Fixes inorganic carbon into biomass using:
Operational definition
Ecological role.
An organism or biological system that uses an external energy source to fix inorganic carbon into new organic matter, thereby introducing newly produced biomass into an ecosystem’s food web.
Primary production may be driven by:
- light in photoautotrophy;
- chemical reactions in chemoautotrophy.
A photoheterotroph is phototrophic but is not a primary producer with respect to the organic carbon it requires.
99.1 Photoautotrophy
External input:
light
99.2 Chemoautotrophy
chemical/geochemical free energy
A phototroph is not automatically a primary producer; a photoheterotroph uses light but still depends upon organic carbon.