Regional ecosystem details for 8.3.12
| Regional ecosystem | 8.3.12 |
|---|---|
| Vegetation Management Act class | Endangered |
| Wetlands | Palustrine |
| Biodiversity status | Endangered |
| Subregion | 2 |
| Estimated extent1 | Pre-clearing 9000 ha; Remnant 2021 2000 ha |
| Short description | Imperata cylindrica and/or Sorghum nitidum forma aristatum and/or Ischaemum australe tussock grassland on alluvial and old marine plains |
| Structure code | Tussock Grassland |
| Description | Imperata cylindrica and/or Sorghum nitidum forma aristatum and/or Ischaemum australe closed tussock grassland to open tussock grassland. Other frequent to occasional associated species are Fimbristylis ferruginea, Eremochloa bimaculata, Centella asiatica, Cyperus flavidus, C. polystachyos, C. victoriensis, C. scariosus, Bothriochloa decipiens, Eriochloa procera, Diplachne fusca, Lobelia concolor, Flemingia lineata, Glycine tabacina and Lobelia concolor. The most common emergent is Pandanus cookii. Level alluvial or old marine plains (which no longer receive any tidal inundation, often on black cracking clays) of lowlands. Geology mapped variously as Qf, Qa and Qha (Quaternary sand, gravel, clay and silt: flood-out sheets, small fans, some colluvium, residual soil, active stream channels and low terraces). Palustrine. (BVG1M: 32a). |
| Supplementary description | Batianoff, Dillewaard and Franks (1997), Vegetation unit 9; Nexus Environmental Studies Pty Ltd (1998), 5b |
| Protected areas | Bakers Creek CP, Sandringham Bay CP |
| Special values | 8.3.12: The regional ecosystem was previously very extensive, and a large percentage has now been ploughed and drained (and planted with sugar cane), sown with pasture grasses, and/or invaded by weeds. A common misconception is that these areas were timbered pre-clearing (this misconception is exacerbated by some areas now supporting regrowth Melaleuca spp. Or Eucalyptus spp. Perhaps due to changes in drainage). How these areas remained treeless over long periods of time is not well understood but is likely to be a combination of soil and drainage properties, and frequency of burning. Habitat for the Red-cheeked Dunnart. |
| Fire management guidelines | SEASON: Burn types should be varied to include early winter burns, late winter burns and storm burns. INTENSITY: Low to moderate. INTERVAL: 3-4 years. INTERVAL_MIN: 3. INTERVAL_MAX: 4. STRATEGY: Aim to burn no more than 30% in any given year. ISSUES: Weed species including exotic pastures are typically present and fire management will need to consider making available suitable conditions for regeneration of native ground layers species. |
| Comments | 8.3.12: Large areas once existed on black cracking clays for which their species dominance is unknown (all areas now either planted with sugar cane or pasture grasses). These may have been dominated by Ischaemum spp. Large areas which are highly disturbed still remain on the Goorganga plains. Intact areas are restricted to eastern parts of the Goorganga plains and tiny remnants in the Mackay area. Threatened by extensive conversion to agricultural and pastoral lands and associated invasion by weeds, including pasture grasses. Some of the lower elevation grasslands are inundated by water for periods over the wet season and can be considered to be wetlands. There is only one other grassland RE on alluvium - 8.3.14, and this is distinguished by occurring in upland areas (rather than lowlands). Once widely distributed particularly in the Goorganga area, west of Mackay around Victoria Plains, and between Marian and Pleystowe. Now restricted to northern parts of the Goorganga plains and tiny remnants in the Mackay area. Remnants of this grassland in a relatively intact condition are very rare. Weeds and pasture species are now abundant in many remnants, and species which often dominate are *Cynodon dactylon, *Sporobolus jacquemontii, *Sporobolus natalensis, *Urochloa mutica, *Echinochloa polystachya. Near the edges of this community where it abuts estuarine ecosystems, species such as Fimbristylis ferruginea, Some small areas in far northern parts of the Goorganga Plain are very low in weed cover and dominated by the native Sorghum nitidum forma aristatum. |
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.
