Regional ecosystem details for 2.4.1
| Regional ecosystem | 2.4.1 |
|---|---|
| Vegetation Management Act class | Least concern |
| Wetlands | Not a Wetland |
| Biodiversity status | No concern at present |
| Subregion | 2, 3, (8), (1.3), (7), (1), (1.2), (5), (1.4) |
| Estimated extent1 | Pre-clearing 918000 ha; Remnant 2021 915000 ha |
| Short description | Dichanthium spp., Eulalia aurea, Chrysopogon fallax and Themeda avenacea in mixed tussock grasslands on Tertiary clay plains |
| Structure code | Tussock Grassland |
| Description | Mixed perennial tussock grassland to closed tussock grassland, including combinations of the species Dichanthium spp., Eulalia aurea, Chrysopogon fallax, Themeda avenacea, Astrebla spp. and Aristida latifolia. Occasional species include Iseilema spp., Panicum decompositum and Sarga plumosum. Emergent Atalaya hemiglauca, Grevillea striata or Eucalyptus microtheca may occur. Occurs on broad, Tertiary clay plains. Brown cracking clay soils. Not a Wetland. (BVG1M: 30b). Vegetation communities in this regional ecosystem include: 2.4.1a: Mixed tussock grassland to closed tussock grassland, including combinations of the species Dichanthium spp., Astrebla spp., Aristida latifolia, Chrysopogon fallax and Iseilema spp. Occasional species include Panicum decompositum, Sarga plumosum, Ophiuros exaltatus and Flemingia pauciflora. Emergent Atalaya hemiglauca, Grevillea striata or Eucalyptus microtheca may occur. Occurs on broad, Tertiary clay plains (Armraynald Plains subregion). Brown cracking clay soils. Not a Wetland. (BVG1M: 30b). 2.4.1b: Eulalia aurea, Dichanthium spp. and Chrysopogon fallax tussock grassland. Occasional species include Aristida latifolia, Iseilema spp., Astrebla spp., Panicum decompositum and Ophiuros exaltatus. Emergent Atalaya hemiglauca may occur. Occurs on broad, Tertiary clay plains (Wondoola Plains subregion). Brown cracking clay soils. Not a Wetland. (BVG1M: 30b). 2.4.1c: Mixed tussock grassland, including combinations of the species Themeda avenacea, Chrysopogon fallax, Aristida latifolia, Dichanthium fecundum and Eulalia aurea. Occasional species include Panicum decompositum and 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). 2.4.1x1: Mixed perennial tussock grassland (with sedges), with combinations of the species Cyperus spp., Astrebla elymoides, Cenchrus basedowii, Panicum larcomianum and Dichanthium sericeum subsp. polystachyum. Other species include Marsilea hirsuta (after rainfall), Panicum decompositum var. decompositum and Brachyachne convergens. Emergent Excoecaria parvifolia may occur. Occurs on broad, Tertiary clay plains (Wondoola Plains subregion). Brown cracking clay soils. Not a Wetland. (BVG1M: 30b). |
| Protected areas | Lawn Hill (Gregory) RR, Boodjamulla (Lawn Hill) NP, Lawn Hill (Gregory River Base) RR, Lawn Hill (Creek) RR, Lawn Hill (Lilydale) RR |
| Special values | 2.4.1c: A proven impact structure in Geology of Queensland, 2013. (Ed: Peter A. Jell). |
| Fire management guidelines | SEASON: March to April, with occasional storm burns if woody weeds are a problem. INTENSITY: Low, occasionally moderate and high intensities. INTERVAL: 3-6 years south of latitudes below Karumba, 1-3 years to the north. INTERVAL_MIN: 1. INTERVAL_MAX: 6. STRATEGY: Commence burning early in dry season to break up continuity of fuel across the landscape. Mosaic burning across the landscape at varying frequency will create patches at varying stages of post-fire response. Burn with good soil moisture to promote regeneration. ISSUES: Retaining grasslands by preventing woody thickening may be an issue in some situations. A long absence of fire or low intensity fire too early in the season may lead to overabundant seedlings and saplings. Invasive and high biomass grasses (e.g., buffel, Para and grader grasses) may increase fire severity to the detriment of these ecosystems. |
| Comments | 2.4.1: May be invaded by exotic Vachellia spp. Subject to degradation from high total grazing pressure. 2.4.1a: Was previously mapped as 2.3.4x46a. May be invaded by exotic Vachellia spp. Subject to degradation from high total grazing pressure. 2.4.1b: Was previously mapped as 2.3.4x46c. Subject to degradation from high total grazing pressure. May be invaded by exotic Vachellia spp. and Calotropis sp. 2.4.1c: Contained within a rare geological formation. Was previously mapped as 2.3.4x46b. Potential threatening processes associated with mining on the rim of the crater. May be invaded by exotic Vachellia spp. and Calotropis spp. Subject to degradation from high total grazing pressure. 2.4.1x1: Was previously mapped as part of 2.3.4. Detailed data collected in this ecosystem suggests that perennial grasses make up the majority of the biomass. This means this ecosystem is a tussock grassland, despite Cyperus spp. being the most common species. Subject to degradation from high total grazing pressure. May be invaded by exotic Vachellia spp. and Calotropis sp. |
1 Estimated extent is from version 13.1 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.
