Rainforest Gully Garden

The school recently turned an unused and weed-infested slope at the rear of the school into a Rainforest Gully Garden featuring local provenance plants, bush tucker and plants found in rainforest gullies in the Sydney region. The aim was to increase the amenity and biodiversity of the school grounds providing an enriched and educational experience for pupils living in a highly urbanised area.

We added a number of enhancements to the project:

(a) a path was constructed through the garden providing access for students;

(b) rainwater was diverted from a nearby down pipe into a swale at the top of the slope, allowing it to infiltrate through the site, both improving conditions for the plants, and reducing stormwater run-off to the Cooks River; and

(c) we consulted with Carol Green, the Local Aboriginal Educational Consultant, and the school’s Koori community in relation to incorporating Indigenous stories and knowledge into the garden.

Once the initial planted area is consolidated, we plan to extend the garden on both sides along the slope. We are considering adding some birdbaths to attract fauna. We are also interested in adding artworks and educational features.

Study of plankton

During World Environment Week, Year 6 students went on a Grime Scene Investigation to Georges River. During a river cruise, water samples were collected for studying under a microscope back at base.

We learnt that plankton is the start of the foodchain in the marine environment. The water samples we gathered were studied under a microscope and projected onto a screen for all to see. Unfortunately, in all the samples studied only one type of zooplankton (animal) was found in amongst the phytoplankton (plant). This was compared to a chart and determined to be Veliger (larva of the limpet) [image 1 below].





DVD footage of previous zooplankton finds was then screened and students identified those from the charts as well.

Activity - Click on the images below to view large versions of the charts and use them to identify the zooplankton in images 2, 3 and 4 above.






















Answers: 2=m (second chart) 3=b (second chart) 4=f (first chart)

Why is plankton important to marine food chains? Because it is the starting point. Without it, there would be nothing for fish to eat; without fish there would be nothing for water birds to eat.

Fish dissection

During World Environment Week, Year 6 students went on a Grime Scene Investigation to Georges River.

A very popular part of the day involved disecting fish!

Grime Scene Investigation

On a particularly grim and grey June day in 2008, nine Year 6 students attended a Grime Scene Investigation on the Georges River. The day started with a river cruise looking at activities around the River's edge and the impacts of these on the water. Historically the main post-European river activity was oyster farming.

The following diagram (representing the same area as the aerial photo above) had locations A to H marked and, listening to the commentary, students had to identify the types of landuse activities from the key below.


KEY: 1 = factories/industry 2 = residential (housing) 3 = water sports/clubs 4 = open spaces /parks 5 = natural vegetation 6 = boat moorings 7 = landing ramp/wharf

Answers: A=4, 7 B=6 C=4 D=2 E=2, 4, 7 F=1 G=5 H=3


We learnt:
- that there are 235 different organisms in the water!
- that sea grass is the estuary supermarket being home to many of these organisms.
- that the catchment area for George's River is 960 square kilometres (which is a lot of stormwater run off)
- there is a 50km stretch of saltwater before the weir at Liverpool

Environmental issues include:
- stormwater drains emptying into the river, many without gross pollutant traps (GPTs)
- unnatural edges around most of the Bay prevent saltmarsh plants and mangroves from growing
- pollution from sewerage leaks, chemicals from boat washing get into the river
- Kogarah Council collected 113 tonnes of litter from one GPT in one year!
- litter from waterside picnic areas (particularly plastic bags which are eaten by birds mistaking them for jellyfish)

Environment solutions include:
- the use of boom nets to contain pollution (for eg at waterside building sites)
- installation of more GPTs
- fines for polluting practices
- establishment of "no wash" zones (eg Sylvania Waters)















During the cruise, water samples were taken for studying back at base.

See Study of Plankton for the results.

See also Fish dissection.








The excursion required certain roles to be played by the students. They were:
biologist
ecologist
water quality chemist
environmental scientist

to be continued...

Silkworms

Silkworms are a great species for studying the life-cycle of a caterpillar. This can be done in your home or classroom with a few simple items and a steady supply of mulberry leaves. They are not native to Australia so you will not find them in the wild and you should not release them into the wild when you're finished with them. You can source your eggs from pet shops or local breeders.



From larva to moth via silk coccoon.

Habitat

In their own country, silkworms would live on mulberry trees as this is their only source of food and their waste would drop to the ground. In captivity, you need to provide a clean and comfortable alternative. A shoebox with plastic wrap is an easy option. Keep the box at room temperature but out of direct sunlight. Puncture the plastic wrap with small air holes, but make sure they're not big enough for your silkworms to escape! You may need to place the shoebox above a moat of water to stop ants getting in!



About six weeks after the eggs have hatched they will start to spin coccoons. At this stage you need to add some sticks, curved bark or cardboard rolls to the shoebox so the caterpillars have edges to attach their silk to.

