Why are invasive species a concern in ecosystems?

Invasive species are a significant concern in ecosystems primarily because they can disrupt local ecosystems and harm native species. They often outcompete native species for resources such as food, space, and light. This competition can lead to a decline in native populations, which may struggle to survive against the more aggressive and adaptable invasive species.

Invasive species can also alter habitat structures and the interactions within food chains, leading to broader ecological changes. These disruptions may reduce biodiversity, which is crucial for maintaining resilient ecosystems. Invasive species might introduce diseases to which local wildlife have no immunity, further threatening native species' survival.

On the other hand, the other statements do not accurately reflect the impacts of invasive species. For instance, the idea that invasive species reproduce slower than native species underestimates their ability to proliferate rapidly in new environments. Furthermore, while nutrient contributions are essential for soil health, invasive species typically do not provide essential nutrients; rather, they can degrade the quality of the ecosystem. Lastly, the notion that they help preserve biodiversity in their new environments overlooks the negative consequences they bring to the existing native species and their habitats.