Net productivity is

Solution(By Examveda Team)

Net productivity is Gross production - respiration.
Primary production is sometimes broken down into Net Primary Production (NPP) and Gross Primary Production (GPP). Net primary production measures the organic molecules by primary producers.
Net primary production also measures the amount of carbon assimilated into organic molecules by primary producers but does not include organic molecules that are then broken down again by the organism for biological processes such as cellular respiration. NPP = GPP - respiration [by plants]