Which of the following types of ecosystem is expected in an area where evaporation exceeds precipitation, and mean annual rainfall is below 100mm?

Options

A. Grassland
B. Shrubby forest
C. Desert
D. Mangrove

Explanation

To determine the type of ecosystem expected in an area where evaporation exceeds precipitation and the mean annual rainfall is below 100 mm, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Conditions**: The question states that evaporation exceeds precipitation, meaning that the area is losing more water to evaporation than it is receiving from rainfall. Additionally, the mean annual rainfall is below 100 mm, indicating a very dry environment.

2. **Identify Ecosystem Characteristics**:
- **Desert Ecosystem**: Deserts are characterized by extremely low rainfall (often less than 250 mm annually), high evaporation rates, and limited vegetation. They are typically arid and can have conditions where rainfall is less than 100 mm.
- **Grasslands**: Grasslands usually have moderate rainfall (between 250 mm to 750 mm) and support a variety of grasses and some shrubs. This does not fit the criteria of low rainfall and high evaporation.
- **Shrubby Forests**: Shrubby forests require more moisture and typically have higher rainfall than deserts. They cannot thrive in conditions where annual rainfall is below 100 mm.
- **Mangroves**: Mangroves grow in coastal areas and require a significant amount of water, typically found in regions with high humidity and rainfall, making them unsuitable for areas with less than 100 mm of rainfall.

3. **Evaluate the Options**:
- **Grasslands**: Incorrect, as they require more rainfall.
- **Shrubby Forests**: Incorrect, as they also require more moisture.
- **Desert**: Correct, as deserts fit the criteria of high evaporation and low rainfall.
- **Mangroves**: Incorrect, as they thrive in wet coastal environments.

4. **Conclusion**: Based on the analysis, the ecosystem expected in an area where evaporation exceeds precipitation and mean annual rainfall is below 100 mm is the **Desert Ecosystem**.

### Final Answer:
The expected type of ecosystem is **Desert**.

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