This distinction arises due to Australia’s unique biodiversity and evolutionary history. As you likely know, Earth’s continents have moved multiple times over geologic history. Throughout these shifts, the Australian continent has remained isolated from the rest of Earth’s landmasses more often than most of the other modern continents. As a result, Australian flora and fauna have mostly evolved in geographic isolation. That’s why Australian species such as Eucalyptus trees and kangaroos are so distinctive from what grows elsewhere on the plant.
While this unique biodiversity is part of what makes Australia so fascinating, it also makes Australian ecosystems especially susceptible to damage by invasive species. Since plants and animals from other areas on the planet evolved separately from Australian species, their introduction can greatly disturb native ecosystems. And in our increasing global world, encounters with invasive species are becoming more and more frequent. Most new species are introduced by people who move them. While many introduced species have a neutral effect, some become invasive and harm native ecosystems.
The threat of invasive species is being counteracted at numerous levels. Federal and State governments have strict biosecurity laws, which seek to prevent the introduction of pests and diseases from outside of Australia. There are also several non-governmental organizations, such as the Invasive Species Council, that help to educate the public about invasive species and support policies to prevent their spread.
Average people, too, play a role in minimizing the spread of invasives.
