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Energy flow in Ecosystems

                        Energy is the most essential requirement of all living organisms. Solar energy is the only source to our planet earth. Solar energy is transformed to chemical energy in photosynthesis by plants (called as primary producers). Though a lot of sunlight falls on the green plants, only 1% of it is utilized for photosynthesis. This is the most essential step to provide energy for all living organisms in the ecosystem.
               Some amount of chemical energy is used by the plants for their growth and the remaining is transferred to consumers by the process of eating.
                Thus the energy enters the ecosystem through photosynthesis and passes through the different trophic levels ( feeding levels )



Energy flow through atmosphere to an ecosystem.
             Sun is the ultimate source of the energy, it's radiations travel through the space in the form of waves and reaches the earth's atmosphere. The atmosphere absorbs 50% of the radiations and  allow the remainings to reach the earth surface. Of the solar radiations, reached the earth's surface, some of which is absorbed by organisms (primary producers) to produce the organic through Photosynthesis.

Photosynthetic equation : 

The plants (producers) are used by herbivores and herbivores are used by carnivores as their food. In this way energy is transferred from one organism to another and so on. The conversion of solar energy is governed by law of thermodynamics.

CO2 + 2H2O.  ---------sunlight-----------> CH2O +                                                                O2 + H2O

1. 1st Law of Thermodynamics 
 It states that, "energy can neither be created nor destroyed, but it can converted from one form to another." 

Illustration: Energy for an ecosystem comes from sun. It is absorbed by plants,wherein it is converted into stored chemical energy. 

i.e., Solar energy in convered into chemical energy . 
Solar energy ----------> chemical energy                                                   (plants) 

2. 2nd law of Thermodynamics 
It states that, whenever energy is transformed, there is a loss of energy through the release of heat." 

Illustration: This occurs when energy is transferred between tropic levels. There will be loss of energy ( about 80- 90% ) in the form of heat as it moves from one tropic level to another tropic level. The loss of energy takes place through respiration, running, hunting etc.,

Respiration equation 

CH2O + O2 -------------------> CO2 + H2O 

Net production of biomass is only about 0.5% of the total incident radiation 
(3000 k.cal/M2/day) and 1.0% of energy absorbed and the remaining gets wasted. 

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