Different populations interact with each other for the sake of food, shelter and for defense purposes. Interspecific interaction arise from the interaction between populations of two different species. These interactions may be positive, negative or neutral in nature to one of the species or both. The different interactions are summarised in Table 1. Type # 1. Positive Interaction: Mutualism and [...]
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 [...]