A dynamic equilibrium is established between community and environment when -

Options

A. climax is attained
B. pioneers are found
C. serai communities are growing
D. none

Answer

**Step-by-Step Solution:**

1. **Understanding Dynamic Equilibrium**: Dynamic equilibrium in an ecosystem refers to a stable state where the community of organisms and their environment are in balance. This means that the populations of different species remain relatively constant over time, despite any changes that may occur.

2. **Identifying Climax Community**: The climax community is the final stage of ecological succession, where the ecosystem reaches a stable state. In this stage, the species composition remains relatively unchanged, and the environment is conducive to the growth and reproduction of these organisms.

3. **Evaluating the Options**: The question provides several options regarding what establishes a dynamic equilibrium between community and environment. The first option suggests that "Climax is attained," which indicates that the ecosystem has reached its final developmental stage.

4. **Analyzing Other Options**: Other options may refer to pioneer species or intermediate stages of succession. Pioneer species are the first organisms to colonize an area, and they initiate the process of ecological succession. However, during this phase, the ecosystem is still developing and not yet in a state of equilibrium.

5. **Conclusion**: Since the dynamic equilibrium is best represented by the climax community, where the ecosystem is stable and balanced, we conclude that the correct answer is that a dynamic equilibrium is established when "Climax is attained."

**Final Answer**: A dynamic equilibrium is established between community and environment when Climax is attained.

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