Prospects for genetic improvement of Eucalyptus cladocalyx in Western Australia

Sugar gum (Eucalyptus cladocalyx F. Muell.) produces high value timber over a medium- length rotation in the 400-600 mm rainfall zone of southern Australia. We evaluated growth and tree form in sugar gum family trials on three sites in Western Australia. The trials contain 42 open-pollinated families originating from the southern Flinders Ranges and Kangaroo Island (wild families) and four planted stands. Height and diameter were assessed at 3.5 and 5.5 years and stem volume was calculated. Branch size and stem straightness were scored at 3.5 years and axis persistence was assessed at 5.5 years. Mixed model equations were fitted to determine narrow-sense within-provenance heritability (h2) for all traits, genetic