Fungal and Insect Parasites Contributing to Niche Differentiation in Mixed Species Stands of Eucalypt Saplings

Parasitic damage to the leading shoot of young regrowth eucalypts was found to vary considerably between trees and between different stands but it averaged greater than 20 % 'effective leaf area loss' overall. Many fungal parasites and some of the phytophagous insects responsible for this damage exhibited host specificity or host preference towards trees of a particular subgenus of Eucalyptus. These findings are discussed in relation to the hypothesis that parasites play an important role in the maintenance of stable associations between codominant species of Eucalyptus.