Secondary Production: Accumulation of Carbon Compounds in Biomass by Heterotrophs
Definition
Secondary production
Secondary production is the accumulation of carbon compounds in biomass by animals and other heterotrophs, which ingest food and build these compounds into proteins and other macromolecules.
- Secondary production works through:
- Ingestion: Carbon compounds like sugars and amino acids are ingested from food.
- Assimilation: These compounds are used to build biomass (e.g., muscles, tissues).
- Respiration Loss: Some carbon compounds are oxidized for energy, with carbon dioxide released as a byproduct.
Why Is Secondary Production Lower Than Primary Production?
- Energy Loss: Cell respiration results in a loss of biomass at every trophic level.
- Trophic Decline: Secondary production declines with each successive trophic level, as energy and carbon are lost in respiration and waste.
Reflected in Farm Yields
- Differences in production efficiency can be seen in farm yields:
- Crop Yields: Production of crops like wheat yields much more per hectare than meat.
- Animal Yields: Producing meat requires far more energy input and land, resulting in lower yields.
- Wheat: 8.7 tonnes ha⁻¹ yr⁻¹.
- Beef: 0.2 tonnes ha⁻¹ yr⁻¹.
This efficiency disparity is why plant-based diets are considered more sustainable by environmentalists.
