Flow of Matter

The pyramid of biomass

Let us see, how we can represent the quantity of the loss of matter in the different trophic levels in the form of a pyramid. Suppose the herbivores in a food chain feeds on 100 kg of plant tissues. Is there an increase of 100 kg in their body mass? It is sure that the answer is 'No'. If we consider that the increase is only 10 kg, it is clear that the body mass of the carnivores that feed on them does not show any proportional increase. At the upper trophic levels there is only a nominal increase in their body mass.

If the different living beings at different trophic levels are arranged one above the other on the basis of their biomass will it form a pyramid? Such a representation is called the pyramid of biomass. Demonstrate a biomass pyramid by considering a food chain.

Is energy alone transferred in a food chain? Is there also a transfer of matter? Let us examine how it occurs. The chemical energy fixed in the plant tissues is utilized by different organisms as the source of their food. It is well known that food gives us the necessary energy requirement for the life activities as well as the building up of body tissues. It is also evident that tissues are transferred through food chain. These are decomposed into abiotic factors later. How do they get back in to the body of the living organisms?

Study the diagramatic Illustration III. Find out how matter flows and how it differs from the flow of energy.

It is now clear that the flow of matter is cyclic and it thus differs from the flow of energy.

Дата добавления: 2014-12-29