Wet Schlerophyll

“Rose Gums” is named after the most prominent tree on the property – the Rose Gum or Eucalyptus grandis. It is easily seen from the house because of its towering height and brilliant white trunks and branches. It can grow to 55m tall and 1.8 m in diameter. This tree typifies the “Wet Sclerophyll Forest” (WSF) in the highlands of North Queensland.

There are only 83,000 ha of WSF in North Queensland. This compares with nearly a million ha of rainforest in the World Heritage area. Whilst the rainforest is now well protected WSF is disappearing fast. The intriguing thing is that the threat to WSF is because it is too well protected!

WSF must be burnt from time to time - otherwise rainforest takes over. WSF only grows in the wettest parts of the ecosystem, which is really naturally dominated by rainforest.

Fires start in the drier country and sweep towards the rainforest. The rainforest won’t burn but the margin gets pushed back by the fire. An unstable band of grassy, wet Eucalyptus forest establishes along the rainforest margin. The rainforest seedlings establish in the grassland and unless they are killed by subsequent fires, they grow to form a canopy, which shades out the grass and the young Rose gum seedlings. Eventually the forest becomes not burnable, and rainforest replaces the rose gums.

WSF has been around a long time. At times it has been very extensive in north Queensland. It has unique animals and plants, which indicates a period of mutual evolution of many hundreds of thousands of years. The Yellow-bellied Glider, Northern Bettong, northern race of the Eastern Yellow Robin, White-naped Honeyeater and some bat species appear to be dependent on this vegetation type. If we lose WSF we will lose these species completely.

WSF shares some species of animals with the rainforest and some with the drier country as well as having its own specialties. Because it is so damp it is an important drought refuge for animals and plants.
Turpentine Syncarpia glomulifera is another common tree in WSF and can also grow to a great size (45m tall). Red Stringy bark Eucalyptus resinifera, Red Bloodwood E. intermedia, and Rose She-oak Allocasuarina torulosa are other common trees. They combine with other trees shrubs, grasses, sedges and herbs to give a richly biodiverse ecosystem of grandeur and beauty.

Rose gums are important for a whole range of animal species. They are always hollow and they have huge branches at right angles to the trunk. The branches break off and provide wonderful dens for Gliders, Possums, Owls and Parrots. Lorikeets and Honeyeaters are abundant when the Eucalypts are in flower.

Rose gums grow where it is wettest. Sometimes they occur on the ridges and in the valleys but not on the hillsides. Up on the ridges they can use their foliage to filter out moisture from the clouds and in the valleys they depend on the water draining down the hillsides.

Courtesy: Dr Graham Harrington