| Abstract: | Two adjacent mature trees of New England peppermint (Eucalyptus nova-anglica) were harvested with the aid of a cherry picker to determine their biomass distribution and insect damage. One suffered from obvious symptoms of rural dieback and the other was healthy. Weights of foliage and wood were measured, and insect damage for all leaves and branches was quantified. For each tree 25% of the roots were extracted from the soil using a bulldozer and manual methods; they were then weighed and damage by insects estimated. The healthy tree lost more leaf surface area to insects (11% or 1.1 kg vs 9.2% or 0.3 kg); but the dieback tree had four times more wood affected by boring insects (19% cf. 5%); and only 20% root biomass remaining (92 kg cf. 488 kg). The accuracy of sampling techniques needed to measure defoliation and the consequences of insect damage to dieback of rural eucalypts are discussed. |
