Which of the following terms describes the introduction of harmful substances into nature?

The term that describes the introduction of harmful substances into nature is pollution. Pollution occurs when contaminants are released into the environment, adversely affecting air, water, and land quality. This can involve a variety of harmful substances, including chemicals, waste products, and toxins, which can have detrimental effects on ecosystems, wildlife, and human health.

Understanding pollution is crucial for natural resource specialists as it highlights the importance of managing and reducing these harmful substances to preserve ecological health and promote a sustainable environment. The other terms provided, while related to environmental practices, do not specifically address the idea of introducing harmful substances. Conservation refers to the protection and management of natural resources, habitat restoration deals with returning degraded habitats to a stable and healthy state, and sustainability focuses on meeting current needs without compromising future generations' ability to meet theirs.