Primary Production: Autotrophs Build Biomass by Fixing Carbon
- Production in ecosystems is the accumulation of carbon compounds in biomass.
- This process forms the foundation of life on Earth, as both autotrophs and heterotrophs contribute to biomass production through growth and reproduction.
Definition
Primary production
Primary production refers to the synthesis of organic carbon compounds from carbon dioxide by autotrophs, such as plants and algae, using external energy sources like sunlight.
- Plants are termed primary producers because they generate the carbon compounds that sustain other organisms in the ecosystem.
This measurement focuses on carbon because it is the backbone of organic molecules, making it a key indicator of biomass accumulation.
Key Metrics of Primary Production
- Gross Primary Production (GPP): The total biomass of carbon compounds made by plants during photosynthesis.
- Net Primary Production (NPP): The biomass available to consumers after accounting for carbon lost due to plant respiration. NPP = GPP - Respiration.
Units of Measurement
- GPP and NPP are typically measured over long time intervals (e.g., a year) and at the ecosystem level.
