Regional ecosystem details for 4.7.4
| Regional ecosystem | 4.7.4 |
|---|---|
| Vegetation Management Act class | Least concern |
| Wetlands | Not a Wetland |
| Biodiversity status | No concern at present |
| Subregion | 3, 5, 2, 4, (1.3), (6), (5.5), (10.1), (7), (5.4), (2.8), (9.5) |
| Estimated extent1 | Pre-clearing 334000 ha; Remnant 2021 323000 ha |
| Short description | Acacia cambagei tall open shrubland with Triodia spp. +/- Senna spp. near eroding edges of Tertiary plateaus |
| Structure code | Tall Open Shrubland |
| Description | Acacia cambagei tall open shrubland to woodland, with scattered Capparis anomala shrubs present frequently and Senna artemisioides subsp. Oligophylla and/or S. phyllodinea shrubs locally prominent. Scattered Cassia spp., Eremophila spp. And Hemichroa mesembryanthema shrubs occurs infrequently. The ground stratum is sparse to open and usually dominated by Triodia brizoides, T. longiceps, or in some areas T. pungens. The perennial grass Enteropogon acicularis and short-lived Dactyloctenium radulans and Enneapogon polyphyllus occur frequently, while Aristida latifolia may be locally common. A variety of other ephemeral grasses, including Enneapogon spp. And Sporobolus spp., and forbs, including many species from the Chenopodiaceae, occur infrequently but maybe seasonally important. Occurs on lower slopes of scarp retreat zones formed from lateritised Cretaceous mudstones with a dense surface ironstone or lateritic gravel cover derived from weathered Tertiary land surface. Soils mainly very shallow to shallow, stony red clays with minor desert loams. Lithosols occurs adjacent to the scarp minor cracking clays occurs lower in the landscape. Ironstone and lateritic gravel occur throughout the profile and on the surface. Surfaces are usually crusty. Not a Wetland. (BVG1M: 26a). Vegetation communities in this regional ecosystem include: 4.7.4a: Acacia cambagei low woodland, occasionally with A. aneura. A. cambagei shrubs commonly occur. The ground layer is sparse, with Triodia spp. and tussock grasses. Occurs around the margins of Tertiary lateritic plateaus of deeply weathered Cretaceous mudstones. Skeletal soils. Not a Wetland. (BVG1M: 26a). 4.7.4b: Acacia cambagei and/or A. georginae tall open shrubland to low open woodland, occasionally with A. aneura. A. cambagei and/or A. georginae may occur as shrubs. The ground layer is commonly Triodia spp. Occurs around the margins of Tertiary lateritic surfaces of deeply weathered Cambrian shales. Skeletal soils. Not a Wetland. (BVG1M: 26a). 4.7.4c: Mixed low open woodland, including combinations of the species A. cambagei, A. shirleyi and A. cyperophylla. The ground layer is dominated by Triodia spp. Occurs on rises and breakaways on deeply weathered Cretaceous siltstones and mudstones. Not a Wetland. (BVG1M: 26a). 4.7.4d: Acacia cambagei low open woodland. The ground layer is mostly bare with sparse tussock grasses. Occurs on broken siliceous and chalcedony residuals of deeply weathered Tertiary lacustrine mudstone and limestone (Old Cork Beds). Not a Wetland. (BVG1M: 26a). 4.7.4e: Acacia cambagei woodland, occasionally with Flindersia maculosa, Atalaya hemiglauca, Acacia shirleyi and Archidendropsis basaltica. Acacia cambagei shrubs may occur. The ground layer is sparse tussock grasses and forbs. Occurs on eroding margins of lateritic plateaus in the north-east of the bioregion (often adjacent the Desert Uplands). Not a Wetland. (BVG1M: 26a). |
| Supplementary description | Neldner (1991), 8a (19); Turner et al. (1993), T1; Wilson and Purdie (1990a), T1 (LU 36) |
| Protected areas | Diamantina NP, Bladensburg NP |
| Special values | 4.7.4: Potential habitat for NCA listed species: Eremophila tetraptera. |
| 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 | 4.7.4: Some clearing is occurring. 4.7.4c: Some clearing is occurring. 4.7.4d: Some clearing is occurring. 4.7.4e: Some clearing is occurring. |
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.
