Iowa Certified Handler Practice Test

The impact of pesticide overuse on biodiversity is significant and largely negative, as it leads to a reduction of species diversity. Pesticides can have detrimental effects on various organisms in the ecosystem, including non-target species such as pollinators, birds, amphibians, and beneficial insects. When pesticides are applied excessively, they can disrupt the natural balance of ecosystems, leading to the decline or extinction of sensitive species. This loss reduces the overall variety of life forms, habitat resilience, and ecosystem services that are vital for environmental health and stability.

In contrast, other options suggest outcomes that are either neutral or positive, which do not align with the well-documented effects of pesticide overuse. For instance, enhancing species diversity or promoting beneficial insect populations would indicate a favorable interaction with the ecosystem, which is not the case when pesticides are applied inappropriately. Therefore, the correct understanding revolves around recognizing that pesticide overuse threatens and diminishes the variety of living organisms within an ecosystem.