Rate of biomass production is expressed as :

Options

A. `(kcalm^(-2))yr^(-1)`
B. `kcalg m^2yr^(-1)`
C. `gm^3yr`
D. `gm^(-2)yr`

Answer

To solve the question regarding how the rate of biomass production is expressed, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Biomass Production**:
- Biomass production refers to the amount of organic matter produced by living organisms in a given area over a specific time period.

2. **Defining Productivity**:
- The rate of biomass production is commonly referred to as productivity. It quantifies how much biomass is generated in a specific area over a certain time frame.

3. **Units of Measurement**:
- Productivity is typically expressed in terms of energy or mass per unit area per unit time. The most common unit used for expressing the rate of biomass production is kilocalories (Kcal) per square meter (m²) per year.

4. **Types of Productivity**:
- There are two main types of productivity:
- **Primary Productivity**: This is the rate at which producers (like plants) create organic matter through photosynthesis. It is measured in Kcal/m²/year.
- **Secondary Productivity**: This refers to the rate of formation of new organic matter by consumers (organisms that eat producers).

5. **Conclusion**:
- Based on the above understanding, the rate of biomass production is expressed as Kcal/m²/year. Therefore, the correct answer to the question is option number 1.