Guests who choose to do the Outback Tours with Perentie Tours get a rainforest experience. The Dutch knew about the west coast of Australia well before Captain Cook arrived in 1770 but never claimed the land as the west coast is barren due to the absence of mountain ranges and prevailing winds. There are as least three basic factors required to form a rainforest:
- High temperature/humidity
- Prevailing winds
Perhaps the most bewildering element is the Mountains. It’s because the shape of the mountains are directly related to the amount of rainfall that falls in any particular area and can be quite specific. As the prevailing winds in Australia (trade winds) blow from the south-east, they need to rise sharply to pass over the Great Dividing Range that extends up the East Coast. This sudden lift causes moisture in the form of mist, fog, clouds or rain. Examples of this can often be seen along the coast, but one of the best examples I have seen was at Uluru (Ayres Rock), where the cloud that forms as the air has to rise over the rock, extends for many kilometres, sometimes raining on just one side of this huge sandstone formation.
Because of the dramatic variations in elevation along the East Coast, vegetation in the Cairns area can vary from tropical rainforest, open eucalypt forests, wetlands and mangrove forests. The base of the range adjacent the Cairns coastal plain is initially eucalyptus with rainforest often beginning quite abruptly where the moisture begins the form. That moisture runs down the mountain slopes to create more rainforest in the gullies and coastal plains in addition to mangrove forests and wetlands, therefore the rainforest on the tablelands is very different from that on the coastal plain. There is no rainforest after the land begins to level out on top of the range and it soon becomes wooded savannah relying on seasonal rain depressions from the monsoon. This all happen less than 100kms from the coastline. Many think that the further north from Cairns, the more rainforest but this isn’t true because there are no ranges along the coast towards the north.
For more than 200 million years, successive climate changes have resulted in the contraction and expansion of rainforest throughout much of Australia and during the drier ice ages, many plants and animals didn’t adapt to the new conditions and were driven to extinction. But in Cairns and the surrounding area, the cloudy wet mountaintops and deep moist valleys provided refuge from these climatic fluctuations for many life forms. Those that survived have evolved into the plants and animals in the region today, many of which have changed very little since those ice-age ancestors. Some recently discovered plants are not found anywhere else in the world and can provide an insight into the evolution of flowering plants, which began about 120 million years ago. This is one of the main elements that inspired the Daintree area (including Cape Tribulation) to be classified as a World Heritage National Park.
To learn more, have a look at the Perentie Tours home page