Why is energy transfer between trophic levels inefficient?
Trophic transfer is inefficient largely because organisms respire assimilated substrates to make ATP for maintenance, movement, thermoregulation, and biosynthesis. This process disperses chemical energy as heat, leaving only the production fraction as new biomass available to predators. Further losses arise because some production is never consumed and some ingested material is egested. Heat loss is thermodynamically irreversible at ecosystem temperatures, whereas unconsumed matter can still enter detrital pathways; together these routes sharply reduce upward transfer. Ecological pyramids must
Ref: Fundamentals of Ecology, Odum & Barrett, 5th Ed., Ch. 3
