Ecology
Autotroph
[object Object]
An organism that produces its own food from inorganic substances, typically through photosynthesis or chemosynthesis. The foundation of nearly all food webs.
Biological Context
Autotrophs capture energy from non-living sources—sunlight for photoautotrophs, chemical reactions for chemoautotrophs—and convert it into organic compounds that sustain all other life. Plants fix approximately 100-115 billion tons of carbon annually. At hydrothermal vents 2.5km deep, bacteria achieve the same function using hydrogen sulfide, demonstrating that autotrophy requires an energy gradient, not necessarily solar radiation.