a post-fire, Acacia-dominated tall shrub layer was rapidly established from seed, and became senescent about 10 years post fire. It capitalised on the opening of the eucalypt canopy, and suffered when the canopy closed again about three years post-fire. Final loss also coincided with peak drought. The Acacia layer is major risk from year 3 to year 10, especially Cootamundra Wattle and similar species.
Dead biomass also produces risk for two years after die-off. Remove in APZs.
5. C) a later tall-shrub layer appeared after the Acacia layer died off. This usually came from eucalypt seedlings suppressed in the low shrub layer. These are still growing, and may become a replacement canopy, or may simply be recruited into the existing canopy. Some areas had a repeat of the Acacia layer. The eucalypt surge should be promoted in the outer APZs, as it assists with long-term maintenance of fuel moisture levels. For their first seven years they are NOT sufficiently seperated from the ground cover to prevent them contributing to fire behaviour, and thus being killed. Removal or protection from fire are thus the goals during this period.
Another area where interesting findings arise from the photoseries is the urban edge.
Some features of note are: