Springbrook National Park

Springbrook National Park is recognised as part of one of the world's most outstanding places. In December 1994, the UNESCO World Heritage Committee officially declared the Gondwana Rainforests of Australia World Heritage Area over the Scenic Rim (including nearly all of Lamington and Springbrook national parks and most of Main Range and Mount Barney national parks) and the rainforests of northern and central New South Wales. World Heritage listing is a prestigious international recognition of the important conservation values of this area, especially its unique geology, subtropical and cool temperate rainforests and rare fauna.

Although the total area of Australia's remnant rainforest is small on a global scale, its value to the world is immense. In the past 200 years, three-quarters of Australia's rainforests have been destroyed or degraded. However, Gondwana Rainforests of Australia World Heritage Area conserves a rich diversity of wildlife, including more than 1700 species of flowering plants and 500 vertebrate animals. Protecting these areas in national parks or other reserves ensures this biological diversity is secure. It also allows natural processes such as evolution to continue, undisturbed by human influence.

Geology

The landscape of the Springbrook plateau is a remnant of the northern side of a once huge shield volcano that dominated the region about 23 million years ago. The volcano was built up of highly mobile basalt lavas, and although centred on Mount Warning, it was about 80 km across. At about 2000 m high, the volcano poured lava over 6000 km (north to Tamborine, south past Lismore to Coraki and west to Kyogle). Some lava flows were 270 m deep. Basalt, rhyolite and pyroclastic rock were formed. Later eruptions laid down the acidic rhyolite that is responsible for the sheer cliffs of Springbrook plateau.

About 10 million years ago the volcano began to die. The remaining lava plugged the numerous vents and over the millennia, weathering and water erosion have relentlessly sculpted the volcano to form a classic erosion caldera landform. The Mount Warning caldera - the crescent of perpendicular cliffs extending from Springbrook to Lamington plateau and the Tweed Range above the Mount Warning vent valley is the largest and best of its age in the world. Visit Best of All lookout to view the grand scale of this magnificent landform.

Rainfall that feeds streams and powers waterfalls continues to shape the landscape in this ongoing erosion process. Natural Bridge is an example of water's tremendous power. The hard basalt rock bridge we see today was once the lip of an old waterfall. At its base, softer, broken up basalt in a different flow was gradually eroded by swirling waters into an undercut cave. Rocks in the stream bed above swirled around to drill a pot-hole, which gradually deepened and broke through to the cave beneath. The creek fell into the cave and then enlarged it further. Another pot-hole now forming in the creek above is already leaking into the cave, suggesting another break-through in the future.

The lip of the old waterfall now forms a bridge, while the cave below has since eroded further back from the foot of the falls.

Other unusual volcanic formations include Egg Rock and Pages Pinnacle in the Numinbah Valley and the distinctive rhyolite twin peaks of Mount Cougal.

Flora and Fauna - a diverse environment

The forests of Springbrook National Park can be grouped into five classifications depending upon the dominant tree species, soil, location and rainfall. These forest types are subtropical, warm temperate and cool temperate rainforests, open eucalypt forest and heath. Subtropical rainforest characterised by a closed canopy, vines, palms, epiphytes and large trees such as strangler figs, can be seen at Mount Cougal, Natural Bridge and in the sheltered gorges of Springbrook plateau. There is a small population of the endangered plant, southern ochrosia (Ochrosia moorei) in Springbrook's subtropical rainforests.

Flora

Warm and cool temperate rainforest is of interest on the higher parts of the plateau. Distinguished by the pink-trunked brush box (Lophostemon confertus) and the mottled, lichen-encrusted coachwood (Ceratopetalum apetalum), warm temperate rainforest can be observed in the Canyon area.

Antarctic beech (Nothofagus moorei), relics of an earlier cooler, wetter age, now occur only at high altitude. Visit the cool temperate rainforest on the highest part of the plateau at Best of All lookout to view some of these ancient trees - some are around 3000 years old.

Two kinds of open eucalypt forest are seen on Springbrook plateau and in the Numinbah Valley. Tall white-trunked flooded gums (Eucalyptus grandis) tower over palms and treeferns. On poorer soils grow the uncommon and attractive Blue Mountains ash (Eucalyptus oreades), with its lemon-coloured trunk, and the brown fibrous-barked New England blackbutt (E. campanulata). Tall silky oaks (Grevillea robusta) line the Nerang River and Waterfall Creek in Numinbah section. Prickly-leaved heath plants, including the golden banksia, red bottlebrush and purple hovea, make a colourful understorey.

Fauna

Of the many mammals living in the park, pademelons (small rainforest wallabies) are most frequently seen by day visitors. Please drive slowly to avoid the pademelons that can dart across the road without warning, particularly on the way to Best of All lookout. These shy creatures may feed on grass seeds on the road edges at dusk and in the cool of the morning.

Campers are usually rewarded with sightings of nocturnal animals, especially the greyish brushtail possum and the smaller, reddish, ringtail possum that has a distinctive white tip on its tail. A glimpse of the tiny and elusive sugar glider or large greater glider is the reward for those interested enough to take a red-filtered torch and explore the tracks at night. Koalas are occasionally seen on the drier western ridges of the plateau and in the open forest areas of Numinbah section.

Over a hundred different bird species can be seen and heard in Springbrook National Park. Noteworthy species include the raucous and distinctively plumed yellow-tailed black cockatoo, which can sometimes be seen feeding on the seeds of banksia, casuarina and wattle.

The slender brown cuckoo-dove is often heard calling a plaintive 'oop oop' throughout the park. The elusive Albert's lyrebird is another species that is more often heard than seen. In the winter months its vibrant composite call can be heard from the depths of the valleys. A true songbird, the lyrebird is part of an ancient, unique bird group that probably evolved when flowering plants began to dominate the landscape. The Gondwana Rainforests of Australia reserves provide an important refuge for this species. If you see a lyrebird, record the date, time and contact the Springbrook National Park office.

Smaller bush birds that may be seen along the tracks include the yellow robin, rufous fantail and the dainty superb fairy-wren. Three species of rosella are present in the park. The most striking is the descriptively named crimson rosella with its plumage of scarlet and royal blue. The black and gold regent bowerbird and the larger midnight-blue satin bowerbird represent the bowerbird family. These are spectacular examples of the diversity of bird life that can be seen by the patient and interested observer.

The most frequently seen reptiles are prehistoric-looking lace monitors, glossy black skinks known as land mullets, and sleepy carpet pythons. These are all harmless if not provoked. Remember though, that not all snakes are harmless. Stand well away, avoid aggravating them and allow time and room for them to get out of your way.

The abundance of water in the park and reserve has resulted in a diverse selection of water-dwelling animals. Frogs are the most vocal, blue spiny crayfish the most colourful and eels the most surprising. Orange-eyed treefrogs and large beige-coloured great barred-frogs are often seen on the tracks at night.

Long-finned eels (Anguilla reinhardti) are common in the larger pools such as Warringa on the Springbrook plateau and in the upper reaches of Waterfall Creek and Nerang River. They are remarkable for their breeding behaviour. Adults travel enormous distances to breed in the tropical ocean and the young eels, known as elvers, return to the freshwater streams to continue the cycle. Platypus make their home in the large waterholes of the upper reaches of the Nerang River in Numinbah section and Currumbin Creek. Using their large bills to search for food by sifting through sand and gravel on the creek or river bed, platypus feed on shrimps, small crayfish, worms and the nymph life stages of many insects - dragonflies, damselflies, mayflies, stoneflies, caddis-flies and beetles.

Glow-worms

Natural Bridge section is known for the small, brilliant blue-green lights seen at night decorating the ceiling, rocky overhangs and steep earth banks along the one kilometre circuit. These lights are emitted by tiny creatures that are not actually worms, but the larval stage of a small fly (Arachnocampa flava).

Arachnocampa glow-worms are a primitive fly species found only in Australia and New Zealand and rely on rainforests of Gondwanan origin for their survival. These diverse, green havens provide the rainfall and dense canopy cover glow-worms require.

As Gondwana drifted north and split up, the glow-worms survived in the humid and dark conditions of rainforests and caves. As the Australian continent dried, these rainforests gradually contracted to tiny, green islands and glow-worms became isolated.

Over millions of years of isolation glow-worm colonies changed, the species' physical structure and genetics modified. Today there are eight recognised glow-worm species in Australia and each of these is restricted to a region of rainforest or permanently wet caves.

The colony of thousands of glow-worms found in the cave's roof at Natural Bridge can only be seen after sunset. The 'light' you see is produced within the glow-worm's body. It is the reaction of four chemicals that produces the cold light or bioluminescence, meaning 'living light'. Glow-worms generate this bioluminescence to lure their prey. By producing long, sticky threads that work like a spider web, glow-worms entangle small invertebrates such as midges, mosquitoes and mayflies that are drawn to the blue-green bioluminescence.

The best bioluminescence displays are usually during the warmer, wetter months of the year (December to March).

It is only during this larval stage that the species feeds - a period of about nine months. Adults emerge to live only three to four days, long enough to mate and lay eggs.

Important information regarding glow-worms:

Glow-worms are sensitive to changes to their environment, so please follow these basic cave rules:

1. Bring sufficient torches - allow one torch between two people
2. Do not shine torchlight directly on the glow-worms at any time. This can cause the glow-worms to stop glowing and interrupts their feeding
3. Don't use flash photography - it disturbs the glow-worms. Allow for longer exposure on your camera to capture the glow-worms at night
4. Please keep noise to a minimum
5. Smoking is not permitted in the cave as cigarette smoke is known to kill glow-worms
6. Apply any insect repellent before entering the park (freshly applied repellent can kill glow-worms)
7. Keep group sizes to a minimum - a maximum of 10-12 per group is recommended

Following these simple guidelines minimises visitor impact on the glow-worm colony, ensuring the population will be here for future generations to enjoy