Which of these are common to hydrach succession and xerarch succession ?

Options

A. Pioneer species
B. Seral stages
C. Climax community
D. Area where succession begins

Answer

To determine what is common to both hydrach succession and xerarch succession, we can analyze the characteristics of each type of succession step by step.

### Step-by-Step Solution:

1. **Definition of Succession**:
- Succession is the process of change in the species structure of an ecological community over time. It can occur in various environments, leading to the establishment of a stable ecosystem.

2. **Types of Succession**:
- **Hydrach Succession**: This occurs in aquatic environments, starting from shallow water bodies and progressing to a mature ecosystem.
- **Xerarch Succession**: This occurs in dry environments, beginning from bare rocks or dry land and moving towards a more complex ecosystem.

3. **Pioneer Species**:
- In hydrach succession, the pioneer species are typically phytoplankton and other aquatic plants.
- In xerarch succession, the pioneer species are lichens and mosses that can colonize bare rock.

4. **Seral Stages**:
- In the seral stages of hydrach succession, free-floating angiosperms (flowering plants) are present.
- In xerarch succession, bryophytes (mosses) are found during the early stages.

5. **Climax Community**:
- Both types of succession eventually lead to a climax community, which is a stable and mature ecosystem. In both hydrach and xerarch successions, this climax community consists of large plants, including angiosperms and gymnosperms.

6. **Conclusion**:
- The commonality between hydrach and xerarch succession is the presence of a climax community that consists of large plants. This indicates that regardless of the starting conditions (water vs. land), both successions can lead to a similar endpoint in terms of ecosystem structure.

### Final Answer:
The common aspect of hydrach succession and xerarch succession is the **Climax Community**, which consists of large plants (angiosperms and gymnosperms) in both cases.