Invasive species can have various negative effects on native ecosystems, such as outcompeting native species for resources, disrupting the natural balance of the ecosystem, altering habitats, and reducing biodiversity. They can also introduce new diseases and predators that native species are not equipped to handle, leading to declines in native populations. Additionally, invasive species can cause economic losses and impact human health. It is important to manage and control invasive species to protect native ecosystems.