Question

the amount of energy at each trophic level in an ecosystem decreases as it moves through the ecosystem. typically, only about 10 percent of the energy at one trophic level is transferred to the next level. the remaining energy is lost through metabolic processes as heat. suppose that, in the ecosystem modeled above, 150,000 kcal (kilocalories) of energy are contained within green plants. assuming that the amount of energy transferred from one trophic level to the next is exactly 10 percent, determine the following amounts of energy in the ecosystem. kcal of energy will be transferred from green plants to rabbits. kcal of energy will be transferred from rabbits to weasels. kcal of energy will be transferred from weasels to eagles.

Explanation:

Step1: Energy from green plants to rabbits

To find the energy transferred from green plants to rabbits, we calculate 10% of 150,000 kcal. The formula for 10% of a number is \( \text{Energy} = 0.10 \times \text{Energy of previous level} \). So, \( 0.10 \times 150000 = 15000 \) kcal.

Step2: Energy from rabbits to weasels

Now, the energy in rabbits is 15,000 kcal (from Step 1). We calculate 10% of 15,000 kcal. Using the same formula, \( 0.10 \times 15000 = 1500 \) kcal.

Step3: Energy from weasels to eagles

The energy in weasels is 1,500 kcal (from Step 2). We calculate 10% of 1,500 kcal. Using the formula, \( 0.10 \times 1500 = 150 \) kcal.

Answer:

• Energy from green plants to rabbits: 15000 kcal
• Energy from rabbits to weasels: 1500 kcal
• Energy from weasels to eagles: 150 kcal