MVG 21 – Other Grasslands, Herblands, Sedgelands and Rushlands

MVG 21 – Other Grasslands, Herblands, Sedgelands and Rushlands

NVIS Fact sheet MVG 21 – Other grasslands, herblands, sedgelands and rushlands Australia’s native vegetation is a rich and fundamental • communities and support a large range of species, partly element of our natural heritage. It binds and nourishes as a result of their geographical range, and variation in our ancient soils; shelters and sustains wildlife, protects soils and site conditions streams, wetlands, estuaries, and coastlines; and absorbs • include many plant species capable of vegetative carbon dioxide while emitting oxygen. The National reproduction by rhizomes, or stolons Vegetation Information System (NVIS) has been developed • can comprise associated species that may include and maintained by all Australian governments to provide perennial forbs or/and short-lived ephemeral plants that a national picture that captures and explains the broad proliferate after seasonal or cyclonic rains, to longer-term diversity of our native vegetation. perennials that rely on underground organs such This is part of a series of fact sheets which the Australian as rhizomes Government developed based on NVIS Version 4.2 data to • occur on a range of sites including intermittently provide detailed descriptions of the major vegetation groups inundated depressions, margins of perennial freshwater (MVGs) and other MVG types. The series is comprised of lagoons and brackish tidal or inland wetlands. Ferns tend a fact sheet for each of the 25 MVGs to inform their use by to dominate specific humid areas where the environment planners and policy makers. An additional eight MVGs are is less variable between seasons available outlining other MVG types. • have structurally distinctive features of landscape that provide a variety of habitats for faunal species For more information on these fact sheets, including its limitations and caveats related to its use, please see: • may be associated with an overstorey of scattered and ‘Introduction to the Major Vegetation Group (MVG) isolated trees fact sheets’. • has many structurally and compositionally simple communities, with a wide range of dominant species across different subgroups Overview • has widespread but locally restricted distribution. As Typically, vegetation areas classified under MVG 21 – Other such, many occurrences are not mapped individually on grasslands, herblands, sedgelands and rushlands: broadscale maps • are dominated by non-woody or herbaceous species • provide a variety of environments that are critical for such as grasses, sedges, ferns or a mixture of these. The many rare and endangered species sedgelands and rushlands are often referred to as wetland • some are fire-prone, others not. Turtle Lagoon, Blue Lake National Park, North Stradbroke Island, Qld (Photo: M. Fagg) SSD18U.0117 environment.gov.au Facts and figures Major Vegetation Group MVG 21 - Other grasslands, herblands, sedgelands and rushlands 38. Wet tussock grassland with herbs, sedges or rushes, herblands or ferns Major Vegetation Subgroups 41. Saline or brackish sedgelands or grasslands (number of NVIS descriptions) 63. Sedgelands, rushes or reeds 64. Other grasslands Sedgeland Rushland Forbland Typical NVIS structural formations Grassland Aquatic bed Fernland (The above formations can have a wide range of covers and heights) Number of IBRA regions 65 Most extensive in IBRA region Channel Country (Qld, SA, NT and NSW) (Est. pre-1750 and Present) Estimated pre-1750 extent (km2) 52 739 Present extent (km2) 49 630 Area protected (km2) 12 844 Namadgi National Park, ACT environment.gov.au Structure and physiognomy species of Alternanthera, Azolla, Eleocharis, Isoetopsis, Juncus, Mimulus, Myriophyllum, Marsilea, Nymphoides • Tussock or rhizomatous sedges, cord rushes, rushes, and Persicaria. Eragrostis australasica dominates simple reeds or grasses are the dominant growth form, typically communities on ephemeral clay pans. Aquatic forbs with a continuous canopy cover and less than two m tall. include species of Alisma, Azolla, Persicaria, Philydrum, • Often form mosaics of patches with largely Lemna and Spirodela, with species of Nelumbo, monospecific dominants. Nymphaea, Nymphoides and Utricularia characteristic of • Many of the dominant plant species have reduced leaves tropical floodplains. and photosynthetic cladodes. • Saline or brackish sedgelands are closely associated with • Ephemeral sedges and forbs may be abundant in coastal saltmarshes (within MVG 22), and often form ephemeral wetlands. fine-scale mosaics. These are dominated by relatively few species including Juncus kraussii, Baumea juncea, • Scattered shrubs or low trees may be present in Bolboschoenus caldwellii, Phragmites australis and some communities. Typha species. • Many plants have morphological