Productivity of Ecosystem

It is usually expressed in units of mass per unit surface per unit time

Productivity of an ecosystem is the rate of generation of organic matter in an ecosystem. Productivity is a measurable parameter of an ecosystem. Also, important characteristics of an ecosystem.

  • Most productive ecosystems - tropical rainforest, estuaries, coral reefs
  • Least productive ecosystem - open oceans, deserts
Different ecosystems can be directly compared on the basis of productivity.
Two main factors determine the productivity of an ecosystem. There are,
  1. Availability of solar radiation to primary producers for photosynthesis.
  2. The efficiency with which autotrophs convert the solar energy into usable form by photosynthesis.

Primary productivity


Produces organic food from inorganic substances. In this process, autotrophs convert solar energy to chemical energy by synthesizing carbohydrates.
Primary productivity is the rate at which the accumulation of organic matter or energy takes place in green plants through photosynthesis.

Primary productivity at the trophic level 1 can be expressed as Net primary productivity and Gross primary productivity.

Gross Primary Productivity(GPP)

GPP also known as "Total photosynthesis" or "Total assimilation"

The total rate of photosynthesis or the total energy or total production of organic matter in the plants over a period of time.

Net Primary Productivity(NPP)

The rate of storage of organic matter in plant tissues in excess of respiratory use during the period of measurement.

Net Primary Productivity is expressed as,

NPP = GPP - R

  • NPP - Net Primary Productivity
  • GPP - Gross Primary Productivity
  • R      - Respiration

Net Community Productivity(NCP)


The amount left over from the net primary productivity after consumption by herbivores of the ecosystem.

Net Community Productivity is expressed as,

Net Community Productivity =  Net Primary Productivity - Heterotrophic consumption

(Heterotrophic consumption - Consumption of plants by herbivores)

Secondary Productivity


The rate of storage of the organic matter either at second, third, or fourth trophic levels of an ecosystem.

Secondary Productivity is measured by considering the growth of individuals and the reproduction of individuals. 
It is also expressed as a rate of biomass production.

Estimation of primary productivity

  1. Rate of absorption of carbon dioxide during photosynthesis.
  2. Rate of production of oxygen that is produced in the process of photosynthesis.
  3. Rate of accumulation of organic matter in plant tissue.
  4. Estimating plant biomass.
  5. Chlorophyll concentration.