What defines autotrophs in an ecosystem?

Autotrophs are primarily defined by their ability to synthesize their own organic compounds using inorganic materials and an energy source. This process typically occurs through photosynthesis in plants, where they convert carbon dioxide and water into glucose using sunlight. In aquatic ecosystems, some autotrophs, such as certain bacteria, may use chemosynthesis, deriving energy from chemical reactions rather than sunlight.

By obtaining inorganic nutrients from the abiotic environment—like minerals, water, and carbon dioxide—autotrophs play a crucial role in the food web as primary producers. This ability allows them to form the base of the ecosystem's energy pyramid, supporting a variety of consumer organisms that depend on them for energy. Therefore, the defining feature of autotrophs is their capacity to utilize inorganic compounds to create organic matter, which is vital for ecosystem functioning.