The biotic and abiotic components of an ecosystem are controlled by the ecology of that system and remain active in a certain process. Energy is required to stay active. This energy makes an ecosystem dynamic. This entire process is called energy flow. This energy flow keeps the environment naturally controlled, which results in balance in that ecosystem. There may be a crisis in this ecosystem if there is a slight change due to human or natural reasons in this process.

Continuous energy flow is required to keep any ecosystem moving smoothly. Sun is the main source of energy on Earth, but infact, very subtle amount of solar energy can only be used in the ecosystems. Just 0.02 percent of solar energy is converted into chemical energy by plants and some part can be used in other functions of the ecosystem. This micro part of solar energy is able to make an ecosystem dynamic.

The green pigment found in plants (chlorophyll) absorbs solar energy and turns it into organic particles. This process is called photosynthesis. With the help of carbon – dioxide and water, the plants work to convert solar energy into food (starch) by the process of photosynthesis. The plant develops with the help of glucose and carbohydrates and oxygen and water vapor is released into the atmosphere by the respiratory action of plants.

The accumulated chemical energy in plants is obtained by herbivores as food. Energy is lost during its transfer from plants to herbivores. After this, carnivorous organisms eat the herbivorous organisms, and even then, there is loss of energy. Thus, energy continues to flow from one nutritional level to another nutritional level. Along with this transfer of energy, it also gets lost. Thus, the quantity of energy at every consumer level decreases continuously.

According to odum, an average daily energy of 3000 k cal per square meter is obtained by insolation. Out of this, 1500 k cal energy is absorbed by plants, of which only 1% (15 k cal) is converted into chemical energy. At secondary and tertiary nutritional levels, it decreases to 1.5 k cal and 0.3 k cal respectively.

Usually, most of the energy is lost while transferring from one nutritional level to another nutritional level, but its quality increases. Energy is neither created nor destroyed, although the nature of energy can change. Thus the amount of inherent and outflow of energy in an ecosystem remains the same.