Karri oak

Allocasuarina decussata

Karri oak is a medium-sized understorey species in the karri (E. diversicolor) forest in the south-west of Western Australia. Karri oak is closely related to the rose sheoak (Allocasuarina torulosa) of the eastern states, and in the karri forest is commonly associated with karri wattle (Acacia pentadenia).

Wood description [more info]
Heartwood is a pale reddish brown, and has the distinctive rays that are best shown by quartersawing the log. Sapwood is whitish.

Wood density [more info]
Green density is about 1190 kg/m3, air-dry density about 840 kg/m3, and basic density about 640 kg/m3.

Shrinkage [more info]
Tangential and radial shrinkage are estimated as about 8.0 and 6.5 per cent respectively.

Workability [more info]
CALM Timber Technology rated working properties such as sawing, sanding and gluing as good, and planing and routing as average.

Durability [more info]
Durability has not been assessed, but the CSIRO Durability ratings would be of limited use because specialty timber would not be used in-ground. Sapwood is Lyctus-susceptible.

Strength group and properties [more info]
The green and dry strength groups are (S4) and (SD4). The brackets indicate conservative provisional ratings based on the air-dry density. The more important strength properties based on the strength group are given in the table below.

Uses [more info]
Overall use has been limited, but the species has potential for craftwork using the 'natural feature grade' specification now.

Availability [more info]
Very limited availability because karri oak is an understorey species in the karri forest, most of which is in conservation reserves.