Regional ecosystem details for 4.4.1
| Regional ecosystem | 4.4.1 |
|---|---|
| Vegetation Management Act class | Least concern |
| Wetlands | Not a Wetland |
| Biodiversity status | No concern at present |
| Subregion | 2, 7, 3, (1), (1.1), (4), (1.3), (5), (1.2), (5.2), (5.5), (5.4), (5.3), (2.8), (5.1), (2.3) |
| Estimated extent1 | Pre-clearing 3106000 ha; Remnant 2021 3102000 ha |
| Short description | Astrebla pectinata +/- Aristida latifolia +/- Eulalia aurea grassland on Tertiary clays overlying limestone |
| Structure code | Tussock Grassland |
| Description | Astrebla pectinata tussock grassland to open tussock grassland, occasionally with Astrebla elymoides, Aristida latifolia, Eulalia aurea or Astrebla lappacea. Ephemeral grasses commonly occur, including Iseilema vaginiflorum, Dichanthium spp., Panicum spp. The forb diversity is high, and many species are ephemerals, which may also become seasonally abundant. Frequent species include Abutilon malvifolium, Sclerolaena glabra, S. lanicuspis, Calotis hispidula, Crotalaria dissitiflora, Euphorbia drummondii, Salsola australis, Sida fibulifera and Sida trichopoda. Other species including many from the Asteraceae, Brassicaceae, Chenopodiaceae, Convolvulaceae, Euphorbiaceae Fabaceae, Liliaceae, Malvaceae and Zygophyllaceae occur infrequently. Occurs extensively on flat plains formed from Tertiary clay deposits overlying limestone deposits. Soils generally red and brown, heavy cracking clays with surface stone present in some areas. Not a Wetland. (BVG1M: 30b). Vegetation communities in this regional ecosystem include: 4.4.1a: [RE not in use]²: This vegetation community is now mapped as 4.9.14x41. Aristida latifolia, Enneapogon polyphyllus open grassland sometimes wooded with scattered Atalaya hemiglauca and Ventilago viminalis. Gilgai depressions dominated by perennial grasses such as Bothriochloa ewartiana, Eulalia aurea and Astrebla spp. Occurs on level to gently undulating plains formed from Tertiary alluvium and parna. 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: 27a). 4.4.1b: Astrebla spp. grassland wooded with Vachellia sutherlandii. Occurs on fine textured Tertiary alluvium. Not a Wetland. (BVG1M: 30b). 4.4.1c: Astrebla pectinata, Aristida latifolia tussock grassland to open tussock grassland. Other species include Astrebla elymoides, Iseilema vaginiflorum, Sida fibulifera, Brachyachne convergens Dactyloctenium radulans and Dichanthium sericeum spp. humilius. A range of forbs occur, depending on seasonal conditions. Occurs on old alluvial plains in the north west of the bioregion. Soils predominately Very deep, neutral to very strongly alkaline, red, brown and grey-brown cracking clays with a crusted or self-mulching surface. Gypsum may be present at depth. Not a Wetland. (BVG1M: 30a). 4.4.1d: Astrebla pectinata tussock grassland, commonly with Eulalia aurea, Astrebla spp., Aristida latifolia, Iseilema spp., annual grasses and forbs. Emergent Atalaya hemiglauca, Acacia georginae, Acacia cambagei and Ventilago viminalis may occur. Occurs on broad, Tertiary clay plains, commonly overlying limestones. Occasionally overlain by Quaternary sand deposits. Cracking clay soils. Surface gravel lag may occur. Not a Wetland. (BVG1M: 30b). 4.4.1e: Astrebla pectinata tussock grassland, commonly with Eulalia aurea, Astrebla spp., Aristida latifolia, Iseilema spp. Emergent Atalaya hemiglauca and Acacia cambagei may occur. Occurs on old alluvial clay plains (early Pleistocene surface). Cracking clay soils. Not a Wetland. (BVG1M: 30b). 4.4.1f: Astrebla lappacea tussock grassland, commonly with Aristida latifolia, Iseilema spp., Astrebla spp.. Emergent Acacia cambagei and Acacia tephrina may occur. Occurs on Tertiary high-level clay alluvial deposits near the Thomson River. Commonly gravelly. Not a Wetland. (BVG1M: 30b). 