Q. Assertion : Net primary productivity is gross primary productivity minus respiration.
Reason : Secondary productivity is produced by heterotrophs.

 4609  197 AIIMSAIIMS 2018Ecosystem Report Error

Solution:

Net primary productivity is the rate of organic matter built up or stored by producers in their bodies in a unit area/volume per unit time. Net productivity is equal to gross primary productivity minus loss due to respiration and other reasons. Rate of increase in energy containing organic matter or biomass by heterotrophs or consumers per unit time and area is known as secondary productivity.