FACTORS INFLUENCING THE ESTABLISHMENT OF SEEDLINGS OF THE MALLEE, EUCALYPTUS-LUEHMANNIANA (MYRTACEAE)

Factors influencing the survival of seedlings of the wet mallee-eucaly pt Eucalyptus luehmanniana F. Muell. were examined using seedlings ger minated in the laboratory and planted into the field. The effects of t ime since fire (0, 13 and 26 years), predation and position relative t o adult canopy on seedling survival and growth in the first year after establishment were tested experimentally. Drought, predation by inver tebrates and burial in leaf litter were identified as factors causing seedling mortality. Seedlings were most susceptible to predation at un burnt sites. Seedlings planted at burnt sites were more susceptible to drought, although a small percentage were killed by invertebrate pred ators. Burial of seedlings in leaf litter was most common under eucaly pt canopies. After 200 days, seedlings in burnt sites were significant ly more advanced in height, leaf area and leaf number than those in un burnt sites. It is predicted that E. luehmanniana seedlings are unlike ly to achieve fire tolerance before fire occurs (assuming a fire inter val of 10-20 years) unless they establish immediately after fire. The results suggest that mass establishment cued by fire allows seedlings to avoid predation, however mortality due to drought was greater at bu rnt sites than mortality due to predation at unburnt sites.