Answer:
Net Primary productivity
Step-by-step explanation:
In an ecosystem, primary productivity is a term used for autotrophic organisms. It is the process by which these organisms like plants, green algae etc. make their own food using inorganic sources. However, they do not utilize all the matter they make from this process.
The NET PRIMARY PRODUCTIVITY (NPP) is the amount of organic material that is available for transfer to the next trophic level after subtracting material used for respiration. This means that NPP is the amount available after removal of the one to be lost via respiration i.e. NPP = GPP - respiration.