Question

why energy flow is unidirectional in ecosystem​

Answer 1

Thus, the flow of energy in the ecosystem is said to be unidirectional because the energy lost as heat from the living organisms of a food chain cannot be reused by plants in photosynthesis. During the transfer of energy through successive trophic levels in an ecosystem, there is a loss of energy all along the path.

Answer 2

Since the transferred energy is lost in the form of heat in the food chain . This flow do not reverse and the energy cannot be be absorbed by the preceding organism