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COASTAL UPLAND SWAMPS IN THE SYDNEY BASIN BIOREGION: DRAFT
DESCRIPTION
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Description
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The Coastal Upland Swamps in the Sydney Basin Bioregion includes a range of vegetation and
fauna associated with periodically waterlogged soils on the Hawkesbury sandstone plateaus.
Vegetation types include open graminoid heath, sedgeland and tall scrub. This ecological
community, proposed for national listing under the Commonwealth Environment Protection
and Biodiversity Conservation Act 1999, is based on the NSW listed community of the same
name. Information regarding the NSW ecological community can be found at:
http://www.environment.nsw.gov.au/determinations/coastaluplandswampfd.htm
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Name of the ecological community
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Coastal Upland Swamps in the Sydney Basin Bioregion
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Location and physical environment
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The Coastal Upland Swamps in the Sydney Basin Bioregion ecological community is endemic
to NSW, within the eastern Sydney Basin.
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In the south the community occurs on the Woronora plateau, in the north it occurs on the
Somersby-Hornsby plateaus. The southern part of this distribution is separated from the north
by an area of non-sandstone substrates, less rainfall and lower elevation, and by the urban
development of Sydney.
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Geology
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The community occurs primarily on impermeable sandstone plateaus in the headwater valleys
of streams and on sandstone benches with abundant seepage moisture (Buchanan, 1980;
Young, 1986; Keith and Myerscough, 1993; Keith et al. 2006 in NSW Scientific Committee,
2012). They are occasionally associated with weathered shale lenses and ironstone (Buchanan,
1980; Keith 1994 in NSW Scientific Committee, 2012). While the majority of swamps occur
within 200-450m above sea level, elevation varies from about 20m to around 600m. Soils are
acidic and vary from yellow or grey mineral sandy loams with shallow organic horizon to
highly organic spongy black peats with pallid subsoils (NSW Scientific Committee, 2012).
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Hydrology
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There are strong hydrological controls on the distribution of the Coastal Upland Swamps
ecological community, both regionally and locally. Development of the swamps is driven by
positive feedbacks that operate when there is significant excess of precipitation over
evaporation. This, along with high run-on from catchments and low rates of percolation and
run-off, promotes soil water logging (Young 1982, 1986 in NSW Scientific Committee, 2012).
Lateral transportation and deposition of sediment via overland flows lead to the choking of
headwater valleys, impeding drainage. Higher levels of soil moisture lead to increased density
of ground cover, trapping more sediment, further impeding drainage and killing trees that are
unable to tolerate raised water tables (NSW Scientific Committee, 2012).
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Climate
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The ecological community shows a strong relationship to climatic gradient, reaching its
greatest development on the central portion of the Woronora plateau. The Illawarra escarpment
produces orographic rainfall and fogs (i.e. rainfall and fogs produced when moist air is lifted as
it moves over a mountain range), and enhanced cloud cover, which in turn reduces evaporation
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(NSW Scientific Committee, 2012). The orographic climatic effects rapidly diminish with
distance inland from the escarpment and the occurrence of swamps is much reduced on the
western third of the plateau (NSW Scientific Committee, 2012).
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Vegetation
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The Coastal Upland Swamps ecological community is characterised by highly diverse and
variable mosaics of vegetation depending on soil condition, size of the site, recent rainfall
conditions, fire regimes and disturbance history (NSW Scientific Committee, 2012). More than
170 species of vascular plants species were recorded by Keith and Myerscough (1993) within
the Coastal Upland Swamps within the O’Hares Creek catchment alone, with the total for the
community likely to exceed 200 species (NSW Scientific Committee, 2012). An indicative list
of vascular plant species is included at Table 1. The community also includes micro-organisms,
fungi, and cryptogamic plants (i.e. plants such as ferns, mosses and algae that reproduce with
spores rather than flowers and seeds) (NSW Scientific Committee, 2012).
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Larger swamps may include a range of structural forms which include tall open scrubs, tall
closed scrubs, closed heaths, open graminoid (grassy) heaths, sedgelands and fernlands.
