Not all species introduced to a new area become invasive. Why have some introduced species become invasive, while others have either died off or become a harmless addition to our landscape?

Question

What will be an ideal response?

Answer 1

Invasive species generally grow quickly and displace native species by outcompeting native species for resources such as water or nutrients and by changing the ecosystem so dramatically that the native species can no longer survive. Some invasive species are generalists, able to use a variety of resources or live in a wide variety of habitats. Also, many invasive species spread when introduced because the new environment does not contain the natural predators or diseases that would control their populations in their native area. Introduced species that have either died off or simply become a harmless addition to the landscape may be held in check through interspecific competition or by predators and/or disease. They may also have been introduced into habitats that are not optimal (e.g., colder than their native habitat), thus limiting their reproductive and competitive success.