Any disturbance during successions

Options

A. Encourage the growth of some species
B. Discourage the growth of some species
C. Make some species extinct
D. All of the above

Answer

### Step-by-Step Solution:

1. **Understanding Succession**: Succession is the process through which ecosystems change and develop over time. It involves a series of stages where different communities of organisms replace one another.

2. **Identifying Disturbances**: Disturbances can be natural (like wildfires, floods, or storms) or human-induced (like deforestation or pollution). These disturbances can significantly impact the process of succession.

3. **Effects of Disturbance on Species Growth**:
- **Encouragement of Some Species**: Disturbances can create opportunities for certain species to thrive. For example, after a fire, some plants may grow faster due to reduced competition and increased sunlight.
- **Genetic Variations and New Species**: Disturbances can lead to mutations and genetic variations, which may result in the emergence of new species that can adapt to the changed environment.

4. **Discouragement of Some Species**: Increased competition due to the introduction of new species can lead to the decline of some existing species. Those that cannot compete effectively may struggle to survive.

5. **Extinction of Some Species**: In severe cases, if the competition becomes too intense and resources become scarce, some species may go extinct. This is especially true for species that cannot adapt to the new conditions created by the disturbance.

6. **Conclusion**: All these effects—encouraging the growth of some species, discouraging others, and leading to extinctions—are typical outcomes of disturbances during ecological succession. Therefore, the correct answer is that disturbances can lead to all of the above effects.