The sequence of communities of primary succession in water is

Options

A. Phytoplankton , sedges , free - floating hydrophytes , rooted hydrophytes , grasses and trees.
B. Phytoplankton , free - floating hydrophytes, sedges , sedges , grasses and trees.
C. Free - floating hydrophytes , sedges , phytoplankton , rooted hydrophytes , grasses and trees.
D. Phytoplankton , rooted submerged hydrophytes , floating hydrophytes , reed swamp , marsh meadow and trees .

Answer

To solve the question regarding the sequence of communities in primary succession in water, we can break it down into several clear steps:

### Step-by-Step Solution:

1. **Understanding Primary Succession**:
- Primary succession in aquatic environments is referred to as hydrosere. It involves a series of stages where different communities of organisms establish themselves over time.

2. **Identifying the First Stage**:
- The initial stage of hydrosere is the **Phytoplankton Stage**. In this stage, algae and phytoplankton are the primary colonizers. They thrive in the water and are crucial for starting the succession process.

3. **Second Stage - Submerged Stage**:
- After the phytoplankton stage, the next stage is the **Submerged Stage**. Here, rooted aquatic plants begin to establish themselves as the water becomes shallower due to sediment accumulation.

4. **Third Stage - Floating Stage**:
- The third stage is the **Floating Stage**. In this stage, plants with floating leaves emerge, which can shade out the submerged plants, leading to their decline.

5. **Fourth Stage - Reed Swamp Stage**:
- The fourth stage is the **Reed Swamp Stage**. In this stage, the environment becomes suitable for reed grasses and similar plants, forming marshes or swamps.

6. **Fifth Stage - Sedge Meadow Stage**:
- Following the reed swamp stage, we have the **Sedge Meadow Stage**. Here, the water surface is covered with various vegetation, which helps bind the soil and creates a habitat for different herbaceous plants.

7. **Final Stage - Woodland Stage**:
- The last stage is the **Woodland Stage**. In this stage, the soil dries out enough to support the growth of shrubs and trees, leading to the establishment of a climax forest.

8. **Conclusion**:
- The correct sequence of communities in primary succession in water is:
1. Phytoplankton Stage
2. Submerged Stage
3. Floating Stage
4. Reed Swamp Stage
5. Sedge Meadow Stage
6. Woodland Stage

### Final Answer:
The sequence of communities of primary succession in water is:
**Phytoplankton → Submerged Hydrophytes → Floating Hydrophytes → Reed Swamps → Sedge Meadows → Trees.**