An  environmental  project  inspired  by the  children of Baldivis  Primary School
 

Baldivis Children's Forest

The Swan Coastal Plain is the area of land between the Darling Range and the Indian ocean. Wetlands that occur on the Swan Coastal Plain can be areas of waterlogged soil, flooded land, or permanent water areas. Water may not be seen on these areas all year round, but they are still wetland areas because of the plants and animals that used to, or still do grow and live there.

Outridge Swamp

At the bottom of the ridge (hill) at the Baldivis Children’s Forest is a wetland area called Outridge Swamp. The swamp is a seasonally inundated basin (sumpland), which means it usually fills with rainwater and run-off (water that runs down the slope) during the winter season. Historically, the water can get as deep as 2.2 metres, however we have not seen it that deep since we have been working at the Forest.

Photo: Inner wetland area of Outridge Swamp covered with a herbland of seablite

Outridge Swamp is a ‘Conservation Category’ wetland which means it is looked after to protect the plants and animals that grow and live in the wetland. At the edge of the wetland, plants such as flooded gums (Eucalyptus rudis), paper barks (Melaleuca rhaphiophylla and M.teretifolia), sedges and rushes grow. As you walk into the wetland the land dips and the plants change to paperbarks (M.teretifolia) overgrown with a creeper called dodder (Cassytha racemosa). In the wettest area of the wetland a herbland of seablite (Suaeda australis) grows, forming a purple carpet in spring. Different fungi and moss grow on the plants and fallen logs during wet times of the year.

In 2007/08 plans for weed control and planting of fringing vegetation (plants that grow around the edge of the wetland) will help restore the wetland.

Photo: Paperbarks, rushes and sedges grow in the outer wetland area of Outridge Swamp.

BCF Wetland Flora Survey (click to view or download a copy)

Many animals such as bandicoots, native rats, goannas, snakes, frogs and long-necked turtles live in the wetland. The wetland is important as it provides food and water for these and many other animals. It would have been an important wetland for Nyoongar people as they moved through the area – hunting turtle and snakes, and collecting bush tucker such as tubers (plant root bulbs) and bulrush flower spikes.

If enough rain falls during the winter months then water quickly begins to fill Outridge Swamp. The wetland may have puddles of water for only 3 weeks as it did in 2007 or if enough rain falls the water gets deeper and deeper and can last for many weeks as it did in 2008.

Photo: Outridge Swamp fills with water and aquatic life after winter rains.

Macro-invertebrates quickly colonise the water, long-necked turtles emerge from their winter sleep and frogs begin to call for a mate. You are now listening to the chorus of squelching froglets and banjo frogs recorded during winter 2008. We have seven species of frogs living in the Forest; five burrowing ground frogs (red thighed froglet Crinia georgiana, Glauert's froglet Crinia glauerti, sandplain froglet Crinia insignifera, moaning frog Heleioporus eyrei, banjo or pobblebonk frog Limnodynastes dorsalis, turtle frog Myobatrachus gouldii) and two tree frogs (slender tree frog Litoria adelaidensis, green tree or motorbike frog Litoria moorei).

Red thighed froglet (Crinia georgiana)	Glauert's froglet (Crinia glauerti)	Pobblebonk or banjo frog (Limnodynastes dorsalis)
Moaning frog (heleioporus eyrei)	Longed necked turtle (Chelodina oblonga)	Sandplain froglet (crinia insignifera)

 

 

 

 

Photo: Using microscopes to identify macroinvertebrates.

 

 

Water quality monitoring

The Department of Environment’s ‘Ribbons of Blue’ program involves school students and community groups in monitoring water quality. Students learn about aquatic macroinvertebrates and physical parameters (temperature, pH, salt and turbidity). Data collected from the sampling provides valuable information for identifying environmental problems and preparing management plans.

During 2008 with water once again in Outridge Swamp students have been able to once again monitor what macroinvertebrates are in Outridge Swamp and found amphipods, copepods, hover fly larvae, ostracods, tadpoles, water fleas and mites.

Until funding for a boardwalk becomes available we discourage people from entering the wetland area as it tramples the plants and spreads weeds into the wetland.

Useful links