Regional ecosystem details for 4.9.1
| Regional ecosystem | 4.9.1 |
|---|---|
| Vegetation Management Act class | Least concern |
| Wetlands | Not a Wetland |
| Biodiversity status | No concern at present |
| Subregion | 5, (6), (4), (2.5), (3), (2.3), (9.5), (10.1), (2.8), (5.4) |
| Estimated extent1 | Pre-clearing 4841000 ha; Remnant 2021 4823000 ha |
| Short description | Astrebla lappacea +/- Aristida latifolia +/- Panicum decompositum tussock grassland on Cretaceous sediments |
| Structure code | Tussock Grassland |
| Description | Astrebla lappacea tussock grassland, commonly with Aristida latifolia and Panicum decompositum. Sparsely scattered low shrubs and low trees may occur. Short-lived grasses such as Iseilema spp. and Dichanthium spp. and ephemeral forbs vary in abundance with seasonal conditions. Winter rain favours the forbs, while summer rainfall promotes the growth of grasses. Occurs on flat to gently undulating plains formed from fine grained Cretaceous sediments. Soils generally moderately deep to deep grey, brown and red cracking clays with self-mulching surface of high fertility. Not a Wetland. (BVG1M: 30b). Vegetation communities in this regional ecosystem include: 4.9.1a: Astrebla lappacea tussock grassland to closed tussock grassland, commonly with Aristida latifolia and Iseilema vaginiflorum. Emergent Atalaya hemiglauca and Ventilago viminalis may occur. Occurs on undulating plains formed from Cretaceous mudstones. Associated soils are generally shallow to deep, red clays and minor texture contrast soils with moderate to abundant amounts of ironstone and lateritic or siliceous gravel on the surface. Not a Wetland. (BVG1M: 30b). 4.9.1b: Aristida spp., Enneapogon spp. tussock grassland wooded with Atalaya hemiglauca +/- Ventilago viminalis. Occurs on shallow low rises, limestone ridges on flat/gently undulating clay plains. Not a Wetland. (BVG1M: 30b). 4.9.1c: Astrebla spp., Iseilema spp. tussock grassland, commonly with Panicum decompositum, Dichanthium spp., Eulalia aurea, Chrysopogon fallax, Sarga plumosum. Emergent Atalaya hemiglauca commonly occur. Occurs on level to gently undulating downs derived from Cretaceous mudstones (predominantly Allaru Mudstone) in the north of the bioregion. Not a Wetland. (BVG1M: 30b). |
| Supplementary description | Mills (1980), F2-F7; Neldner (1991), 42a; Turner et al. (1993), F1, F3, F6, F7, F8; Wilson and Purdie (1990a), F1 |
| Protected areas | Bladensburg NP, Combo CP 2 |
| Special values | 4.9.1: Potential habitat for endemic fauna species including Spencer's goanna Varanus spenceri, and threatened fauna species including Julia Creek dunnart Sminthopsis douglasi, Collett's snake Pseudechis colletti and skink Ctenotus schevilli. 4.9.1b: Potential habitat for endemic fauna species including Spencer's goanna Varanus spenceri, and threatened fauna species including Julia Creek dunnart Sminthopsis douglasi, Collett's snake Pseudechis colletti and skink Ctenotus schevilli. 4.9.1c: Potential habitat for endemic fauna species including Spencer's goanna Varanus spenceri, and threatened fauna species including Julia Creek dunnart Sminthopsis douglasi, Collett's snake Pseudechis colletti and skink Ctenotus schevilli. |
| 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 | 4.9.1: Abundance of Aristida latifolia increases in heavily grazed and degraded areas. The exotic low tree *Vachellia nilotica (2-5m tall) forms tall open shrublands in some areas in north-east, particularly where cattle grazing has occurred for years. 4.9.1b: Abundance of Aristida latifolia increases in heavily grazed and degraded areas. The exotic low tree *Vachellia nilotica (2-5m tall) forms tall open shrublands in some areas in north-east, particularly where cattle grazing has occurred for years. 4.9.1c: Abundance of Aristida latifolia increases in heavily grazed and degraded areas. The exotic low tree *Vachellia nilotica (2-5m tall) forms tall open shrublands in some areas in north-east, particularly where cattle grazing has occurred for years. |
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.
