Aquatic ecology and Biodiversity

Unit 5- Productivity

5.3. Measurement of primary production
Primary production
Gross primary production: GPP is the total amount of CO₂ that is fixed by the plant in photosynthesis. Net primary production: NPP is the net amount of primary production after the costs of plant respiration are included. Therefore, NPP = GPP - R respiration: R is the amount of CO₂ that is lost from an organism or system from metabolic activity. Respiration can be further divided into components that reflect the source of the CO₂.