Food

The caterpillars feed mainly on mulberry leaves. If you obtain eggs before the mulberry trees have developed leaves then you can put the eggs "on hold" in the fridge. If they hatch anyway, you can feed them on carefully washed lettuce leaves.

When your caterpillars are young, tear the mulberry leaves into smaller pieces so there are lots of edges for them to eat along.



You will need to clean the box out every day as the silkworms eat a lot of leaves and that creates a lot of caterpillar poo! As they grow larger they will moult so old skins need to be thrown out too. The bigger the caterpillars get, the more leaves they eat. Eventually, you will need to feed them every few hours. But you can plan ahead and pick lots of mulberry leaves which last several days in a plastic bag in the fridge.

To clean the box without damaging the delicate caterpillars pick up the leaves they are on rather than picking up the caterpillars themselves.

Coccoons

About six weeks (or up to 47 days) after hatching from eggs the caterpillars start to spin their coccoons. These are made from one long strand of silk about 800-1200 metres long and this process can take 3 to 6 days.


In this picture you can still make out some of the features of the caterpillar as it spins its coccoon within the silk anchors.

Parts of the caterpillar


Silworms have a head, a thorax and an abdomen. The head has simple eyes and tiny feelers. The silk is made by two glands near the mouth. The thorax has three segments and each of these has a pair of legs. Along the abdomen there are false legs that silkworms use for gripping and balancing. The whole abdomen has 10 segments.

Moths

The moth will hatch about 15 days after the coccoon is finished. The moths cannot eat or fly and they only live for a few days which is enough time to mate and lay eggs so that the cycle can start all over again.





Activity - Watch an online slideshow about silkworms. What extra facts does it contain?

Activity - Draw and label a silkworm or draw and label your own life cycle of a silkworm.

World Environment Day - nature activities

On 19 September 2007, the whole school celebrated World Environment Day with an excursion to Girrahween Park in the Wolli Valley. From this central location, 12 separate groups had guided bushwalks and experienced nature-based activities in their spare time.

One area was set aside as an "Explore nature area". This contained a large feely box with seedpods, banksia cones, sticks, smooth pebbles and a stuffed bandicoot! Students were encouraged to explore by touch and try to identify and distinguish the contents. In another area, feely boxes contained one item only and students were encouraged to feel the object and try to draw what it was without looking.

This area also contained magnifying glasses and objects to study up close including bug boxes and a cat skull.

There were books and posters identifying birds and binoculars to help spot some. There were also bird nests set up as a puzzle where students had to match the nest materials to the type of bird or the kind of location it would be found. For example, a nest made of sheep's wool might come from a farm and a nest of paperbark might be from the Wolli Valley.

There were also structured activities for classes to undertake including paperbark craft; wax resist, a stone game and a smell game. Following are the instruction sheets for these.

Paperbark

Traditional Aboriginal people used paperbark for many different things:
- huts;
- coolamons (carrying baskets for food and water);
- food wraps and plates
- toys like balls.

Yr 6 crafted Aboriginal-style coolamons and balls out of paperbark and string.

Make your own!

Paperbark ball – wrap bark around scrunched newspaper and tie with string. NB: Aboriginal people would not have had newspapers or string. What would they have used?

Paperbark carrying basket – make a small canoe shape. Tie the ends together with string.

This bark was gathered outside the National Park. It is not OK to take things from inside the Park no matter how small. You may be moving a rare seed and stopping it from growing. You may be spreading an invasive weed.

You can take these bark creations back to your school or home. Try playing football or netball. Try carrying something in your basket.

Share your knowledge with others.

Stone game

Sit the class in a circle on the grass. Choose a quiet, shady location.

Select roughly 6 pairs. The remainder can observe first then have a turn later.

One partner in each pair is blindfolded and then chooses a rock from the center. They examine the rock by touch for 3-5 minutes then put it back.

Their “seeing” partner must remember which rock it was. They should have a good look at it before it is returned.

The blindfolded person then has to remember how the rock felt and identify it by sight.

Wax resist

The class should take a sheet of paper and make impressions of natural textures: rocks; bark; leaves, seed pods, etc.

Paint over the wax drawing with coloured water to reveal the textures.

Or, simply use coloured crayons to create an impression directly onto the paper. See if you can find trees or rocks with different textures and capture the patterns on each half of one page.

Remember: This is a National Park.

DO NOT pick anything living, or remove anything from its location.

Smells from nature

Encourage children to smell the hidden leaves and think about what they're smelling. Some questions to provoke thought. Is the smell:

- pleasant or unpleasant?

- strong or mild?

- from an edible plant or not?

- from a native plant or not?

- from a tree? bush? garden plant?

* Does the smell remind them of anything? A certain place or time?

* Do they recognize any of the hidden plants?

