Productivity of an ecosystem is the rate of production or the amount of organic matter formed or accumulated per unit area in unit time.
Primary productivity is the rate at which radiant energy is stored by the producers.
Gross Primary Productivity (GPP)
1. It is the amount of organic matter synthesized by producers per unit area in unit time
2. It refers to the total productivity including the energy utilized for respiration by the producers
3. It depends on chlorophyll content
4. GPP = Rate of increase in body wt or rate of organic matter synthesized by producers + the rate of respiration ( R )and other damages.
Net Primary Productivity (NPP)
1. It is the amount of organic matter stored by producers per unit area in unit time
2. It refers to the net productivity that is converted to organic matter excluding the energy utilized for respiration ( R ) by the producers
3. It depends on chlorophyll content
4. NPP= Rate of organic matter synthesized by photosynthesis by producers - the rate of energy utilized for respiration (R ) and other damages.
Summary

Primary productivity is the rate at which radiant energy is stored by the producers.
Gross Primary Productivity (GPP)
1. It is the amount of organic matter synthesized by producers per unit area in unit time
2. It refers to the total productivity including the energy utilized for respiration by the producers
3. It depends on chlorophyll content
4. GPP = Rate of increase in body wt or rate of organic matter synthesized by producers + the rate of respiration ( R )and other damages.
Net Primary Productivity (NPP)

1. It is the amount of organic matter stored by producers per unit area in unit time
2. It refers to the net productivity that is converted to organic matter excluding the energy utilized for respiration ( R ) by the producers
3. It depends on chlorophyll content
4. NPP= Rate of organic matter synthesized by photosynthesis by producers - the rate of energy utilized for respiration (R ) and other damages.
Summary
