One of the reasons that invasive species are able to succeed is that they often leave their predators and competitors behind in their native ecosystems. Without these natural checks and balances they are able to reproduce rapidly and out-compete native species.
Invasive species can alter ecological relationships among native species and can affect ecosystem function, economic value of ecosystems, and human health.
To learn more about invasive plants visit: What are Invasive Species?
For a list of terrestrial invasives visit: Terrestrial Invasives
Why should we care about invasives? Visit: Invasive Species, Why Should we Care?