SEB:A Eucalyptus diversicolor F. Muell.family Myrtaceae

karriEucalyptus diversicolor is the tallest tree of Western Australia and is only exceeded in height by a few eucalypt species in Victoria and Tasmania. One tree felled in 1901 at Pemberton was 87 m. The more usual dimensions are 45—70 m tall with dbh commonly 1 ‘ 5—3 m. The trunk is straight and up to two-thirds of the tree height.

Karri occupies a limited area of high rainfall country in the extreme southwest of Western Australia. The main occurrence extends from Nannup and the upper Donnelly River in the north, southeast to Denmark. It consists of about 300 000 ha in a long narrow belt mainly about 16—25 km wide and almost parallel to the coast between Albany and Cape Leeuwin, with several outliers. One outlier is on coastal limestone immediately inland of the massive coastal dune system between Karridale and Forest Grove, and other smaller ones usually around granite gneiss bosses are at Mount Many Peaks, Torbay and Rocky Gully near Mt Barker; another is in the Porongorup Range. Most of the occurrence is between latitudes 34—35°S and the altitude is mainly from just above sea level to about 300 m. The climate is mostly warm humid with the mean maximum temperature of the hottest month in the range 25—30°C and the mean minimum of the coldest month around 5—8°C. Frosts are absent in the lower altitude, coastal areas while a few each year may be experienced elsewhere. The mean annual rainfall is mainly from 900—1300 mm, with a distinct winter maximum. During the summer period the mean monthly fall may be less than 25 mm.

This species occurs on undulating to hilly country. In the lower rainfall zones it is confined to the valleys, but where the rainfall is higher it extends up hill slopes and on to ridges. Karri soils are acidic, with textures varying from fine sands to sandy loams derived from underlying granitic rocks. Such soils are very low in nutrient for agriculture and are deficient in such trace elements as zinc, copper and cobalt. Karri occurs mostly in tall open-forest formation and invthe main commercial forest area of about 120 000 ha it is mainly in pure stands while the balance is usually in mixture with marri (Eucalyptus calophylla) and, to a considerably lesser extent, Jarrah (E. marginata), Red Tingle (E. jacksonii), or Yellow Tingle (E. guilfoylei). She-oak (Casuarina decussata) and Acacia pentadenia are common understorey species.

Wood: Heartwood red, hard, heavy, strong, stiff and tough, moderately durable, grain often interlocked; density about 900 kg m‘J; the second most important commercial timber in Western Australia and was, before World War II, exported in large quantities for use as building timbers, flooring and guides or sliding beams in mines. Larger lengths are available than from any other hardwood. Also used for plywood which is especially favoured for concrete formwork and truck flooring. Cull Karri logs are used in the pulp and paper industry.


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