Reed-swamp stage is characterised by the occurrence of :

Options

A. Free floating plants
B. Floating leaved plants
C. Submerged plants
D. Emergent plants

Answer

To answer the question "Reed-swamp stage is characterised by the occurrence of:", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Reed-Swamp Stage**:
- The reed-swamp stage is a specific stage in the ecological succession of aquatic environments, particularly in ponds and lakes. It is characterized by the presence of certain types of plants that thrive in wet conditions.

2. **Identify the Types of Plants**:
- The options given are:
- Free-floating plants
- Floating leaf plants
- Submerged plants
- Emergent plants

3. **Analyze Each Option**:
- **Free-floating plants**: These are plants that float freely on the surface of the water, like phytoplankton. They do not have roots that are submerged in the soil, so this option is incorrect.
- **Floating leaf plants**: These plants have leaves that float on the water's surface while their roots are submerged. However, they do not have parts that emerge above the water, making this option also incorrect.
- **Submerged plants**: These plants are completely underwater and do not have any part that emerges above the surface. Therefore, this option is incorrect as well.
- **Emergent plants**: These plants are rooted in the water but have parts that extend above the water surface. They are often found in wetlands and are characteristic of the reed-swamp stage.

4. **Conclusion**:
- Based on the analysis, the correct answer is **emergent plants**, as they are the ones that are partially submerged and partially above the water, which is a defining characteristic of the reed-swamp stage.

### Final Answer:
The reed-swamp stage is characterised by the occurrence of **emergent plants**.

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