Byron Flora and Fauna Study 1999 - Byron Shire Council

A GREENPRINT FOR A SUSTAINABLE FUTURE
Durobby (Syzygium moorei FAMILY MYRTACEAE)
Introduction. Durobby (also known as Coolamon) is a highly ornamental tree which has a restricted distribution in
lowland rainforests of southeast Queensland and northeast New South Wales. It is well known in the Byron Shire, with
conspicuous specimens occurring along the Brunswick River, in the coastal reserves and scattered as isolated paddock
trees and in small remnants. Its name is reflected in the Coolamon Scenic Drive which transverses the Shire and the
Coolamon Villa at Mullumbimby. It is widely planted as a street tree and ornamental. No recovery plan has been prepared
for Durobby. A detailed species outline has been compiled by Barry and Thomas (1994) (Queensland).
Conservation status. Durobby is listed on Schedule 2 (Vulnerable) of the TSC Act, 1995 and has a ROTAP code of 2VCi
(Briggs and Leigh 1996).
Habit. A tree attaining a height of 40 m and a stem diameter of 60 cm. (Floyd 1989). The tree has dense dark green
foliage.
Flowers. Showy pink flowers are borne on the branches (Harden 1991). Barry and Thomas (1994) note that the plant
pollinators of Durobby are unknown. Floyd (1989) records that bees are attracted to the flowers. The cauliflorous
flowering habit is often indicative of bat pollination. Several different pollinators may operate, as in the case of the related
Syzygium cormiflorum in north Queensland (Crome and Irvine 1986).
Fruit. Berry white, suffused with green, flattened, globular, fleshy, up to 6-cm diameter. Seeds dull, rough, creamy fawn,
2-3 cm broad, 1.0-1.5 cm thick. Ripe March-May (Floyd 1989). Neither Floyd (1989) nor Holmes (1987) record bird
species as eating the fruit, but seed is likely to be dispersed by the larger fruit pigeons. Seed may also be carried by water.
Habitat. Riverine and gully rainforest at low altitude (Floyd 1989).
Distribution. Restricted to the Richmond, Brunswick and Tweed Rivers in NSW and Upper Mudgeeraba Creek in Queensland.
Recorded in NSW from Emigrant Creek; Hayters Hill; Mullumbimby; Brunswick Heads NR; Crabbes Creek;
Burringbar; Dum Dum; Eungella; Couchy Creek; Durobby Creek; Hogans Scrub (Floyd 1989). Details of 75 locations in
the study area have been compiled, including sixteen new sites found by the authors during this study.
Regeneration and horticulture. Germination may take several months (Nicholson and Nicholson 1985). Floyd (1989)
suggests that grub attack of seeds may be reduced if collected before fully ripe. Cuttings are successful and may be grown
from healthy tip cuttings (Floyd 1989). Natural regeneration of Durobby is only rarely observed throughout the species’
range, and the factors that are limiting have not been studied. In the study area and surrounds, many trees exist as
remnant paddock trees, where seed dispersal to suitable sites for regeneration is unlikely. Remnant and regrowth rainforest
along creeks and gullies provides suitable habitat for this species. The best chance for regeneration opportunity is
likely to be in large areas of forest where microsites suiting the requirements of the species at successive lifecycle phases
may be present.
Economic and cultural significance. Floyd (1989) notes that little is known about the timber and its possible uses. The
species is well known in horticulture. The white fleshy fruits are edible though insipid in flavour (Nicholson and Nicholson
1985), and were eaten by Aboriginals (Floyd 1989).
Abundance and reservation. Durobby is scattered through suitable habitat and trees have been retained as ornamental
paddock trees throughout the Tweed and Brunswick region. No estimate of numbers has been made. Durobby is reserved
in the Shire in the Inner Pocket NR, Billinudgel NR, Brunswick Heads NR, Hayters Hill NR and Broken Head NR.
Briggs and Leigh (1996) consider that its reservation is inadequate.
Threats and amelioration. Land clearing and weed invasion are listed by Barry and Thomas (1994) as threats to Durobby
in Queensland. Poor dispersal and lack of regeneration threaten the species, and grazing, roadworks, hardwood plantation
establishment, streambank erosion, fire and coastal storms are additional threats in NSW.
Although mature trees persist for long periods, opportunities for natural regeneration are limited outside existing rainforest
environments. Seedlings are unlikely to establish in the vicinity of isolated paddock trees and regenerating rainforest
in the region is generally suppressed by woody weeds. Much of the well-drained lowlands of the Shire would provide
suitable habitat if rehabilitated and planted. However, many of these areas consist of prime agricultural land or residential
areas.
To improve the conservation status of Durobby, the health of the population and its regeneration potential should be
enhanced by weed management, grazing exclusion, fire protection and replanting of surrounding habitat.
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