Question

Choose the correct statement

• A. With in few years rocky soil changed into fertile soil based on the climate
• B. In xerarch succession, lichens pave way to small plants like bryophytes
• C. In hydrarch, pioneers are free floating angiosperms
• D. The climax community also will change in due course

Hint:

Pioneer species:
Xerarch = Lichens.
Hydrarch = Phytoplankton.
Climax community is always stable and does not change unless the climate changes drastically.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks us to identify the correct statement regarding ecological succession from the given options.

Step 2: Key Concepts and Approach:
Ecological succession is the gradual and predictable change in species composition of a given area.
Xerarch succession occurs in dry areas (like bare rocks), while Hydrarch succession occurs in wet areas (like water bodies).

Step 3: Detailed Explanation:

• Statement A: Primary succession on bare rock is an extremely slow process.
It takes hundreds to thousands of years to weather rocks and generate fertile soil, not just "a few years". Hence, this statement is incorrect.

• Statement B: In xerarch succession on bare rock, lichens are the pioneer species.
They secrete organic acids that weather the rock and help form a thin layer of soil.
This soil layer allows small plants, like bryophytes, to establish themselves. This statement is correct.

• Statement C: In hydrarch succession, the pioneer species are phytoplanktons, not free-floating angiosperms. Thus, this statement is incorrect.

• Statement D: The climax community is the final stage of ecological succession.
It is stable and in near-equilibrium with the local climate, remaining unchanged as long as the climate remains stable. Hence, this statement is incorrect.


Step 4: Final Answer:
Statement B is correct because lichens pave the way for bryophytes during xerarch succession.