Almost every year, Australia experiences a ‘bushfire season.’ A bushfire is a fire that occurs in a large area of bush or forest and spreads very fast. Bushfires are started either by careless human activity or by natural causes. When the ground and vegetation are very dry, like they are in a drought, the fires spread quickly.
The major cause of bushfire in Australia is dry lightning. Dry lightning happens when it rains, but most or all of the rain evaporates before reaching the ground because of intense heat. Australia has had a long period of drought and high temperatures. This has led to a lot of vegetation drying up. When dry lightning occurs, it strikes the dry leaves and trees and starts a fire. Some irresponsible people have also started the fire.
Australia has also had very strong winds. The winds have helped spread fire by fanning the flames across forests. This has made it very difficult for fire-fighters to control or stop the fire. A common way to stop a big bushfire is to light-controlled fires in their path. For a fire to start and spread, there needs to be three things: heat, oxygen, and fuel.
In this case, the heat is caused by the dry lightning strikes, the oxygen is in the open air, and the fuel is the dry leaves, twigs, and trees. By lightning controlled fires, fire-fighters burn up the fuel, and the fire cannot spread because there is nothing to burn.
The Australia fires have had a big effect on the environment. Many insects, plants, and animals have been destroyed. The fires have also caused huge plumes of smoke that have polluted the air, making it difficult for people to breathe properly around affected areas. The destruction of vegetation means that there is likely to be a food shortage and large areas that humans cannot live in.
Water bodies like the ocean are also polluted by ash from the fires. This is affecting marine life by changing the acidity of the water.
One positive thing is that the fires burning the vegetation return nutrients back to the soil as ash. Plants can also regenerate. For example, eucalyptus seeds are protected by a thick shell and can survive a fire.
Some grasses grow from deep in the soil, so their roots are insulated from the fire.