Succulent with herb

Long description

Saltpan communities with succulent and herbaceous plants (i.e. saltmarshes) including Suaeda australis, Sarcocornia quinqueflora subsp. quinqueflora, Suaeda arbusculoides, Sesuvium portulacastrum, Tecticornia spp. (e.g. Tecticornia indica subsp. julacea, Tecticornia indica subsp. leiostachya, Tecticornia australasica) and Salsola australis. These ecosystems may be associated with salt crusts, benthic microalgal (BMA) crusts, Sporobolus virginicus, sedges and sparse stunted mangroves such as Avicennia marina, Ceriops tagal and Aegialitis annulata. Occurs on supratidal flats with deep saline clay soils and is formed from Quaternary estuarine sediments. Occurs along the landward edge of the intertidal zone in a hypersaline environment that is only inundated by the highest spring tides. The maximum height of vegetation is usually only 10 to 30 centimetres.[9]

Special values

Important fisheries habitat providing for feeding, growth and reproduction[1]. Vegetated and non-vegetated saltpan ecosystems are used by a high number and diversity of fishes, many of economic importance, particularly in association with intertidal mangrove-lined creeks.[10]

Can provide habitat for the water mouse (Xeromys myoides). This species has been recorded from coastal saltmarsh ecosystems, including succulent shrublands, saline sedgelands and grasslands, mangroves and freshwater wetlands. Water mice are known to hunt amongst mangrove pneumatophores and in shallow pools, for grapsid crabs and other intertidal crustaceans, pulmonate snails and marine gastropods. These species are common in succulent and herbaceous saltmarsh ecosystems[11][3].

Potential feeding areas and roosting areas for shorebirds provided by the habitat include a complex of bare areas adjacent to mangroves. Different species feed and roost in different habitat units of the complex.

Many shorebirds and their ecosystems are listed under the Environment Protect and Biodiversity Conservation Act 1999 (EPBC).

Fiddler (e.g. Uca signata) and marsh crabs (scientific name) feed in these ecosystems following inundated by rainfall or tide, and shelter in burrows at other times.

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.[9]

Diagnostic Attributes

Inundation 'Intertidal – Lower 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 – Succulent

Qualifiers

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 fluctuate in extent over time and relevant qualifiers are Period and Trend. Changing tidal inundation due to sea level rise is causing mangroves to colonise the saltmarsh ecosystems (1, 2, 4)[6].

Invasion of mangrove into saltmarsh due to sea level rise.

Breaking the BMA mat or crust (e.g. motorbikes and 4WDs) can damage the ecology of the area and bring about erosion, and it may take a long time to restore.

Distribution

Saltmarshes occur discontinuously along the entire coastline of Queensland and represent more than a third of the total saltmarsh area in Australia. More than 32 saltmarsh species have been described in Queensland. Saltmarsh ecosystems are often narrower where rainfall is high or spread throughout the year, and broader in extent where rainfall is relatively low or where there is a severe dry season. Plant species diversity generally increases with increasing latitude (i.e. saltmarshes are more diverse in temperate systems than tropical systems) as opposed to mangroves, which are more diverse in tropical systems[8][4][7].

The upper (landward) limits of succulent ecosystems may not be easily delineated because communities may merge into, or form, complex patterns with more freshwater grass and/or sedge communities. This transitional zone (ecotone) is not necessarily static and more freshwater plants can invade succulents during wetter periods and the more salt-tolerant succulents may advance landward during drier times.[8]

Succulent ecosystems are able to tolerate high salinity, and temporary inundation from tides or, less often, from freshwater. This highly-specialised salt-tolerant vegetation has adapted to this harsh environment however it could become a weakness if tidal regimes shift (i.e. climate change), particularly in conjunction with coastal development and mangrove encroachment. That is, these succulent ecosystems could become squeezed out of the coastal zone[7].

Some of the largest saltmarshes in Queensland include:

• around the Gulf of Carpentaria in the Gulf Plains bioregion and extending into lower western Cape York
• the Fitzroy River delta and Broad Sound areas
• along the Brigalow Belt coastline between Townsville and Bowen.[8][7]

The following relates to distribution of this ecosystem type within the Central Queensland mapping area:

