Formula of net primary production

Question

Write down the formula of net primary production (or NPP)? How NPP relate to the energy pyramids.

Answer 1

Net primary production is gross primary productivity less the organic material consumed as energy source in metabolism of producers: NPP = GPP - (organic material spent in the aerobic respiration). It represents organic material which is accessible in first tropic level. The base of energy pyramids should represent the NPP and not the GPP because the idea of these pyramids is to prove the accessible energy in each tropic level of food chain.