Ecological Productivity

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