Regional ecosystem details for 11.3.21
| Regional ecosystem | 11.3.21 |
|---|---|
| Vegetation Management Act class | Of concern |
| Wetlands | Not a Wetland |
| Biodiversity status | Endangered |
| Subregion | 15, 10, 37, 4.4, 7, 26, (6), (31), (35), (11), (36), (24), (13), (23), (6.4), (4), (12), (21), (8), (22), (20), (29), (6.1), (3), (27) |
| Estimated extent1 | Pre-clearing 453000 ha; Remnant 2021 58000 ha |
| Short description | Dichanthium sericeum and/or Astrebla spp. grassland on alluvial plains. Cracking clay soils |
| Structure code | Tussock Grassland |
| Description | Dichanthium sericeum and/or Astrebla spp. (A. lappacea, A. elymoides and A. squarrosa) tussock grassland. Frequently occurring species include the grasses Aristida leptopoda, A. latifolia, Bothriochloa bladhii subsp. bladhii, Brachyachne convergens, Heteropogon contortus, Panicum decompositum, Eriochloa spp., Sporobolus mitchellii and Thellungia advena and the forbs Abelmoschus ficulneus, Corchorus trilocularis, Commelina ensifolia, Euphorbia coghlanii, Ipomoea lonchophylla, Neptunia gracilis, Phyllanthus maderaspatensis, Sida trichopoda and Trichodesma zeylanicum var. latisepaleum. Scattered emergent trees and shrubs may occur, including Eucalyptus coolabah, E. populnea, E. tereticornis and Acacia spp. Occurs on Cainozoic alluvial plains on flats associated with rivers and creeks, including back-plains, terraces, low levees and back-swamps. Associated soils are usually heavy cracking clays. Not a Wetland. (BVG1M: 30a). |
| Supplementary description | Gunn et al. (1967), Alpha (4), Comet (2), Funnel (2), Karalee (5), Mantuan (2), Somerby (6), Waterford (2), Wondabah (4); Speck et al. 1967), Kiddell (10), Westwood (7); Story et al. (1967), Funnel (2), Waterford (3); Galloway et al. (1974), LU 69; Dawson |
| Protected areas | Carnarvon NP, Belmah CP, Vandyke Creek CP |
| Special values | 11.3.21: Habitat for threatened flora species including Thesium australe, Picris evae, Dichanthium queenslandicum and the near threatened flora species Digitaria porrecta and fauna species including grassland earless dragon Tympanocryptis pinguicolla, five-clawed worm skink Anomalopus mackayi and grey snake Hemiaspis damelii. |
| Fire management guidelines | INTERVAL: Fire return interval not relevant. INTERVAL_MIN: 100. INTERVAL_MAX: 100. STRATEGY: Do not burn deliberately. The grasses and forbs of Astrebla spp. dominated communities do not require fire for regeneration. Protection relies on management of fire in the surrounding country to prevent running fires entering Astrebla spp. communities, particularly at times of low soil moisture. ISSUES: Fire can sometimes be used as a tool to control woody thickening and woody weeds in grasslands. Moderate intensity fire is required for a successful kill of the woody species but good moisture levels are required to ensure recovery of the ground layer. Large scale germination of woody species is most likely to occur in high rainfall years. The best management opportunity is usually after storms at the end of the subsequent dry season, although exclusion of grazing pressure may still be required to ensure sufficient fuel loads. |
| Comments | 11.3.21: In some areas e.g. Nebo Shire, this RE occurs within larger areas of RE 11.3.4 along broad alluvial plains that are associated with adjacent or upstream basaltic or andesitic landscapes. Remnant areas may be over-estimated due to mapping scale and difficulty in remotely assessing condition of grasslands. Many of the larger areas have been extensively cultivated for cropping and pasture. Extensive areas are subject to invasion by *Parthenium hysterophorus in northern parts of the bioregion and to a lesser extent the exotic grass *Cenchrus ciliaris (Fensham 1999) particularly after periods of heavy grazing or drought. Presence of the dominant grass species varies with grazing and seasonal conditions. In the south-western part of its occurrence, the ground layer of grasses and forbs may be 0.5-1 m high, with a projected foliage cover of 10-40% (Neldner 1984). Grazing may adversely impact on fauna values particularly during periods of drought (Hobson 2002). Naturalised species associated with this regional ecosystem include *Sida spinosa. |
1 Estimated extent is from version 13 pre-clearing and 2021 remnant regional ecosystem mapping. Figures are rounded for simplicity. For more precise estimates, including breakdowns by tenure and other themes see remnant vegetation in Queensland.
