Nature & Geoheritage

Protecting the rocks, soil and landscapes

To protect the whole habitat we also need to protect the underlying soils, rocks and water.

All too often the geological aspects of a natural area are ignored, yet without the soils and water and the microbes that live in them the whole eco-system collapses. At Mt Misery Habitat Reserve the entire system is protected from the tops of the tall trees to the bedrock below.

Looking toward the skyline from the main village the scene is dominated by the escarpment. The soft sandstone that underlies the village and forested areas is capped with harder rocks. This sandstone slowly erodes away from under the hard rock, leaving it overhanging. These overhangs create rock shelters that may have been used in the past by aboriginal people.

Rock  Hills in Mist

Eventually the weight of the over hang is too great and it breaks off, leaving a cliff with a boulder field below. The boulders may roll down the slope as a whole or may be eroded to sands and soils and move down as landslides or carried by water or animals. When ice freezes inside the tiny cracks in the rock, it expands and opens the crack. This process is repeated every freeze and the crack slowly opens over many years until the parent rock sheds a flake or a boulder. The whole process is excruciatingly slow with pieces breaking off so infrequently that we have found no recent scars.

Plants such as lichens play an important role in breaking the rock down into soil particles. They exude enzymes that partially dissolve the rocks, releasing nutrients. Some areas of the rock are absorbed by the lichen. The lichen can be eaten by animals or may die and decompose into the soil, making the nutrients available for other higher plants. You can see this process in action at the lookout, where lichens are covering the exposed rocks and small fragments are breaking off and building the soils at the bottom of the cliff.

Walking Track  Sun Through Trees

Another process in rock to soil conversion is soil microbes and plant roots dissolving and fracturing the bedrock surface. This is the process occurring in the rainforest area. Here these actions take place at the bottom of the peat layer. Peat is the organic layer composed of mineral and vegetable components. These ingredients are mixed by the movement of soil creatures such as worms. The peat is often several metres deep and forms a thick sponge that holds an enormous amount of water and releases it to plant roots and to the streams.