Attributes of logs on the floor of Australian Mountain Ash (Eucalyptus regnans) forests of different ages

We describe the results of a study of the characteristics of 984 logs measured on 60 sites located in four distinct age classes of Mountain Ash (Eucalyptus regnans F. Muell) forest in the Central Highlands of Victoria, south-eastern Australia. The age classes were young regrowth (approximately 20 years old), 59 year old forest (dating from the 1939 wildfires), mature stands (dating from fires in the 1820s) and old growth stands (>250-350+ years old). Statistical relationships were established between log attributes (number, diameter, length, and moss cover) and site attributes or covariates (stand age, slope, aspect, topographic position). Our data showed that the diameter of logs and the cover of mosses on logs was significantly greater in mature and old growth stands than forests in younger cohorts (p=0.03 and p=0.002, respectively). No relationships were found between log length and any of the measured site-based covariates. Estimated log volumes did not vary significantly between stands of different ages. Other site attributes (slope, aspect, topographic position) also showed no significant effects. Estimated log volumes for each age class were high and the mean estimate for all sites was approximately 350 m³/ha. At some sites, log volumes exceeded 1000 m³/ha; an estimate higher than calculated for many other temperate forest types around the world.