But wait, what exactly does it mean when we call a species “invasive”? A species becomes invasive when it spreads beyond the area where it is from and negatively impacts its new environment, to the detriment of native species. It’s important to remember that no species are inherently invasive, as all species are native somewhere. While the blue morning glory is a welcome sight in Florida, it can wreak havoc here in Australia. Further, many introduced species do not become invasive. I often see jasmine flowers around the city, but they don’t tend to spread beyond where they’re planted and aren’t considered invasive. Whether or not a plant acts invasively thus depends on the plant’s traits and the context in which it grows.
What makes invasives so harmful is that they disrupt native ecosystems. The maintenance of native ecosystems is important for numerous reasons. For one, native ecosystems are integrally tied to a region’s cultural heritage. Here in Australia, Aboriginal peoples have developed a rich, centuries-old tradition centered around native plants and animals. Further, native ecosystems provide humans with benefits known as “ecosystem services”. Ecosystem services include things such as the storage of carbon in forests that reduces greenhouse gases and the way that long tree roots can stabilize mountain slopes to help prevent landslides. When invasive species arrive, they degrade native ecosystems, thus disrupting traditions built around them and the ecosystem services that they provide.
