Regional ecosystem details for 7.3.1
| Regional ecosystem | 7.3.1 |
|---|---|
| Vegetation Management Act class | Endangered |
| Wetlands | Palustrine |
| Biodiversity status | Endangered |
| Subregion | 1, 3, (2), (8) |
| Estimated extent1 | Pre-clearing 14000 ha; Remnant 2021 1000 ha |
| Short description | Hemarthria uncinata and/or Ischaemum australe +/- Sorghum spp. grassland and/or ephemeral sedgelands on seasonally inundated alluvial plains |
| Structure code | Tussock Grassland |
| Description | Hemarthria uncinata (matgrass) and/or Ischaemum australe (bluegrass) +/- Sorghum spp. grassland, and/or ephemeral sedgelands. Occurs on seasonally inundated coastal plains on humic gley, acid peat and gleyed podzolic alluvial soils. Palustrine. (BVG1M: 34c). Vegetation communities in this regional ecosystem include: 7.3.1a: Hemarthria uncinata and/or Ischaemum australe var. arundinaceum closed grassland. Seasonally inundated lowland alluvial plains. Palustrine. (BVG1M: 34c). 7.3.1b: Ischaemum spp., Imperata cylindrica +/- Sorghum spp. grassland. Hard-setting, poorly drained alluvial soils. Palustrine. (BVG1M: 34c). 7.3.1c: Ephemeral freshwater swamp dominated by sedges. Drainage depressions of coastal floodplains. Palustrine. (BVG1M: 34c). |
| Supplementary description | Stanton and Stanton (2005), A82, A62, A279; Kemp and Morgan (1999), 14, 15; Kemp et al. (1999), 13, 14; Tracey and Webb (1975), 23a (part) |
| Protected areas | Eubenangee Swamp NP, Girringun NP, Orpheus Island NP |
| Special values | 7.3.1: Habitat for threatened flora including Fimbristylis adjuncta. Remnants of a once extensive lowlands ecosystem in Australia, of which only 0.5% is considered to remain (Kirkpatrick et al., 1995). Eubenangee swamp examples are in excellent condition due to a National Parks management regime over the last few decades which has involved persistent and rigorous weed removal and prevention of new weed invasions. This is an outstanding example of weed management resulting in a show-case remnant of coastal lowlands grassland in good condition. This management is largely due to the efforts of motivated individuals within QPWS. It requires constant vigilance, for which the resources are usually scarce, hence the park is under severe threat due to possible future lapses in maintenance. |
| Fire management guidelines | SEASON: Aug-Dec. c: Early (June-Sep) to late (Oct-Dec) dry season. INTENSITY: Moderate, sometimes high. c: Moderate. INTERVAL: 3-5 years. INTERVAL_MIN: 3. INTERVAL_MAX: 5. STRATEGY: Apply mosaic burning at a range of frequencies to create patches of varying post-fire age. Burn at least 25% of these communities over the WET in any year. c: Burn 25-30%; variation in topography and moisture will create a mosaic. ISSUES: Grasslands and sedgelands have different fire regimes, but since they are frequently contiguous application of regimes can be difficult. Favourable conditions for burning native grasslands are rare, so opportunities should be taken when they arise. c: Opportunities to burn sedgelands are rare. High biomass grasses may increase fire intensity. Dense regeneration of melaleuca may require a subsequent fire. |
| Comments | 7.3.1: Formerly extensive on the Herbert River floodplain. This regional ecosystem includes areas of modified natural grassland in very poor condition, dominated by *Cynodon dactylon (couch), and introduced species such as *Mimosa pudica (sensitive weed) and *Chrysopogon aciculatus (Mackie's pest). The pre-European species composition of these areas are unknown, but are suspected to have been Ischaemum spp. and various herbs. This regional ecosystem is highly susceptible to weed invasion and species changes, due to hydrological changes and grazing pressure. Very sparsely distributed across most parts of the coastal lowlands (once much more common), now predominantly the Herbert and Innisfail subregions. What remains of this almost extinct ecosystem is highly modified, with the notable exception being those examples within Eubenangee Swamp NP, which remain in excellent condition. Most of the other remnants are dominated by *Cynodon dactylon (couch) which is currently considered to be introduced to Queensland. Other weeds of major concern include Mimosa pudica (sensitive weed), Chrysopogon aciculatus (Mackie's pest), Sporobolus natalensis (rat's-tail grass) and Psidium guajava (guava). 7.3.1a: This regional ecosystem is highly susceptible to weed invasion and species changes, due to hydrological changes and grazing pressure. What remains of this almost extinct ecosystem is highly modified, with the notable exception being those examples within Eubenangee Swamp NP, which remain in excellent condition. Central coastal parts of the bioregion, predominantly the Herbert and Innisfail subregions. Weeds of major concern in include Hymenachne amplexicaulis, some of those pasture grasses etc. 7.3.1b: Possible former dominants (judging from low-density natives remaining) include Ischaemum spp., Imperata cylindrica, and Sorghum spp. This regional ecosystem should possibly be merged with 7.3.1a. Herbert River floodplain. The ecosystem is now almost entirely dominated by *Cynodon dactylon which is currently considered to be an introduced species. The ecosystem is highly modified by cattle and horse grazing, with all remnants in poor condition. The true pre-European species composition is not known. |
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.
