I need to draw an energy pyramid for a five-step food chain. If 100% of the energy is available at the first trophic level, what percentage of the total energy is available at the highest trophic level?
Though not an absolute rule, the "rule of thumb" is that 10% of the energy flows to the next trophic level, and 90% is "lost" through metabolism.
factors of 10 are easy to work with, we just slide the decimal over:
level 1: 100%
level 2: 10%
level 3: 1%
level 4: 0.1%
level 5: 0.01%