Regional ecosystem details for 11.2.4
| Regional ecosystem | 11.2.4 |
|---|---|
| Vegetation Management Act class | Of concern |
| Wetlands | Palustrine |
| Biodiversity status | Of concern |
| Subregion | 1, 14 |
| Estimated extent1 | Pre-clearing 30 ha; Remnant 2021 20 ha |
| Short description | Lagoons in coastal dune swales |
| Structure code | Bare |
| Description | Lagoons in coastal swales. May contain or be fringed by Melaleuca spp., including Melaleuca leucadendra, Melaleuca viridiflora or Melaleuca dealbata with Nauclea orientalis in places. Where trees are not prominent, there may be sedges such as Eleocharis spp., Fimbristylis spp., or Cyperus spp., grasses e.g. Leersia hexandra, Pseudoraphis spinescens, and forbs including Glinus oppositifolius, Dentella repens and Dichondra repens. Occurs in narrow swales associated with Quaternary coastal dunes and beaches. Associated soils are often pale to dark humic sands or grey clay loams underlying dune systems. Palustrine. (BVG1M: 34c). |
| Supplementary description | Forster and Barton (1995), Joskeleigh; Christian et al. (1953), Littoral; Cumming (2000), 27; |
| Protected areas | Magnetic Island NP, Magnetic Island CP 1, Magnetic Island CP 2, Horseshoe Bay Lagoon CP |
| Special values | 11.2.4: Provides wetland habitat for a flora and fauna. |
| Fire management guidelines | SEASON: As swamps dry out in the mid to late dry season. INTENSITY: Moderate to high (depending on weed presence). INTERVAL: Occasional fires (every 5 - 10 years) in the absence of weeds; every 3 - 5 years where there is abundant grass weeds, especially Para grass. INTERVAL_MIN: 3. INTERVAL_MAX: 10. STRATEGY: Burning regimes will depend on the species composition and hydrology of wetlands. Seasonal wetlands with native grasses and sedges can benefit from occasional dry season burning every 5 to 10 years. Wetlands smothered by exotic grasses can benefit from a series of frequent fires (every 2 to 4 years) that reduce the density of exotic grass thatch and promote native flora and fauna and re-establish hydrology. Post-fire herbicide is important for the management of exotic species. ISSUES: Native grasses (e.g. Leersia hexandra and Oryza meridionalis) and sedges (e.g. Eleocharis spp) are promoted by burning. Aquatic plants will have died back to bulbs or seeds by the time fire can carry through these wetlands. Fire, coupled with herbicide spraying, is important for managing exotic wetland plants, such as Olive Hymenachne and Para grass. Burning temporarily opens gaps within exotic grass patches, allowing native flora to establish and re-opening water channels. Native wetland flora and fauna should be promoted after burning, while exotic grasses are reduced in density. |
| Comments | 11.2.4: This RE always occurs within a beach dune landscape, either between two or more series of longitudinal dunes, or as a depression within a dune plain. It is always mappable at 1:100 000 scale, unlike the swale section of RE 11.2.5. Of very limited extent, probably less than 1000 ha in pre-clearing. Some areas have been invaded by annual weeds, such as *Solanum nodiflorum and *Heliotropium indicum. |
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.
