Question

Which of the following best describes Net Primary Productivity (NPP)?

Options

• The total rate of organic matter produced during photosynthesis

• The organic matter remaining after respiratory losses by producers are subtracted from GPP

• The total energy available to all trophic levels combined

• The rate of formation of new organic matter at the consumer level

Answer 1

NPP is calculated by subtracting respiratory loss (R) from Gross Primary Productivity (GPP) using the formula NPP = GPP − R. This represents the actual biomass available to consumers (herbivores and decomposers) after plants have used energy for their own metabolic processes.