Phytoplanktons in the hydrosere constitute

Options

A. Members of climax community
B. Pioneer community
C. First seral members
D. All of the above

Explanation

To answer the question regarding the role of phytoplanktons in the hydrosere, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding the Terms:**
- **Phytoplanktons:** These are microscopic, photosynthetic organisms found in aquatic environments. They are crucial for the ecosystem as they produce oxygen and serve as the base of the aquatic food web.
- **Hydrosere:** This refers to a type of ecological succession that occurs in aquatic environments, leading to the development of a community over time.

2. **Concept of Succession:**
- Succession is the process by which ecosystems change and develop over time. It involves a series of stages, starting from pioneer species to climax community.
- In aquatic environments, the process begins with pioneer species, which are the first organisms to colonize a new or disturbed area.

3. **Role of Phytoplanktons:**
- In the context of hydrosere, phytoplanktons are considered the pioneer community. They are the first organisms to establish themselves in the aquatic environment, paving the way for other species.
- As the succession progresses, phytoplanktons are gradually replaced by more complex organisms, such as free-floating angiosperms and rooted hydrophytes.

4. **Identifying the Correct Option:**
- Given the options: Climax community, Pioneer community, Serial member, and all of the above, we can conclude that phytoplanktons are specifically part of the **Pioneer community** in the hydrosere.
- Therefore, the correct answer is **Pioneer community**.

### Final Answer:
Phytoplanktons in the hydrosere constitute the **Pioneer community**.

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