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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3.27 paspalidium grandispiculatum B.K. Simon3.27.1 SummaryP. grandispiculatum occurs from north of Grafton, New South Wales to near Helidon, Queensland. In Queensland, the species is known only from three sites over a range of approximately 100 km and encompasses an area of occurrence of approximately 1600 km2. None of the sites are within a conservation reserve. There is no quantitative information about population size. It has been recorded growing in tall open forest on brown loam soils along a gently sloping gully at an altitude of 220 m. A potential threat to the survival of the species in one of the Queensland locations is physical disturbance from quarry operations. 3.27.2 Species description and identificationThe genus Paspalidium is placed in the grass family (Poaceae). Paspalidium is widespread throughout the tropical regions of the world with approximately 40 species (Jacobs and Wall 1993b). In Australia it comprises approximately 22 species of which 12 occur in south east Queensland (Stanley and Ross 1989). Paspalidium grandispiculatum B.K. Simon was formally described in 1982 from material collected 14 km north of Helidon (Simon 1982). The botanical description of Paspalidium grandispiculatum is as follows: Perennial grass up to 150 cm tall with robust woody underground rhizomes. Culms woody smooth, glaucous to pruinose, branched at some nodes throughout the culm length. The leaf-sheaths are glabrous and smooth. The leaf-blades are linear, up to 10 cm long by 0.4 cm wide and scaberulous on nerves particularly on the underside. At the junction of the leaf-sheath and leaf-blade there is a fringe of whitish hairs. Spikelets are 3.5-4.5 mm long and have 2 flowers. Each spikelet is accompanied by a bristle arising from the stalk beneath the spikelet. The bristles are 3-8 mm long. The spikelets are irregularly gathered at the end of the stems. For a more detailed description and illustration refer to Simon (1982). P. grandispiculatum is distinguished from all other Australian species of Paspalidium by its large spikelets and characteristic woody culms arising from robust woody rhizomes (Simon 1982). 3.27.3 Current conservation statusP. grandispiculatum is presently listed on the schedule of the Queensland Nature Conservation Act 1992 as “vulnerable wildlife”. The species has been assigned a national conservation status of V (vulnerable) by ANZECC (1993). It is also listed on Schedule 1 Part 2 (vulnerable) of the Commonwealth Endangered Species Protection Act 1992. 3.27.4 Distribution and abundanceP. grandispiculatum was not surveyed during the present study. Details from Queensland Herbarium specimens of P. grandispiculatum are listed in Appendix 1.26. Five specimens of P. grandispiculatum have been collected in Queensland. Four of the specimens come from a single locality along the Helidon-Ravensbourne Road, while the other record is from the Beaudesert district. There is no information available on population size at either of the localities. P. grandispiculatum has been recorded recently in Doubleduke State Forest, north east of Grafton, New South Wales. It is apparently a dominant species in the understorey of the open forest where it occurs (A. Benwell pers. comm.). One other locality has been recorded in the CORVEG database from Queensland. This is 5 km north north west of Helidon on private land. At the time (February 1997) the area was being used for the extraction of gravel by the Gatton Shire Council (P. Grimshaw pers. comm.). P. grandispiculatum was a common understorey species at the site (P. Grimshaw pers. comm.). None of the sites is in an area set aside for conservation of habitat. In Queensland the distribution of P. grandispiculatum has a range of approximately 100 km and encompasses an area of occurrence of approximately 1600 km2. 3.27.5 HabitatVery little habitat information is available. At the original collection site P. grandispiculatum was recorded growing in an open eucalypt forest with Acacia complanata in the shrub layer. The only other information available comes from the CORVEG database. The species was growing in a tall open forest on sandstone in brown loam along a gently sloping gully at an altitude of 220 m. The common canopy species are Corymbia trachyphloia, Eucalyptus acmenoides and E. taurina. The common understorey species were Leptospermum trinervium, Acacia complanata, A. julifera, Bursaria spinosa, Paspalidium grandispiculatum, Entolasia stricta, Themeda triandra, Lepidosperma laterale, Daviesia villifera, Leucopogon biflorus and Notelaea linearis. 3.27.6 Life history and ecologyThere have been no studies into the biology or autecology of P. grandispiculatum. P. grandispiculatum is a perennial grass with a stout rhizome. The main methods of reproduction are by sexually produced seeds and vegetatively by the division of the rhizome. It has been recorded flowering from January to May. There is no information available about the viability or longevity of the seed. The species’ response to grazing or habitat disturbance is unknown. The above-ground parts of P. grandispiculatum are killed by fire but the species is capable of regenerating from the rhizome. 3.27.7 ThreatsThe lack of information about the present population levels and precise habitat requirements of P. grandispiculatum make it difficult to assess threats to this species. The extraction of gravel from near the site on private land may be a major threat to the population. 3.27.8 Management, research and conservation measuresThis species requires detailed surveys to assess previously recorded localities and to collect information on habitat requirements. Additional surveys are also required to establish if any further populations of this species occur in the region. These surveys would need to be carried out during the flowering period from January to May. For those populations that occur on freehold land, liaison should be undertaken with land owners and the Gatton Shire Council to make them aware of the presence of the species and the importance of protecting the populations. Discussions should be undertaken with the land holders in regard to protecting the areas with Conservation Agreements under the Queensland Nature Conservation Act 1992. |