Wildfires Are Obliterating Australia's Iconic Ecosystems


Australians haven’t seen anything like the bushfires currently tearing through their country. The conflagrations are obliterating landscapes and their ecosystems, reshaping the continent in irreparable ways.

Bushfires aren’t supposed to behave like this. In a normal world, every so often a lightning-sparked fire will roll through a landscape, clearing away old foliage to make way for the new. Such periodic, relatively mild fires allow many animals to escape: Birds fly away and koalas shimmy farther up trees as fire burns the ground vegetation below. Insects and small mammals might even take refuge in a log to wait out the firestorm passing above.

But this is not a normal world. Climate change has supercharged these wildfires, turning whole landscapes into tinder. Fires are marching so fast across Australia that untold numbers of animals can’t escape, even kangaroos and birds, which should have the means. “The numbers are fairly hard to determine, because nothing like this has happened before, especially across this scale,” says University of New England entomologist Nigel Andrew, former president of the Ecological Society of Australia. “Previously, it's that fires have been patchy in their distribution. They haven't been completely taking out entire landscapes.”

The ferocious bushfires have killed at least 25 people, with 15 million acres scorched so far. On south Australia’s Kangaroo Island, perhaps half of the koala population has been killed. One estimate puts the bushfires’ total tally at over a billion mammals, birds, and reptiles, but that doesn’t include other animals like insects, whose toll could be much, much higher. One of Andrew’s colleagues estimates that more than 3 trillion insects from one family alone, the rove beetles, may have perished so far. A note of caution here, though: Scientists have no way of knowing exactly how many organisms died—these calculations are done by scaling up species surveys done in smaller areas.

article image

The world is getting warmer, the weather is getting worse. Here's everything you need to know about what humans can do to stop wrecking the planet.

We won’t know the real toll for some time, but this much is clear: The bushfires burning in Australia have crippled iconic habitats that make the continent an ecological wonder. Not even the continent’s rainforests, which typically can resist the advance of a blaze, are safe from the firestorm. “There will be a lot of species that are going to go extinct because of this,” says Andrew. For species already threatened with extinction, already clinging to the edge, this may have been the swift and final blow.

Australia is a continent of fire, and as such, its organisms are adapted to the flames. Some trees, for instance, time their germination to occur after a fire, when nutrients have been injected into the soil and fewer trees are competing for light and other resources. But seeds that can survive a typical bushfire might not be able to withstand these uber-fires. Scientists won’t know which species made it until the first rains come and they can watch what germinates.

The decimation of a landscape’s vegetation may draw in opportunists as well. Weedier species that grow quicker could take hold, perhaps turning what used to be a thick forest into a thinner, grassier one. Hardier invasive species could rapidly dominate. “A lot of the potentially more charismatic or more unique species might not be able to survive in their natural landscapes,” says Andrew. “So that's going to be the biggest issue: The diversity of our natural environments is going to change.”

Plants also make up a critical link in the food chain, and when they exit, so too does the food source for a range of animals. Even if plant-eaters survive the blaze itself, they may starve in the aftermath. “If the youngsters survive and their parents can't find enough food to produce enough milk,” says Andrew, “then the parents will just abandon the offspring, so they can't survive.”