Survey of threatened plant species in South East Queensland biogeographical region queensland cra/rfa steering committee survey of threatened plant species in
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3.14 Eucalyptus taurina A.R. Bean & Brooker3.14.1 SummaryE. taurina is restricted to south east Queensland where it occurs from Crows Nest south to near Haldon south east of Toowoomba. It has a distribution range of approximately 60 km and encompasses an area of occurrence of approximately 750 km2. There is no quantitative data on population sizes. E. taurina is most commonly found in open eucalypt forest or woodland on gentle to steep slopes and ridge tops. The soils are generally well drained, shallow, sandy to sandy loam in texture. Current or perceived threats to the continued survival of E. taurina are timber harvesting, clearing of habitat and too frequent and intense fires. 3.14.2 Species description and identificationThe genus Eucalyptus is placed in the family Myrtaceae and has approximately 700 species mostly which are endemic to Australia but several species extending to parts of Malesia and the Philippines (Chippendale 1988). Eucalyptus taurina A.R. Bean & Brooker was formally described in 1994 from material collected near Helidon, approximately 80 km west of Brisbane (Bean & Brooker 1994). The botanical description of Eucalyptus taurina is as follows: A tree to approximately 20 m high with rugged grey ironbark on the trunk and larger branches, branches less than 8 cm diameter, smooth. Juvenile leaves petiolate, lanceolate, 9-13.5 x 1.5-2.5 cm, strongly discolorous, not glossy, alternate. Adult leaves with petioles 14-18 mm long, lanceolate to narrowly lanceolate or slightly falcate, 9.5-15 x 1.5-2.5 cm, concolorous, dull, grey-green, alternate. Inflorescences axillary in upper leaf axils or apparently compound and terminal; umbellasters 7-flowered or less by abortion; peduncles angular, 4-7 mm long; pedicels absent or up to 2 mm long; buds fusiform when young, becoming elliptical at maturity, 7-8 x 3-3.5 mm. Fruits sessile or shortly pedicellate, 5-6.5 x 5-6 mm, obconical, disc obscure; valves 3-5, exserted (Bean & Brooker 1994). For a more detailed description refer to Bean & Brooker (1994). The species is illustrated in Brooker and Kleinig(1994) and Bean & Brooker (1994). Eucalyptus taurina can be confused with Eucalyptus crebra which it superficially resembles. However it can be distinguished by its smooth outer branches, fusiform buds and the sessile or almost sessile fruits with exserted valves. 3.14.3 Current conservation statusEucalyptus taurina is presently not listed on the schedule of threatened wildlife of the Queensland Nature Conservation Act 1992 or the Commonwealth Endangered Species Act 1992. However its inclusion on the Queensland Schedule of threatened wildlife as ‘Vulnerable’ is pending. It is proposed to be added to the schedule because it has a restricted distribution and the majority of the known populations are not in any formal conservation reserve. 3.14.4 Distribution and abundanceE. taurina was not surveyed during the present study. Details from the 11 Queensland Herbarium specimens of E. taurina are listed in Appendix 1.13. Six CORVEG sites have also been recorded but are presently not vouchered. E. taurina has a distribution from near Crows Nest south to near Haldon south east of Toowoomba. The species is conserved in Crow’s Nest Falls National Park, but the known population in the park is small (A.R Bean pers. comm.). Presently the main area for this species is just north of Helidon on freehold and State Forest land (SF 564 Fty 1444 and SF 616 Fty 1512). There is no quantitative data available on the number of individuals in the wild. E. taurina has a distributional range of approximately 60 km and encompasses an area of occurrence of approximately 750 km2. 3.14.5 HabitatEucalyptus taurina is most commonly found in open eucalypt forest or woodland at altitudes of 300 to 450 m. It occurs in hilly terrain on gentle to steep slopes and on ridge tops. The soils are generally well drained, shallow, sandy to sandy loam in texture and derived from sandstone or granitic rocks. The more frequent tree species recorded with this species are Eucalyptus acmenoides, Corymbia citriodora and Angophora woodsiana. Other associated trees and shrubs are C. gummifera, C. trachyphloia, Eucalyptus baileyana and E. dura. 3.14.6 Life history and ecologyEucalyptus taurina is a tree reaching 22 m high. The longevity of individual plants is unknown. However, it is suspected to live for at least 100 years. The main method of reproduction is by sexually produced seeds. Flowering has been observed in October. No pollinators have been reported for E. taurina. The most common pollinators of Australian Myrtaceae are insects (Beardsell et al. 1993). Fruits have been recorded in June and August. It is unknown how long the seed is retained in the woody fruits on the tree. Pryor and Johnson (1981) reported that many tropical eucalypt species shed their seeds and drop their fruit a few months after flowering, whereas southern species may retain their fruits for more than a year. The seed once released from the fruit falls to the ground. The seed has no adaptation for secondary dispersal by animals. Cremer (1977) observed that wind is probably the only important agent of seed in the eucalypts. The seeds readily germinate given moisture and reasonable temperature conditions. Fire is a major environmental factor in Australia, in particular in dry sclerophyll forest. Eucalypts are among the most resistant of trees to intense fire. E. taurina has the capacity to sprout from proventitious buds on the trunk, producing epicormic shoots and very thick bark which acts as a efficient insulator. Also, as with most eucalypt species E. taurina forms a lignotuber in the early stages of its life cycle. If for some reason the seedling which has development from the tuber is destroyed, growth is vigorously renewed by the development of new shoots from the lignotuber. 3.14.7 ThreatsTimber harvesting in the State Forest where this species occurs is considered to be a threat to E. taurina. The species produces a millable log and has been harvested in the past. The clearing and harvesting of trees on private land are a threat in the Helidon area. The occurrence of fire in the habitat of E. taurina should not be viewed as being incompatible with the long term survival of the species. However the lack of ecological information about this species’ response to fire makes it impossible to assess what would be an appropriate level of frequency and intensity for the long term benefit of the species. If fires are too frequent and intense, the plants will have insufficient time to replace plants that are killed in the fires, and this will lead to population decline. 3.14.8 Management, research and conservation measuresKnown populations should be examined to establish their size and extent and to identify threats to the populations. Further populations of this species should be searched for within its currently known range. A survey should be conducted to establish whether this species occurs in SF 665 Fty 947. Research is required into the fire ecology, reproduction biology and the population dynamics of the species. The effect of grazing of domestic cattle on the population dynamics of E. taurina needs to be assessed if grazing on crown land is to be permitted out in areas where E. taurina grows. Landholders should be contacted and made aware of the significance of the species on their land. |