For the ecosystem to function energy must be available and it must be transferred. Why? Because of the First and Second Laws of Thermodynamics.
To illustrate these laws, let’s consider a car with a full tank of gasoline. The gasoline is burnt, the car goes, and the gasoline
is broken down into gases and heat, but, following the First Law, the total amount of energy is constant although now it is in a different form, namely heat. Heat is a very disorganized form of energy. However, what of the Second Law? It, too, has been operating.
Life exists because it has found a way to reverse the Second Law of Thermodynamics, if only temporarily, but, to do this, living things need constantly to invest energy. There is, however, only one energy source available to earth’s organisms and that is the sun. Photosynthesis is the only means available to use this source energy. Autotrophs are organisms that produce their own food through photosynthesis.
Heterotrophs are organisms that consume autotrophs and use the energy of their bodies to survive. The transfer of energy from the autotrophs to the heterotrophs always involves the conversion of some of the energy into heat. Only a small percentage of the energy of the autotrophs is actually used. For example, a flock of birds descends on a bush and eats its berries, but 98% of what is eaten is excreted as water and other waste or converted to energy. In addition, the bird becomes food for other organisms.
Any ecosystem can be viewed as consisting of producers (the autotrophs) and consumers (heterotrophs). These concepts are the bases of the ECOSYSTEM PYRAMID OF ENERGY. ecosystem pyramid ecological pyramid of numbers pyramid of biomass and pyramid of numbers pyramid numbers three types ecological pyramids an ecological pyramid can depict biomass pyramid definition trophic levels pyramid ecological food pyramid ecological pyramid of biomass ecosystem energy pyramid