What defines a primary producer in an ecosystem?

A primary producer in an ecosystem is defined as an organism that produces organic material through the process of photosynthesis. This process involves converting light energy from the sun into chemical energy, allowing these organisms—typically plants, algae, and certain bacteria—to create food (organic compounds) using carbon dioxide and water. As a fundamental component of the food web, primary producers are crucial because they serve as the foundational energy source for all consumers in the ecosystem.

This ability to synthesize organic material means that primary producers are essential for sustaining life; they convert inorganic substances into organic compounds that form the basis for energy flow within the ecosystem. This role differentiates them from other types of organisms, such as consumers and decomposers, which rely on the organic materials produced by primary producers for their energy needs.