Maddens Creek, Dharawal Nature Reserve, which flows into O’Hares Creek which is the major source of the Georges River. Here
its banks show a mix of both heath and woodland species.
Upland swamps are vegetated freshwater wetlands occurring in shallow basins located in low hills or mountains. This wetland
type includes shallow marshes, sedge swamps, ‘hanging’ swamps1, wet heaths and peat swamps.
Higher altitude swamps
People normally recognise low lying estuarine swamps, with mangroves, around rivers and coastal bays. Yet very different types
of swamps can also be found perched up high on the top of sandstone plateaux. They act like giant sponges, collecting rain
water and sediment. The sediments are far too soggy and oxygen poor for trees, yet ideal conditions for a wide range of wet
heath plants and sedges. These swamps feed water constantly, even in dry times, into a myriad of tiny freshwater streams that
become the headwaters of major rivers.
The Dharawal Reserves
An example of such an ecosystem is the upland swamps of the Dharawal Reserves, on the Woronora Plateau, just south of Sydney
and just north of Wollongong. They occur at an elevation of around 400 metres above sea level, and depend on high rainfall,
with 1500 mm p.a recorded at Maddens Plain in the south-east corner of the Reserves. They have been described as amongst the
most species rich sedge-heath communities in the world, with more than 500 recorded species.
Vital habitat
These upland swamps are the key habitat for at least 12 of the most threatened fauna species in Australia, including the Ground
parrot, Beautiful firetail, Eastern bristlebird and the Giant burrowing frog.
Key water source
Apart from habitat value, they are hydrologically important in terms of both water quantity and quality. They filter and store
water, releasing it constantly and slowly, feeding the network of the small streams that flow out of them. The upland swamps
of the Woronora plateau, for example form the headwaters of 3 important river systems. They are the Cataract and Woronora,
which provide drinking water to Wollongong and southern Sydney respectively and the Georges River that forms the recreational
centre piece of a catchment with almost of million people downstream.
This is an un-named stream of the Dharawal State Conservation Area, that is the known habitat of two threatened frog species,
the Heath frog and the Giant burrowing frog. These frogs have very specific habitat requirements. They are dependant on very
pristine water quality.
Apart from the Woronora Plateau, upland swamps are found scattered in small pockets all along the high sandstone country along
the Great Dividing Range in NSW. Around Sydney they also occur on the Hornsby Plateau to the north and the Blue Mountains
to the west, elsewhere they are found on the Southern and Northern Tablelands.
Characteristics
Whilst they all share similar characteristics in terms of their soggy peat like soils and heath vegetation, they do vary.
The Blue Mountains swamps form hanging swamps that are prominent on steep valley sides. Others like the Wingecarribee Swamp
and many of Dharawal, occur in natural bowl like depressions or along watercourses.
Google Earth
An example of an Upland swamp lies in the Dharawal Nature Reserve on Google Earth2. To move out of street view level and look at the wider area click the yellow person icon in the bottom right hand corner.
This resource will only work in the Google Chrome browser.
This reserve takes its name from the traditional custodians, whose land extends across the Woronora Plateau, and from what
is now Botany Bay to the north, to Nowra to the south and the Georges River to the west. Their occupation, known to be over
15 000 years, is etched across this landscape, with art work in sandstone overhangs where the swamps meet cliffs, and many
axe grinding grooves where the swampy streams flow out across rocky pavements.
Isopogons are one of the many species of plants that grow in upland swamps and headwaters.
Upland swamps are considered particularly fragile, and their recovery is very slow after disturbance. Inappropriate recreational
uses like horse riding, 4WD and trail bike riding, weeds and feral animals like foxes and deer are recognised threats in Dharawal.
Bushfire threat
Whilst fire is part of the Australian landscape, fires that are too frequent or intense are considered a threat. Species extinctions
and declines have been linked to fire in upland swamps. Across the upland swamps of the Woronora Plateau, population declines
in the Eastern bristlebird, Ground parrot, the Eastern Pygmy possum and the Beautiful firetail are linked to the combined
effects of an increase in the fire regime and predation by the introduced species, foxes and feral cats, since European settlement.
Mining
One of the greatest and most current threats recognised to the upland swamps of the Woronora Plateau is surface subsidence
as a result of longwall coal mining7. It is frequently associated with stream bed and rockbar fracturing, and the loss of surface and near to the surface groundwater.
Swamps can be dried out and desiccated, this a particular threat to the vegetation which is highly moisture dependant, and
increases the fire risk across the whole landscape.
The water in headwater pools is usually of high quality and many animals, particularly amphibians depend on the water remaining
clean and clear.
The Georges River EEC8 is located on the Georges River, at the heart of one of the most urbanized river catchments in Australia. Despite this more
than 40% of the land area of the catchment remains natural, and much of that is in protected reserves.
Excursions
Our excursions and fieldtrips are organised quite flexibly to take advantage of both these more pristine areas and smaller
remnants of swamp, bushland, freshwater and saltwater environments. We focus on river quality monitoring, bush care and sustainable
resource management and practise to foster an ethic of care and citizenship in schools and students who participate in our
programs.
Other locations
The following Environmental Education Centres can be contacted regarding upland swamps in their area:
Red crowned froglet on a sundew. Sundews (Drosera) are small carnivorous plants that devour the insects trapped in their sticky
liquid coated hairs. They are common in the moisture rich edges of upland swamps and stream beds.
