Difference Between Energy Flow and Nutrient Cycling

Main Difference

The main difference between energy flow and nutrient cycling is that energy flow is the transfer of energy in a non-cyclic and linear manner from one trophic level to another whereas nutrient cycling is the movement of chemicals back and forth between organisms.

Energy Flow vs. Nutrient Cycling

Energy flow is the transfer of energy in a non-cyclic, and linear manner from one trophic level to another, whereas nutrient cycling is the back and forth movement of chemical elements between organisms. The ultimate source of energy in energy flow is the sunlight; on the contrary, in nutrient cycling, nutrients always present in the earth often atmosphere or lithosphere (reservoir pool). In energy flow, loss of energy occurs at each trophic level mainly as the heat used by organisms for respiration; on the flip side, in nutrient cycling, nutrients recycled in an ecosystem without any loss of nutrients. In energy flow, energy from the sun enters as light and exits primarily as heat from the ecosystem; conversely, nutrients in nutrient cycling are reused and recycled in an ecosystem. The energy in energy flow is not recycled but released mostly as heat during decomposition by decomposers whereas decomposers like bacteria play a vital role in the cycling of nutrients without their any loss in an ecosystem.

Comparison Chart

Energy FlowNutrient Cycling
The transfer of energy in a non-cyclic and linear manner from one trophic level to another through a food chain and food web is known as energy flow.The backward and forward movement of chemical elements and nutrients between organisms and their physical environment in an ecosystem are called nutrient cycling.
The Direction of Energy/Nutrients
Non-cyclic, unidirectional and linearCyclic manner, move back and forth
Source of Energy/Nutrients
Sunlight is the major sourceNutrients always present in the earth often atmosphere or lithosphere (reservoir pool)
Loss of Energy/Nutrients
Energy loss occurs at each trophic level mainly as heatNutrients recycled in an ecosystem without any loss of nutrients
The Phenomenon of Cycling of Energy/Nutrients
Energy from the sun enters as light and exits primarily as heat from the ecosystem.Nutrients in nutrient cycling present on earth are reused and recycled in an ecosystem.
Role of Energy/Nutrients in Decomposition
The energy released from the ecosystem during decompositionPlay a vital role in the cycling of nutrients without their any loss in ecosystem

What is Energy Flow?

The transfer of energy in a non-cyclic and linear manner from one trophic level to another through a food chain and food web is known as energy flow. Each step in the food web or food chain is called trophic level. The energy is passed on to trophic levels from one to another, and each time when energy flows, about 90% of energy is lost by organisms in an ecosystem due to respiration. This flow means the top consumer of a food chain gets the least energy, as a lot of energy of the food chain has lost between trophic levels. The ultimate source of energy in energy flow is the sunlight.

Energy Flow Scenario

  • Primary Producers: solar energy fixed by primary consumers, photoautotrophs like green plants. These consumers absorb most of the deposited energy 10% through digestion and convert it into the form of energy they need.
  • Secondary Consumers: primary consumers then consumed by secondary consumers such as carnivores. Although omnivores also consume them. 1% of the energy transferred into secondary consumers
  • Tertiary Consumers: tertiary consumers like predators then consume the secondary consumers and remaining 0.1% energy transfer into them as they are present on the top of the chain.
  • Decomposers: the final link of the chain are decomposers which break down the organic matter of tertiary consumers and release nutrients into the soil. Decomposers play an important role in life cycles.

What is Nutrient Cycling?

The backward and forward movement of chemical elements and nutrients between organisms and their physical environment without any loss in an ecosystem are called nutrient cycling. It mostly initiates from nutrient pool to producers, producers to consumers, consumers to decomposers and then back to the nutrient pool. Nutrients always present in the earth often atmosphere or lithosphere (reservoir pool). Nutrient cycling is a cyclic manner to move back and forth between living organisms. Plants receive nutrients from the soil and then chemically combine them with carbon dioxide and water from the air to make food. This food is passed onto animals as required nutrients and along the food chain as animals eat each other. All this goes back to the soil as decomposing bodies when animals die or excrete waste. Decomposers break down the organic matter, releasing chemicals back into the soil. These then again used by plants and start the cycle all over again.

Key Differences

  1. Energy flow is the transfer of energy in a non-cyclic, and linear manner from one trophic level to another, whereas nutrient cycling is the back and forth movement of chemical elements between organisms.
  2. The ultimate source of energy in energy flow is the sunlight; on the contrary, in nutrient cycling, nutrients always present in the earth often atmosphere or lithosphere (reservoir pool).
  3. In energy flow, loss of energy occurs at each trophic level mainly as the heat used by organisms for respiration; on the flip side, in nutrient cycling, nutrients recycled in an ecosystem without any loss of nutrients.
  4. In energy flow, energy from the sun enters as light and exits primarily as heat from the ecosystem; conversely, nutrients in nutrient cycling present on earth are reused and recycled in an ecosystem.
  5. The energy in energy flow is not recycled but released mostly as heat during decomposition by decomposers whereas decomposers like bacteria, fungi, etc. play a vital role in the cycling of nutrients without any loss in the ecosystem.

Conclusion

Above discussion concludes that energy flow is the transfer of energy in a non-cyclic and linear manner from one trophic level to another, whereas nutrient cycling is the movement of chemicals back and forth between organisms.

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