Net primary productivity, or NPP, is gross primary productivity minus the rate of energy loss to metabolism and maintenance. In other words, it’s the rate at which energy is stored as biomass by plants or other primary producers and made available to the consumers in the ecosystem.

How do you calculate net productivity?

To calculate NPP, you take the total amount of carbon that the plant ​fixes​ (or turns into usable material) and subtract the amount of carbon lost during respiration. The total amount of carbon taken in by the plant is known as the ​gross primary productivity​ (GPP), and the amount of respiration is known as ​Ra​.

What is net productivity in an ecosystem?

Net productivity is the amount of energy trapped in organic matter during a specified interval at a given trophic level less that lost by the respiration of the organisms at that level. … The table shows representative values for the net productivity of a variety of ecosystems — both natural and managed.