Which of the following best describes the impact of noxious weeds on ecosystems?

Noxious weeds are invasive plant species that can significantly disrupt local ecosystems and reduce biodiversity. These weeds often compete aggressively with native plants for resources such as sunlight, water, and nutrients. As a result, they can outcompete and displace native species, altering habitat structures and functions. This disruption can lead to a decline in native plant populations, which in turn affects the animals that rely on those plants for food and shelter, ultimately diminishing the overall biodiversity of the ecosystem.

In contrast, options that suggest noxious weeds promote native species' growth, uniformly enhance soil quality, or have no substantial ecological impact overlook the ways in which these invasive species can alter ecological dynamics and harm the balance of natural ecosystems. The presence of noxious weeds is widely associated with negative outcomes, making the assertion that they disrupt ecosystems and reduce biodiversity the most accurate description of their impact.