Regional ecosystem details for 4.9.5
| Regional ecosystem | 4.9.5 |
|---|---|
| Vegetation Management Act class | Least concern |
| Wetlands | Not a Wetland |
| Biodiversity status | No concern at present |
| Subregion | 5, 3, (6), (5.4), (9.5) |
| Estimated extent1 | Pre-clearing 105000 ha; Remnant 2021 105000 ha |
| Short description | Seasonally variable mosaic of Astrebla lappacea +/- Enneapogon spp. open tussock grassland and sparse to open forbland on Cretaceous sediments |
| Structure code | Open Tussock Grassland |
| Description | Seasonably variable mosaic of Astrebla lappacea +/- Enneapogon spp. open tussock grassland to open forbland. In grassland dominated areas Astrebla lappacea predominates with short grasses and forbs codominant in favourable seasonal conditions. Astrebla elymoides is often present as scattered tussocks, while the ephemeral grasses Iseilema vaginiflorum and Enneapogon avenaceus are abundant after summer rainfall. Ephemeral forbs are abundant after winter rainfall. Astrebla pectinata predominates after several dry years, while Astrebla lappacea and Dichanthium spp. increase in wetter years. Areas dominated by sparse forbland are floristically variable depending on seasonal conditions and local environment and often include Salsola australis, Atriplex spp., Frankenia spp., Sclerolaena spp. and less frequently Maireana spp. Occurs on flat to gently undulating plains. Soils shallow to moderately deep, fertile, red and brown cracking clays. Small to moderate amounts of ironstone gravel on the surface with traces throughout the profile. Soils derived from fresh Cretaceous sediments (land zone 9). Not a Wetland. (BVG1M: 30b). Vegetation communities in this regional ecosystem include: 4.9.5a: Aristida contorta usually predominates forming an open to sparse tussock grassland. Other short grasses such as Oxychloris scariosa, Enneapogon avenaceus and Sporobolus actinocladus may be codominant. Ephemeral grasses such as Brachyachne prostrata, Eriachne pulchella and Tripogon loliiformis occur frequently, while the perennial Aristida latifolia and Eragrostis xerophila may be locally common. Ephemeral forbs such as Gnephosis arachnoidea, Rhodanthe floribunda, Maireana dichoptera and Sclerolaena lanicuspis may predominate after winter rain. Sparsely scattered shrubs may occur in places. Ground cover always sparse, varies with amount of stone cover and seasonal conditions. Short grasses build up after wet summers, while forbs common after winter rainfall. Occurs on level to gently undulating plains formed from fine grained sediments. 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). 4.9.5b: Astrebla pectinata tussock grassland to open tussock grassland. Associated species include Iseilema vaginiflorum and Sporobolus australasicus. Occurs on undulating plains derived from Cretaceous mudstones, commonly with a shallow covering of Tertiary material. Brown and red cracking clays with surface ironstone gravel. Not a Wetland. (BVG1M: 30b). 4.9.5d: [RE not in use]²: This vegetation community is now mapped as 4.4.1x4b. Astrebla spp., Aristida spp., Enneapogon spp. tussock grassland, wooded with Atalaya hemiglauca +/- Ventilago viminalis. Occurs on rises with variable layer of Tertiary deposit over mudstone. Large amounts of ironstone gravel in the profile. Red-brown clays. Not a Wetland. (BVG1M: 30b). |
| Supplementary description | Neldner (1991), 47b, 47a (84); Wilson and Purdie (1990a), F2 (48, 59) |
| Special values | 4.9.5: Potential habitat for NCA listed species: Sclerolaena blakei. |
| 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 | 4.9.5: In overgrazed areas, around watering points, ephemeral grasses such as Dactyloctenium radulans and Iseilema vaginiflorum, and ephemeral forbs predominate. Floristic composition varies with seasonal conditions and land use. 4.9.5b: In overgrazed areas, around watering points, ephemeral grasses such as Dactyloctenium radulans and Iseilema vaginiflorum, and ephemeral forbs predominate. Floristic composition varies with seasonal conditions and land use. 4.9.5d: In overgrazed areas, around watering points, ephemeral grasses such as Dactyloctenium radulans and Iseilema vaginiflorum, and ephemeral forbs predominate. Floristic composition varies with seasonal conditions and land use. |
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.
2 Superseded: Revision of the regional ecosystem classification removed this regional ecosystem code from use. It is included in the regional ecosystem description database because the RE code may appear in older versions of RE mapping and the Vegetation Management regulation.
