What is a Food Chain and How Does It Work in an Ecosystem?

A food chain is a hierarchical series of organisms in an ecosystem, in which each group of organisms is dependent on the next as a source of food. It starts with producers, such as plants, which are then consumed by primary consumers, such as herbivores, and then by secondary and tertiary consumers. Decomposers, such as fungi and bacteria, break down the dead organisms and waste, returning nutrients to the soil. This continuous flow of energy and nutrients through the ecosystem sustains life and maintains balance in nature.