Edge effect refers to

Options

A. Occurrence of ecophenes and ecotypes in a community
B. Low diversity of organisms in ecotone
C. High diversity of organisms in ecotone
D. Defense of territories by organisms

Answer

**Step-by-Step Solution:**

1. **Understanding Edge Effect**: The term "edge effect" refers to the changes in population or community structure that occur at the boundary between two or more habitats. This means that the characteristics of the area where two ecosystems meet can differ significantly from those of the individual ecosystems.

2. **Definition of Ecotone**: An ecotone is a transitional zone where two biomes or ecosystems meet. In this zone, you may find species and environmental conditions that are characteristic of both adjacent ecosystems.

3. **Diversity in Ecotones**: The edge effect is often associated with high biodiversity. This is because ecotones can support a greater variety of species than either of the individual ecosystems alone. The mixing of species from both habitats can lead to an increase in the number of different organisms present.

4. **Evaluating the Options**:
- The first option refers to the occurrence of ecophenes and ecotypes, which is not directly related to the edge effect.
- The second option mentions low diversity of organisms in ecotones, which contradicts the concept of edge effect.
- The third option states high diversity of organisms in ecotones, which aligns with the definition of edge effect.
- The fourth option discusses the defense of territories by organisms, which is not a defining characteristic of edge effect.

5. **Conclusion**: Based on the understanding of edge effect and ecotones, the correct answer is that edge effect refers to high diversity of organisms in ecotones.

**Final Answer**: Edge effect refers to high diversity of organisms in ecotones (Option 3).

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