(a) Primary productivity : amount of biomass / organic matter produced per unit area over a time ** by the plant during photosynthesis.
Factors : availability of nutrients / quality of light available / availability of water / temperature of the given place / type of plant species of the area / photosynthetic capacity of the plants.
(b) Oxygen increases rate of decomposition.
Decomposition is an oxygen consuming Process. It takes place under aerobic conditions i.e., in presence of oxygen.
Chemical decomposition is slow when chitin and lignin are present and fast when cellulose and water soluble substances are present.
