Explain primary productivity and the factors that influence it.

Hint: In ecology, productivity refers to the rate at which the energy is added to the bodies of a group of organisms in the form of biomass such as primary producers. It can also be referred to as energy accumulated in plants by the process of photosynthesis.

Complete answer:
Primary productivity refers to the generation of biomass (amount of matter stored in the body of an organism) from autotrophic organisms like plants in an ecosystem. Photosynthesis is the primary source for the making of organic material from inorganic compounds such as carbon dioxide and water. Primary productivity has two features: gross primary productivity, and net primary productivity.
-Gross primary productivity- Solar energy which is trapped by the photosynthetic organism or overall rate of energy capture is known as gross primary productivity. All organic matters produced come under gross primary productivity. It depends upon the photosynthetic activity and environmental factors.
-Net primary productivity- Net primary productivity is the rate at which the energy is stored as biomass by plants or primary producers and made available to the consumers in an ecosystem. It is estimated by gross productivity minus energy lost in respiration;

NPP= GPP- Energy lost in respiration

If this net energy is stored in the plants, then this energy serves as food for the animals that feed on plants.

Factors influencing the primary productivity are:
-Temperature: It controls the enzyme-mediated dark reaction rate of photosynthesis.
-Availability of nutrients and photosynthetic capacity of plants also influence the rate of primary productivity.
-Species succession is also a regulating factor.
-Composition of species also influences the rate of primary productivity.

Note: Primary producers such as plants and other photosynthetic organisms are the approach for the energy to enter food webs. So, primary productivity is important as it forms the foundation for the food webs in an ecosystem.