Smaller swamps are more typically characterised by open graminoid heaths and/or sedgelands,
but may include tall scrubs (NSW Scientific Committee, 2012).
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Table 1: Characteristic plant species (NSW Scientific Committee, 2012)
Vegetation
type
herb
shrub
shrub
shrub
shrub
Actinotus minor
Almaleea paludosa
Baeckea imbricata
Baeckea linifolia
Banksia ericifolia
shrub
Banksia oblongifolia
shrub
Banksia robur
shrub
sedge
sedge
herb
herb or low
shrub
herb
twiner
sedge
Bauera microphylla
Baumea acuta
Baumea teretifolia
Blandfordia nobilis
Boronia parviflora
shrub
subshrub
shrub
herb
herb
sedge
grass
shrub
shrub
shrub
Scientific name
Burchardia umbellata
Cassytha glabella
Chorizandra
sphaerocephala
Cryptandra ericoides
Dampiera stricta
Dillwynia floribunda
Drosera binata
Drosera spathulata
Empodisma minus
Entolasia stricta
Epacris microphylla
Epacris obtusifolia
Epacris paludosa
Common name
Lesser Flannel-flower
Swamp Baeckea
Golden Banksia, Heath-leaved
Banksia, Heath Banksia
Dwarf Banksia, Fern-leaved Banksia,
Wallum Banksia
Eastern Swamp Banksia, Swamp
Banksia, Broad-leaved Banksia,
Large-leaf Banksia, Large-leaved
Wallum
Dog Rose
Twigrush
Christmas Bells
Swamp Boronia, Small Boronia, Tiny
Boronia, Small-flowered Boronia
Milkmaids
Dodder Laurel, Devil's Twine, Dodder
Roundhead Bristle-sedge
Showy Parrot Pea
Forked Sundew
Spreading Rope Rush
Wiry Panic
Coral Heath
Swamp Heath
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Listing status
EPBC
NSW
Vegetation
type
herb
sedge
fern
herb
herb
herb
herb
shrub
shrub
sedge
herb
shrub
shrub
herb
sedge
grass
shrub
shrub
shrub
herb
fern
shrub or
small tree
shrub
herb
subshrub
shrub
grass
grass
shrub
sedge
sedge
sedge
herb
herb
shrub
shrub
herb
herb
subshrub
grass
grass
herb
shrub
Scientific name
Eurychorda
complanata
Gahnia sieberiana
Gleichenia microphylla
Gonocarpus micranthus
Gonocarpus salsoloides
Gonocarpus tetragynus
Goodenia dimorpha
Grevillea oleoides
Grevillea parviflora
Gymnoschoenus
sphaerocephalus
Haemodorum
corymbosum
Hakea teretifolia
Hibbertia serpyllifolia
Leptocarpus tenax
Lepidosperma
limicolum
Lepidosperma neesii
Leptospermum
grandiflorum
Leptospermum
juniperinum
Leptospermum
squarrosum
Lepyrodia scariosa
Lindsaea linearis
Melaleuca squarrosa
Mirbelia rubiifolia
Mitrasacme
polymorpha
Opercularia varia
Petrophile pulchella
Plinthanthesis
paradoxa
Ptilothrix deusta
Pultenaea aristata
Schoenus brevifolius
Schoenus lepidosperma
subsp.pachylepis
Schoenus paludosus
Selaginella uliginosa
Sowerbaea juncea
Sphaerolobium
vimineum
Sprengelia incarnata
Stackhousia nuda
Stylidium lineare
Symphionema
paludosum
Tetraria capillaris
Tetrarrhena turfosa
Thysanotus juncifolius
Viminaria juncea
Listing status
EPBC
NSW
Common name
Sword Grass, Sawsedge
Scrambling Coral-fern, Coral-fern,
Umbrella Fern
Creeping Raspwort
Red spider flower
Small-flower Grevillea
Bloodroot
Dagger Hakea, Narrow-fruited
Needlebush
Hairy Guinea Flower
Mountain Tea-tree, Woolly Tea-tree
Prickly Tea-tree, Juniperinum Tea-tree
Pink Teatree, Peach Blossom Teatree
Screw Fern, Necklace Fern
Scented Paperbark
Heathy Mirbelia
Variable Stinkweed
Conesticks
Wiry Wallaby-grass
Bearded Bush-pea
Zig-zag Bog-rush
Slender Bog Sedge
Swamp Selaginella, Swamp Clubmoss
Rush Lily, Vanilla Plant, Chocolate
Flower, Chocolate Lily
Leafless Globe-pea
Pink Swamp-heath
Narrow-leaved Triggerplant
Branching Fringe Lily
Golden Spray, Native Broom
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v
v
Vegetation
type
grass-tree
subshrub
herb
herb
herb
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Scientific name
Xanthorrhoea resinosa
Xanthosia tridentata
Xyris gracilis subsp.
