(See also The Rainforests of Australia, below)
As much land has been cleared in the last 50 years in Australia as was cleared in the previous 150 years. For the year of 1990, land clearing in Australia totalled more than half of that which was cleared in Brazilian Amazonia. Land cleared in Australia in 1994 was equal to that which was cleared in the previous five years. (This included 640,000 hectares of virgin bushland.)
Without the introduction of legislation, this rate of clearance will probably continue to increase. As it is, the eucalyptus forests of mainland Australia, where logging is the major cause of forest degradation and loss, are being destroyed and replaced by plantations. This is especially so in the southwest of the country and Tasmania. (It is ironic to think that, overall, many forests were probably once rainforests prior to their being disturbed - ie, logged, burned and cleared - by European settlers.)
The rainforests in northern Queensland are still threatened by development and poor planning laws which do not protect the large areas of rainforest existing on private land.
The Australian Conservation Foundation's Michael Krockenberger has said that "native vegetation clearance represents one of the largest contributors to greenhouse emissions in Australia". In 1990, carbon dioxide emissions from forest clearing for agriculture totalled 156 million tonnes, which is some 27.3 percent of Australia's nett emissions in carbon dioxide equivalent. (Note: the rate of clearing has doubled since 1990!)
About 20% of Australia's known species of flowering plants and conifers are endangered, vulnerable, or threatened with extinction, especially in the south-west of the country and Tasmania.
Historically, Australia's rainforests have suffered far more negative impact than our eucalypt forests. The clearing of rainforests has happened on such a massive scale that it has altered our perception of native forests. Most Australian people now conceive of native forests as being comprised mostly of eucalypts ('gum trees'). The following quote from W.D. Francis, published in 1929, virtually spelt-out the recipe for destruction of rainforests by new settlers in order to make way for eucalypt forests.
"When it was found that trees of the rain forest or 'scrubs', when felled or burnt were killed, it was realised that the rain forest was often more easily cleared than the Eucalyptus forests.
"Very many of the Eucalyptus and open forest constituents persistently shoot after being felled and fired. The revival of these forests in this way makes the task of the settler in clearing operations a difficult one. On the other hand, the extreme sensitiveness to the effects of fire which is exhibited by rain forests allows them to be cleared fairly expeditiously after they have been felled.
"...It has been noticed that, when small patches of rainforest are left in cleared areas, the large living trees on the margins often die gradually. Presumably their death is the result of exposure to which they are unaccustomed... The writer's informant believes that mature trees are much more subject to this kind of injury than are young, vigorous ones."
It is clear that rainforests are particularly vulnerable to long-term damage as a result of logging. Rainforest trees benefit from a continuous forest canopy, and adjacent clearcutting or road-making can cause far more devastation in the forest than is intended.
Rainforest buffer areas which may include some old growth eucalypts, give natural protection to rainforests, which are generally in moist, sheltered pockets and creek valleys where fire seldom penetrates. Vegetation migrates as climate change occurs. The canopy of shelter provided by the rainforest buffer areas can encourage growth of rainforest species.
Dry forests occur in locations such as ridges, where fire is a more common occurrence. Fires become more likely after roads bring an increase of human activity into a forest. After logging in rainforest buffer zones, the regrowth of fire-promoting species such as eucalypts can increase fire danger to the adjacent rainforest.
Mixed forests represent a stage in the succession of rainforests. They have a history of disturbance by fire. In mixed forests, a tall eucalypt overstorey shelters a rainforest understorey. Unfortunately, the different status given to mixed forests in forestry legislation makes them available for logging, whereas in most instances, rainforest are protected.