How much of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores?

Options

A. `1%`
B. `10%`
C. `40%`
D. `90%`

Answer

To determine how much of the net primary productivity (NPP) of a terrestrial ecosystem is eaten and digested by herbivores, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Net Primary Productivity (NPP)**:
- Net Primary Productivity is defined as the amount of organic matter (energy) produced by plants after accounting for the energy they use for respiration.
- Formula: NPP = Gross Primary Productivity (GPP) - Respiration.

2. **Know the 10% Law**:
- In ecological terms, the 10% law states that only about 10% of the energy from one trophic level is transferred to the next trophic level.
- This means that when herbivores consume plants, they only utilize a fraction of the energy available from the plants.

3. **Calculate Energy Consumed by Herbivores**:
- According to the 10% law, approximately 10% of the net primary productivity (NPP) is consumed and digested by herbivores.
- This means that if we consider the total NPP of a terrestrial ecosystem, herbivores will consume about 10% of that energy.

4. **Conclusion**:
- Therefore, the answer to the question is that **10% of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores**.