Energy flow
From Free net encyclopedia
In ecology, energy flow (calorific flow) refers to the flow of energy through a food chain.
In following energy flow in an ecosystem, ecologists seek to quantify the relative importance of different component species and feeding relationships.
A general energy flow scenario follows:
- Energy is taken up from the sun by the autotrophs, the so called primary producers, like green plants which transform it to glucose and ATP by photosynthesis.
- The primary consumers eating these autotrophs are herbivores. They extract most of the energy stored in the plant through digestion, and transform it into the form of energy they need. A part of the energy received by the herbivore is converted to bodily heat, which is radiated away and lost from the system.
- Carnivores feed on the herbivores, recovering their energy for themselves. Again some energy is lost from the system.
- Other carnivores prey on those carnivores, and most of the energy is passed along, while some is again lost.
The energy is passed on from trophic level to trophic level and each time some of the energy is lost. So the top consumer of a food chain receives the least energy. This loss of energy at each level limits typical food chains to only 4-6 links.