The number of taxa present within a particular area or an ecosystem is

Options

A. `alpha`-diversity
B. `beta`-diversity
C. Gamma diversity
D. Delta diversity.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term that describes the number of taxa present within a particular area or ecosystem.

2. **Identifying the Options**: The options given are:
- Alpha diversity
- Beta diversity
- Gamma diversity
- Delta diversity

3. **Defining Alpha Diversity**: Alpha diversity refers to the mean species diversity in different sites or habitats at a local scale. It is specifically concerned with the number of taxa in a specific area.

4. **Calculating Alpha Diversity**: Alpha diversity can be measured by counting the number of taxa present in a particular ecosystem. This aligns directly with the question as it focuses on the number of taxa.

5. **Examining Other Options**:
- **Beta Diversity**: This is a ratio between regional and local species diversity, which does not directly measure the number of taxa in a specific area.
- **Gamma Diversity**: This term refers to the total species diversity in a landscape, not the number of taxa in a specific area.
- **Delta Diversity**: This describes the change in species composition and abundance, which also does not relate to the number of taxa present.

6. **Conclusion**: Based on the definitions and explanations, the correct answer to the question is **Alpha Diversity**.

**Final Answer**: The number of taxa present within a particular area or an ecosystem is called **Alpha Diversity**.

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