100 Places To Remember: Greater Blue Mountains New South Wales, Australia
Geschreven op 20-5-2010 - Erik van Erne. Geplaatst in Natuur
A Blue Haze of Eucalyptus Vapour. This rugged sandstone plateau, with its steep mountainsides, deep gorges and inaccessible valleys, rivers and lakes, takes its name from the blue haze that emanates from its eucalyptus forest.
Covering 10,000 square kilometres west of Sydney, the Greater Blue Mountains are home to more than 100 eucalyptus genera, many of which are believed to be evolutionary relict species that have survived for almost 200 million years.
The blue haze is caused by vapour from highly flammable eucalyptus oil released into the atmosphere by the leaves in response to heat. It has been this way for millions of years, and occasional wildfires caused by the heat and vapour are part of the ecosystem. Many of the eucalyptus and other native floral species are so adapted to fire that they only release their seeds to allow new plants to grow after fires.
This is a very delicately balanced system, and the projected rise in average annual temperature and decrease in rainfall due to climate change could lead to an increased risk of more frequent, intense and destructive wildfires within the next 20-60 years.
If the fires become too frequent, they could kill the plants before they have matured sufficiently to produce new seeds. This would lead to a significant decline in the diversity of eucalyptus species and other flora, and alter the fragile ecosystem of the Greater Blue Mountain area.