or physiological • Sedgeland, rush or reed communities including Mires, traits to tolerate low soil oxygen availability, such as are dominated mostly by sclerophyllous species of aerenchymatous (large intercellular air spaces) stems and Cyperaceae and Restionaceae. Mires usually have roots, submerged or floating leaves, etc. a conspicuous sclerophyll shrub component that • Fire regimes may affect growth and in some instances distinguishes them from other communities within rapid shifts in floristic and structural components may MVG 21. Common genera of sedges (Cyperaceae) and occur in relation to these events. cord rushes (Restionaceae) include Chorizandra, Gahnia, Gymnoschoenus, Lepidosperma, Schoenus, Baloskion, Indicative flora Empodisma, Lepyrodia and, Leptocarpus. Characteristic sclerophyll shrubs include species of Bauera, Banksia, • Prominent plant families include Cyperaceae, Callistemon, Epacris, Leptospermum, Melaleuca, Sprengelia Restionaceae, Juncaceae, Poaceae, Typhaceae, and Xanthorrhoea. Forbs include species of Drosera, Hydrocharitaceae, Potamogetonaceae, Polygonaceae, Gonocarpus and Goodenia. Species of Sphagnum, Juncaginaceae, Marsileaceae, Lemnaceae and peat-forming mosses, may be prominent in some mires Nymphaeaceae. Species composition varies with in cooler climates. hydrological regime, nutrient status and salinity. • Often associated with an overstorey of scattered and Environment isolated trees (e.g. distribution of sedgelands in Western Australia is associated with Eucalyptus, Acacia and • Associated with locally moist conditions created by high Melaleuca species). Other associated species can vary rainfall, near-surface groundwater and seepage or run-on from the large range of short lived ephemeral plants from catchments. that proliferate after seasonal or cyclonic rains to longer • Typically in depressions, lowland floodplains or term perennials that rely on underground organs such as headwater valleys where flat slopes inhibit rapid run off. rhizomes. Although the range of species varies in their • Occur in a wide range of landscape types except steep time of flowering, each tends to flower en masse which mountainous terrain and desert sand dune fields. provided a colour feature in the landscape. • Alluvial substrates derived from a wide range of • Coastal and inland wetland communities include parent materials. mosaics of amphibious, emergent, floating and submerged aquatic vegetation with aquatic grasses • Although these communities are widespread and tend to prominent. Coastal genera include grass species be related to specific environmental and site conditions, Isachne, Ischaemum, Oryza, Paspalum, Pseudoraphis and they are generally localised in their extent. As such, Sporobolus and larger emergent graminoids of Baloskion, many are not mapped individually on broadscale maps Baumea, Carex, Cladium, Cyperus, Fimbristylis, Lepironia and may require finer scale mapping. Nevertheless they and Schoenoplectus. Inland species typically include a provide a variety of environments that are critical for range of forbs, grasses and graminoids such as Phragmites many rare and endangered species. australis, Typha domingensis, Ludwigia peploides and environment.gov.au Geography Great Dividing Range from the New England region on the New South Wales-Queensland border, south to the • Occur across Australia in locally moist conditions created central Victorian Highlands and throughout much of by high rainfall, near-surface groundwater and seepage or Tasmania. Mires occur in eastern Australia where mean run-on from catchments. annual rainfall exceeds 1000 mm. • Variable positions ranging from low-lying sites and The below image outlines the location of this MVG group floodplains to montane and exposed highlands in in Australia. semi-arid to temperate areas of Australia. Extent of communities is generally very restricted in area as a result of the controlling site factors e.g. Gahnia sedgelands Change in South Australia and Victoria. Others may occur more widely e.g. Gymnoschoenus button grass plains • Approximately six per cent (3 000 km2) of the estimated in Tasmania. pre-1750 extent cleared, accounting for 0.3 per cent of total clearing in Australia. • It is likely that many areas are unmapped and that the restricted and biodiverse nature of the wetland • Generally, many of these communities have persisted communities requires a finer scale of mapping. with time as they tend to occur on extreme sites. • Largest area occurs in Queensland (227 731 km2). • Altered hydrological conditions (through both natural and anthropogenic changes), particularly damming. • Wetland communities occur on coastal floodplains, lagoons and estuaries; and on inland watercourses • Clearing for agriculture, irrigated crops, pasture throughout Australia.

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