A community of interacting organisms plus the physical environment in which they live.
gross primary production (GPP)
The amount of energy that autotrophs capture by photosynthesis and chemosynthesis.
leaf area index
The area of leaves per unit of ground area (a dimensionless number, since it is an area divided by an area).
net ecosystem exchange
See net ecosystem production.
net ecosystem production
The combined ecosystem fluxes of CO2, including net primary production and heterotrophic respiration.
net primary production (NPP)
The amount of energy (per unit time) that autotrophs capture by photosynthesis and chemosynthesis, minus the amount used in cellular respiration.
net secondary production
The balance between energy gain through ingestion, and energy losses by cellular respiration and egestion in heterotrophs.
primary production
The chemical energy in an ecosystem generated by autotrophs, derived from the fixation of carbon during photosynthesis and chemosynthesis. See also gross primary production, net primary production.
secondary production
Energy in an ecosystem that is derived from the consumption of organic compounds produced by other organisms. Compare primary production.
