Natural populations

Allocasuarina huegeliana is endemic to the south west of Western Australia where it extends south from the Murchison Region, through the 300-600 mm rainfall zone to the Esperance region. Occurrences are highly fragmented as it only grows on sandy loams at the base of granite rock outcrops. This species is a medium-sized tree rarely greater than 15 m tall.

Flowering and seeds

This species is dioecious with male and female flowers on separate plants. Mature cones are held on female plants for at least a season and have been collected during winter [1]. There are over 200 viable seeds per gram; seeds start to germinate in about 7 days if grown at 15-20°C with no pretreatment required [1].

Cultivation and uses

Allocasuarina huegeliana is a moderate to fast growing, nitrogen-fixing tree with potenial as a windbreak. It is adapted to sandy, well-drained sites and not recommended for poorly drained or saline soils. The foliage of this species is highly palatable to grazing animals and has potential as a source of stock fodder. Allocasuarina huegeliana produces dense, attractively figured wood that is in demand as a speciality timber for furniture [2].

Key descriptors:
Climate parameters
Mean annual rainfall: 300-800 mm
Mean annual temperature: 15-22 °C
Mean max. temperature of the hottest month: 21-32 °C
Mean min. temperature of the coldest month: 4-9 °C
Frosts (approx. no. per year): up to 20
Frost intensity: light to moderate (0 to -5°C)
Altitude: 70-450 metres
Tolerance of climate extremes
Drought: known to be moderately drought tolerant
Fire: killed by damaging fire does not regenerate foliage
Frost: tolerates frosts in the 0° to -5°C range
Wind: known or has attributes to make an excellent windbreak
Soil factors
Texture: clay loam, light to medium clay (35-50% clay), loam, sandy loam, sandy clay loam or sand
Soil pH reaction: acidic (less than 6.5) or neutral (6.5-7.5)
Soil depth: skeletal to shallow (less than 30 cm) or moderate to deep (30-100 cm or greater)
Drainage: well-drained
Salinity: non-saline
Tolerance of adverse soils
Extremes in texture: sand
Salinity: nil - sensitive to saline soils
Soil waterlogging tolerance: nil - sensitive to waterlogged soils
Biological traits under cultivation
Habit: evergreen tree 5-10 m tall
Longevity: moderate to long lived (>15 years)
Growth rate: moderate or fast
Root system: shallow and spreading or fixes nitrogen via root symbiot
Erosion control potential: excellent for sandy sites
Windbreak potential: excellent (known or has good attributes)
Shade tolerance: grows best in full sunlight
Wood density: mod. to high (greater than 600 kg/cubic metre)
Carbon sequestration potential: moderate to high
Uses
Potential farm use: excellent windbreak, good for fence posts, shelterbelt or shade for stock, foliage has stock fodder potential
Urban use: suitable as a screen or hedge
Wood products: craftwood (for turnery etc.), flooring (including parquetry), light construction, panelling, posts (including fencing), speciality timber for quality furniture
Potentially undesirable attributes
Fire sensitivity: killed by severe fires (seeder)
Susceptibility to disease or predation: foliage highly susceptible to insect predation or pathogenic leaf diseases or susceptible to stem girdling by parrots
Foliage: highly susceptible to browsing by animals

References

[1] Gunn BV (2001) Australian Tree Seed Centre Operations Manual. Internal Publication, CSIRO Australian Tree Seed Centre, ACT. [Online at http://www.ensisjv.com/Portals/0/atsc-opmanualcomplete.pdf Accessed March 2008]

[2] Agroforestry News (2005) No. 53: http://www.mtg.unimelb.edu.au/AgroNews/AgroforestryNews53.pdf p.10

Internet links

FloraBase Western Australian Herbarium: http://florabase.dec.wa.gov.au/browse/profile/1731

Western Australian Department of Agriculture and Food: http://www.agric.wa.gov.au/content/lwe/vegt/trees/fs03400.pdf

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