The ecosystem is characterized by the energy flow and the circulation of materials through its members. Different organisms of an ecosystem are linked together by their nutritional requirements. Individuals related in this manner constitute a food chain.
Each food chain contains many steps comprising of producers, herbivores, primary carnivores and so on. Each step of the food chain is called trophic level.
An ecological pyramid is a graphical representation in the shape of a pyramid to show the feeding relationship of groups of organisms and the flow of energy or biomass through the different trophic levels in a given ecosystem. It is a standard practice to place producers at the bottom of the pyramid with primary consumers, secondary consumers, tertiary consumers, etc. above them.
The concept of ecological pyramids was introduced by Charles Elton (1927) and are therefore also known as Eltonian Pyramids.
Upright :The pyramid has larger base that gradually tapers towards the tip.
Inverted : The pyramid has narrow base that gradually broadens towards the tip.
Spindle shaped :The pyramid is narrow both at base and tip with a broader part in the middle.
TYPES OF ECOLOGICAL PYRAMIDS
Ecological pyramids are of three main types – pyramid of numbers, pyramid of biomass and pyramid of energy.
Pyramid of numbers
A bar diagram that indicates the number of individuals per unit area at each trophic level in a food chain represents the pyramid of numbers. The length of each bar gives the measure of