Regional ecosystem details for 2.3.4
| Regional ecosystem | 2.3.4 |
|---|---|
| Vegetation Management Act class | Least concern |
| Wetlands | Not a Wetland |
| Biodiversity status | No concern at present |
| Subregion | 3, 2, 8, (5), (4.5), (7), (1.3), (1), (1.4) |
| Estimated extent1 | Pre-clearing 290000 ha; Remnant 2021 289000 ha |
| Short description | Eulalia aurea, Panicum decompositum, Astrebla pectinata and Dichanthium spp. in mixed tussock grasslands on active Quaternary alluvial plains within Tertiary clay deposits |
| Structure code | Tussock Grassland |
| Description | Mixed perennial tussock grassland to closed tussock grassland, including combinations of the species Eulalia aurea, Panicum decompositum, Astrebla pectinata, Dichanthium spp., Sarga plumosum and Chrysopogon fallax. Occasional species include Cyperus sp., Ophiuros exaltatus and Eriachne triodioides. Emergent Atalaya hemiglauca may occur. Occurs on active Quaternary alluvial plains within broad, Tertiary clay deposits. Brown cracking clay soils, occasionally with gilgai. Not a Wetland. (BVG1M: 30a). Vegetation communities in this regional ecosystem include: 2.3.4x1a: [RE not in use]²: This vegetation community is now mapped as 2.3.4. Mixed tussock grassland, including combinations of the species Eulalia aurea, Panicum decompositum, Astrebla pectinata, Sarga plumosum, Chrysopogon fallax, Cyperus sp., Ophiuros exaltatus and Eriachne triodioides. Emergent Atalaya hemiglauca may occur. Occurs on Quaternary alluvial plains within broad Tertiary clay plains. Brown cracking clay soils, occasionally with gilgai. Not a Wetland. (BVG1M: 30a). 2.3.4x1b: [RE not in use]²: This vegetation community is now mapped as 2.3.67. Mixed tussock grassland, including combinations of the species Dinebra neesii, Panicum trachyrhachis, Dichanthium sericeum subsp. polystachyum, Oryza sp., Cyperus sp. and Astrebla spp. Small areas of Chenopodium auricomum dwarf shrubland may occur. Occurs in shallow depressions on broad Tertiary clay plains. Mottled brown cracking clay soils. Not a Wetland. (BVG1M: 30a). 2.3.4x46a: [RE not in use]²: This vegetation community is now mapped as 2.4.1a. Mixed tussock grassland, including combinations of the species Dichanthium spp., Chrysopogon fallax, Astrebla spp., Iseilema spp., Panicum decompositum, Aristida latifolia, Sarga plumosum and Flemingia pauciflora. Emergent Atalaya hemiglauca, Grevillea striata or Eucalyptus microtheca commonly occur. Small areas of Ophiuros exaltatus may occur. Occurs on broad Tertiary clay plains. Brown cracking clay soils. Not a Wetland. (BVG1M: 30b). 2.3.4x46b: [RE not in use]²: This vegetation community is now mapped as 2.4.1c. Mixed tussock grassland, including combinations of the species Themeda triandra, Chrysopogon fallax, Aristida latifolia, Dichanthium fecundum, Eulalia aurea, Panicum decompositum, Iseilema sp. Occurs on Tertiary clay plains associated with Lawn Hill impact structure. Yellow-brown cracking clay soils, commonly gravelly. Not a Wetland. (BVG1M: 30b). 2.3.4x46c: [RE not in use]²: This vegetation community is now mapped as 2.4.1b. Mixed tussock grassland, including combinations of the species Eulalia aurea, Dichanthium spp., Chrysopogon fallax, Aristida latifolia, Iseilema spp., Astrebla spp. Panicum decompositum and Ophiuros exaltatus. Emergent Atalaya hemiglauca may occur. Occurs on broad Tertiary clay plains. Brown cracking clay soils. Not a Wetland. (BVG1M: 30b). |
| Supplementary description | Christian et al. (1954), Balbarini; Neldner (1991), 45; Perry et al. (1964), Gregory, Balbarini, Georgina |
| Protected areas | Lawn Hill (Widdallion) RR |
| Special values | 2.3.4x46b: A proven impact structure in Geology of Queensland, 2013. (Ed: Peter A. Jell). |
| 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 | 2.3.4: Was previously partly mapped as 2.3.4.x1a. Subject to degradation from high total grazing pressure. Threatening processes associated with potential expansion of intensive agriculture in the area. 2.3.4x1a: Subject to degradation from high total grazing pressure. 2.3.4x1b: A rare vegetation comminity. Subject to degradation from high total grazing pressure. 2.3.4x46a: May be invaded by exotic Vachellia spp. Subject to degradation from high total grazing pressure. 2.3.4x46b: Contained within a rare geological formation. Potential threatening processes associated with mining on the rim of the crater. Subject to degradation from high total grazing pressure. 2.3.4x46c: May be invaded by exotic Vachellia spp. and Calotropis spp. Subject to degradation from high total grazing pressure. |
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.
