However, human influence caused an increase in fire frequency.
It is confined to areas of high rainfall and low fire frequency.
An optimum fire frequency for growth is every 3 to 10 years.
The drier western region, which receives lower average rainfall, had higher natural fire frequencies.
In the Mediterranean region, the current fire frequency due to human activity is considered much larger than the natural rate.
However, higher temperatures and a long dry season mean increased fire frequency, which could serve to offset the new woody growth.
Settlement increased fire frequency in the late 19th century until fire suppression became popular.
The distribution of tree species is determined by fire frequency and extent.
"As humans move into an area, you see changes in fire frequency," he said.
However fire frequency has likely been altered by the activities of European settlers and their industries since 1803.
