Tidal grasslands typically dominated by Sporobolus virginicus.
Disclaimer: Ecosystem type descriptions are based on biophysical attributes identified in Central Queensland through expert advice and supported by scientific literature. Not all ecosystem types are mapped based on current inventory, and many of the ecosystems described here may also occur in other parts of Queensland.
Sporobolus virginicus open tussock grassland to closed tussock grassland, with occasional emergent mangroves (usually Avicennia marina or Ceriops australis), Melaleuca spp., Acacia spp. and Clerodendrum inerme. Can also include Paspalum vaginatum, Fimbristylis ferruginea, Cyperus victoriensis and Cyperus scariosus, together with Eleocharis spiralis, Mnesithea rottboellioides, Marsilea mutica, Vincetoxicum carnosum, Ischaemum australe, Cyperus polystachyos, Ceratopteris thalictroides, Diplachne fusca, Suaeda australis, Suaeda arbusculoides, Sarcocornia quinqueflora subsp. quinqueflora and Tecticornia australasica.
Occurs on supratidal flats adjacent to mangroves and saltpans but on slightly more elevated substrate. Often only inundated by highest spring tides and dissected by small tidal channels. Typically forms a narrow belt between mangroves and alluvial communities, but can be extensive where there are large areas of low-lying sediments. Often the most landward tidally influenced habitat (i.e. upper boundary of tidal influence) and the presence of S. virginicus can be a good indicator of tidal inundation and used to delineate upper tidal limit.
A variant of this ecosystem type that includes Aegicaras mangroves may be present in riverine channels - see Distribution.
Sporobolus virginicus grasslands may accumulate land through self-made detritus that builds up to elevate the level of the substrate. Stabilises intertidal area and creek banks and can trap terrestrial run-off/sediment.
Can provide habitat for the water mouse (Xeromys myoides). This species has been recorded in coastal saltmarsh ecosystems including saline grasslands, together with saline sedgelands, succulent shrublands, mangroves and freshwater wetlands.
Vegetated saltpan areas are generally inundated by the tide less frequently than mangroves, and these systems are under threat from sea level rise along seaward margins.
Sporobolus grasslands provide important fisheries habitat.
Inundation ‘Intertidal – Lower low’, ‘Intertidal – Mid low’, ‘Intertidal – Upper low’, ‘Intertidal – Low undifferentiated’, ‘Intertidal – Lower medium’, ‘Intertidal – Upper-medium’, ‘Intertidal – Medium undifferentiated’, ‘Intertidal – High’, ‘Intertidal – Undifferentiated’, ‘Intertidal – High undifferentiated’ although they occur closer to the higher tidal planes which remain unmapped
Structural macrobiota 'Grass'
The Naturalness qualifier is relevant as tidal inundation may sometimes be modified by barriers, and excavated channels, modifying Inundation and Terrain morphology. Changes in tidal inundation will be reflected by changes in Structural macrobiota.
These ecosystems may fluctuate in extent over time and the relevant qualifiers are Period and Trend. Changing tidal inundation due to sea level rise is causing mangroves to colonise the saltmarsh ecosystems (list their numbers).
Saline grasslands occur throughout Queensland towards Highest Astronomical Tide, in association with sedgelands and saltpan.
The following relates to distribution of this ecosystem type within the Central Queensland mapping area:
Last updated: 12 July 2019
This page should be cited as:
Department of Environment and Science, Queensland (2019) Grass, WetlandInfo website, accessed 13 April 2023. Available at: https://wetlandinfo.des.qld.gov.au/wetlands/ecology/aquatic-ecosystems-natural/estuarine-marine/descriptions/2/