Ten Percent Law: Ten percent law for the transfer of energy from one trophic level to the next was introduced by Lindeman (1942). According to this law, during the transfer of energy from organic food from one trophic level to the next, only about ten percent of the of energy from organic matter is stored as flesh. The remaining is lost during transfer, broken down in respiration, or lost to incomplete digestion by higher trophic levels. The ten percent law suggests or implies that exactly 90% of the energy is lost in the transfer at each trophic level, and that only 10% is passed on as useable biological energy. That implied preciseness is misleading, however, and is one of the reasons that many scientists discount the concept, even label it a myth. Instead, it should be considered a rule of thumb, a teaching device, or perhaps best, a mnemonic device that serves as a reminder of the striking inefficiencies of natural systems.
The ten percent law does stand for a real fact of nature: most of the energy available at one level in an ecosystem is lost in the transfer to the next level. A very small percentage of the light energy that reaches the leaf surface of plants is actually assimilated, or turned by photosynthesis into organic compounds. Most of the light energy absorbed by plants is converted directly to heat and lost. Many plant parts are inedible by herbivores (the next trophic level) and is lost for energy transfer. The plants use much of the energy absorbed to live, as do the herbivores that eat them. So if there are 40,000 kg of producers, how many kg of primary consumers are there? 40,000 kg/ 10 = 4,000 kg. How many kg of secondary consumers? 400 kg How many kg of tertiary consumers? 40 kg
Questions based on Ten Percent Law:
Q.1 Ten percent law is given by
A. Lindmann
B. Goldmann
C. Beckmann
D. None of these
Ans: A
Q.2 If the energy available to the plants from the sun is 20,000J. What would be the energy available to the lion in the food chain , Plant? Dear? Lion
A. 20J
B. 200J
C. 2000J
D. 20000J
Ans: B
