Question

Which of the following is expected to have the highest value (gm/m2/yr) in a grassland ecosystem

• A. Tertiary production
• B. Gross production (GP)
• C. Net production (NP)
• D. Secondary production

Answer 1

Answer: (B)

Gross production (GP)

Answer 2

Gross primary productivity, or GPP, represents the speed at which producers synthesize organic matter within a specific area over a given time. The portion of this productivity that remains available for heterotrophs is termed net primary productivity, or NPP. NPP serves as a measure of the energy or biomass that remains after producers have covered their respiration and maintenance costs. Secondary productivity, on the other hand, signifies the rate at which new biomass is generated by heterotrophic organisms or consumers. In a grassland ecosystem, GPP is likely to be at its highest because abundant grass, as the primary producers, incurs relatively low expenses in terms of respiration and metabolic needs.