Net Community Productivity (NCP) is:
Net community productivity is the net rate at which organic carbon accumulates in an ecosystem after respiration by both autotrophs and heterotrophs. Ecosystem respiration, RE, includes plant respiration plus respiration by consumers and decomposers, so subtracting RE from gross primary productivity gives NCP. Carbon accounting separates gross fixation from respiratory expenditure. Gross primary productivity records all photosynthetic carbon fixation; net primary productivity subtracts autotrophic respiration, while net community productivity subtracts total ecosystem respiration. Keeping flux
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 17