To calculate the energy available to tertiary consumers in a forest ecosystem, we can use the 10% energy transfer rule at each trophic level.
- Primary Producers: 50,000 kcal (this is the initial energy).
- Primary Consumers: 10% of 50,000 kcal = 5,000 kcal.
- Secondary Consumers: 10% of 5,000 kcal = 500 kcal.
- Tertiary Consumers: 10% of 500 kcal = 50 kcal.
Thus, the energy available to tertiary consumers would be 50 kcal.
The correct response is 50 kcal.