Energy entering food chains
After respiratory losses from producers have been taken into account, the chemical energy still stored in plant biomass forms the net primary production (NPP).
This remaining energy can support plant growth and reproduction. It can also be transferred to other organisms when plant material is eaten by herbivores or broken down by decomposers.
Organisms in a food chain occupy different trophic levels. Producers form the first trophic level, with consumers occupying the levels above them.
At each feeding step, only part of the chemical energy available at one trophic level becomes stored in the biomass of the next.