Secondary productivity

Options

A. is measured by the standing crop
B. is the rate of biomass production in consumers
C. is greater than primary productivity
D. is 10% less than primary productivity

Answer

**Step-by-Step Solution:**

1. **Understanding Productivity:**
- Productivity refers to the rate of formation of biomass in an ecosystem. It is a measure of how much organic matter is produced over a specific period.

2. **Types of Productivity:**
- There are two main types of productivity:
- **Primary Productivity:** This is the amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis.
- **Secondary Productivity:** This refers to the generation of biomass by consumers (herbivores, carnivores, etc.) in an ecosystem.

3. **Defining Secondary Productivity:**
- Secondary productivity is the biomass produced by consumers in an ecosystem. It is influenced by the amount of primary productivity available, as consumers rely on the biomass produced by plants.

4. **Understanding Standing Crop:**
- The standing crop is the total mass of living material (biomass) present at a particular trophic level at a specific time. It is an important measure in understanding the productivity of an ecosystem.

5. **Comparing Secondary and Primary Productivity:**
- The question asks whether the rate of biomass production in consumers (secondary productivity) is greater than, less than, or equal to primary productivity.
- Generally, secondary productivity is less than primary productivity because not all biomass produced by plants is converted into consumer biomass; some energy is lost through metabolic processes.

6. **Conclusion:**
- Therefore, the correct answer is that secondary productivity is less than primary productivity.