laxa
Xyris juncea
Xyris operculata
Listing status
EPBC
NSW
Common name
Rock Xanthosia
Dwarf Yellow-eye
Tall Yellow-eye
v: vulnerable.
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Fauna
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The ecological community provides habitat to a wide variety of birds, mammals, amphibians,
reptiles and invertebrates (Table 2). The Australian crayfish, hairy crayfish and Sydney crayfish
are abundant (NSW Scientific Committee, 2012). Stygofauna (fauna that live in groundwater
systems or aquifers) are abundant and exhibit high levels of local endemism (Hose 2008, 2009
in NSW Scientific Committee, 2012). A number of threatened frogs have been recorded as
occurring within the community including the nationally threatened green and gold bell frog
(Litora aurea) and the giant burrowing frog (Heleiporus australiacus) (NSW Scientific
Committee, 2012). The community also provides habitat for the NSW listed giant dragonfly
(Petalura gigantean), which is now uncommon in coastal regions (NSW Scientific Committee,
2012).
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Table 2: Typical species found in Coastal Upland Swamp habitat. (NSW Scientific
Committee, 2012)
Scientific name
Common name
Listing status
EPBC
mammals
birds
Wallabia bicolor
Swamp wallaby
Antechinus stuartii
Brown antechinus
Rattus lutreolus
Swamp rat
Phylidonyris
New Holland honeyeater
NSW
novaehollandiae
Stipiturus malachurus
Southern Emu-wren
Rhipidura albiscarpa
Grey fantail
Stagonopleura bella
Beautiful firetail
Pezoporus wallicus
Eastern ground parrot
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wallicus
amphibians
invertebrates
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Heleiporus australiacus
Giant burrowing frog
Pseudophryne austalis
Red-crowned toadlet
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Varanus rosenbergi
Rosenberg’s goanna
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Litora aurea
Green and gold bell frog
Euastacus australasiensis
Australian crayfish
Euastacus hirsutus
Hairy crayfish
Euactacus spinifer
Sydney crayfish
Petalura gigantea
Giant dragonfly
e: endangered. v: vulnerable.
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e
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Key diagnostic characteristics
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The formation of swamps and wetlands are dependent on a range of factors including location
in the landscape, underlying geology, and climate. These play an important role in determining
the level of water-logging and sedimentation levels in the swamps. Swamp vegetation can be
highly variable depending on water flows, substrates, rainfall and altitude. Fire history also
plays an important role in the development and persistence of swamp boundaries.
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The ecological community is the assemblage of organisms including and associated with
coastal upland swamps in the Sydney Basin. Key diagnostic characteristics for describing the
the Coastal Upland Swamps in the Sydney Basin Bioregion ecological community are that it:
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
is confined to the Sydney Basin Bioregion, from the Somersby district in the north, to the
Robertson district in the south;
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occurs on the Hawkesbury sandstone plateaus with shallow groundwater aquifers in the
headwaters and impeded drainage lines of streams, and on sandstone benches with
abundant seepage moisture;
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includes open graminoid heath, sedgeland and tall scrub associated with periodically waterlogged soils, larger swamps may comprise a complex of these forms;
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is generally associated with soils that are acidic and vary from yellow or grey mineral
sandy loams with a shallow organic horizon to highly organic spongy black peat soils with
pallid subsoils; and
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occur in elevations from 20 m to around 600 m above sea level, although the majority of
swamps occur between 200-450 m.
