The fire season hit the Australian state of New South Wales particularly hard this year. Usually the first Australian fires don't start to fire until December. This year they started in October, and some fires have been smoldering since spring. Long-lasting drought and strong winds continue to fuel the fires.
More than 100 fires are still raging in forests and bush areas near the southeast coast, including subtropical rainforests and eucalyptus forests.
Easily flammable
By mid-December, an area of over 2.7 million hectares had burned down, which corresponds to about half of Switzerland. Whole cities are covered in smoke. Sydney is also affected. The clouds of smoke can even be seen from space, show satellite images.
The fires are particularly raging in eucalyptus forests, which mostly thrive on dry, nutrient-poor soils. Their leaves are rich in oil and easily flammable.
This map from the Australian Department of Agriculture shows the problem. The green areas represent eucalyptus forests. The red dots indicate fires that the infrared radiometer of NASA's Suomi NPP satellite registered between November and early December. They are not to scale because of the zoom, but show several smaller fires.
NASA Earth Observatory
In some cases, bushfires even help many types of eucalyptus. "During a fire, the woody capsules of the eucalyptus open and the seeds they contain land on nutrient-rich ash," says biologist Ayesha Tulloch from the University of Sydney. This would allow the seeds to germinate better. In addition, many herbivorous insects die in the fires, which could be dangerous to the seedlings.
However, the current fires would come at the wrong time. Because it hardly rained and there shouldn't be any precipitation in the coming weeks, the seeds lack water to germinate.
The fires are far more threatening for rainforests and damp eucalyptus forests. "These systems don't tolerate fire," emphasizes Tulloch. In addition, they do not recover nearly as quickly as dry eucalyptus forests.
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Satellite image of the week: snapshots from spaceThe destroyed eucalyptus forests are also a problem for koalas, which feed almost exclusively on this tree species. It is estimated that more than 2,000 koalas have been burned in the bushfires. Some even speculated that the fires could completely extinguish the species. In fact, the situation with the animals is far less bad than feared. (Read more here.) "The fires only affect a small part of the koala population in Australia," says Tulloch.
It is likely that the fires will continue until at least March. At this time of year there are frequent bush fires anyway. However, meteorologists expect the coming months in southeast and northeast Australia to be even drier than usual.