Which organism group is primarily responsible for primary production?
Autotrophs are responsible for primary production because they synthesize organic molecules from inorganic carbon using an external energy source. Photoautotrophs—including plants, algae, and cyanobacteria—capture light energy, while chemoautotrophs obtain energy by oxidizing inorganic substances such as ammonia, hydrogen sulfide, hydrogen, or ferrous iron. In both cases, carbon fixation builds biomass without consuming preformed organic food. This production forms the energetic and carbon base for consumers and decomposers. Chemoautotrophs are therefore a valid subset, but “autotrophs” is the
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 17
