Enter the gross primary productivity and the respiration into the Calculator. The calculator will evaluate the Net Productivity. 

Net Productivity Formula

NPP = GPP - R

Variables:

  • NPP is the Net Productivity ()
  • GPP is the gross primary productivity
  • R is the respiration

To calculate the Net Productivity, subtract the respiration from the gross primary productivity.

How to Calculate Net Productivity?

The following steps outline how to calculate the Net Productivity.


  1. First, determine the gross primary productivity. 
  2. Next, determine the respiration. 
  3. Next, gather the formula from above = NPP = GPP – R.
  4. Finally, calculate the Net Productivity.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

gross primary productivity = 1780

respiration = 200

FAQs

What is Gross Primary Productivity (GPP)?
Gross Primary Productivity is the total amount of energy or biomass produced by photosynthesis in a given area and time by plants and other photosynthetic organisms. It represents the rate at which these organisms convert solar energy into chemical energy.

Why is Net Primary Productivity (NPP) important?
Net Primary Productivity represents the amount of biomass or energy that remains available for consumption by heterotrophic organisms (such as animals and fungi) after accounting for the energy used by plants in respiration. It is a crucial indicator of the health and productivity of an ecosystem.

How does respiration affect the calculation of Net Productivity?
Respiration is the process by which organisms use oxygen to break down food molecules to get chemical energy for cell functions. It represents the energy expenditure of plants and is subtracted from Gross Primary Productivity (GPP) to calculate Net Productivity (NPP), as it is the energy used by plants for growth, maintenance, and other metabolic activities.

Can Net Productivity be negative, and what does that indicate?
Yes, Net Productivity can be negative if the respiration rate exceeds the Gross Primary Productivity. This indicates that the ecosystem is using more energy than it is producing, which can be a sign of ecological stress or degradation. Negative NPP values are more common in ecosystems with high respiration rates, such as decaying forests or polluted water bodies.