Eucalyptus camaldulensis

Eucalyptus canaldulensis

Country of Origin:

Australia

Common names:

Murray Red Gum, Red Gum,River Gum, River Red Gum

Synonyms:

Eucalyptus camaldulensis, Eucalyptus rostrata

Species Summary:

A hardy, fast growing gum that is tolerant of salinity,waterlogging, drought and frost, with a range of amenity and wood uses. As the eucalyptus with the widest natural distribution, provenance variation for many traits is large, so selection of stock is important when planting. It is grown extensively, so much of its silvicultural and pest information is known. Due to its naturally spreading crown, close spacing and good management are required to develop a desirable form for timber production. The wood is hard, heavy and durable; care is needed in drying, but it is sought after for a range of uses and is prized for use in heavy furniture. It is regarded as excellent firewood.

Description and Form:

Eucalyptus camaldulensis is a relatively large riparian tree, commonly growing to 20 m in height, but rarely exceeding 50 m. In open woodlands it usually has a short, thick bole and a large, spreading crown with heavy branching. In plantations it can have a clear bole up to 20 m with a lightly-branched crown.

Northern and southern forms of Eucalyptus camaldulensis are generally recognised:

Eucalyptus camaldulensis variable camaldulensis refers to the southern form and Eucalyptus camaldulensis variable obtusa is the northern form.

Eucalyptus camaldulensis variable camaldulensis has a basal stocking of rough bark for the first 1–2 m of the trunk. Above this, the bark is smooth, cream to white, pale grey or buff with grey and reddish patches. Leaves are non-glaucous and the flower buds form a beaked cap. Eucalyptus camaldulensis variety obtusa has smooth bark to ground level.

Bark is white to cream, sometimes with reddish brown patches. Leaves are glaucous (with a white wax bloom) and flower buds are more rounded in shape.

Eucalyptus camaldulensis is generally fast growing. Tree form is variable but is typically poor in southern Australia.

Weediness and Toxicity:

Both variable camaldulensis and variable obtusa have become naturalised away from their natural distribution in areas of southern Western Australia (WA), Victoria (VIC) and Queensland (QLD).

Natural and Planted Distribution

Eucalyptus camaldulensis has the widest distribution of all eucalypts and is the only species to occur naturally in all mainland states of Australia. It occurs along, or near, almost all of the seasonal watercourses in arid and semi-arid inland areas. It is also found along many other streams and rivers in the south-east of the continent, mainly on the inland side of the Great Dividing Range. It is generally a riparian tree, but sometimes extends to floodplains, for example, at Barmah on the Murray River in New South Wales (NSW), and to the slopes of ranges as in the Mt Lofty Ranges near Adelaide in South Australia (SA).

Eucalyptus camaldulensis variable camaldulensis has a mainly temperate distribution in the Murray-Darling River system, extending from southern QLD to VIC.

Eucalyptus camaldulensis variable obtusa comprises all other populations occurring outside the Murray-Darling Basin. It occurs extensively throughout tropical and subtropical Australia. Eucalyptus camaldulensis subsp. simulata occurs along a few river systems in northeastern QLD.

Eucalyptus camaldulensis occurs on a variety of soil types and is mainly a tree of depositional or alluvial sites, although it sometimes occurs on the margins of salt lakes. It is common on heavy clays in southern Australia, but usually occurs on sandy alluvial soils in the north. It also grows on calcareous clay loams derived from limestone in SA.

Latitude 24°S is used as an indicator to separate northern and southern forms. The southern form is best suited for Mediterranean winter-rainfall climates and grows best on deep silty soils. The northern form is best suited to tropical, summer rainfall regions with sandy and alluvial soils, but will grow well on alkaline sodic sites.

Globally, Eucalyptus camaldulensis is the most widely planted tree in arid and semi-arid lands. There have been extensive plantings in the Mediterranean region using seed from southern Australian provenances. Planting in the tropics, especially in South East Asia, Mexico and Brazil is increasing with the availability of seed from northern Australian provenances.

Commercial Product Information:

Basic density ranges from 502–879 kg/m3 . Wood from young trees is pink in colour with an air-dry density of around 650 kg/m3 . An air-dry density of 778 kg/m3 for 17 year old trees has been measured. Young plantation-grown trees are used overseas for pulpwood but pulp yields and quality are low in southern Australia. It is also used overseas for hardboard and particle board and shows potential for fibreboards.

Eucalyptus camaldulensis is a good producer of pollen and honey. It often exudes an astringent gum with medicinal properties and the leaves of some provenances e.g., ‘Petford’ (QLD) give cineole-rich eucalyptus oil with fresh weights ranging from 0.3% to 2.8%.

Products and Service

Environmental Services Information

Useful for shade, shelter and in windbreaks; deeprooted, which allows grass growth right up to the base; bark is resistant to stock damage. For south eastern Australia, Eucalyptus camaldulensis along with Eucalyptus melliodora (Yellow Box) and Acacia melanoxylon (Blackwood) are considered superior shade trees. It is also attractive as an ornament for acreage plantings.

Useful for the reclamation of degraded lands,especially salt-affected land subject to seasonal waterlogging.

Excellent habitat; provides prolific pollen and nectar for a wide range of insects and birds. The foliage is an important food source for koalas and provides nesting sites for many birds. Stream bank trees are important for fish habitat—they provide shade, an insect source, and fallen branches for snags which provide egg-laying sites for native fish such as the Murray Cod.

Limiting Factors

Poor form and susceptibility to insect attack limit its use for plantation establishment in the low-rainfall zone of south QLD. Eucalyptus camaldulensis is not well adapted to calcareous soils, except one provenance on the lower Eyre Peninsula, SA, where it grows with Eucalyptus porosa low, poorly-for Diseases and Pests Due to widespread planting and use, considerable disease and pest information is known about this species. It has low to high susceptibility to insect attack, depending on provenance and individual, but sapwood is susceptible to attack by lyctid borers.

Riverine provenances are damaged by sawfly (Perga spp.), gumleaf skeletoniser (Uraba lugens), Christmas beetle (Anoplagnathus spp.), psyllid/lerp (Cardiaspina spp., Glycaspis spp.), leafblister sawfly (Phylacteophaga froggatti), leaf beetle (Chrysophtharta spp., Paropsis spp.), shothol miner (Perthida sp.) and cup mouthj (Doratifera Inland provenances e.g., ‘Silverton’. ‘Flinders Ranges’ and clones are more resistant to lerp and leafblister sawfly, but susceptible to sawfly, gumtree hopper (Eurymela spp.) and tip-feeding bug (Amorbus spp.).

Diseases and pest problems may be reduced by careful selection of provenances and by minimising environmental stresses through watering and edequate nutrient status, with fertiliser used where  appropriate.

Authors:

Lynne McMahon Farm Forestry Extension Officer

Brendan George Industry Leader Bioenergy & Private Forestry Industry Development, Agriculture & Forestry

Robyn Hean Natural Resource Economist