Which one of the following statements about ecological succession in incorrect ?

Options

A. A community that is in near equilibrium with the environment and that is called a climax community .
B. The gradual and fairly predictable change in the species composition of a given area is called ecological succession .
C. Primary succession takes place in those areas which somehow lost all the living organisms that existed there .
D. At any time during primary or secondary succession , natural or human induced disturbances (fire , deforestation , etc) , can convert a particular seral stage of succession to an earlier stage.

Answer

To determine which statement about ecological succession is incorrect, we need to analyze the provided statements based on our understanding of ecological succession. Here’s a step-by-step breakdown:

### Step 1: Understand Ecological Succession
- **Definition**: Ecological succession is the process of change in the species structure of an ecological community over time. It involves a series of stages leading to a climax community, which is a stable and mature ecosystem.

### Step 2: Identify Types of Succession
- **Primary Succession**: This occurs in lifeless areas where no soil exists, such as bare rock or newly formed volcanic islands. It starts from scratch with pioneer species like lichens and mosses.
- **Secondary Succession**: This occurs in areas where a disturbance has destroyed an existing ecosystem but soil and some organisms still remain, such as after a forest fire or flood.

### Step 3: Analyze Each Statement
1. **Statement 1**: A community that is near equilibrium with the environment is called a Climax Community.
- **Evaluation**: This statement is correct. The climax community is stable and in equilibrium with the environment.

2. **Statement 2**: Gradual and fairly predictable changes in the species composition of a given area is called ecological succession.
- **Evaluation**: This statement is also correct. It accurately describes the nature of ecological succession.

3. **Statement 3**: Primary succession takes place in areas that have lost all living organisms.
- **Evaluation**: This statement is correct. Primary succession occurs in areas where no life previously existed.

4. **Statement 4**: Primary succession occurs in areas where vegetation was present but has been destroyed.
- **Evaluation**: This statement is incorrect. This describes secondary succession, not primary succession.

### Step 4: Conclusion
- The incorrect statement regarding ecological succession is **Statement 4**: "Primary succession occurs in areas where vegetation was present but has been destroyed."