Answers:

1. Pine or conifer tree.

2. Lemon-scented tea-tree (Leptospermum petersonii). Native tree.

3. Eucalypt leaves. Native tree.

4. Mint leaves from Ferncourt's herb spiral.

World Environment Day - guided walks

On 19 September 2007, the whole school celebrated World Environment Day with an excursion to Girrahween Park in the Wolli Valley. From this central location, 12 separate groups had guided bushwalks and experienced nature-based activities in their spare time.

Guided walks

Respect to Country
We acknowledge the traditional owners
of the land on which we live and learn.
We pay our respects to them for their care
of this land over countless generations.
We hope they will walk with us on our journey.

The guided walks covered different aspects of the built and natural environment. Older classes went as far as Turrella Reserve and Nannygoat Hill to the North or Illoura Reserve to the South. Younger classes explored the Bray Ave wetland, Paperbark Creek or the interesting features of Girrahween Park itself including a de-nutrification wetland.

Shelter under rock escarpments with evidence of smoke from Aboriginal cooking fires.

Turrella Reserve and Nannygoat Hill



Students walking to Turrella Reserve saw rock shelters used by the Bidjigal people and saw remnant vegetation that has been restored to how it might have looked in Aboriginal times. They saw paperbark trees used for Aboriginal huts, canoes, food wrapping and toys. They learned Aboriginal place names:

Girrahween = “place of flowers”;
Turrella = “reeds growing in water”;
Minnamorra = “plenty of fish”
Wolli = “camping place”

The Turrella Weir was identified as the divide between fresh water on right and tidal salt water on left. Different species occur downstream to upstream. Plants include mangroves, saltmarsh and casuarinas on the tidal side. Native fish such as Sea Mullet, Port Jackon Perchlets and Eels are found in the saltwater side. In the freshwater side there are various species of gudgeon.

Turrella Reserve had been wetlands full of reeds and subject to flooding then later Chinese market gardens but Council filled in the area to create parkland. It still functions as water bird habitat to some extent.

At Nannygoat Hill students observed the proximity of gardens to bushland, enabling the spread of weeds and exotic plants like “Mother of Millions”. They also learnt about stormwater issues: the streets here (Minnamorra etc) drain into Wolli Creek (so does rubbish) .

Illoura Reserve and Paperbark Creek



Students who walked towards Bexley found an area still needing much bush restoration and regeneration and saw the effects of garden plants becoming invasive weeds.

Bray Avenue Wetland was seen as a haven for birds; much bush regeneration has been undertaken and Canterbury council have made efforts to control stormwater.

Students observed a “no mow” area which allows native seedstock to grow where it belongs. These have been established by volunteer bush regenerators with the co-operation of Council.

Students observed:
- the proximity of gardens to bushland, enabling the spread/or dumping of weeds;
- the proximity of roads to bushland, enabling the dumping of truckloads of rubbish (roof tiles, washing machines, filing cabinets)

Stormwater issues were evident: the streets here Bray Ave, etc drain into Wolli Creek (so does rubbish)

European history: A road reservation relating to this stretch of land meant that the bushland was subject to years of neglect (compare to Girrahween Park which is well maintained by NPWS). Prior to the road reservation, Kings Farm existed (near Bexley end of track).


Students explore Paperbark Creek – a stormwater channel restructured by Council

Girrahween Park - De-nutrification wetland

"De-nutrification" is a big word! so lets break it down. We've all heard about nutrients and are often told about having nutritious food instead of junk food. Nutrients make things grow. They’re good if they’re in our food but not so good in our waterways.

Nutrients in our waterways make plants grow.

Too many nutrients make water plants grow too fast and too big.

Why is this bad?

Water gets oxygen from the air (waves and wind help stir it in).
Fish need that oxygen in the water.

BUT, if plants cover the water, they stop the oxygen from dissolving in the water, so fish die.

Rotting dead plants take even more oxygen out of the water.

HOWEVER, if we are clever, we can use this system to clean up our dirty water. We must simply keep the water flowing and harvest the plants to keep them from growing too big.

Look upstream from the bridge: Here we can see water flowing down from a stormwater outlet near the Earlwood shops. It’s bringing some pretty rich nutrients with it!

The reeds have been planted to eat up the nutrients and stop so much getting into Wolli Creek (downstream from the bridge).

So, de-nutrification is just a big word that means taking the nutrients out. This makes Wolli Creek healthier.

Wetlands: Natural and Constructed

Wetlands were long regarded as wastelands but are now recognised as important features in the landscape that provide benefits for people and other animals. Wetlands are home to an abundant variety of plants, water bugs, reptiles, birds, fish, frogs and mammals - they are considered to be 'biological supermarkets'. They are among the most productive environments in the world and form a link between our land and water resources.

Stormwater comes from urban areas after rain. As water flows across roads and other hard surfaces it can pick up pollution such as rubbish, chemicals and sediment. This polluted stormwater can be caught and filtered by constructed wetlands before it enters a waterway.