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Surrounding environment and national context
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The Coastal Upland Swamps of the Sydney Basin Bioregion ecological community is endemic
to New South Wales, being restricted to the Hawkesbury sandstone plateaus of the Sydney
Basin Bioregion (IBRA 7). The Interim Biogeographic Regionalisation of Australia (IBRA)
divides the Australian continent into bioregions and sub-regions. IBRA is endorsed by all levels
of government as a key tool for identifying land for conservation. More information regarding
IBRA, including maps are available at: http://www.environment.gov.au/topics/land/nrs/sciencemaps-and-data/australias-bioregions-ibra.
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Defining a patch
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Coastal Upland Swamps are characterised by a diverse assemblage of vegetation and are
essentially treeless, although trees may be present as scattered individuals or isolated clumps of
mallee or eucalypts (NSW Scientific Committee, 2012). Many plant species within the swamps
are absent from or uncommon in the surrounding landscape, making swamps distinctive and
recognisable (Keith et al., 2013). Boundaries between Coastal Upland Swamps and adjacent
communities can be quite distinct across distances of a few metres or more diffuse transitions
across tens of metres, and may not follow tree lines precisely (D. Keith pers comm. 2011 in
NSW Scientific Committee, 2012). Substantial shifts may occur in swamp and adjoining
woodland boundaries over decadal time scales (Keith et al., 2010).
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Swamps are naturally small, with approximately 42% of those mapped being less than 1 ha.
The largest 5% of swamps (>14 ha) account for just under half of the total area of the
community (NSW Scientific Committee, 2012).
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The larger swamps are made up of distinctive mosaics of multiple sub-communities that can
include a number or structural forms including tall closed or open shrubland, closed heaths,
open graminoid heaths, sedgelands and fernlands (NSW Scientific Committee, 2012).
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Area critical to the survival of the ecological community
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The landscape distribution of swamp ecosystems is a function of local climate, landform and
substrate variables which influence hydrological regimes. Given the very specific set of
variables required for Coastal Upland Swamps to exist and persist, the areas currently occupied
are considered to be areas critical to the survival of the community.
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Bibliography
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Buchanan RA (1980). The Lambert Peninsula, Ku-ring-gai Chase national Park, Physiography
and the distribution of podzols, shrublands and swamps, with details of the swamp vegetation
and sediments. Proceedings of the Linnean Society New South Wales 104, 73-94.
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Keith DA (1994). Floristics, structure and diversity of natural vegetation in the O’Hares Creek
catchment, south of Sydney. Cunninghamia 3, 543-594.
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Keith DA, Rodoreda S, Bedward M (2010). Decadal change in wetland-woodland boundaries
during the late 20th century reflects climatic trends. Global Change Biology 16, 2300-2306.
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Keith DA, Rodoreda S, Holman L, Lemmon J (2006). Monitoring change in upland swamps in
Sydney’s water catchments: the roles of fire and rain. Department of Environment and
Conservation, Sydney.
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Keith DA, Myerscough PJ (1993). Floristics and soil relations of upland swamp vegetation near
Sydney. Australian Journal of Ecology 18, 325-344.
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Keith DA, Rodríguez JP, Rodríguez-Clark KM, Nicholson E, Aapala K, et al. (2013) Scientific
Foundations for an IUCN Red List of Ecosystems. PLoS ONE 8(5): e62111.
doi:10.1371/journal.pone.0062111
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NSW Scientific Committee (2012). Coastal Upland Swamp in the Sydney Basin Bioregion –
endangered ecological community listing – final determination. Accessed 3rd December 2013.
http://www.environment.nsw.gov.au/determinations/coastaluplandswampfd.htm
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Young ARM (1982). Upland Swamps (Dells) on the Woronora Plateau, NSW. PhD thesis,
University of Wollongong, NSW.
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Young ARM (1986). The geomorphic development of dells (upland swamps) on the Woronora
plateau, N.S.S., Australia. Zeitschrift fur Geomorphologie 30, 317-327.
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