Energy Loss - Energy Flow
Let us now take the second point that is the loss of some energy at each trophic level. You might recall that the second law of thermodynamics states that when energy is transformed from one form into another, some fit is converted into unusable energy, such as heat.
Let us understand this with another example. When you slide a box along the floor, some of the energy you are putting into pushing the box is being converted into heat energy, due to friction. And this heat energy escapes into the surrounding environment. In the same way when the energy stored in muscle cells is used to contract arm muscles, some of the useful energy is lost as body heat from the body. Since heat energy cannot be used to do useful work, more energy must be supplied to a biological system from outside to compensate the inevitable energy loss. In order to continue to function, organisms and ecosystems must receive energy supply on a continuing basis.