“The energy flow in the ecosystem | Class 12 Biology Chapter Ecosystem, Ecosystem NCERT Solutions

All the organisms require matter for their energy for the activities. Organisms in the ecosystem capture solar radiations, transforms, transfers and stores energy. Energy flow is the important function in the ecosystem. The ecosystem functions is consistent with the laws of thermodynamics which deals with the relationship between energy and matter. There are two basic laws of thermodynamics on which the behaviour of energy in the ecosystem is based. The First Law of Thermodynamics is also called law of conservation of energy which states that energy cannot be created or nor be destroyed but can only transformed. Energy in the form of heat that does not do any work goes to increase the randomness or disorder of the universe. The degree of randomness or disorder in a system is known as entropy. The Second Law of Thermodynamics states that every energy transformation cannot be 100% efficient; some energy is always lost as heat; or the energy accumulated by the producers pass on to the consumers in the form of food chain with the gradual loss of energy. Furthermore, this energy is used for performing the metabolic activities for the formation of food and is stored as biomass. This energy is then transferred to next trophic level as we have discussed in Lindeman’s law of 10 %. Ecosystem needs constant supply of energy for the synthesis of molecules, to counteract the tendency towards the increasing randomness. Thus, ecosystem is not exactly exempt from the second law of thermodynamics.