Question

Differentiate between gross primary productivity and net primary productivity.

Differentiate between Net primary productivity and Gross primary productivity in an ecosystem.

Answer 1

Sr. No.	Gross Primary Productivity (GPP)	Net Primary Productivity (NPP)
1.	It is the total rate of production of organic matter during photosynthesis.	It is the rate of storage of organic matter after subtracting respiration.
2.	Measured as the total photosynthesis in the ecosystem.	Defined as GPP minus respiration losses (R).
3.	Represents the gross amount of energy fixed by producers.	Represents the energy available to the next trophic level.
4.	A considerable amount is used up by plants in respiration.	Net organic matter available for consumption by herbivores and decomposers.
5.	Indicates total organic matter produced irrespective of use.	Indicates biomass available for growth and consumption.

Answer 2

Differentiate between Net primary productivity and Gross primary productivity in an ecosystem.

Feature	GPP	NPP
Definition:	Total amount of organic matter produced by photosynthesis	The actual amount of energy retained in biomass following respiration.
Formula:	GPP = NPP + Respiration (R)	NPP = GPP − Respiration (R)
Usage:	includes the energy required for plant development, reproduction, and care.	Just the energy required to create new biomass.
Represents:	The total amount of energy that an ecosystem receives.	Energy available to decomposers and herbivores.