4.4.1g: Astrebla lappacea tussock grassland, commonly with Astrebla spp. and Aristida latifolia. Occurs on flat to gently undulating clay deposits in the north-east of the bioregion. Not a Wetland. (BVG1M: 30b). 4.4.1x2: [RE not in use]²: This regional ecosystem is now mapped as 4.5.6x5. Low open woodland and woodland of Eucalyptus microtheca. Occurs around the edge of cracking clay plains, usually where there is a thin surface layer of sand. Not a Wetland. (BVG1M: 18c). 4.4.1x3: [RE not in use]²: This regional ecosystem is now mapped as 4.9.14x40. Acacia cambagei low woodland with a sparse tussock grass ground layer of Astrebla spp., Iseilema spp. and Eulalia aurea. Occurs on older alluvium; self-mulching clays. Not a Wetland. (BVG1M: 26a). 4.4.1x4: Seasonally variable mosaic of Astrebla pectinata +/- Astrebla spp. tussock grassland and sparse forbland. In tussock grassland dominated areas Astrebla pectinata (5-25% cover) predominates, In places, Astrebla lappacea and Astrebla elymoides may be codominant. Aristida latifolia and Iseilema vaginiflorum occur frequently and may be abundant in some areas. Other short lived grasses may be abundant in wet summers. 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 undulating plains formed on Cainozoic deposits. Soils deep, usually with a weak gilgai microrelief, stony surface, red cracking clays. Not a Wetland. (BVG1M: 30b). 4.4.1x4a: Mixed herbland to open herbland (seasonally variable), including combinations of the species Trianthema triquetra, Iseilema vaginiflorum, Sida fibulifera, Pycnosorus thompsonianus, Astrebla pectinata and Salsola australis. Other species include Frankenia serpyllifolia, Portulaca spp. and Dichanthium sericeum subsp. humilius. Occurs on undulating plains of wind-blown clay (parna) overlying Cretaceous mudstones. Red-brown clays with variable amounts of ironstone gravel in the profile. Not a Wetland. (BVG1M: 30b). 4.4.1x4b: Mixed open tussock grassland, including a combination of the species Astrebla spp., Aristida spp. and Enneapogon spp. Emergent Atalaya hemiglauca, Acacia cambagei and Ventilago viminalis may occur. Includes areas of ferruginous surface gravel. Rises with variable layer of Tertiary deposit over Cretaceous mudstones. Large amounts of ironstone gravel in the profile. Red-brown clays. Not a Wetland. (BVG1M: 30b). 4.4.1x5: Seasonably variable mosaic of Astrebla lappacea +/- Enneapogon spp. open grassland and sparse 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. Low to high amounts of ironstone gravel on the surface with traces throughout the profile. Soils derived from Cainozoic sediments (land zone 4). Not a Wetland. (BVG1M: 30b). 4.4.1x6: Astrebla spp. (predominantly A. elymoides), Aristida latifolia, Dichanthium spp., tussock grassland. Atalaya hemiglauca may occur as an emergent or in small patches. Occurs on undulating Tertiary clay plains (southern Wondoola Plain) overlying Cretaceous mudstones. Cracking clay soils, commonly with surface gravel lag. Not a Wetland. (BVG1M: 30b). 4.4.1x7: Astrebla lappacea tussock grassland. Emergent Acacia cambagei commonly occur. Occurs on gently undulating plains of wind-blown clay (parna) overlying Tertiary limestones/mudstones. Red powdery clays. Not a Wetland. (BVG1M: 30b). |
| Supplementary description | Wilson and Purdie (1990a), F2 (48, 55); Neldner (1991), 43a (88) |
| Protected areas | Astrebla Downs NP, Diamantina NP, Lochern NP, Wiliyan-ngurru NP, Lark Quarry CP, Elizabeth Springs CP |
| 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 | 4.4.1: Barkly Tableland. 4.4.1c: was 4.3.17a in version 7, changed to correct land zone in version. 4.4.1f: Barkly Tableland. 4.4.1g: Barkly Tableland. 4.4.1x2: Barkly Tableland. 4.4.1x4a: Was previously mapped predominantly as 4.9.5b. 4.4.1x4b: Was previously mapped as 4.9.5d. 4.4.1x5: Barkly Tableland. 4.4.1x7: Barkly Tableland. |
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.
