The role of bark type in relative tolerance to fire of three central Victorian Eucalypts

Abstract

A laboratory approach to the study of fire resistance in trees is described and the method applied to three central Victorian eucalypts which possess different types of bark. For each species, bark thickness increases with the girth of the trunk or older branches. The fibrous bark of E. obliqua is thicker than the subfibrous bark of E. radiata, and this in turn is thicker than the decorticating bark of E. cypellocarpa for the same girth of trunk or branch. The rate of heat penetration to the cambium, however, is greatest in E. obliqua and least in E. cypellocarpa. This apparent anomaly is due to the greater inflammability of the fibrous bark. It is suggested that the fire tolerance of a species should be evaluated against fuel accumulation and the fire intensity of the site, as well as the extent of damage to various parts of the tree and the ability of these parts to recover.