Stem damage and crown recovery following high intensity fire in a 16-year-old stand ofEucalyptus diversicolorandEucalyptus muellerana

Abstract

The extent of stem damage and rate of crown recovery were studied following a high intensity fire in a 16-year-old planted stand of Eucalyptus diversicolor and Eucalyptus muellerana in Western Australia. Trees defoliated by fire were killed back substantially further than trees which were fully crown scorched, with E. diversicolor being killed back further than E. muellerana in each of the fire intensity classes. The greater resistance of E. muellerana to fire damage was attributed to the fact that it had thicker bark than E. diversicolor over much of the length of the stem. Five years after fire all E. muellerana had apically dominant crowns, whereas up to 40% of E. diversicolorstill had crowns dominated by lateral epicormic branches originating from the stem. Fire-caused wounds on the lower stem were uncommon, probably because most woody debris had been removed during site preparation prior to establishment. Overall, E. muellerana exhibited greater tolerance to fire than E. diversicolor, being more resistant to stem damage and having a greater capacity to re-establish an apically dominant crown from epicormic buds following crown damage.