The branch of science which deals with the flow of energy into the ecosystem and its transformation into the living organisms is referred as a bio-energetics. The energy is essential for the existence of organisms. It helps to overcome entropy and to perform various life activities. The energy occurs in multiple forms and the one form of energy can be converted into the other form. Sun is the main source of energy. There is a need of constant flow of energy from the sun to earth. The flow is unidirectional. It occurs from the sun to plants and from the plants to animals leading to the microbes with the dissipation of heat. The radiations from the sun can be short wave or long wave. The short wavelength radiations include the gamma rays, U.V rays and cosmic rays. The long wavelength radiations include the infrared waves. The very short wavelengths are very harmful to the organisms. They cause the breakdown of inorganic components. The harmful radiations are filtered by the ionosphere and ozonosphere. The ionosphere is formed of the gamma rays, x rays and cosmic rays. The ozonosphere is formed by the U.V radiations. Almost half of the radiations which enter into the atmosphere are reflected back and are absorbed by the clouds and gases. The reflected radiations are rich in the infra red rays. The earth receives only 50 percent of the radiations from the sun. It includes the visible light, UV light and heat waves. The energy received in the Varanasi of India is three times more than the energy received in the Britain. Some part of the energy is used by the producers and the rest is dissipated.
The energy regulates the humidity of atmosphere and forms the air currents. It determines the different types of climates like the tropical, temperate, subtropics and arctic. The heating effect of the solar radiations determines the atmosphere and soil temperature. They are dependent on the angle of radiations which play an important role in the determination of season. The energy forms the water vapors, clouds and rain.
The amount of living matter present in an organism presents the biomass. It does occur in community also. The autotrophs are also known as the producers. They make the food by the process of photosynthesis from the inorganic materials. They not only make their food but also for the other organisms. They absorb the energy from sun and convert into the chemical energy. They release oxygen. The organic compounds release energy during respiration. They are also referred as the transducers as they can convert one form of energy to the other form. The organic compounds which are formed play an important role in the building of bodies and help in the release of energy. This energy is used to overcome the entropy and helps to work. The amount of biomass can be calculated with the help of energy.
There is a ten percent law which is also known as the lindmans law of trophic efficiency. This law was given by Lindeman. It was given in the year 1942. It states that when the organic food is transferred from one trophic level to the other around one tenth of the food is stored. The storage is in the form of flesh. The remaining nine tenth of the food is broken down in the process of respiration. So, one can say that the net productivity of the higher trophic level is around one tenth of the previous one.