Question

Write a difference between net primary productivity and gross productivity

Answer 1

Hint: There are two types of primary productivity. The net primary productivity is basically the gross primary productivity excluding the energy required for respiration.

Complete answer: Primary productivity can further be divided into two aspects, viz. net primary productivity (NPP) and gross primary productivity (GPP).
There are certain differences between the two as mentioned below.

Net Primary Productivity (NPP)	Gross Primary Productivity (GPP)
NPP refers to the amount of organic substance stored by autotrophs or producers in unit time per unit area.	GPP refers to the amount of organic substance synthesized by the producers in unit time per unit area.
It describes how much glucose is produced excluding the amount of energy utilized for respiratory processes.	It describes how much glucose is produced during photosynthesis.
The value of NPP is always comparatively lower.	The value of GPP is always comparatively higher.

Additional information: You can observe that your bank account balance is determined as follows:
Your Net production is equal to your Gross Production minus Respiration, which is similar to the equation above that states the Net Primary Production (NPP) = the Gross Primary Production (GPP) minus Respiration (R).

Note: The word ‘productivity’ has several meanings in different contexts. In ecology, productivity refers to the amount of food produced by the autotrophs (producers).
Another term used in ecology is the primary productivity.
It describes the rate at which green plants and other autotrophs (photosynthetic organisms) produce organic compounds.