• Particularly important fisheries habitat from Round Hill Head to Tin Can Inlet, in term of productivity, includes the Kolan, Elliott, Burrum, Mary and Susan rivers, Baffle and Kauri creeks, Great Sandy Strait and Tin Can Inlet. The smaller Broadwater, Littabella and Beelbi creeks are also important in terms of habitat diversity and connectivity with the larger nearby systems (Baffle Creek, and the Kolan and Burrum rivers).[2]
• Port Curtis communities are typically dominated by Suaeda spp. and S. quinqueflora in association with S. virginicus,[5] whereas communities from Tin Can Inlet to Round Hill Head are typically dominated by Arthrocnemum spp., S. quinqueflora and Suavela sp. in association with S. virginicus [2]. Other saltmarsh species recorded in Port Curtis include the shrubs Diospyros ferrea var. geminate, Salsola kali, Enchylaena tomentosa, Halosarcia halocnemoides, Halosarcia inica var leiostachyum and Myoporum acuminatum; the grasses and herbs Aristida calycina, Limonium austral, Branchyscombe basaltica, Paspalidium gracile, Bulbostylis barbarta, Portulaca napiformis, Cyperus polyustachyos, Scirpus litoralis, Cyperus scariousus, Eleocharis geniculate, Spergularia media, Emilia sonchifolicacus, Spergularia rubra, Epaltes australis, Eragrostis elongate, Veronia cinerea, Fimbristylis ferruginea, Vittadinia triloba sens. Lat., Fimbristylis punctata; and the algae Anabaena torulosa, Lyngbya aesturii, Anacystis marina, Microcoleus lyngbyaceus, Calothrix crustacea, Oscillatoria nigro-viridis, Chroococcus turgidus, Phormidium angustissimum, Hormidium subtile and Thizoclonium capillare.
• Parts of these ecosystems have been converted to salt evaporation ponds in the Fitzroy River Delta.[9]
• In Bioregion 12, all saltmarsh ecosystems are EPBC-listed (i.e. grass-herb-sedge (1) and other saltmarsh ecosystem types (2, 3, 4 and 17) Curtis Island southward).

Comments

Other relevant attributes include Consolidation, Energy and Sediment texture as saltmarshes typically grow on unconsolidated muds and fine sediments in low energy environments.

Additional Information

• Saltmarsh wetlands - Wetland Management Profile
• Saltmarshes, seagrasses and algae - Queensland Department of Primary Industries
• Saltmarsh and saltflat areas - OzCoasts
• Field Guide to common saltmarsh plants of Queensland

References

1. ^ Beumer, J & Halliday, I (1994), Effects of Habitat Disturbance on Coastal Fisheries Resources of Tin Can Bay/Great Sandy Strait. Report to the Fisheries Research and Development Corporation.. [online], vol. FRDB No 91/41, Fisheries Services, Queensland Department of Primary Industries, Brisbane. Available at: https://catalogue.nla.gov.au/Record/2907027.
2. ^ a b Bruinsma, C & Danaher, K (2001), Queensland Coastal Wetland Resources: Round Hill Head to Tin Can Inlet.. [online], vol. QI99081, Department of Primary Industries, Queensland Government., Brisbane. Available at: http://era.daf.qld.gov.au/id/eprint/3545/.
3. ^ Department of the Environment and Resource Management (2010), National recovery plan for the water mouse (false water rat) Xeromys myoides - Report to the Department of the Environment, Water, Heritage and the Arts, Canberra, Brisbane, Queensland.
4. ^ Johns, L (2006), Field Guide to Common Saltmarsh Plants of Queensland, Department of Primary Industries and Fisheries, Brisbane.
5. ^ K. Danaher et al. (2005), Intertidal wetlands of Port Curtis. [online] Available at: https://www.researchgate.net/publication/242536512_Intertidal_wetlands_of_Port_Curtis.
6. ^ Lovelock, C & Ellison, J (2007), Vulnerability of mangroves and tidal wetlands of the Great Barrier Reef to climate change.
7. ^ a b c Melissa Dixon et al (21 October 2011), Saltmarsh habitats - Queensland's fisheries haven under threat of coastal squeeze. [Accessed 2 June 2019].
8. ^ a b c Queensland Government, Wetland Management Profile Saltmarsh Wetlands. [online] Available at: https://wetlandinfo.des.qld.gov.au/resources/static/pdf/resources/fact-sheets/profiles/p01719aa.pdf.
9. ^ a b c Queensland Herbarium & Environmental Protection Agency, B (2005), Regional Ecosystem Description Database (REDD). Version 5.0. [online], Environmental Protection Agency, Brisbane. Available at: https://apps.des.qld.gov.au/regional-ecosystems/.
10. ^ Thomas, B & Connolly, R (2001), 'Fish use of subtropical saltmarshes in Queensland, Australia: relationships with vegetation, water depth and distance onto the marsh', Marine Ecology Progress Series. [online], vol. 209, pp. 275-288. Available at: http://www.int-res.com/abstracts/meps/v209/p275-288/ [Accessed 22 May 2019].
11. ^ Van Dyck, S & Gynther, I (January 2003), Nesting strategies of the water mouse Xeromys myoides in southeast Queensland. [online] Available at: https://www.researchgate.net/publication/290249920_Nesting_strategies_of_the_Water_Mouse_Xeromys_myoides_in_southeast_Queensland.

Last updated: 11 July 2019