A preliminary study of eucalypt dieback in the Dandenong Ranges.  B. K. Ward and F. G. Neumann.  June 1981.  12 pp. (unpubl.)

SUMMARY

This report describes results of a survey and investigation, during 1978, of dieback in mixed eucalypt forest on the slopes of the Dandenong Ranges near Melbourne. The survey area covered about 26 000 ha, of which approximately 10 600 ha contained mixed eucalypt forest. Black and white, 1:32 500 scale, aerial photographs, taken in 1976, were scanned stereoscopically for patches of dieback; and the occurrence of these patches was confirmed by aerial reconnaissance in 1978. Twelve patches, varying from small to large in size, were examined in more detail on the ground.

This study showed that the total area of forest affected by dieback was 779 ha (7.4% of the forested land), distributed in a total of 77 patches, varying in size from less than 5 ha to 101 ha. Most of the dieback patches occurred between 100 and 200 m above sea-level, in gullies, and on lower slopes with northerly and north-easterly aspects.

Of the seven species of eucalypts common to the survey area, those affected by dieback included members of the Monocalyptus group (ash and stringybark eucalypts) : Eucalyptus radiata Sieber ex DC. (narrow-leaf peppermint), E. dives Schauer (broad-leaved peppermint), E. baxteri (Benth.) Maid. & Blakely (brown stringybark) and E. obliqua L’Hérit. (messmate stringybark); and of Symphyomyrtus (gums) : E. aromaphloia Pryor & Willis (scent-bark) and E. ovata Labill. (swamp gum). Only E. cypellocarpa L. Johnson (mountain grey gum) was found to have any resistance to attack. E. sieberi L. Johnson (silvertop), E. viminalis Labill. (manna gum), E. goniocalyx F. Muell. ex Miq. (bundy (long-leaf box)), E. macrorhyncha F. Muell. ex Benth. (red stringybark) and E. rubida H. Deane & Maiden (candlebark) were not sufficiently common to be studied.

Psyllid insects of the genus Glycaspis and subgenera Synglycaspis and Glycaspis were found to be the principal causal agents. Glycaspis (Synglycaspis) spp. damaged leaves from trees of the Monocalyptus group (ash and stringybark eucalypts), whereas G. (Glycaspis) spp. were confined to leaves from the Symphyomyrtus group (gums).

Also published:

Ward, B.K. and Neumann, F.G. (1982)  Eucalypt dieback in foothill forests of the Dandenong Ranges.  For. Comm. Vic., For. Tech. Pap. 29: 10-14.