Regional ecosystem details for 4.3.8
| Regional ecosystem | 4.3.8 |
|---|---|
| Vegetation Management Act class | Least concern |
| Wetlands | Not a Wetland |
| Biodiversity status | No concern at present |
| Subregion | 3, 2, 4, 5, (7), (1.3), (1.1), (5.4), (1), (5.5), (5.2), (2.3), (10.4), (6.9), (1.2), (10.1), (6.6), (10.2) |
| Estimated extent1 | Pre-clearing 221000 ha; Remnant 2021 215000 ha |
| Short description | Acacia cambagei low woodland on braided channels in dissected landscapes |
| Structure code | Low Woodland |
| Description | Acacia cambagei low woodland to low open forest, occasionally with Eucalyptus coolabah. A shrub layer may occur, typically dominated by A. cambagei. The ground layer is dominated by tussock grasses, including Astrebla spp., Eulalia aurea, Chrysopogon fallax and Sporobolus mitchellii, Cyperus bifax and C. victoriensis. A large number of mostly ephemerals forbs occur infrequently, including Abutilon spp., Atriplex spp., Sclerolaena spp., Calotis spp., Neptunia spp., Sida spp. Occurs on fringes of braided channels, commonly in eroding, dissected lateritised landscapes. Very deep, crusted, red, brown and grey cracking clays with minor crusted non-cracking red clays. Gravel may occur in the profile and gypsum usually occurs at depth. Not a Wetland. (BVG1M: 26a). Vegetation communities in this regional ecosystem include: 4.3.8a: Acacia cambagei, Astrebla spp. low woodland. Occurs on fringes of minor braided channels in broad clay landscapes. Cracking clay soils. Not a Wetland. (BVG1M: 26a). 4.3.8b: Acacia cambagei, Astrebla spp. low open woodland. Occurs on fringes of minor braided channels in broad clay landscapes. Cracking clay soils. Not a Wetland. (BVG1M: 26a). 4.3.8c: Acacia cambagei, Astrebla spp. low woodland in shallow drainage depressions with no distinct channel. Occurs on fringes of minor braided channels in broad clay landscapes. Cracking clay soils. Not a Wetland. (BVG1M: 26a). 4.3.8d: Low woodland of Acacia cambagei 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). 4.3.8e: Acacia cambagei low woodland to low open forest, occasionally with Eucalyptus coolabah, Atalaya hemiglauca. A shrub layer, dominated by Acacia cambagei, may occur. The ground layer is tussock grasses, commonly Astrebla spp. Occurs on fringes of minor braided channels in broad clay landscapes. Cracking clay soils. Riverine. (BVG1M: 26a). 4.3.8f: Acacia georginae and/or Acacia cambagei low open woodland, occasionally with Eucalyptus coolabah. A lower shrub layer of Acacia georginae and/or Acacia cambagei commonly occurs. The ground layer is patchy tussock grasses. Occurs on fringes of narrow channels, commonly dissecting sandy outwash deposits around the Northwest Highlands bioregional boundary. Gravelly clays and loams. Riverine. (BVG1M: 26a). |
| Supplementary description | Neldner (1991), 5b, 7, 26b (16); Turner et al. (1993), W3 (26); Wilson and Purdie (1990a), W2 (72) |
| Protected areas | Diamantina NP, Bladensburg NP, Lochern NP, Idalia NP, Wiliyan-ngurru NP, Lark Quarry CP, Welford NP, Elizabeth Springs CP |
| Special values | 4.3.8: High fauna diversity compared to surrounding grasslands. |
| 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 | 4.3.8: Currently subject to clearing in some flatter alluvial areas. Ground layer substantially modified by total grazing pressure. In many areas 10-15% of the A. cambagei trees stand dead. Some areas associated with increased woody cover between 1951 and 1994 (Fensham and Fairfax, 2004).Tree heights 7-11m in wetter situations. 4.3.8b: Currently subject to clearing in some flatter alluvial areas. Ground layer substantially modified by total grazing pressure. In most areas, 10-15% of the A. cambagei trees stand dead. |
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.
