NPP = GPP - R
Productivity is the rate of production of biomass at any trophic level at any given interval of time.
Gross productivity : It is the rate of production of organic matter by green plants per unit time per unit area. On the other hand we can say that total amount of productivity.
Net Primary Productivity : It is the different between gross primary productivity and the loss due to respiration.
Secondary Productivity : It is rate of production or formation of new organic matter by consumers especially the consumers of the first order or herbivores.
