- Title:
-
The Accumulation and Structural Development of the Wiregrass (Tetrarrhena Juncea) Fuel Type in East Gippsland
- Date:
- June 1993
- Organisations
- DSE
- Authors:
- Liam G. Fogarty
- Location:
- Victoria, VIC, Australia
Overview
Wiregrass fuels, which form an elevated and highly flammable understorey in much of the economically valuable forest of the coastal and foothill areas of East Gippsland, Victoria, were measured and destructively sampled in clusters of 3-4 plots at 69 sites in 10 age classes.
Negative exponential models fitted the data well and showed that after a fire the level of total fine fuel can be expected to reach 95 percent of its average long-term value of 16 t/ha (comprising 6 t/ha elevated fuel and 10 t/ha surface fuel) in about 15 years, with half that level being reached in four years. Similarly, the fuel height and cover can be expected to reach 1.1m and 67 percent in 6.5 years, or half those levels in 1.5 years.
Fuels reach the Department's existing prescribed maximum hazard levels for Protection Priority 1 Zones in four years and for Protection Priority 2 Zones in seven years; and remain low enough to provide some lesser protection for perhaps 10-12 years.
A strong relationship was established for predicting elevated fuel load from fuel height and (to a lesser extent) fuel cover; and surface fuel load was found to be correlated with fuel depth. These relationships should enable field personnel to appraise fuels readily and hence to meet the objectives of prescribed burn operations more effectively and with greater confidence.
The models were compared with those derived by multiple linear regression and were found to provide similar predictions. Negative exponential models that were fitted to the 0-10 year data were found to be suitable for predicting fuel levels over that 0-10 range of fuel ages.
Fire managers can use the models strategically to plan and monitor the protection provided by existing or future programs of fuel reduction burning. The protection of lives and of private and public assets, including a regrowth timber (especially sawlog) resource that is very susceptible to fire damage, may therefore increase and be more efficient.
