The rate of biomass production or the amount of food energy produced or obtained or stored by a particular trophic level per unit area in a unit time is called productivity. It can also be defined as the energy accumulated in plants by photosynthesis. The unit of productivity is gm/m2/year or kcal/m2/year. According to Odum there are three types of [...]
There is 78% nitrogen in atmosphere. But this cannot be taken in by the organisms. It needs to be fixed as nitrates and then utilised. This cycle is divided into four phases - nitrogen fixation, ammonification, nitrification, and denitrification (Fig. 12). Phase # 1. Nitrogen Fixation: Fixation of nitrogen takes place by atmospheric and biological agents. Other than this it [...]
Decomposers are the final step in the food chain and they reduce the organic matter into inorganic forms so that it is once again available to the producers. The upper layer of soil is the main site for the action of decomposers. In this way, decomposers provide energy and nutrients to the producers. The upper layer of soil consists of [...]