Regional ecosystem details for 4.5.6
| Regional ecosystem | 4.5.6 |
|---|---|
| Vegetation Management Act class | Least concern |
| Wetlands | Not a Wetland |
| Biodiversity status | No concern at present |
| Subregion | 2, 7, 1, 1.3, 5, 4, (1.1), (3), (6), (5.3), (5.2), (5.4) |
| Estimated extent1 | Pre-clearing 135000 ha; Remnant 2021 129000 ha |
| Short description | Acacia cambagei, Senna spp., Sida platycalyx tall open shrubland on Quaternary sand sheets |
| Structure code | Tall Open Shrubland |
| Description | Acacia cambagei tall open shrubland. A number of Senna spp. and Eremophila spp. are present, and form a distinct, open, low shrub layer (1-1.5m tall) in places. The ground layer is open and dominated by the forbs Sida platycalyx and Sclerolaena cornishiana, and tussock grasses Aristida holathera var. holathera and Eragrostis eriopoda. Occurs on Quaternary sand sheets. Associated soils are moderately deep to deep texture contrast soils and some earthy sands. Hard setting surfaces are common. Not a Wetland. (BVG1M: 26a). Vegetation communities in this regional ecosystem include: 4.5.6x1: Mixed low open woodland, with a combination of the species Atalaya hemiglauca, Corymbia terminalis, Acacia cambagei, Corymbia aparrerinja, Grevillea striata, Acacia cambagei, Eucalyptus leucophylla and Acacia aneura. The ground layer is patchy tussock grasses. Occurs on outwash plains and residual sand sheets, commonly overlying Tertiary clay deposits. Red-brown loamy soils, commonly with surface gravel lag. Not a Wetland. (BVG1M: 27b). 4.5.6x2: Acacia georginae and/or Acacia cambagei tall open shrubland to low open woodland, occasionally with Atalaya hemiglauca, Corymbia terminalis, Eucalyptus leucophylla and Grevillea striata. A shrub layer of Acacia georginae and/or Acacia cambagei may occur. The ground layer is sparse tussock grasses. Occurs on sandy and loamy Tertiary outwash and residual sand deposits. Red-brown loams and clay loams, commonly with surface gravel lag. Not a Wetland. (BVG1M: 26a). 4.5.6x2a: Acacia cambagei low open woodland, occasionally with Atalaya hemiglauca, Corymbia terminalis, Eucalyptus leucophylla and Grevillea striata. Acacia cambagei shrubs may occur. A shrub layer of Acacia georginae and/or Acacia cambagei may occur. The ground layer is sparse tussock grasses. Occurs on sandy and loamy Tertiary outwash deposits. Red-brown loamy soils, commonly with surface gravel lag. Not a Wetland. (BVG1M: 26a). 4.5.6x2b: Acacia georginae and/or Acacia cambagei tall open shrubland, occasionally with Atalaya hemiglauca and Corymbia terminalis. The ground layer is sparse tussock grasses. Occurs on Tertiary residual sand deposits, commonly dissected by current drainage lines. Red-brown loamy soils, commonly with surface gravel lag. Not a Wetland. (BVG1M: 26a). 4.5.6x2c: Acacia georginae and/or Acacia cambagei tall open shrubland, occasionally with Atalaya hemiglauca and Corymbia terminalis. A shrub layer of Acacia georginae and/or Acacia cambagei may occur. The ground layer is sparse tussock grasses. Occurs on broad, Tertiary sand sheets, commonly at the margins of erosional surfaces and clay plains. Red-brown loamy soils, commonly with surface gravel lag. Not a Wetland. (BVG1M: 26a). 4.5.6x2d: Acacia cambagei tall open shrubland. Isolated A. cambagei shrubs may occur. A variable ground layer occurs, including Astrebla pectinata and annual grasses. Occurs on gravelly residuals formed from deeply weathered sandstone deposits. Ferruginous gravel and cobble lad commonly occurs. Not a Wetland. (BVG1M: 26a). 4.5.6x4: Acacia cambagei low open woodland to low woodland, occasionally with A. aneura. A. cambagei shrubs may occur. The ground layer is commonly sparse, annual tussock grasses. Occurs on Quaternary sand sheets formed from outwash around the Winton Plateau (CHC). Red loamy soils with gravel lag on the surface. Not a Wetland. (BVG1M: 26a). 4.5.6x5: Eucalyptus microtheca low open woodland. The ground layer is perennial tussock grasses. Occurs on sandy outwash deposits overlying Tertiary clay plains. Not a Wetland. (BVG1M: 18c). |
| Supplementary description | Mills (1980), S5 (93); Neldner (1991), 26c (25); Turner et al. (1978), S1 (86); Purdie and Wilson (1990), LU 73 |
| Protected areas | Bladensburg NP, Wiliyan-ngurru NP |
| Fire management guidelines | SEASON: Wet to early dry season when soil is moist. INTENSITY: Low. INTERVAL: Broad interval range of 6-10 years for open acacia with grassy understorey. INTERVAL_MIN: 6. INTERVAL_MAX: 10. STRATEGY: Patchy, within the 20-30% range of area burnt. ISSUES: Acacias (e.g., gidgee) germinate infrequently following high rainfall events, mature slowly and are long-lived. Acacias are vulnerable to frequent and high-severity fires. Fire in surrounding fire-adapted communities can be used to mitigate against wildfire. Fuel loads within Acacia communities can sometimes also require infrequent patchy burns, particularly following years of good rain, to protect them from wildfire and promote diversity at the ground layer. Long absence of fire can result in canopy closure by Acacias and lead to self-protection of these communities. Introduced invasive grasses (e.g., buffel Cenchrus ciliaris) may increase the risk and severity of fires. |
| Comments | 4.5.6: Occurs east of about 139o longitude. 4.5.6x2d: Occurs east of about 139o longitude. 4.5.6x4: Occurs east of about 139o longitude. 4.5.6x5: Was previously mapped as 4.4.1x2. 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.
