Tag: zoology

The ecosystem is an interaction between living beings (biotic component) and their physical environment (abiotic component).

The first trophic level is represented as T$ _1$. It includes producers. The second trophic level is represented as T$ _2$. It includes primary consumers. Similarly, third trophic level is represented as T$ _3$. It includes secondary consumers. In terrestrial ecosystem, maximum energy is present in T$ _1$, that is producers.

Large amount of assimilated energy is used in respiration. In herbivores, 30% of assimilated energy is used in respiration. Herbivores are more efficient in using energy for their growth and development than animals. Hence, plants grow faster than animals. 

Energy flow is the amount of energy that flows from one trophic level to another trophic level in an ecosystem. It is unidirectional or one-way passage. In an ecosystem, flow of free energy occurs through different trophic levels. Producers or plants obtain their energy from the sun by photosynthesis. The primary consumers (herbivores) obtain their energy from the producers. The secondary consumers (carnivores) obtained their energy by using herbivores as a source of food and so on. The energy present at each successive trophic level is 10% of the previous trophic level.

Ecosystem is made up of living and nonliving things. Living things or biotic things include plants and animals. Nonliving things or abiotic things include air, water, land.  It is composed of organisms interacting within communities. The driving force for an ecosystem is solar energy. Producers use solar energy to synthesize their food by the process of photosynthesis. From producers, the energy is transferred to herbivores. Herbivores eat producers. The energy is transferred from herbivores to carnivores. Carnivores eat herbivores. From carnivores, the energy is transferred to decomposers. They decompose organic matter of plants and animals.

Pyramid of energy represents the amount of energy at each trophic level. In any ecosystem, flow of energy declines as it passes from lower to higher trophic level. Hence, the pyramid of energy is always upright. Each successive trophic level has less total energy. In this, the energy decreases from one trophic level to the next trophic level because energy is lost as metabolic heat during transfer of energy. When food energy passes from producers to herbivores to carnivores, only 10% of energy is transferred from one trophic level to another trophic level.

According to the Lindeman's trophic efficiency rule, the 10% of energy is transferred from one trophic level to the next successive trophic level. The rest of the energy, that is 90% of energy is lost during transfer of energy from one trophic level to next higher trophic level. The first trophic level has the maximum energy. 

Ten percent law of energy transfer in food chains was given by Reymond LIndeman. It is also called as Lindeman's trophic efficiency rule. According to this rule, the 10% of transfer of energy is transferred from one trophic level to the next successive trophic level. The rest of the energy is lost during transfer of energy and during respiration. The first trophic level has the maximum energy.