Fire and Silvicultural Management of Restored Bauxite Mines in Western Australia

To be self-sustaining in the longer-term and meet defined completion criteria, it is important that the management of restored bauxite mines can be integrated with the surrounding unmined Jarrah (Eucalyptus marginata) forest. A number of research projects relating to fire management have been undertaken in restored areas over the past 15 years. The broad objectives of these studies have been to assess the resilience of different-aged restored sites to fire and define the most suitable fire regime (season, intensity, and frequency) to utilize in the management of these areas. Restored areas were found to be a low fire risk up to five years of age because litter fuel was discontinuous and could not normally carry the fire. Between the ages of five and 12-15 years, restored areas were very susceptible to fire due to high fuel loads and a prominent midstory of senescent legume species. However, if burnt at this age, restoration areas were extremely resilient. Restored areas that are older than 12-15 years can be integrated with prescribed burning of the surrounding unmined forest because the midstory layer has collapsed and the overstory is now separated from the understory fuel. The most suitable fire regime to utilize in restored areas is low- to moderate-intensity spring burns. Silvicultural management of restored areas has recently been investigated incorporating noncommercial thinning and commercial harvesting operations in association with prescribed burning. Restored areas of suitable ages appear to be able to be integrated with the management regimes commonly used in the Jarrah forest.