Question

Describe the energy flow that occurs through an ecosystem. How does this energy flow influence the number of top carnivores?

Answer 1

Sun is the source of energy for all ecosystem on earth. Only less than 50% is phosynthetically active radiation(PAR) and 2-10 percent of it is captured by plants to synthesize food from inorganic materials such as carbon dioxide and water and all organisms are dependent upon this food as source of energy directly or indirectly. The organisms which synthesize food are known as producers and animal depending upon plants are known as consumers. If they feed on producers then they are called primary consumers . If an organism feed on an animal which feed on producer then that organism is called secondary consumer and the organism feeding on secondary consumer is called tertiary consumer. Primary consumers are known as herbovores and those feeding on herbivores are carnivores.These organism occupy a position in the food chain known as trophic level. Producers belong to first trophic level and energy from them to primary consumer at second trophic level , then to secondary consumer at third trophic level and to tertiary consumer at fourth trophic level.The amount of energy decreases at it flows through trophic level.This transfer of energy follows 10 per cent law which states only 10 per cent of the energy is transferred to each trophic level from the lower trophic level.

There are more herbivores as compared to carnivores. When a herbivore eats, only a fraction of the energy becomes new body mass and  the rest of the energy is lost as waste . Similarly, when a carnivore eats another animal, only a portion of the energy from the animal food is stored in its tissues. Because of the large amount of energy that is lost at each trophic level as we along the trophic level less energy remains available and the animals at the end of the chain would not get enough food or energy to stay alive. This is the reason why number of carnivores is less than that of herbivores.