Role of Energy in an Ecosystem in relation to Thermodynamics

Laws of Thermodynamics in an EcosystemMridul Bora Animal Ecology & Wildlif BiologyGauhati University

1Energy Flow in an Ecosystem Laws of thermodynamics describes the energy flow in an Ecosystem. 1st law of thermodynamics- Energy can not be created or destroyed, only transformed from one step to another. 2nd law of thermodynamics- In the path of energy transformation some energy loss in the form of heat and the entropy increases.1st law of thermodynamics in Ecosystem

Energy From Sun to Plant

Chlorophyll of green plants traps the light energy from sun and produce food with the help of water, CO2 and minerals.Energy usersProducers Green plants use light energy (sunlight) to produce food (chemical energy).Primary consumers Feed on herbivores and get energy from plants (Carnivores).Secondary consumers Feed on primary consumers and get energy form them.Tertiary consumers- Feed on secondary consumers and get energy. Decomposers- Break down dead or decaying organism (decomposition) and get energy. Food chain or food web support the 1st law of thermodynamics

Energy RecyclingPlants or Producers1st tropic levelEnergySunThe energy houseEnergyConsumers2nd tropic levelDecomposers3rd tropic levelEnergyEnergySoil, Air, Waterwith matterHeat 2nd Law of Thermodynamics

In the path of energy transformation some energy loss in the form of heat and the entropy increases.

The Path Way of Energy Loss Not all food consumed by heterotrophs (consumers) is transformed into biomass.

At each tropic level about 90% of energy is loss to perform metabolic activities.

Entropy increases.What is Entropy?According to Great Physicist Peter Higgs, Entropy is the every types of error or unrestrained activities of a system.Different Forms of entropy among organisms

What happens to the energyin the end?Solar energy is used by plants for food production. That energy transformed from green plants to decomposers in different steps. In the energy transformation path, energy is lost into space in the form of heat. That is used in endothermic reaction(an animal that is dependent on the internal generation of heat).

Conclusion Sun is the ultimate energy source of ecosystem (excluding chemoautotrophs). Energy transformed from sun to decomposers. In each tropic level maximum energy is released as heat. Ecosystem obeys 1st and 2nd law of thermodynamics.