In ecology, production (or productivity) refers to the rate of generation of biomass in an ecosystem
- It is usually expressed in units of mass per area per time (e.g. kg m–2 day–1)
Primary Production
Primary production describes the production of chemical energy in organic compounds by producers
- The main source of energy for primary production is sunlight, but a fraction may be driven by chemosynthesis by lithotrophs
Primary production may be categorised as one of two types:
- Gross primary production (GPP) is the amount of chemical energy as biomass that a producer creates in a given length of time
- Net primary production (NPP) is the amount of chemical energy that is not consumed by respiration (NPP = GPP – respiration)
Secondary Production
Secondary production describes the generation of biomass by heterotrophic organisms (consumers)
- This biomass generation is driven by the transfer of organic compounds between trophic levels via feeding
- Secondary production may also be categorised according to gross (total) and net (usable) amounts of biomass
Ecological Productivity
