What describes chemical agents that target invasive plant species and require control measures?

The choice of noxious weeds is appropriate because these are defined as invasive plant species that are harmful to natural ecosystems, agriculture, or human health. They often outcompete native plants for resources like sunlight, water, and nutrients, leading to a decline in biodiversity.

Noxious weeds are typically regulated by various governmental entities, and control measures may include the use of chemical agents such as herbicides to prevent their spread and mitigate their negative impacts. These chemical agents are specifically designed to target and reduce populations of these invasive species, helping to restore balance to ecosystems.

The other options refer to concepts that do not involve the need for targeted chemical control measures. Native species are those plants that are indigenous to a specific area and play crucial roles in their ecosystems. Endangered plants are species at risk of extinction and require conservation efforts, while companion plants are selected for their beneficial relationships with other plants in gardening and agriculture, but they are not associated with invasive management. Therefore, noxious weeds specifically describe the scenario concerning chemical agents and the need for control measures against invasive plant species.