Regional ecosystem details for 4.3.20
| Regional ecosystem | 4.3.20 |
|---|---|
| Vegetation Management Act class | Least concern |
| Wetlands | Not a Wetland |
| Biodiversity status | No concern at present |
| Subregion | 2, 3, 4, 5, 1, (7), (1.1), (5.3), (1.3), (6.9), (5.5), (6), (5.4), (2.3), (5.2), (11.26), (6.8), (6.6), (5.1), (10.4), (10.1), (10.2) |
| Estimated extent1 | Pre-clearing 986000 ha; Remnant 2021 976000 ha |
| Short description | Short grasses +/- Astrebla spp., Sclerolaena spp. and Atriplex spp. tussock grassland to open herbland on silty alluvial plains |
| Structure code | Tussock Grassland |
| Description | Mixed tussock grassland to open herbland (or bare when dry), including a combination of the species Sporobolus actinocladus, Eragrostis setifolia, Tripogon loliiformis, Aristida spp., Astrebla spp., Sclerolaena spp. and Atriplex spp. After favourable seasons, herbs may temporarily dominate. Ephemerals include Iseilema vaginiflorum, Arabidella nasturtium, Atriplex velutinella, Brachyscome dentata, Pycnosorus pleiocephalus, Ethuliopsis cunninghamii, Euphorbia drummondii, Goodenia fascicularis and Senecio pinnatifolius var. pinnatifolius. Isolated emergent trees may occur, including Acacia cambagei and Eucalyptus coolabah. Occurs on silty alluvial plains of major watercourses. Soils very deep, grey and brown cracking clays with thin sandy or silty material on the surface. Flooding frequency is variable, depending on position in landscape. Not a Wetland. (BVG1M: 31a). Vegetation communities in this regional ecosystem include: 4.3.20x1: Mixed tussock grassland, including combinations of the species Aristida contorta, Eragrostis spp., Eulalia aurea, Astrebla spp., Aristida latifolia and Chrysopogon fallax. Emergent Eucalyptus coolabah and Acacia cambagei may occur. Occurs on highly active Quaternary alluvial plains of major watercourses. Reddish to pale sandy and loamy soils. Not a Wetland. (BVG1M: 31a). |
| Supplementary description | Mills (1980), A3; Neldner (1984), 68a, b, c, d; Wilson and Purdie (1990a), A1, A2, W1, W2 (83); Neldner (1991), 48; Turner et al. (1993), A3, C1 |
| Protected areas | Diamantina NP, Astrebla Downs NP, Lochern NP, Idalia NP, Bladensburg NP, Lark Quarry CP, Welford NP, Combo CP 1, Combo CP 2, Elizabeth Springs CP |
| Special values | 4.3.20: Potential habitat for threatened fauna species including plains-wanderer Pedionomus torquatus, fierce snake (western taipan) Oxyuranus microlepidotus and night parrot Pezoporus occidentalis. |
| 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 | 4.3.20: Highly modified floristic composition due to total grazing pressure. Scalding frequent (Mills, 1980). |
1 Estimated extent is from version 13.1 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.
