Question #3f4a0

1 Answer
Dec 4, 2017

10% of the energy stored passes to the upper tropic level; the rest (90%) is useless as heat energy.

Explanation:

Energy transfer in ecosystem is an interesting issue. If you have a food, you are lucky. If you do not have, you have to find food to survive (in the nature).

Theoretically only 10% of energy stored in lower tropic level passes to upper tropic level. Let me give an example. Let's say solar energy (1000 calories) hits the ground (per unit area) and water and minerals are not limited. An apple tree provides apples but not all of them are in good quality, some are not edible. Stored energy in edible apples can be estimated as 100 calories. One person harvests these apples but he/she cannot eat some parts of apples. He/she can get only 10 calories (energy). This is an energy flow in an ecosystem. Take a look at the following sketch. (Khan Academy).

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