Secondary productivity is defined as:

Define the following terms:
$(i)$ Productivity
$(ii)$ Decomposition

Rate of production of organic matter by producers per unit time and area is

The idea of the productivity of an ecosystem can be obtained from:

State whether the following statements are True or False:
$I.$ The total organic matter synthesized by the producers in the process of photosynthesis per unit time and area is known as gross primary productivity.
$II.$ Net primary productivity is the weight of the organic matter stored by the producers in a unit area/volume per unit time.

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