Energy Flow Through an Ecosystem Essay Example | Topics and Well Written Essays - 500 words

Energy Flow Through an Ecosystem - Essay Example As Lindeman (1942) stated, â€Å"Only 10% of the total chemical energy is retained at each trophic level.† This is known as the ten per cent law. The second law of thermodynamics says that at each progressive trophic level in the food chain, there is a gradual decrease in the available energy. The pyramid of energy is always upright or straight because out of the total amount of energy transferred from the lower trophic level, as much as 80-90% is lost in the form of heat. The net primary productivity (the resultant plant biomass) is the difference of the gross primary productivity (total plant biomass) and the amount used for plant respiration. Therefore, it is only the net photosynthesis that is presented to the next trophic level of the food chain or the herbivores. The carnivores receive the gross secondary productivity from the herbivores. Lakes, ponds, rivers and steams are representative of fresh water biomes. There are the shallow or eutrophic lakes and deep or olitrophic lakes. On the basis of the penetration of light, a deep lake has three zones. The transition zone or thermocline, the basal layer or the hypolimnion and the upper layer that is warmer in summer and cooler in winter called the