The rule of thumb concerning ecosystems as units that capture energy and transport it is as follows: For every jump in trophic level, the amount of available energy drops by 90%. Discuss in detail what accounts for this loss of energy? Please give examples.
It means that living organisms of the next trophic level utilize only 10% of the food from previous level (due to the laws of thermodynamics), 90% is lost as unmetabolized molecules. Thus 1 pound of carnivore (lion) requires 10 pounds of herbivores (cows) or 100 pound of plants.